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Odroidxu4 4.2 aufs #4
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Applying the patches for Aufs 4.2. Signed-off-by: Christian Stewart <[email protected]>
This patch applies (from aufs 4.2): - vfs-ino.patch - lockdep-debug.patch - tmpfs-idr.patch Signed-off-by: Christian Stewart <[email protected]>
Thank you for patches. |
mhaehnel
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Sep 6, 2016
Sunrise Point PCH with SPS Firmware doesn't expose working MEI interface, we need to quirk it out. The SPS Firmware is identifiable only on the first PCI function of the device. Cc: <[email protected]> tobetter#4.6+ Tested-by: Sujith Pandel <[email protected]> Signed-off-by: Tomas Winkler <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
mhaehnel
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Sep 26, 2016
Problems with the signal integrity of the high speed USB data lines or noise on reference ground lines can cause the i.MX6 USB controller to violate USB specs and exhibit unexpected behavior. It was observed that USBi_UI interrupts were triggered first and when isr_setup_status_phase was called, ci->status was NULL, which lead to a NULL pointer dereference kernel panic. This patch fixes the kernel panic, emits a warning once and returns -EPIPE to halt the device and let the host get stalled. It also adds a comment to point people, who are experiencing this issue, to their USB hardware design. Cc: <[email protected]> tobetter#4.1+ Signed-off-by: Clemens Gruber <[email protected]> Signed-off-by: Peter Chen <[email protected]>
mhaehnel
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Sep 26, 2016
Since commit 4d4c474 ("perf/x86/intel/bts: Fix BTS PMI detection") my box goes boom on boot: | .... node #0, CPUs: tobetter#1 tobetter#2 tobetter#3 tobetter#4 tobetter#5 tobetter#6 tobetter#7 | BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 | IP: [<ffffffff8100c463>] intel_bts_interrupt+0x43/0x130 | Call Trace: | <NMI> d [<ffffffff8100b341>] intel_pmu_handle_irq+0x51/0x4b0 | [<ffffffff81004d47>] perf_event_nmi_handler+0x27/0x40 This happens because the code introduced in this commit dereferences the debug store pointer unconditionally. The debug store is not guaranteed to be available, so a NULL pointer check as on other places is required. Fixes: 4d4c474 ("perf/x86/intel/bts: Fix BTS PMI detection") Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Reviewed-by: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
bkrepo
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Oct 28, 2016
commit 86a574d upstream. Don't allow RNDADDTOENTCNT or RNDADDENTROPY to accept a negative entropy value. It doesn't make any sense to subtract from the entropy counter, and it can trigger a warning: random: negative entropy/overflow: pool input count -40000 ------------[ cut here ]------------ WARNING: CPU: 3 PID: 6828 at drivers/char/random.c:670[< none >] credit_entropy_bits+0x21e/0xad0 drivers/char/random.c:670 Modules linked in: CPU: 3 PID: 6828 Comm: a.out Not tainted 4.7.0-rc4+ tobetter#4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffffffff880b58e0 ffff88005dd9fcb0 ffffffff82cc838f ffffffff87158b40 fffffbfff1016b1c 0000000000000000 0000000000000000 ffffffff87158b40 ffffffff83283dae 0000000000000009 ffff88005dd9fcf8 ffffffff8136d27f Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82cc838f>] dump_stack+0x12e/0x18f lib/dump_stack.c:51 [<ffffffff8136d27f>] __warn+0x19f/0x1e0 kernel/panic.c:516 [<ffffffff8136d48c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:551 [<ffffffff83283dae>] credit_entropy_bits+0x21e/0xad0 drivers/char/random.c:670 [< inline >] credit_entropy_bits_safe drivers/char/random.c:734 [<ffffffff8328785d>] random_ioctl+0x21d/0x250 drivers/char/random.c:1546 [< inline >] vfs_ioctl fs/ioctl.c:43 [<ffffffff8185316c>] do_vfs_ioctl+0x18c/0xff0 fs/ioctl.c:674 [< inline >] SYSC_ioctl fs/ioctl.c:689 [<ffffffff8185405f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680 [<ffffffff86a995c0>] entry_SYSCALL_64_fastpath+0x23/0xc1 arch/x86/entry/entry_64.S:207 ---[ end trace 5d4902b2ba842f1f ]--- This was triggered using the test program: // autogenerated by syzkaller (https://github.com/google/syzkaller) int main() { int fd = open("/dev/random", O_RDWR); int val = -5000; ioctl(fd, RNDADDTOENTCNT, &val); return 0; } It's harmless in that (a) only root can trigger it, and (b) after complaining the code never does let the entropy count go negative, but it's better to simply not allow this userspace from passing in a negative entropy value altogether. Google-Bug-Id: #29575089 Reported-By: Dmitry Vyukov <[email protected]> Signed-off-by: Theodore Ts'o <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
bkrepo
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Oct 28, 2016
commit 6039892 upstream. With debugobjects enabled and using SLAB_DESTROY_BY_RCU, when a kmem_cache_node is destroyed the call_rcu() may trigger a slab allocation to fill the debug object pool (__debug_object_init:fill_pool). Everywhere but during kmem_cache_destroy(), discard_slab() is performed outside of the kmem_cache_node->list_lock and avoids a lockdep warning about potential recursion: ============================================= [ INFO: possible recursive locking detected ] 4.8.0-rc1-gfxbench+ tobetter#1 Tainted: G U --------------------------------------------- rmmod/8895 is trying to acquire lock: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811c80d7>] get_partial_node.isra.63+0x47/0x430 but task is already holding lock: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811cbda4>] __kmem_cache_shutdown+0x54/0x320 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&n->list_lock)->rlock); lock(&(&n->list_lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by rmmod/8895: #0: (&dev->mutex){......}, at: driver_detach+0x42/0xc0 tobetter#1: (&dev->mutex){......}, at: driver_detach+0x50/0xc0 tobetter#2: (cpu_hotplug.dep_map){++++++}, at: get_online_cpus+0x2d/0x80 tobetter#3: (slab_mutex){+.+.+.}, at: kmem_cache_destroy+0x3c/0x220 tobetter#4: (&(&n->list_lock)->rlock){-.-...}, at: __kmem_cache_shutdown+0x54/0x320 stack backtrace: CPU: 6 PID: 8895 Comm: rmmod Tainted: G U 4.8.0-rc1-gfxbench+ tobetter#1 Hardware name: Gigabyte Technology Co., Ltd. H87M-D3H/H87M-D3H, BIOS F11 08/18/2015 Call Trace: __lock_acquire+0x1646/0x1ad0 lock_acquire+0xb2/0x200 _raw_spin_lock+0x36/0x50 get_partial_node.isra.63+0x47/0x430 ___slab_alloc.constprop.67+0x1a7/0x3b0 __slab_alloc.isra.64.constprop.66+0x43/0x80 kmem_cache_alloc+0x236/0x2d0 __debug_object_init+0x2de/0x400 debug_object_activate+0x109/0x1e0 __call_rcu.constprop.63+0x32/0x2f0 call_rcu+0x12/0x20 discard_slab+0x3d/0x40 __kmem_cache_shutdown+0xdb/0x320 shutdown_cache+0x19/0x60 kmem_cache_destroy+0x1ae/0x220 i915_gem_load_cleanup+0x14/0x40 [i915] i915_driver_unload+0x151/0x180 [i915] i915_pci_remove+0x14/0x20 [i915] pci_device_remove+0x34/0xb0 __device_release_driver+0x95/0x140 driver_detach+0xb6/0xc0 bus_remove_driver+0x53/0xd0 driver_unregister+0x27/0x50 pci_unregister_driver+0x25/0x70 i915_exit+0x1a/0x1e2 [i915] SyS_delete_module+0x193/0x1f0 entry_SYSCALL_64_fastpath+0x1c/0xac Fixes: 52b4b95 ("mm: slab: free kmem_cache_node after destroy sysfs file") Link: http://lkml.kernel.org/r/[email protected] Reported-by: Dave Gordon <[email protected]> Signed-off-by: Chris Wilson <[email protected]> Reviewed-by: Vladimir Davydov <[email protected]> Acked-by: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Dave Gordon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
bkrepo
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Oct 28, 2016
[ Upstream commit 94d9f1c ] Panic occurs when issuing "cat /proc/net/route" whilst populating FIB with > 1M routes. Use of cached node pointer in fib_route_get_idx is unsafe. BUG: unable to handle kernel paging request at ffffc90001630024 IP: [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0 PGD 11b08d067 PUD 11b08e067 PMD dac4b067 PTE 0 Oops: 0000 [tobetter#1] SMP Modules linked in: nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscac snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep virti acpi_cpufreq button parport_pc ppdev lp parport autofs4 ext4 crc16 mbcache jbd tio_ring virtio floppy uhci_hcd ehci_hcd usbcore usb_common libata scsi_mod CPU: 1 PID: 785 Comm: cat Not tainted 4.2.0-rc8+ tobetter#4 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff8800da1c0bc0 ti: ffff88011a05c000 task.ti: ffff88011a05c000 RIP: 0010:[<ffffffff814cf6a0>] [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0 RSP: 0018:ffff88011a05fda0 EFLAGS: 00010202 RAX: ffff8800d8a40c00 RBX: ffff8800da4af940 RCX: ffff88011a05ff20 RDX: ffffc90001630020 RSI: 0000000001013531 RDI: ffff8800da4af950 RBP: 0000000000000000 R08: ffff8800da1f9a00 R09: 0000000000000000 R10: ffff8800db45b7e4 R11: 0000000000000246 R12: ffff8800da4af950 R13: ffff8800d97a74c0 R14: 0000000000000000 R15: ffff8800d97a7480 FS: 00007fd3970e0700(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffffc90001630024 CR3: 000000011a7e4000 CR4: 00000000000006e0 Stack: ffffffff814d00d3 0000000000000000 ffff88011a05ff20 ffff8800da1f9a00 ffffffff811dd8b9 0000000000000800 0000000000020000 00007fd396f35000 ffffffff811f8714 0000000000003431 ffffffff8138dce0 0000000000000f80 Call Trace: [<ffffffff814d00d3>] ? fib_route_seq_start+0x93/0xc0 [<ffffffff811dd8b9>] ? seq_read+0x149/0x380 [<ffffffff811f8714>] ? fsnotify+0x3b4/0x500 [<ffffffff8138dce0>] ? process_echoes+0x70/0x70 [<ffffffff8121cfa7>] ? proc_reg_read+0x47/0x70 [<ffffffff811bb823>] ? __vfs_read+0x23/0xd0 [<ffffffff811bbd42>] ? rw_verify_area+0x52/0xf0 [<ffffffff811bbe61>] ? vfs_read+0x81/0x120 [<ffffffff811bcbc2>] ? SyS_read+0x42/0xa0 [<ffffffff81549ab2>] ? entry_SYSCALL_64_fastpath+0x16/0x75 Code: 48 85 c0 75 d8 f3 c3 31 c0 c3 f3 c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 a 04 89 f0 33 02 44 89 c9 48 d3 e8 0f b6 4a 05 49 89 RIP [<ffffffff814cf6a0>] leaf_walk_rcu+0x10/0xe0 RSP <ffff88011a05fda0> CR2: ffffc90001630024 Signed-off-by: Dave Forster <[email protected]> Acked-by: Alexander Duyck <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
bkrepo
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Oct 28, 2016
commit 420902c upstream. If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can deadlock our own worker - mount blocks kworker/3:2, sleeps forever more. crash> ps|grep UN 715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2] 9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg 9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon 10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount crash> bt ffff880220734d30 PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2" #0 [ffff8802244c3c20] schedule at ffffffff8144584b tobetter#1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3 tobetter#2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5 tobetter#3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs] tobetter#4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs] tobetter#5 [ffff8802244c3e08] process_one_work at ffffffff81073726 tobetter#6 [ffff8802244c3e68] worker_thread at ffffffff81073eba tobetter#7 [ffff8802244c3ec8] kthread at ffffffff810782e0 tobetter#8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064 crash> rd ffff8802244c3cc8 10 ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2.".... ffff8802244c3cd8: 0000000000000000 0000000000000286 ................ ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms .... ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............ ffff8802244c3d08: 0000000000000000 0000000000000002 ................ crash> struct rt_mutex ffff880222e8f628 struct rt_mutex { wait_lock = { raw_lock = { slock = 65537 } }, wait_list = { node_list = { next = 0xffff8802244c3d48, prev = 0xffff8802244c3d48 } }, owner = 0xffff880222f22c71, save_state = 0 } crash> bt 0xffff880222f22c70 PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount" #0 [ffff8802216a9868] schedule at ffffffff8144584b tobetter#1 [ffff8802216a9910] schedule_timeout at ffffffff81446865 tobetter#2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74 tobetter#3 [ffff8802216a9a30] flush_work at ffffffff810712d3 tobetter#4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463 tobetter#5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba tobetter#6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632 tobetter#7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c tobetter#8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs] tobetter#9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs] RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202 RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0 RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0 RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001 R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b Signed-off-by: Mike Galbraith <[email protected]> Acked-by: Frederic Weisbecker <[email protected]> Acked-by: Mike Galbraith <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
tobetter
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Oct 16, 2017
This patch fixes a regression caused by the new changes in the "run wake" handlers. The mei devices that support D0i3 are no longer receiving an interrupt after entering runtime suspend state and will stall. pci_dev_run_wake function now returns "true" for some devices (including mei) for which it used to return "false", arguably incorrectly as "run wake" used to mean that wakeup signals can be generated for a device in the working state of the system, so it could not be enabled or disabled before too. MEI maps runtime suspend/resume to its own defined power gating (PG) states, (D0i3 or other depending on generation), hence we need to go around the native PCI runtime service which eventually brings the device into D3cold/hot state, but the mei devices cannot wake up from D3 unlike from D0i3/PG state, which keeps irq running. To get around PCI device native runtime pm, MEI uses runtime pm domain handlers which take precedence. Cc: <[email protected]> #4.13+ Signed-off-by: Alexander Usyskin <[email protected]> Signed-off-by: Tomas Winkler <[email protected]> Acked-by: Rafael J. Wysocki <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
tobetter
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Oct 16, 2017
ppp_release() tries to ensure that netdevices are unregistered before decrementing the unit refcount and running ppp_destroy_interface(). This is all fine as long as the the device is unregistered by ppp_release(): the unregister_netdevice() call, followed by rtnl_unlock(), guarantee that the unregistration process completes before rtnl_unlock() returns. However, the device may be unregistered by other means (like ppp_nl_dellink()). If this happens right before ppp_release() calling rtnl_lock(), then ppp_release() has to wait for the concurrent unregistration code to release the lock. But rtnl_unlock() releases the lock before completing the device unregistration process. This allows ppp_release() to proceed and eventually call ppp_destroy_interface() before the unregistration process completes. Calling free_netdev() on this partially unregistered device will BUG(): ------------[ cut here ]------------ kernel BUG at net/core/dev.c:8141! invalid opcode: 0000 [#1] SMP CPU: 1 PID: 1557 Comm: pppd Not tainted 4.14.0-rc2+ #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc26 04/01/2014 Call Trace: ppp_destroy_interface+0xd8/0xe0 [ppp_generic] ppp_disconnect_channel+0xda/0x110 [ppp_generic] ppp_unregister_channel+0x5e/0x110 [ppp_generic] pppox_unbind_sock+0x23/0x30 [pppox] pppoe_connect+0x130/0x440 [pppoe] SYSC_connect+0x98/0x110 ? do_fcntl+0x2c0/0x5d0 SyS_connect+0xe/0x10 entry_SYSCALL_64_fastpath+0x1a/0xa5 RIP: free_netdev+0x107/0x110 RSP: ffffc28a40573d88 ---[ end trace ed294ff0cc40eeff ]--- We could set the ->needs_free_netdev flag on PPP devices and move the ppp_destroy_interface() logic in the ->priv_destructor() callback. But that'd be quite intrusive as we'd first need to unlink from the other channels and units that depend on the device (the ones that used the PPPIOCCONNECT and PPPIOCATTACH ioctls). Instead, we can just let the netdevice hold a reference on its ppp_file. This reference is dropped in ->priv_destructor(), at the very end of the unregistration process, so that neither ppp_release() nor ppp_disconnect_channel() can call ppp_destroy_interface() in the interim. Reported-by: Beniamino Galvani <[email protected]> Fixes: 8cb775b ("ppp: fix device unregistration upon netns deletion") Signed-off-by: Guillaume Nault <[email protected]> Signed-off-by: David S. Miller <[email protected]>
tobetter
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Oct 16, 2017
The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 1990.972058] ====================================================== [ 1990.978172] WARNING: possible circular locking dependency detected [ 1990.984327] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 1990.989783] ------------------------------------------------------ [ 1990.995937] qtdemux0:sink/2765 is trying to acquire lock: [ 1991.001309] (&gsc->lock){+.+.}, at: [<bf1729f0>] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.009108] but task is already holding lock: [ 1991.014913] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.021932] which lock already depends on the new lock. [ 1991.030078] the existing dependency chain (in reverse order) is: [ 1991.037530] -> #1 (&mm->mmap_sem){++++}: [ 1991.042913] __might_fault+0x80/0xb0 [ 1991.047096] video_usercopy+0x1cc/0x510 [videodev] [ 1991.052297] v4l2_ioctl+0xa4/0xdc [videodev] [ 1991.057036] do_vfs_ioctl+0xa0/0xa18 [ 1991.061102] SyS_ioctl+0x34/0x5c [ 1991.064834] ret_fast_syscall+0x0/0x28 [ 1991.069072] -> #0 (&gsc->lock){+.+.}: [ 1991.074193] lock_acquire+0x6c/0x88 [ 1991.078179] __mutex_lock+0x68/0xa34 [ 1991.082247] mutex_lock_interruptible_nested+0x1c/0x24 [ 1991.087888] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.093029] v4l2_mmap+0x54/0x88 [videodev] [ 1991.097673] mmap_region+0x3a8/0x638 [ 1991.101743] do_mmap+0x330/0x3a4 [ 1991.105470] vm_mmap_pgoff+0x90/0xb8 [ 1991.109542] SyS_mmap_pgoff+0x90/0xc0 [ 1991.113702] ret_fast_syscall+0x0/0x28 [ 1991.117945] other info that might help us debug this: [ 1991.125918] Possible unsafe locking scenario: [ 1991.131810] CPU0 CPU1 [ 1991.136315] ---- ---- [ 1991.140821] lock(&mm->mmap_sem); [ 1991.144201] lock(&gsc->lock); [ 1991.149833] lock(&mm->mmap_sem); [ 1991.155725] lock(&gsc->lock); [ 1991.158845] *** DEADLOCK *** [ 1991.164740] 1 lock held by qtdemux0:sink/2765: [ 1991.169157] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.176609] stack backtrace: [ 1991.180946] CPU: 2 PID: 2765 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 1991.189608] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 1991.195686] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 1991.203393] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 1991.210586] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 1991.218644] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 1991.227049] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 1991.235281] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 1991.242993] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 1991.250620] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 1991.259812] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf1729f0>] (gsc_m2m_mmap+0x24/0x5c [exynos_gsc]) [ 1991.270159] [<bf1729f0>] (gsc_m2m_mmap [exynos_gsc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 1991.279510] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 1991.287792] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 1991.294986] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 1991.302178] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 1991.309977] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 2106.181412] ====================================================== [ 2106.187563] WARNING: possible circular locking dependency detected [ 2106.193718] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 2106.199175] ------------------------------------------------------ [ 2106.205328] qtdemux0:sink/2614 is trying to acquire lock: [ 2106.210701] (&dev->mfc_mutex){+.+.}, at: [<bf175544>] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.218672] [ 2106.218672] but task is already holding lock: [ 2106.224477] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.231497] [ 2106.231497] which lock already depends on the new lock. [ 2106.231497] [ 2106.239642] [ 2106.239642] the existing dependency chain (in reverse order) is: [ 2106.247095] [ 2106.247095] -> #1 (&mm->mmap_sem){++++}: [ 2106.252473] __might_fault+0x80/0xb0 [ 2106.256567] video_usercopy+0x1cc/0x510 [videodev] [ 2106.261845] v4l2_ioctl+0xa4/0xdc [videodev] [ 2106.266596] do_vfs_ioctl+0xa0/0xa18 [ 2106.270667] SyS_ioctl+0x34/0x5c [ 2106.274395] ret_fast_syscall+0x0/0x28 [ 2106.278637] [ 2106.278637] -> #0 (&dev->mfc_mutex){+.+.}: [ 2106.284186] lock_acquire+0x6c/0x88 [ 2106.288173] __mutex_lock+0x68/0xa34 [ 2106.292244] mutex_lock_interruptible_nested+0x1c/0x24 [ 2106.297893] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.302747] v4l2_mmap+0x54/0x88 [videodev] [ 2106.307409] mmap_region+0x3a8/0x638 [ 2106.311480] do_mmap+0x330/0x3a4 [ 2106.315207] vm_mmap_pgoff+0x90/0xb8 [ 2106.319279] SyS_mmap_pgoff+0x90/0xc0 [ 2106.323439] ret_fast_syscall+0x0/0x28 [ 2106.327683] [ 2106.327683] other info that might help us debug this: [ 2106.327683] [ 2106.335656] Possible unsafe locking scenario: [ 2106.335656] [ 2106.341548] CPU0 CPU1 [ 2106.346053] ---- ---- [ 2106.350559] lock(&mm->mmap_sem); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.365897] lock(&dev->mfc_mutex); [ 2106.369450] [ 2106.369450] *** DEADLOCK *** [ 2106.369450] [ 2106.375344] 1 lock held by qtdemux0:sink/2614: [ 2106.379762] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.387214] [ 2106.387214] stack backtrace: [ 2106.391550] CPU: 7 PID: 2614 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 2106.400213] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 2106.406285] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 2106.413995] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 2106.421187] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 2106.429245] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 2106.437651] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 2106.445883] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 2106.453596] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 2106.461221] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 2106.470425] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf175544>] (s5p_mfc_mmap+0x28/0xd4 [s5p_mfc]) [ 2106.480494] [<bf175544>] (s5p_mfc_mmap [s5p_mfc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 2106.489575] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 2106.497875] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 2106.505068] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 2106.512260] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 2106.520059] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") extended accessing parent pointer fields of struct zfcp_erp_action for tracing. If an erp_action has never been enqueued before, these parent pointer fields are uninitialized and NULL. Examples are zfcp objects freshly added to the parent object's children list, before enqueueing their first recovery subsequently. In zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action fields can cause a NULL pointer dereference. Since the kernel can read from lowcore on s390, it does not immediately cause a kernel page fault. Instead it can cause hangs on trying to acquire the wrong erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl() ^bogus^ while holding already other locks with IRQs disabled. Real life example from attaching lots of LUNs in parallel on many CPUs: crash> bt 17723 PID: 17723 TASK: ... CPU: 25 COMMAND: "zfcperp0.0.1800" LOWCORE INFO: -psw : 0x0404300180000000 0x000000000038e424 -function : _raw_spin_lock_wait_flags at 38e424 ... #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp] #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp] #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp] #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp] #4 [fdde8fe60] kthread at 173550 #5 [fdde8feb8] kernel_thread_starter at 10add2 zfcp_adapter zfcp_port zfcp_unit <address>, 0x404040d600000000 scsi_device NULL, returning early! zfcp_scsi_dev.status = 0x40000000 0x40000000 ZFCP_STATUS_COMMON_RUNNING crash> zfcp_unit <address> struct zfcp_unit { erp_action = { adapter = 0x0, port = 0x0, unit = 0x0, }, } zfcp_erp_action is always fully embedded into its container object. Such container object is never moved in its object tree (only add or delete). Hence, erp_action parent pointers can never change. To fix the issue, initialize the erp_action parent pointers before adding the erp_action container to any list and thus before it becomes accessible from outside of its initializing function. In order to also close the time window between zfcp_erp_setup_act() memsetting the entire erp_action to zero and setting the parent pointers again, drop the memset and instead explicitly initialize individually all erp_action fields except for parent pointers. To be extra careful not to introduce any other unintended side effect, even keep zeroing the erp_action fields for list and timer. Also double-check with WARN_ON_ONCE that erp_action parent pointers never change, so we get to know when we would deviate from previous behavior. Signed-off-by: Steffen Maier <[email protected]> Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") Cc: <[email protected]> #2.6.32+ Reviewed-by: Benjamin Block <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]>
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Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL pointer deref when he ran it on a data with namespace events. It was because the buildid_id__mark_dso_hit_ops lacks the namespace event handler and perf_too__fill_default() didn't set it. Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x (gdb) where #0 0x0000000000000000 in ?? () #1 0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18, evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888, tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287 #2 0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>, sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340 #3 perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470, file_offset=file_offset@entry=1136) at util/session.c:1522 #4 0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>, data_offset=<optimized out>, session=0x0) at util/session.c:1899 #5 perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953 #6 0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>) at builtin-buildid-list.c:83 #7 cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115 #8 0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0) at perf.c:296 #9 0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348 #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392 #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536 (gdb) Fix it by adding a stub event handler for namespace event. Committer testing: Further clarifying, plain using 'perf buildid-list' will not end up in a SEGFAULT when processing a perf.data file with namespace info: # perf record -a --namespaces sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ] # perf buildid-list | wc -l 38 # perf buildid-list | head -5 e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux 874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko 5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so # It is only when one asks for checking what of those entries actually had samples, i.e. when we use either -H or --with-hits, that we will process all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c neither explicitely set a perf_tool.namespaces() callback nor the default stub was set that we end up, when processing a PERF_RECORD_NAMESPACE record, causing a SEGFAULT: # perf buildid-list -H Segmentation fault (core dumped) ^C # Reported-and-Tested-by: Thomas-Mich Richter <[email protected]> Signed-off-by: Namhyung Kim <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Hari Bathini <[email protected]> Cc: Hendrik Brueckner <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas-Mich Richter <[email protected]> Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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When an EMAD is transmitted, a timeout work item is scheduled with a delay of 200ms, so that another EMAD will be retried until a maximum of five retries. In certain situations, it's possible for the function waiting on the EMAD to be associated with a work item that is queued on the same workqueue (`mlxsw_core`) as the timeout work item. This results in flushing a work item on the same workqueue. According to commit e159489 ("workqueue: relax lockdep annotation on flush_work()") the above may lead to a deadlock in case the workqueue has only one worker active or if the system in under memory pressure and the rescue worker is in use. The latter explains the very rare and random nature of the lockdep splats we have been seeing: [ 52.730240] ============================================ [ 52.736179] WARNING: possible recursive locking detected [ 52.742119] 4.14.0-rc3jiri+ #4 Not tainted [ 52.746697] -------------------------------------------- [ 52.752635] kworker/1:3/599 is trying to acquire lock: [ 52.758378] (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c4fa4>] flush_work+0x3a4/0x5e0 [ 52.767837] but task is already holding lock: [ 52.774360] (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.784495] other info that might help us debug this: [ 52.791794] Possible unsafe locking scenario: [ 52.798413] CPU0 [ 52.801144] ---- [ 52.803875] lock(mlxsw_core_driver_name); [ 52.808556] lock(mlxsw_core_driver_name); [ 52.813236] *** DEADLOCK *** [ 52.819857] May be due to missing lock nesting notation [ 52.827450] 3 locks held by kworker/1:3/599: [ 52.832221] #0: (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.842846] #1: ((&(&bridge->fdb_notify.dw)->work)){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.854537] #2: (rtnl_mutex){+.+.}, at: [<ffffffff822ad8e7>] rtnl_lock+0x17/0x20 [ 52.863021] stack backtrace: [ 52.867890] CPU: 1 PID: 599 Comm: kworker/1:3 Not tainted 4.14.0-rc3jiri+ #4 [ 52.875773] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016 [ 52.886267] Workqueue: mlxsw_core mlxsw_sp_fdb_notify_work [mlxsw_spectrum] [ 52.894060] Call Trace: [ 52.909122] __lock_acquire+0xf6f/0x2a10 [ 53.025412] lock_acquire+0x158/0x440 [ 53.047557] flush_work+0x3c4/0x5e0 [ 53.087571] __cancel_work_timer+0x3ca/0x5e0 [ 53.177051] cancel_delayed_work_sync+0x13/0x20 [ 53.182142] mlxsw_reg_trans_bulk_wait+0x12d/0x7a0 [mlxsw_core] [ 53.194571] mlxsw_core_reg_access+0x586/0x990 [mlxsw_core] [ 53.225365] mlxsw_reg_query+0x10/0x20 [mlxsw_core] [ 53.230882] mlxsw_sp_fdb_notify_work+0x2a3/0x9d0 [mlxsw_spectrum] [ 53.237801] process_one_work+0x8f1/0x12f0 [ 53.321804] worker_thread+0x1fd/0x10c0 [ 53.435158] kthread+0x28e/0x370 [ 53.448703] ret_from_fork+0x2a/0x40 [ 53.453017] mlxsw_spectrum 0000:01:00.0: EMAD retries (2/5) (tid=bf4549b100000774) [ 53.453119] mlxsw_spectrum 0000:01:00.0: EMAD retries (5/5) (tid=bf4549b100000770) [ 53.453132] mlxsw_spectrum 0000:01:00.0: EMAD reg access failed (tid=bf4549b100000770,reg_id=200b(sfn),type=query,status=0(operation performed)) [ 53.453143] mlxsw_spectrum 0000:01:00.0: Failed to get FDB notifications Fix this by creating another workqueue for EMAD timeouts, thereby preventing the situation of a work item trying to flush a work item queued on the same workqueue. Fixes: caf7297 ("mlxsw: core: Introduce support for asynchronous EMAD register access") Signed-off-by: Ido Schimmel <[email protected]> Reported-by: Jiri Pirko <[email protected]> Signed-off-by: Jiri Pirko <[email protected]> Signed-off-by: David S. Miller <[email protected]>
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Oct 29, 2017
The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 1990.972058] ====================================================== [ 1990.978172] WARNING: possible circular locking dependency detected [ 1990.984327] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 1990.989783] ------------------------------------------------------ [ 1990.995937] qtdemux0:sink/2765 is trying to acquire lock: [ 1991.001309] (&gsc->lock){+.+.}, at: [<bf1729f0>] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.009108] but task is already holding lock: [ 1991.014913] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.021932] which lock already depends on the new lock. [ 1991.030078] the existing dependency chain (in reverse order) is: [ 1991.037530] -> #1 (&mm->mmap_sem){++++}: [ 1991.042913] __might_fault+0x80/0xb0 [ 1991.047096] video_usercopy+0x1cc/0x510 [videodev] [ 1991.052297] v4l2_ioctl+0xa4/0xdc [videodev] [ 1991.057036] do_vfs_ioctl+0xa0/0xa18 [ 1991.061102] SyS_ioctl+0x34/0x5c [ 1991.064834] ret_fast_syscall+0x0/0x28 [ 1991.069072] -> #0 (&gsc->lock){+.+.}: [ 1991.074193] lock_acquire+0x6c/0x88 [ 1991.078179] __mutex_lock+0x68/0xa34 [ 1991.082247] mutex_lock_interruptible_nested+0x1c/0x24 [ 1991.087888] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.093029] v4l2_mmap+0x54/0x88 [videodev] [ 1991.097673] mmap_region+0x3a8/0x638 [ 1991.101743] do_mmap+0x330/0x3a4 [ 1991.105470] vm_mmap_pgoff+0x90/0xb8 [ 1991.109542] SyS_mmap_pgoff+0x90/0xc0 [ 1991.113702] ret_fast_syscall+0x0/0x28 [ 1991.117945] other info that might help us debug this: [ 1991.125918] Possible unsafe locking scenario: [ 1991.131810] CPU0 CPU1 [ 1991.136315] ---- ---- [ 1991.140821] lock(&mm->mmap_sem); [ 1991.144201] lock(&gsc->lock); [ 1991.149833] lock(&mm->mmap_sem); [ 1991.155725] lock(&gsc->lock); [ 1991.158845] *** DEADLOCK *** [ 1991.164740] 1 lock held by qtdemux0:sink/2765: [ 1991.169157] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.176609] stack backtrace: [ 1991.180946] CPU: 2 PID: 2765 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 1991.189608] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 1991.195686] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 1991.203393] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 1991.210586] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 1991.218644] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 1991.227049] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 1991.235281] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 1991.242993] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 1991.250620] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 1991.259812] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf1729f0>] (gsc_m2m_mmap+0x24/0x5c [exynos_gsc]) [ 1991.270159] [<bf1729f0>] (gsc_m2m_mmap [exynos_gsc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 1991.279510] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 1991.287792] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 1991.294986] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 1991.302178] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 1991.309977] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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Oct 29, 2017
The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 2106.181412] ====================================================== [ 2106.187563] WARNING: possible circular locking dependency detected [ 2106.193718] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 2106.199175] ------------------------------------------------------ [ 2106.205328] qtdemux0:sink/2614 is trying to acquire lock: [ 2106.210701] (&dev->mfc_mutex){+.+.}, at: [<bf175544>] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.218672] [ 2106.218672] but task is already holding lock: [ 2106.224477] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.231497] [ 2106.231497] which lock already depends on the new lock. [ 2106.231497] [ 2106.239642] [ 2106.239642] the existing dependency chain (in reverse order) is: [ 2106.247095] [ 2106.247095] -> #1 (&mm->mmap_sem){++++}: [ 2106.252473] __might_fault+0x80/0xb0 [ 2106.256567] video_usercopy+0x1cc/0x510 [videodev] [ 2106.261845] v4l2_ioctl+0xa4/0xdc [videodev] [ 2106.266596] do_vfs_ioctl+0xa0/0xa18 [ 2106.270667] SyS_ioctl+0x34/0x5c [ 2106.274395] ret_fast_syscall+0x0/0x28 [ 2106.278637] [ 2106.278637] -> #0 (&dev->mfc_mutex){+.+.}: [ 2106.284186] lock_acquire+0x6c/0x88 [ 2106.288173] __mutex_lock+0x68/0xa34 [ 2106.292244] mutex_lock_interruptible_nested+0x1c/0x24 [ 2106.297893] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.302747] v4l2_mmap+0x54/0x88 [videodev] [ 2106.307409] mmap_region+0x3a8/0x638 [ 2106.311480] do_mmap+0x330/0x3a4 [ 2106.315207] vm_mmap_pgoff+0x90/0xb8 [ 2106.319279] SyS_mmap_pgoff+0x90/0xc0 [ 2106.323439] ret_fast_syscall+0x0/0x28 [ 2106.327683] [ 2106.327683] other info that might help us debug this: [ 2106.327683] [ 2106.335656] Possible unsafe locking scenario: [ 2106.335656] [ 2106.341548] CPU0 CPU1 [ 2106.346053] ---- ---- [ 2106.350559] lock(&mm->mmap_sem); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.365897] lock(&dev->mfc_mutex); [ 2106.369450] [ 2106.369450] *** DEADLOCK *** [ 2106.369450] [ 2106.375344] 1 lock held by qtdemux0:sink/2614: [ 2106.379762] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.387214] [ 2106.387214] stack backtrace: [ 2106.391550] CPU: 7 PID: 2614 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 2106.400213] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 2106.406285] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 2106.413995] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 2106.421187] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 2106.429245] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 2106.437651] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 2106.445883] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 2106.453596] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 2106.461221] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 2106.470425] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf175544>] (s5p_mfc_mmap+0x28/0xd4 [s5p_mfc]) [ 2106.480494] [<bf175544>] (s5p_mfc_mmap [s5p_mfc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 2106.489575] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 2106.497875] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 2106.505068] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 2106.512260] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 2106.520059] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
tobetter
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Nov 1, 2017
The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 2106.181412] ====================================================== [ 2106.187563] WARNING: possible circular locking dependency detected [ 2106.193718] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 2106.199175] ------------------------------------------------------ [ 2106.205328] qtdemux0:sink/2614 is trying to acquire lock: [ 2106.210701] (&dev->mfc_mutex){+.+.}, at: [<bf175544>] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.218672] [ 2106.218672] but task is already holding lock: [ 2106.224477] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.231497] [ 2106.231497] which lock already depends on the new lock. [ 2106.231497] [ 2106.239642] [ 2106.239642] the existing dependency chain (in reverse order) is: [ 2106.247095] [ 2106.247095] -> #1 (&mm->mmap_sem){++++}: [ 2106.252473] __might_fault+0x80/0xb0 [ 2106.256567] video_usercopy+0x1cc/0x510 [videodev] [ 2106.261845] v4l2_ioctl+0xa4/0xdc [videodev] [ 2106.266596] do_vfs_ioctl+0xa0/0xa18 [ 2106.270667] SyS_ioctl+0x34/0x5c [ 2106.274395] ret_fast_syscall+0x0/0x28 [ 2106.278637] [ 2106.278637] -> #0 (&dev->mfc_mutex){+.+.}: [ 2106.284186] lock_acquire+0x6c/0x88 [ 2106.288173] __mutex_lock+0x68/0xa34 [ 2106.292244] mutex_lock_interruptible_nested+0x1c/0x24 [ 2106.297893] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.302747] v4l2_mmap+0x54/0x88 [videodev] [ 2106.307409] mmap_region+0x3a8/0x638 [ 2106.311480] do_mmap+0x330/0x3a4 [ 2106.315207] vm_mmap_pgoff+0x90/0xb8 [ 2106.319279] SyS_mmap_pgoff+0x90/0xc0 [ 2106.323439] ret_fast_syscall+0x0/0x28 [ 2106.327683] [ 2106.327683] other info that might help us debug this: [ 2106.327683] [ 2106.335656] Possible unsafe locking scenario: [ 2106.335656] [ 2106.341548] CPU0 CPU1 [ 2106.346053] ---- ---- [ 2106.350559] lock(&mm->mmap_sem); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.365897] lock(&dev->mfc_mutex); [ 2106.369450] [ 2106.369450] *** DEADLOCK *** [ 2106.369450] [ 2106.375344] 1 lock held by qtdemux0:sink/2614: [ 2106.379762] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.387214] [ 2106.387214] stack backtrace: [ 2106.391550] CPU: 7 PID: 2614 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 2106.400213] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 2106.406285] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 2106.413995] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 2106.421187] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 2106.429245] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 2106.437651] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 2106.445883] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 2106.453596] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 2106.461221] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 2106.470425] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf175544>] (s5p_mfc_mmap+0x28/0xd4 [s5p_mfc]) [ 2106.480494] [<bf175544>] (s5p_mfc_mmap [s5p_mfc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 2106.489575] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 2106.497875] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 2106.505068] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 2106.512260] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 2106.520059] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
tobetter
pushed a commit
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Nov 1, 2017
The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 1990.972058] ====================================================== [ 1990.978172] WARNING: possible circular locking dependency detected [ 1990.984327] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 1990.989783] ------------------------------------------------------ [ 1990.995937] qtdemux0:sink/2765 is trying to acquire lock: [ 1991.001309] (&gsc->lock){+.+.}, at: [<bf1729f0>] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.009108] but task is already holding lock: [ 1991.014913] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.021932] which lock already depends on the new lock. [ 1991.030078] the existing dependency chain (in reverse order) is: [ 1991.037530] -> #1 (&mm->mmap_sem){++++}: [ 1991.042913] __might_fault+0x80/0xb0 [ 1991.047096] video_usercopy+0x1cc/0x510 [videodev] [ 1991.052297] v4l2_ioctl+0xa4/0xdc [videodev] [ 1991.057036] do_vfs_ioctl+0xa0/0xa18 [ 1991.061102] SyS_ioctl+0x34/0x5c [ 1991.064834] ret_fast_syscall+0x0/0x28 [ 1991.069072] -> #0 (&gsc->lock){+.+.}: [ 1991.074193] lock_acquire+0x6c/0x88 [ 1991.078179] __mutex_lock+0x68/0xa34 [ 1991.082247] mutex_lock_interruptible_nested+0x1c/0x24 [ 1991.087888] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.093029] v4l2_mmap+0x54/0x88 [videodev] [ 1991.097673] mmap_region+0x3a8/0x638 [ 1991.101743] do_mmap+0x330/0x3a4 [ 1991.105470] vm_mmap_pgoff+0x90/0xb8 [ 1991.109542] SyS_mmap_pgoff+0x90/0xc0 [ 1991.113702] ret_fast_syscall+0x0/0x28 [ 1991.117945] other info that might help us debug this: [ 1991.125918] Possible unsafe locking scenario: [ 1991.131810] CPU0 CPU1 [ 1991.136315] ---- ---- [ 1991.140821] lock(&mm->mmap_sem); [ 1991.144201] lock(&gsc->lock); [ 1991.149833] lock(&mm->mmap_sem); [ 1991.155725] lock(&gsc->lock); [ 1991.158845] *** DEADLOCK *** [ 1991.164740] 1 lock held by qtdemux0:sink/2765: [ 1991.169157] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.176609] stack backtrace: [ 1991.180946] CPU: 2 PID: 2765 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 1991.189608] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 1991.195686] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 1991.203393] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 1991.210586] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 1991.218644] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 1991.227049] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 1991.235281] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 1991.242993] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 1991.250620] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 1991.259812] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf1729f0>] (gsc_m2m_mmap+0x24/0x5c [exynos_gsc]) [ 1991.270159] [<bf1729f0>] (gsc_m2m_mmap [exynos_gsc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 1991.279510] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 1991.287792] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 1991.294986] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 1991.302178] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 1991.309977] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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Nov 6, 2017
The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 2106.181412] ====================================================== [ 2106.187563] WARNING: possible circular locking dependency detected [ 2106.193718] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 2106.199175] ------------------------------------------------------ [ 2106.205328] qtdemux0:sink/2614 is trying to acquire lock: [ 2106.210701] (&dev->mfc_mutex){+.+.}, at: [<bf175544>] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.218672] [ 2106.218672] but task is already holding lock: [ 2106.224477] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.231497] [ 2106.231497] which lock already depends on the new lock. [ 2106.231497] [ 2106.239642] [ 2106.239642] the existing dependency chain (in reverse order) is: [ 2106.247095] [ 2106.247095] -> #1 (&mm->mmap_sem){++++}: [ 2106.252473] __might_fault+0x80/0xb0 [ 2106.256567] video_usercopy+0x1cc/0x510 [videodev] [ 2106.261845] v4l2_ioctl+0xa4/0xdc [videodev] [ 2106.266596] do_vfs_ioctl+0xa0/0xa18 [ 2106.270667] SyS_ioctl+0x34/0x5c [ 2106.274395] ret_fast_syscall+0x0/0x28 [ 2106.278637] [ 2106.278637] -> #0 (&dev->mfc_mutex){+.+.}: [ 2106.284186] lock_acquire+0x6c/0x88 [ 2106.288173] __mutex_lock+0x68/0xa34 [ 2106.292244] mutex_lock_interruptible_nested+0x1c/0x24 [ 2106.297893] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.302747] v4l2_mmap+0x54/0x88 [videodev] [ 2106.307409] mmap_region+0x3a8/0x638 [ 2106.311480] do_mmap+0x330/0x3a4 [ 2106.315207] vm_mmap_pgoff+0x90/0xb8 [ 2106.319279] SyS_mmap_pgoff+0x90/0xc0 [ 2106.323439] ret_fast_syscall+0x0/0x28 [ 2106.327683] [ 2106.327683] other info that might help us debug this: [ 2106.327683] [ 2106.335656] Possible unsafe locking scenario: [ 2106.335656] [ 2106.341548] CPU0 CPU1 [ 2106.346053] ---- ---- [ 2106.350559] lock(&mm->mmap_sem); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.365897] lock(&dev->mfc_mutex); [ 2106.369450] [ 2106.369450] *** DEADLOCK *** [ 2106.369450] [ 2106.375344] 1 lock held by qtdemux0:sink/2614: [ 2106.379762] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.387214] [ 2106.387214] stack backtrace: [ 2106.391550] CPU: 7 PID: 2614 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 2106.400213] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 2106.406285] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 2106.413995] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 2106.421187] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 2106.429245] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 2106.437651] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 2106.445883] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 2106.453596] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 2106.461221] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 2106.470425] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf175544>] (s5p_mfc_mmap+0x28/0xd4 [s5p_mfc]) [ 2106.480494] [<bf175544>] (s5p_mfc_mmap [s5p_mfc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 2106.489575] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 2106.497875] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 2106.505068] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 2106.512260] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 2106.520059] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 1990.972058] ====================================================== [ 1990.978172] WARNING: possible circular locking dependency detected [ 1990.984327] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 1990.989783] ------------------------------------------------------ [ 1990.995937] qtdemux0:sink/2765 is trying to acquire lock: [ 1991.001309] (&gsc->lock){+.+.}, at: [<bf1729f0>] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.009108] but task is already holding lock: [ 1991.014913] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.021932] which lock already depends on the new lock. [ 1991.030078] the existing dependency chain (in reverse order) is: [ 1991.037530] -> #1 (&mm->mmap_sem){++++}: [ 1991.042913] __might_fault+0x80/0xb0 [ 1991.047096] video_usercopy+0x1cc/0x510 [videodev] [ 1991.052297] v4l2_ioctl+0xa4/0xdc [videodev] [ 1991.057036] do_vfs_ioctl+0xa0/0xa18 [ 1991.061102] SyS_ioctl+0x34/0x5c [ 1991.064834] ret_fast_syscall+0x0/0x28 [ 1991.069072] -> #0 (&gsc->lock){+.+.}: [ 1991.074193] lock_acquire+0x6c/0x88 [ 1991.078179] __mutex_lock+0x68/0xa34 [ 1991.082247] mutex_lock_interruptible_nested+0x1c/0x24 [ 1991.087888] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.093029] v4l2_mmap+0x54/0x88 [videodev] [ 1991.097673] mmap_region+0x3a8/0x638 [ 1991.101743] do_mmap+0x330/0x3a4 [ 1991.105470] vm_mmap_pgoff+0x90/0xb8 [ 1991.109542] SyS_mmap_pgoff+0x90/0xc0 [ 1991.113702] ret_fast_syscall+0x0/0x28 [ 1991.117945] other info that might help us debug this: [ 1991.125918] Possible unsafe locking scenario: [ 1991.131810] CPU0 CPU1 [ 1991.136315] ---- ---- [ 1991.140821] lock(&mm->mmap_sem); [ 1991.144201] lock(&gsc->lock); [ 1991.149833] lock(&mm->mmap_sem); [ 1991.155725] lock(&gsc->lock); [ 1991.158845] *** DEADLOCK *** [ 1991.164740] 1 lock held by qtdemux0:sink/2765: [ 1991.169157] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.176609] stack backtrace: [ 1991.180946] CPU: 2 PID: 2765 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 1991.189608] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 1991.195686] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 1991.203393] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 1991.210586] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 1991.218644] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 1991.227049] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 1991.235281] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 1991.242993] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 1991.250620] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 1991.259812] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf1729f0>] (gsc_m2m_mmap+0x24/0x5c [exynos_gsc]) [ 1991.270159] [<bf1729f0>] (gsc_m2m_mmap [exynos_gsc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 1991.279510] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 1991.287792] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 1991.294986] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 1991.302178] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 1991.309977] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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The warning below says it all: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is __this_cpu_preempt_check CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4 Call Trace: dump_stack check_preemption_disabled ? do_early_param __this_cpu_preempt_check arch_perfmon_init op_nmi_init ? alloc_pci_root_info oprofile_arch_init oprofile_init do_one_initcall ... These accessors should not have been used in the first place: it is PPro so no mixed silicon revisions and thus it can simply use boot_cpu_data. Reported-by: Fengguang Wu <[email protected]> Tested-by: Fengguang Wu <[email protected]> Fix-creation-mandated-by: Linus Torvalds <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Robert Richter <[email protected]> Cc: [email protected] Cc: [email protected]
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The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 2106.181412] ====================================================== [ 2106.187563] WARNING: possible circular locking dependency detected [ 2106.193718] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 2106.199175] ------------------------------------------------------ [ 2106.205328] qtdemux0:sink/2614 is trying to acquire lock: [ 2106.210701] (&dev->mfc_mutex){+.+.}, at: [<bf175544>] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.218672] [ 2106.218672] but task is already holding lock: [ 2106.224477] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.231497] [ 2106.231497] which lock already depends on the new lock. [ 2106.231497] [ 2106.239642] [ 2106.239642] the existing dependency chain (in reverse order) is: [ 2106.247095] [ 2106.247095] -> #1 (&mm->mmap_sem){++++}: [ 2106.252473] __might_fault+0x80/0xb0 [ 2106.256567] video_usercopy+0x1cc/0x510 [videodev] [ 2106.261845] v4l2_ioctl+0xa4/0xdc [videodev] [ 2106.266596] do_vfs_ioctl+0xa0/0xa18 [ 2106.270667] SyS_ioctl+0x34/0x5c [ 2106.274395] ret_fast_syscall+0x0/0x28 [ 2106.278637] [ 2106.278637] -> #0 (&dev->mfc_mutex){+.+.}: [ 2106.284186] lock_acquire+0x6c/0x88 [ 2106.288173] __mutex_lock+0x68/0xa34 [ 2106.292244] mutex_lock_interruptible_nested+0x1c/0x24 [ 2106.297893] s5p_mfc_mmap+0x28/0xd4 [s5p_mfc] [ 2106.302747] v4l2_mmap+0x54/0x88 [videodev] [ 2106.307409] mmap_region+0x3a8/0x638 [ 2106.311480] do_mmap+0x330/0x3a4 [ 2106.315207] vm_mmap_pgoff+0x90/0xb8 [ 2106.319279] SyS_mmap_pgoff+0x90/0xc0 [ 2106.323439] ret_fast_syscall+0x0/0x28 [ 2106.327683] [ 2106.327683] other info that might help us debug this: [ 2106.327683] [ 2106.335656] Possible unsafe locking scenario: [ 2106.335656] [ 2106.341548] CPU0 CPU1 [ 2106.346053] ---- ---- [ 2106.350559] lock(&mm->mmap_sem); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.353939] lock(&dev->mfc_mutex); [ 2106.365897] lock(&dev->mfc_mutex); [ 2106.369450] [ 2106.369450] *** DEADLOCK *** [ 2106.369450] [ 2106.375344] 1 lock held by qtdemux0:sink/2614: [ 2106.379762] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 2106.387214] [ 2106.387214] stack backtrace: [ 2106.391550] CPU: 7 PID: 2614 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 2106.400213] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 2106.406285] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 2106.413995] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 2106.421187] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 2106.429245] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 2106.437651] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 2106.445883] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 2106.453596] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 2106.461221] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 2106.470425] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf175544>] (s5p_mfc_mmap+0x28/0xd4 [s5p_mfc]) [ 2106.480494] [<bf175544>] (s5p_mfc_mmap [s5p_mfc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 2106.489575] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 2106.497875] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 2106.505068] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 2106.512260] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 2106.520059] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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The driver mmap functions shouldn't take lock when calling vb2_mmap(). Fix it to not take the lock. The following lockdep warning is fixed with this change. [ 1990.972058] ====================================================== [ 1990.978172] WARNING: possible circular locking dependency detected [ 1990.984327] 4.14.0-rc2-00002-gfab205f-dirty #4 Not tainted [ 1990.989783] ------------------------------------------------------ [ 1990.995937] qtdemux0:sink/2765 is trying to acquire lock: [ 1991.001309] (&gsc->lock){+.+.}, at: [<bf1729f0>] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.009108] but task is already holding lock: [ 1991.014913] (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.021932] which lock already depends on the new lock. [ 1991.030078] the existing dependency chain (in reverse order) is: [ 1991.037530] -> #1 (&mm->mmap_sem){++++}: [ 1991.042913] __might_fault+0x80/0xb0 [ 1991.047096] video_usercopy+0x1cc/0x510 [videodev] [ 1991.052297] v4l2_ioctl+0xa4/0xdc [videodev] [ 1991.057036] do_vfs_ioctl+0xa0/0xa18 [ 1991.061102] SyS_ioctl+0x34/0x5c [ 1991.064834] ret_fast_syscall+0x0/0x28 [ 1991.069072] -> #0 (&gsc->lock){+.+.}: [ 1991.074193] lock_acquire+0x6c/0x88 [ 1991.078179] __mutex_lock+0x68/0xa34 [ 1991.082247] mutex_lock_interruptible_nested+0x1c/0x24 [ 1991.087888] gsc_m2m_mmap+0x24/0x5c [exynos_gsc] [ 1991.093029] v4l2_mmap+0x54/0x88 [videodev] [ 1991.097673] mmap_region+0x3a8/0x638 [ 1991.101743] do_mmap+0x330/0x3a4 [ 1991.105470] vm_mmap_pgoff+0x90/0xb8 [ 1991.109542] SyS_mmap_pgoff+0x90/0xc0 [ 1991.113702] ret_fast_syscall+0x0/0x28 [ 1991.117945] other info that might help us debug this: [ 1991.125918] Possible unsafe locking scenario: [ 1991.131810] CPU0 CPU1 [ 1991.136315] ---- ---- [ 1991.140821] lock(&mm->mmap_sem); [ 1991.144201] lock(&gsc->lock); [ 1991.149833] lock(&mm->mmap_sem); [ 1991.155725] lock(&gsc->lock); [ 1991.158845] *** DEADLOCK *** [ 1991.164740] 1 lock held by qtdemux0:sink/2765: [ 1991.169157] #0: (&mm->mmap_sem){++++}, at: [<c01df2e4>] vm_mmap_pgoff+0x44/0xb8 [ 1991.176609] stack backtrace: [ 1991.180946] CPU: 2 PID: 2765 Comm: qtdemux0:sink Not tainted 4.14.0-rc2-00002-gfab205f-dirty #4 [ 1991.189608] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 1991.195686] [<c01102c8>] (unwind_backtrace) from [<c010cabc>] (show_stack+0x10/0x14) [ 1991.203393] [<c010cabc>] (show_stack) from [<c08543a4>] (dump_stack+0x98/0xc4) [ 1991.210586] [<c08543a4>] (dump_stack) from [<c016b2fc>] (print_circular_bug+0x254/0x410) [ 1991.218644] [<c016b2fc>] (print_circular_bug) from [<c016c580>] (check_prev_add+0x468/0x938) [ 1991.227049] [<c016c580>] (check_prev_add) from [<c016f4dc>] (__lock_acquire+0x1314/0x14fc) [ 1991.235281] [<c016f4dc>] (__lock_acquire) from [<c016fefc>] (lock_acquire+0x6c/0x88) [ 1991.242993] [<c016fefc>] (lock_acquire) from [<c0869fb4>] (__mutex_lock+0x68/0xa34) [ 1991.250620] [<c0869fb4>] (__mutex_lock) from [<c086aa08>] (mutex_lock_interruptible_nested+0x1c/0x24) [ 1991.259812] [<c086aa08>] (mutex_lock_interruptible_nested) from [<bf1729f0>] (gsc_m2m_mmap+0x24/0x5c [exynos_gsc]) [ 1991.270159] [<bf1729f0>] (gsc_m2m_mmap [exynos_gsc]) from [<bf037120>] (v4l2_mmap+0x54/0x88 [videodev]) [ 1991.279510] [<bf037120>] (v4l2_mmap [videodev]) from [<c01f4798>] (mmap_region+0x3a8/0x638) [ 1991.287792] [<c01f4798>] (mmap_region) from [<c01f4d58>] (do_mmap+0x330/0x3a4) [ 1991.294986] [<c01f4d58>] (do_mmap) from [<c01df330>] (vm_mmap_pgoff+0x90/0xb8) [ 1991.302178] [<c01df330>] (vm_mmap_pgoff) from [<c01f28cc>] (SyS_mmap_pgoff+0x90/0xc0) [ 1991.309977] [<c01f28cc>] (SyS_mmap_pgoff) from [<c0108820>] (ret_fast_syscall+0x0/0x28) Signed-off-by: Shuah Khan <[email protected]> Suggested-by: Hans Verkuil <[email protected]> Acked-by: Hans Verkuil <[email protected]> Signed-off-by: memeka <[email protected]>
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Dec 23, 2017
[ Upstream commit 87943db ] Sai reported a warning during some MBA tests: [ 236.755559] ====================================================== [ 236.762443] WARNING: possible circular locking dependency detected [ 236.769328] 4.14.0-rc4-yocto-standard #8 Not tainted [ 236.774857] ------------------------------------------------------ [ 236.781738] mount/10091 is trying to acquire lock: [ 236.787071] (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8117f892>] static_key_enable+0x12/0x30 [ 236.797058] but task is already holding lock: [ 236.803552] (&type->s_umount_key#37/1){+.+.}, at: [<ffffffff81208b2f>] sget_userns+0x32f/0x520 [ 236.813247] which lock already depends on the new lock. [ 236.822353] the existing dependency chain (in reverse order) is: [ 236.830686] -> #4 (&type->s_umount_key#37/1){+.+.}: [ 236.837756] __lock_acquire+0x1100/0x11a0 [ 236.842799] lock_acquire+0xdf/0x1d0 [ 236.847363] down_write_nested+0x46/0x80 [ 236.852310] sget_userns+0x32f/0x520 [ 236.856873] kernfs_mount_ns+0x7e/0x1f0 [ 236.861728] rdt_mount+0x30c/0x440 [ 236.866096] mount_fs+0x38/0x150 [ 236.870262] vfs_kern_mount+0x67/0x150 [ 236.875015] do_mount+0x1df/0xd50 [ 236.879286] SyS_mount+0x95/0xe0 [ 236.883464] entry_SYSCALL_64_fastpath+0x18/0xad [ 236.889183] -> #3 (rdtgroup_mutex){+.+.}: [ 236.895292] __lock_acquire+0x1100/0x11a0 [ 236.900337] lock_acquire+0xdf/0x1d0 [ 236.904899] __mutex_lock+0x80/0x8f0 [ 236.909459] mutex_lock_nested+0x1b/0x20 [ 236.914407] intel_rdt_online_cpu+0x3b/0x4a0 [ 236.919745] cpuhp_invoke_callback+0xce/0xb80 [ 236.925177] cpuhp_thread_fun+0x1c5/0x230 [ 236.930222] smpboot_thread_fn+0x11a/0x1e0 [ 236.935362] kthread+0x152/0x190 [ 236.939536] ret_from_fork+0x27/0x40 [ 236.944097] -> #2 (cpuhp_state-up){+.+.}: [ 236.950199] __lock_acquire+0x1100/0x11a0 [ 236.955241] lock_acquire+0xdf/0x1d0 [ 236.959800] cpuhp_issue_call+0x12e/0x1c0 [ 236.964845] __cpuhp_setup_state_cpuslocked+0x13b/0x2f0 [ 236.971242] __cpuhp_setup_state+0xa7/0x120 [ 236.976483] page_writeback_init+0x43/0x67 [ 236.981623] pagecache_init+0x38/0x3b [ 236.986281] start_kernel+0x3c6/0x41a [ 236.990931] x86_64_start_reservations+0x2a/0x2c [ 236.996650] x86_64_start_kernel+0x72/0x75 [ 237.001793] verify_cpu+0x0/0xfb [ 237.005966] -> #1 (cpuhp_state_mutex){+.+.}: [ 237.012364] __lock_acquire+0x1100/0x11a0 [ 237.017408] lock_acquire+0xdf/0x1d0 [ 237.021969] __mutex_lock+0x80/0x8f0 [ 237.026527] mutex_lock_nested+0x1b/0x20 [ 237.031475] __cpuhp_setup_state_cpuslocked+0x54/0x2f0 [ 237.037777] __cpuhp_setup_state+0xa7/0x120 [ 237.043013] page_alloc_init+0x28/0x30 [ 237.047769] start_kernel+0x148/0x41a [ 237.052425] x86_64_start_reservations+0x2a/0x2c [ 237.058145] x86_64_start_kernel+0x72/0x75 [ 237.063284] verify_cpu+0x0/0xfb [ 237.067456] -> #0 (cpu_hotplug_lock.rw_sem){++++}: [ 237.074436] check_prev_add+0x401/0x800 [ 237.079286] __lock_acquire+0x1100/0x11a0 [ 237.084330] lock_acquire+0xdf/0x1d0 [ 237.088890] cpus_read_lock+0x42/0x90 [ 237.093548] static_key_enable+0x12/0x30 [ 237.098496] rdt_mount+0x406/0x440 [ 237.102862] mount_fs+0x38/0x150 [ 237.107035] vfs_kern_mount+0x67/0x150 [ 237.111787] do_mount+0x1df/0xd50 [ 237.116058] SyS_mount+0x95/0xe0 [ 237.120233] entry_SYSCALL_64_fastpath+0x18/0xad [ 237.125952] other info that might help us debug this: [ 237.134867] Chain exists of: cpu_hotplug_lock.rw_sem --> rdtgroup_mutex --> &type->s_umount_key#37/1 [ 237.148425] Possible unsafe locking scenario: [ 237.155015] CPU0 CPU1 [ 237.160057] ---- ---- [ 237.165100] lock(&type->s_umount_key#37/1); [ 237.169952] lock(rdtgroup_mutex); [ 237.176641] lock(&type->s_umount_key#37/1); [ 237.184287] lock(cpu_hotplug_lock.rw_sem); [ 237.189041] *** DEADLOCK *** When the resctrl filesystem is mounted the locks must be acquired in the same order as was done when the cpus came online: cpu_hotplug_lock before rdtgroup_mutex. This also requires to switch the static_branch_enable() calls to the _cpulocked variant because now cpu hotplug lock is held already. [ tglx: Switched to cpus_read_[un]lock ] Reported-by: Sai Praneeth Prakhya <[email protected]> Signed-off-by: Reinette Chatre <[email protected]> Tested-by: Sai Praneeth Prakhya <[email protected]> Acked-by: Vikas Shivappa <[email protected]> Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/9c41b91bc2f47d9e95b62b213ecdb45623c47a9f.1508490116.git.reinette.chatre@intel.com Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit 962cc1a ] In commit f2e9ad2 ("xfs: check for race with xfs_reclaim_inode"), we skip an inode if we're racing with freeing the inode via xfs_reclaim_inode, but we forgot to release the rcu read lock when dumping the inode, with the result that we exit to userspace with a lock held. Don't do that; generic/320 with a 1k block size fails this very occasionally. ================================================ WARNING: lock held when returning to user space! 4.14.0-rc6-djwong #4 Tainted: G W ------------------------------------------------ rm/30466 is leaving the kernel with locks still held! 1 lock held by rm/30466: #0: (rcu_read_lock){....}, at: [<ffffffffa01364d3>] xfs_ifree_cluster.isra.17+0x2c3/0x6f0 [xfs] ------------[ cut here ]------------ WARNING: CPU: 1 PID: 30466 at kernel/rcu/tree_plugin.h:329 rcu_note_context_switch+0x71/0x700 Modules linked in: deadline_iosched dm_snapshot dm_bufio ext4 mbcache jbd2 dm_flakey xfs libcrc32c dax_pmem device_dax nd_pmem sch_fq_codel af_packet [last unloaded: scsi_debug] CPU: 1 PID: 30466 Comm: rm Tainted: G W 4.14.0-rc6-djwong #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1djwong0 04/01/2014 task: ffff880037680000 task.stack: ffffc90001064000 RIP: 0010:rcu_note_context_switch+0x71/0x700 RSP: 0000:ffffc90001067e50 EFLAGS: 00010002 RAX: 0000000000000001 RBX: ffff880037680000 RCX: ffff88003e73d200 RDX: 0000000000000002 RSI: ffffffff819e53e9 RDI: ffffffff819f4375 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff880062c900d0 R10: 0000000000000000 R11: 0000000000000000 R12: ffff880037680000 R13: 0000000000000000 R14: ffffc90001067eb8 R15: ffff880037680690 FS: 00007fa3b8ce8700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69bf77c000 CR3: 000000002450a000 CR4: 00000000000006e0 Call Trace: __schedule+0xb8/0xb10 schedule+0x40/0x90 exit_to_usermode_loop+0x6b/0xa0 prepare_exit_to_usermode+0x7a/0x90 retint_user+0x8/0x20 RIP: 0033:0x7fa3b87fda87 RSP: 002b:00007ffe41206568 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 0000000000000000 RBX: 00000000010e88c0 RCX: 00007fa3b87fda87 RDX: 0000000000000000 RSI: 00000000010e89c8 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 R10: 000000000000015e R11: 0000000000000246 R12: 00000000010c8060 R13: 00007ffe41206690 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace e88f83bf0cfbd07d ]--- Fixes: f2e9ad2 Cc: Omar Sandoval <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Omar Sandoval <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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clk_change_rate() propagates rate change down to all its children. Such operation requires managing proper runtime PM state of each child, what was missing. Add needed calls to clk_pm_runtime*() to ensure that set_rate() clock callback is called on runtime active clock. This fixes following issue found on Exynos5433 TM2 board with devfreq enabled: Synchronous External Abort: synchronous external abort (0x96000210) at 0xffffff80093f5600 Internal error: : 96000210 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 5 Comm: kworker/u16:0 Not tainted 4.15.0-rc1-next-20171129+ #4 Hardware name: Samsung TM2 board (DT) Workqueue: devfreq_wq devfreq_monitor task: ffffffc0ca96b600 task.stack: ffffff80093a8000 pstate: a0000085 (NzCv daIf -PAN -UAO) pc : clk_divider_set_rate+0x54/0x118 lr : clk_divider_set_rate+0x44/0x118 ... Process kworker/u16:0 (pid: 5, stack limit = 0xffffff80093a8000) Call trace: clk_divider_set_rate+0x54/0x118 clk_change_rate+0xfc/0x4e0 clk_change_rate+0x1f0/0x4e0 clk_change_rate+0x1f0/0x4e0 clk_change_rate+0x1f0/0x4e0 clk_core_set_rate_nolock+0x138/0x148 clk_set_rate+0x28/0x50 exynos_bus_passive_target+0x6c/0x11c update_devfreq_passive+0x58/0xb4 devfreq_passive_notifier_call+0x50/0x5c notifier_call_chain+0x4c/0x88 __srcu_notifier_call_chain+0x54/0x80 srcu_notifier_call_chain+0x14/0x1c update_devfreq+0x100/0x1b4 devfreq_monitor+0x2c/0x88 process_one_work+0x148/0x3d8 worker_thread+0x13c/0x3f8 kthread+0x100/0x12c ret_from_fork+0x10/0x18 Reported-by: Chanwoo Choi <[email protected]> Fixes: 9a34b45 ("clk: Add support for runtime PM") Signed-off-by: Marek Szyprowski <[email protected]> Reviewed-by: Ulf Hansson <[email protected]> Tested-by: Chanwoo Choi <[email protected]> Reviewed-by: Chanwoo Choi <[email protected]> Signed-off-by: Stephen Boyd <[email protected]>
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[ Upstream commit f8bbc07 ] vhost_worker will call tun call backs to receive packets. If too many illegal packets arrives, tun_do_read will keep dumping packet contents. When console is enabled, it will costs much more cpu time to dump packet and soft lockup will be detected. net_ratelimit mechanism can be used to limit the dumping rate. PID: 33036 TASK: ffff949da6f20000 CPU: 23 COMMAND: "vhost-32980" #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e #3 [fffffe00003fced0] do_nmi at ffffffff8922660d #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663 [exception RIP: io_serial_in+20] RIP: ffffffff89792594 RSP: ffffa655314979e8 RFLAGS: 00000002 RAX: ffffffff89792500 RBX: ffffffff8af428a0 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff8af428a0 RBP: 0000000000002710 R8: 0000000000000004 R9: 000000000000000f R10: 0000000000000000 R11: ffffffff8acbf64f R12: 0000000000000020 R13: ffffffff8acbf698 R14: 0000000000000058 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594 #6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470 #7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6 #8 [ffffa65531497a20] uart_console_write at ffffffff8978b605 #9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558 #10 [ffffa65531497ac8] console_unlock at ffffffff89316124 #11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07 #12 [ffffa65531497b68] printk at ffffffff89318306 #13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765 #14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun] #15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun] #16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net] #17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost] #18 [ffffa65531497f10] kthread at ffffffff892d2e72 #19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors") Signed-off-by: Lei Chen <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Acked-by: Jason Wang <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Acked-by: Michael S. Tsirkin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 88ce010 ] The session has a header in it which contains a perf env with bpf_progs. The bpf_progs are accessed by the sideband thread and so the sideband thread must be stopped before the session is deleted, to avoid a use after free. This error was detected by AddressSanitizer in the following: ==2054673==ERROR: AddressSanitizer: heap-use-after-free on address 0x61d000161e00 at pc 0x55769289de54 bp 0x7f9df36d4ab0 sp 0x7f9df36d4aa8 READ of size 8 at 0x61d000161e00 thread T1 #0 0x55769289de53 in __perf_env__insert_bpf_prog_info util/env.c:42 #1 0x55769289dbb1 in perf_env__insert_bpf_prog_info util/env.c:29 #2 0x557692bbae29 in perf_env__add_bpf_info util/bpf-event.c:483 #3 0x557692bbb01a in bpf_event__sb_cb util/bpf-event.c:512 #4 0x5576928b75f4 in perf_evlist__poll_thread util/sideband_evlist.c:68 #5 0x7f9df96a63eb in start_thread nptl/pthread_create.c:444 #6 0x7f9df9726a4b in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 0x61d000161e00 is located 384 bytes inside of 2136-byte region [0x61d000161c80,0x61d0001624d8) freed by thread T0 here: #0 0x7f9dfa6d7288 in __interceptor_free libsanitizer/asan/asan_malloc_linux.cpp:52 #1 0x557692978d50 in perf_session__delete util/session.c:319 #2 0x557692673959 in __cmd_record tools/perf/builtin-record.c:2884 #3 0x55769267a9f0 in cmd_record tools/perf/builtin-record.c:4259 #4 0x55769286710c in run_builtin tools/perf/perf.c:349 #5 0x557692867678 in handle_internal_command tools/perf/perf.c:402 #6 0x557692867a40 in run_argv tools/perf/perf.c:446 #7 0x557692867fae in main tools/perf/perf.c:562 #8 0x7f9df96456c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 Fixes: 657ee55 ("perf evlist: Introduce side band thread") Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Athira Rajeev <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Disha Goel <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: James Clark <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kajol Jain <[email protected]> Cc: Kan Liang <[email protected]> Cc: K Prateek Nayak <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Song Liu <[email protected]> Cc: Tim Chen <[email protected]> Cc: Yicong Yang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 769e6a1 ] ui_browser__show() is capturing the input title that is stack allocated memory in hist_browser__run(). Avoid a use after return by strdup-ing the string. Committer notes: Further explanation from Ian Rogers: My command line using tui is: $ sudo bash -c 'rm /tmp/asan.log*; export ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a sleep 1; /tmp/perf/perf mem report' I then go to the perf annotate view and quit. This triggers the asan error (from the log file): ``` ==1254591==ERROR: AddressSanitizer: stack-use-after-return on address 0x7f2813331920 at pc 0x7f28180 65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10 READ of size 80 at 0x7f2813331920 thread T0 #0 0x7f2818065990 in __interceptor_strlen ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461 #1 0x7f2817698251 in SLsmg_write_wrapped_string (/lib/x86_64-linux-gnu/libslang.so.2+0x98251) #2 0x7f28176984b9 in SLsmg_write_nstring (/lib/x86_64-linux-gnu/libslang.so.2+0x984b9) #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60 #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266 #5 0x55c94045c776 in ui_browser__show ui/browser.c:288 #6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206 #7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458 #8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412 #9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527 #10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613 #11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661 #12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671 #13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141 #14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805 #15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374 #16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516 #17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350 #18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403 #19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447 #20 0x55c9400e53ad in main tools/perf/perf.c:561 #21 0x7f28170456c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360 #23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId: 84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93) Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746 This frame has 1 object(s): [32, 192) 'title' (line 747) <== Memory access at offset 32 is inside this variable HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork ``` hist_browser__run isn't on the stack so the asan error looks legit. There's no clean init/exit on struct ui_browser so I may be trading a use-after-return for a memory leak, but that seems look a good trade anyway. Fixes: 05e8b08 ("perf ui browser: Stop using 'self'") Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Athira Rajeev <[email protected]> Cc: Ben Gainey <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: James Clark <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kajol Jain <[email protected]> Cc: Kan Liang <[email protected]> Cc: K Prateek Nayak <[email protected]> Cc: Li Dong <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oliver Upton <[email protected]> Cc: Paran Lee <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Bangoria <[email protected]> Cc: Sun Haiyong <[email protected]> Cc: Tim Chen <[email protected]> Cc: Yanteng Si <[email protected]> Cc: Yicong Yang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit 9d274c1 upstream. We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) #1 btrfs_drop_extents (fs/btrfs/file.c:411:4) #2 log_one_extent (fs/btrfs/tree-log.c:4732:9) #3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) #4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) #5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) #6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) #7 btrfs_sync_file (fs/btrfs/file.c:1933:8) #8 vfs_fsync_range (fs/sync.c:188:9) #9 vfs_fsync (fs/sync.c:202:9) #10 do_fsync (fs/sync.c:212:9) #11 __do_sys_fdatasync (fs/sync.c:225:9) #12 __se_sys_fdatasync (fs/sync.c:223:1) #13 __x64_sys_fdatasync (fs/sync.c:223:1) #14 do_syscall_x64 (arch/x86/entry/common.c:52:14) #15 do_syscall_64 (arch/x86/entry/common.c:83:7) #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. CC: [email protected] # 6.1+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 22f0081 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <[email protected]> Suggested-by: Greg KH <[email protected]> Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/[email protected]/ Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit f1e197a ] trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ #7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. Signed-off-by: Wander Lairson Costa <[email protected]> Reported-by: Hu Chunyu <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit af0cb3f ] Xiumei and Christoph reported the following lockdep splat, complaining of the qdisc root lock being taken twice: ============================================ WARNING: possible recursive locking detected 6.7.0-rc3+ torvalds#598 Not tainted -------------------------------------------- swapper/2/0 is trying to acquire lock: ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 but task is already holding lock: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sch->q.lock); lock(&sch->q.lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by swapper/2/0: #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510 #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0 #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 stack backtrace: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ torvalds#598 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x4a/0x80 __lock_acquire+0xfdd/0x3150 lock_acquire+0x1ca/0x540 _raw_spin_lock+0x34/0x80 __dev_queue_xmit+0x1560/0x2e70 tcf_mirred_act+0x82e/0x1260 [act_mirred] tcf_action_exec+0x161/0x480 tcf_classify+0x689/0x1170 prio_enqueue+0x316/0x660 [sch_prio] dev_qdisc_enqueue+0x46/0x220 __dev_queue_xmit+0x1615/0x2e70 ip_finish_output2+0x1218/0x1ed0 __ip_finish_output+0x8b3/0x1350 ip_output+0x163/0x4e0 igmp_ifc_timer_expire+0x44b/0x930 call_timer_fn+0x1a2/0x510 run_timer_softirq+0x54d/0x11a0 __do_softirq+0x1b3/0x88f irq_exit_rcu+0x18f/0x1e0 sysvec_apic_timer_interrupt+0x6f/0x90 </IRQ> This happens when TC does a mirred egress redirect from the root qdisc of device A to the root qdisc of device B. As long as these two locks aren't protecting the same qdisc, they can be acquired in chain: add a per-qdisc lockdep key to silence false warnings. This dynamic key should safely replace the static key we have in sch_htb: it was added to allow enqueueing to the device "direct qdisc" while still holding the qdisc root lock. v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet) CC: Maxim Mikityanskiy <[email protected]> CC: Xiumei Mu <[email protected]> Reported-by: Christoph Paasch <[email protected]> Closes: multipath-tcp/mptcp_net-next#451 Signed-off-by: Davide Caratti <[email protected]> Link: https://lore.kernel.org/r/7dc06d6158f72053cf877a82e2a7a5bd23692faa.1713448007.git.dcaratti@redhat.com Signed-off-by: Paolo Abeni <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 #1 __crash_kexec at ffffffff8c1338fa #2 panic at ffffffff8c1d69b9 #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] #10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] #11 dio_complete at ffffffff8c2b9fa7 #12 do_blockdev_direct_IO at ffffffff8c2bc09f #13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] #14 generic_file_direct_write at ffffffff8c1dcf14 #15 __generic_file_write_iter at ffffffff8c1dd07b #16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] #17 aio_write at ffffffff8c2cc72e #18 kmem_cache_alloc at ffffffff8c248dde #19 do_io_submit at ffffffff8c2ccada #20 do_syscall_64 at ffffffff8c004984 #21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Reviewed-by: Heming Zhao <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: Gang He <[email protected]> Cc: Jun Piao <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 9d274c1 upstream. We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) #1 btrfs_drop_extents (fs/btrfs/file.c:411:4) #2 log_one_extent (fs/btrfs/tree-log.c:4732:9) #3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) #4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) #5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) #6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) #7 btrfs_sync_file (fs/btrfs/file.c:1933:8) #8 vfs_fsync_range (fs/sync.c:188:9) #9 vfs_fsync (fs/sync.c:202:9) #10 do_fsync (fs/sync.c:212:9) #11 __do_sys_fdatasync (fs/sync.c:225:9) #12 __se_sys_fdatasync (fs/sync.c:223:1) #13 __x64_sys_fdatasync (fs/sync.c:223:1) #14 do_syscall_x64 (arch/x86/entry/common.c:52:14) #15 do_syscall_64 (arch/x86/entry/common.c:83:7) #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. CC: [email protected] # 6.1+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 22f0081 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <[email protected]> Suggested-by: Greg KH <[email protected]> Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/[email protected]/ Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit f1e197a ] trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ #7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. Signed-off-by: Wander Lairson Costa <[email protected]> Reported-by: Hu Chunyu <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit af0cb3f ] Xiumei and Christoph reported the following lockdep splat, complaining of the qdisc root lock being taken twice: ============================================ WARNING: possible recursive locking detected 6.7.0-rc3+ torvalds#598 Not tainted -------------------------------------------- swapper/2/0 is trying to acquire lock: ffff888177190110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 but task is already holding lock: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sch->q.lock); lock(&sch->q.lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by swapper/2/0: #0: ffff888135a09d98 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x510 #1: ffffffffaaee5260 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x2c0/0x1ed0 #2: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 #3: ffff88811995a110 (&sch->q.lock){+.-.}-{2:2}, at: __dev_queue_xmit+0x1560/0x2e70 #4: ffffffffaaee5200 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x209/0x2e70 stack backtrace: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.7.0-rc3+ torvalds#598 Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x4a/0x80 __lock_acquire+0xfdd/0x3150 lock_acquire+0x1ca/0x540 _raw_spin_lock+0x34/0x80 __dev_queue_xmit+0x1560/0x2e70 tcf_mirred_act+0x82e/0x1260 [act_mirred] tcf_action_exec+0x161/0x480 tcf_classify+0x689/0x1170 prio_enqueue+0x316/0x660 [sch_prio] dev_qdisc_enqueue+0x46/0x220 __dev_queue_xmit+0x1615/0x2e70 ip_finish_output2+0x1218/0x1ed0 __ip_finish_output+0x8b3/0x1350 ip_output+0x163/0x4e0 igmp_ifc_timer_expire+0x44b/0x930 call_timer_fn+0x1a2/0x510 run_timer_softirq+0x54d/0x11a0 __do_softirq+0x1b3/0x88f irq_exit_rcu+0x18f/0x1e0 sysvec_apic_timer_interrupt+0x6f/0x90 </IRQ> This happens when TC does a mirred egress redirect from the root qdisc of device A to the root qdisc of device B. As long as these two locks aren't protecting the same qdisc, they can be acquired in chain: add a per-qdisc lockdep key to silence false warnings. This dynamic key should safely replace the static key we have in sch_htb: it was added to allow enqueueing to the device "direct qdisc" while still holding the qdisc root lock. v2: don't use static keys anymore in HTB direct qdiscs (thanks Eric Dumazet) CC: Maxim Mikityanskiy <[email protected]> CC: Xiumei Mu <[email protected]> Reported-by: Christoph Paasch <[email protected]> Closes: multipath-tcp/mptcp_net-next#451 Signed-off-by: Davide Caratti <[email protected]> Link: https://lore.kernel.org/r/7dc06d6158f72053cf877a82e2a7a5bd23692faa.1713448007.git.dcaratti@redhat.com Signed-off-by: Paolo Abeni <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit cebae29 ] Shin'ichiro reported that when he's running fstests' test-case btrfs/167 on emulated zoned devices, he's seeing the following NULL pointer dereference in 'btrfs_zone_finish_endio()': Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f] CPU: 4 PID: 2332440 Comm: kworker/u80:15 Tainted: G W 6.10.0-rc2-kts+ #4 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020 Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs] RSP: 0018:ffff88867f107a90 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff893e5534 RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088 RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed1081696028 R10: ffff88840b4b0143 R11: ffff88834dfff600 R12: ffff88840b4b0000 R13: 0000000000020000 R14: 0000000000000000 R15: ffff888530ad5210 FS: 0000000000000000(0000) GS:ffff888e3f800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f87223fff38 CR3: 00000007a7c6a002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die_addr+0x46/0x70 ? exc_general_protection+0x14f/0x250 ? asm_exc_general_protection+0x26/0x30 ? do_raw_read_unlock+0x44/0x70 ? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs] btrfs_finish_one_ordered+0x5d9/0x19a0 [btrfs] ? __pfx_lock_release+0x10/0x10 ? do_raw_write_lock+0x90/0x260 ? __pfx_do_raw_write_lock+0x10/0x10 ? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs] ? _raw_write_unlock+0x23/0x40 ? btrfs_finish_ordered_zoned+0x5a9/0x850 [btrfs] ? lock_acquire+0x435/0x500 btrfs_work_helper+0x1b1/0xa70 [btrfs] ? __schedule+0x10a8/0x60b0 ? __pfx___might_resched+0x10/0x10 process_one_work+0x862/0x1410 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x16c/0x240 worker_thread+0x5e6/0x1010 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c3/0x3a0 ? trace_irq_enable.constprop.0+0xce/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Enabling CONFIG_BTRFS_ASSERT revealed the following assertion to trigger: assertion failed: !list_empty(&ordered->list), in fs/btrfs/zoned.c:1815 This indicates, that we're missing the checksums list on the ordered_extent. As btrfs/167 is doing a NOCOW write this is to be expected. Further analysis with drgn confirmed the assumption: >>> inode = prog.crashed_thread().stack_trace()[11]['ordered'].inode >>> btrfs_inode = drgn.container_of(inode, "struct btrfs_inode", \ "vfs_inode") >>> print(btrfs_inode.flags) (u32)1 As zoned emulation mode simulates conventional zones on regular devices, we cannot use zone-append for writing. But we're only attaching dummy checksums if we're doing a zone-append write. So for NOCOW zoned data writes on conventional zones, also attach a dummy checksum. Reported-by: Shinichiro Kawasaki <[email protected]> Fixes: cbfce4c ("btrfs: optimize the logical to physical mapping for zoned writes") CC: Naohiro Aota <[email protected]> # 6.6+ Tested-by: Shin'ichiro Kawasaki <[email protected]> Reviewed-by: Naohiro Aota <[email protected]> Signed-off-by: Johannes Thumshirn <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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…play [ Upstream commit d182575 ] During inode logging (and log replay too), we are holding a transaction handle and we often need to call btrfs_iget(), which will read an inode from its subvolume btree if it's not loaded in memory and that results in allocating an inode with GFP_KERNEL semantics at the btrfs_alloc_inode() callback - and this may recurse into the filesystem in case we are under memory pressure and attempt to commit the current transaction, resulting in a deadlock since the logging (or log replay) task is holding a transaction handle open. Syzbot reported this with the following stack traces: WARNING: possible circular locking dependency detected 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Not tainted ------------------------------------------------------ syz-executor.1/9919 is trying to acquire lock: ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline] ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 but task is already holding lock: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&ei->log_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 btrfs_log_inode_parent+0x8cb/0x2a90 fs/btrfs/tree-log.c:7079 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x164/0xf40 fs/btrfs/transaction.c:315 start_transaction+0x427/0x1a70 fs/btrfs/transaction.c:700 btrfs_commit_super+0xa1/0x110 fs/btrfs/disk-io.c:4170 close_ctree+0xcb0/0xf90 fs/btrfs/disk-io.c:4324 generic_shutdown_super+0x159/0x3d0 fs/super.c:642 kill_anon_super+0x3a/0x60 fs/super.c:1226 btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2096 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 __do_fast_syscall_32+0x80/0x120 arch/x86/entry/common.c:389 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #1 (btrfs_trans_num_writers){++++}-{0:0}: __lock_release kernel/locking/lockdep.c:5468 [inline] lock_release+0x33e/0x6c0 kernel/locking/lockdep.c:5774 percpu_up_read include/linux/percpu-rwsem.h:99 [inline] __sb_end_write include/linux/fs.h:1650 [inline] sb_end_intwrite include/linux/fs.h:1767 [inline] __btrfs_end_transaction+0x5ca/0x920 fs/btrfs/transaction.c:1071 btrfs_commit_inode_delayed_inode+0x228/0x330 fs/btrfs/delayed-inode.c:1301 btrfs_evict_inode+0x960/0xe80 fs/btrfs/inode.c:5291 evict+0x2ed/0x6c0 fs/inode.c:667 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845 dput+0x1f/0x30 fs/dcache.c:835 ovl_stack_put+0x60/0x90 fs/overlayfs/util.c:132 ovl_destroy_inode+0xc6/0x190 fs/overlayfs/super.c:182 destroy_inode+0xc4/0x1b0 fs/inode.c:311 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 shrink_kill fs/dcache.c:1048 [inline] shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156 super_cache_scan+0x32a/0x550 fs/super.c:221 do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435 shrink_slab_memcg mm/shrinker.c:548 [inline] shrink_slab+0xa87/0x1310 mm/shrinker.c:626 shrink_one+0x493/0x7c0 mm/vmscan.c:4790 shrink_many mm/vmscan.c:4851 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951 shrink_node mm/vmscan.c:5910 [inline] kswapd_shrink_node mm/vmscan.c:6720 [inline] balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411 alloc_inode+0x5d/0x230 fs/inode.c:261 iget5_locked fs/inode.c:1235 [inline] iget5_locked+0x1c9/0x2c0 fs/inode.c:1228 btrfs_iget_locked fs/btrfs/inode.c:5590 [inline] btrfs_iget_path fs/btrfs/inode.c:5607 [inline] btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636 add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline] copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928 btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592 log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline] btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718 btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline] btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xde0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: fs_reclaim --> btrfs_trans_num_extwriters --> &ei->log_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->log_mutex); lock(btrfs_trans_num_extwriters); lock(&ei->log_mutex); lock(fs_reclaim); *** DEADLOCK *** 7 locks held by syz-executor.1/9919: #0: ffff88802be20420 (sb_writers#23){.+.+}-{0:0}, at: do_pwritev+0x1b2/0x260 fs/read_write.c:1072 #1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline] #1: ffff888065c0f8f0 (&sb->s_type->i_mutex_key#33){++++}-{3:3}, at: btrfs_inode_lock+0xc8/0x110 fs/btrfs/inode.c:385 #2: ffff888065c0f778 (&ei->i_mmap_lock){++++}-{3:3}, at: btrfs_inode_lock+0xee/0x110 fs/btrfs/inode.c:388 #3: ffff88802be20610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_sync_file+0x95b/0xe10 fs/btrfs/file.c:1952 #4: ffff8880546323f0 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290 #5: ffff888054632418 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x430/0xf40 fs/btrfs/transaction.c:290 #6: ffff88804b569358 (&ei->log_mutex){+.+.}-{3:3}, at: btrfs_log_inode+0x39c/0x4660 fs/btrfs/tree-log.c:6481 stack backtrace: CPU: 2 PID: 9919 Comm: syz-executor.1 Not tainted 6.10.0-rc2-syzkaller-00361-g061d1af7b030 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __fs_reclaim_acquire mm/page_alloc.c:3801 [inline] fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3891 [inline] slab_alloc_node mm/slub.c:3981 [inline] kmem_cache_alloc_lru_noprof+0x58/0x2f0 mm/slub.c:4020 btrfs_alloc_inode+0x118/0xb20 fs/btrfs/inode.c:8411 alloc_inode+0x5d/0x230 fs/inode.c:261 iget5_locked fs/inode.c:1235 [inline] iget5_locked+0x1c9/0x2c0 fs/inode.c:1228 btrfs_iget_locked fs/btrfs/inode.c:5590 [inline] btrfs_iget_path fs/btrfs/inode.c:5607 [inline] btrfs_iget+0xfb/0x230 fs/btrfs/inode.c:5636 add_conflicting_inode fs/btrfs/tree-log.c:5657 [inline] copy_inode_items_to_log+0x1039/0x1e30 fs/btrfs/tree-log.c:5928 btrfs_log_inode+0xa48/0x4660 fs/btrfs/tree-log.c:6592 log_new_delayed_dentries fs/btrfs/tree-log.c:6363 [inline] btrfs_log_inode+0x27dd/0x4660 fs/btrfs/tree-log.c:6718 btrfs_log_all_parents fs/btrfs/tree-log.c:6833 [inline] btrfs_log_inode_parent+0x22ba/0x2a90 fs/btrfs/tree-log.c:7141 btrfs_log_dentry_safe+0x59/0x80 fs/btrfs/tree-log.c:7180 btrfs_sync_file+0x9c1/0xe10 fs/btrfs/file.c:1959 vfs_fsync_range+0x141/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2794 [inline] btrfs_do_write_iter+0x584/0x10c0 fs/btrfs/file.c:1705 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741 vfs_writev+0x36f/0xde0 fs/read_write.c:971 do_pwritev+0x1b2/0x260 fs/read_write.c:1072 __do_compat_sys_pwritev2 fs/read_write.c:1218 [inline] __se_compat_sys_pwritev2 fs/read_write.c:1210 [inline] __ia32_compat_sys_pwritev2+0x121/0x1b0 fs/read_write.c:1210 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7334579 Code: b8 01 10 06 03 (...) RSP: 002b:00000000f5f265ac EFLAGS: 00000292 ORIG_RAX: 000000000000017b RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000200002c0 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Fix this by ensuring we are under a NOFS scope whenever we call btrfs_iget() during inode logging and log replay. Reported-by: [email protected] Link: https://lore.kernel.org/linux-btrfs/[email protected]/ Fixes: 712e36c ("btrfs: use GFP_KERNEL in btrfs_alloc_inode") Reviewed-by: Johannes Thumshirn <[email protected]> Reviewed-by: Josef Bacik <[email protected]> Reviewed-by: Qu Wenruo <[email protected]> Signed-off-by: Filipe Manana <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 #1 __crash_kexec at ffffffff8c1338fa #2 panic at ffffffff8c1d69b9 #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] #10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] #11 dio_complete at ffffffff8c2b9fa7 #12 do_blockdev_direct_IO at ffffffff8c2bc09f #13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] #14 generic_file_direct_write at ffffffff8c1dcf14 #15 __generic_file_write_iter at ffffffff8c1dd07b #16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] #17 aio_write at ffffffff8c2cc72e #18 kmem_cache_alloc at ffffffff8c248dde #19 do_io_submit at ffffffff8c2ccada #20 do_syscall_64 at ffffffff8c004984 #21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Reviewed-by: Heming Zhao <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: Gang He <[email protected]> Cc: Jun Piao <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 22f0081 upstream. The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <[email protected]> Suggested-by: Greg KH <[email protected]> Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/[email protected]/ Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit f1e197a ] trace_drop_common() is called with preemption disabled, and it acquires a spin_lock. This is problematic for RT kernels because spin_locks are sleeping locks in this configuration, which causes the following splat: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 449, name: rcuc/47 preempt_count: 1, expected: 0 RCU nest depth: 2, expected: 2 5 locks held by rcuc/47/449: #0: ff1100086ec30a60 ((softirq_ctrl.lock)){+.+.}-{2:2}, at: __local_bh_disable_ip+0x105/0x210 #1: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: rt_spin_lock+0xbf/0x130 #2: ffffffffb394a280 (rcu_read_lock){....}-{1:2}, at: __local_bh_disable_ip+0x11c/0x210 #3: ffffffffb394a160 (rcu_callback){....}-{0:0}, at: rcu_do_batch+0x360/0xc70 #4: ff1100086ee07520 (&data->lock){+.+.}-{2:2}, at: trace_drop_common.constprop.0+0xb5/0x290 irq event stamp: 139909 hardirqs last enabled at (139908): [<ffffffffb1df2b33>] _raw_spin_unlock_irqrestore+0x63/0x80 hardirqs last disabled at (139909): [<ffffffffb19bd03d>] trace_drop_common.constprop.0+0x26d/0x290 softirqs last enabled at (139892): [<ffffffffb07a1083>] __local_bh_enable_ip+0x103/0x170 softirqs last disabled at (139898): [<ffffffffb0909b33>] rcu_cpu_kthread+0x93/0x1f0 Preemption disabled at: [<ffffffffb1de786b>] rt_mutex_slowunlock+0xab/0x2e0 CPU: 47 PID: 449 Comm: rcuc/47 Not tainted 6.9.0-rc2-rt1+ #7 Hardware name: Dell Inc. PowerEdge R650/0Y2G81, BIOS 1.6.5 04/15/2022 Call Trace: <TASK> dump_stack_lvl+0x8c/0xd0 dump_stack+0x14/0x20 __might_resched+0x21e/0x2f0 rt_spin_lock+0x5e/0x130 ? trace_drop_common.constprop.0+0xb5/0x290 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_drop_common.constprop.0+0xb5/0x290 ? preempt_count_sub+0x1c/0xd0 ? _raw_spin_unlock_irqrestore+0x4a/0x80 ? __pfx_trace_drop_common.constprop.0+0x10/0x10 ? rt_mutex_slowunlock+0x26a/0x2e0 ? skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_rt_mutex_slowunlock+0x10/0x10 ? skb_queue_purge_reason.part.0+0x1bf/0x230 trace_kfree_skb_hit+0x15/0x20 trace_kfree_skb+0xe9/0x150 kfree_skb_reason+0x7b/0x110 skb_queue_purge_reason.part.0+0x1bf/0x230 ? __pfx_skb_queue_purge_reason.part.0+0x10/0x10 ? mark_lock.part.0+0x8a/0x520 ... trace_drop_common() also disables interrupts, but this is a minor issue because we could easily replace it with a local_lock. Replace the spin_lock with raw_spin_lock to avoid sleeping in atomic context. Signed-off-by: Wander Lairson Costa <[email protected]> Reported-by: Hu Chunyu <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit be346c1 upstream. The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 #1 __crash_kexec at ffffffff8c1338fa #2 panic at ffffffff8c1d69b9 #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] #10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] #11 dio_complete at ffffffff8c2b9fa7 #12 do_blockdev_direct_IO at ffffffff8c2bc09f #13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] #14 generic_file_direct_write at ffffffff8c1dcf14 #15 __generic_file_write_iter at ffffffff8c1dd07b #16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] #17 aio_write at ffffffff8c2cc72e #18 kmem_cache_alloc at ffffffff8c248dde #19 do_io_submit at ffffffff8c2ccada #20 do_syscall_64 at ffffffff8c004984 #21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Reviewed-by: Heming Zhao <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: Gang He <[email protected]> Cc: Jun Piao <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit 59a931c ] If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ #4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ #4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: <TASK> dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo <[email protected]> Reviewed-by: Jakub Kicinski <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 59a931c ] If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ #4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ #4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: <TASK> dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo <[email protected]> Reviewed-by: Jakub Kicinski <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 86a41ea ] When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/[email protected]/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ #34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <[email protected]> Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: [email protected] CC: [email protected] Signed-off-by: James Chapman <[email protected]> Signed-off-by: Tom Parkin <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit b313a8c ] Lockdep reported a warning in Linux version 6.6: [ 414.344659] ================================ [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.356863] scsi_io_completion+0x177/0x1610 [ 414.357379] scsi_complete+0x12f/0x260 [ 414.357856] blk_complete_reqs+0xba/0xf0 [ 414.358338] __do_softirq+0x1b0/0x7a2 [ 414.358796] irq_exit_rcu+0x14b/0x1a0 [ 414.359262] sysvec_call_function_single+0xaf/0xc0 [ 414.359828] asm_sysvec_call_function_single+0x1a/0x20 [ 414.360426] default_idle+0x1e/0x30 [ 414.360873] default_idle_call+0x9b/0x1f0 [ 414.361390] do_idle+0x2d2/0x3e0 [ 414.361819] cpu_startup_entry+0x55/0x60 [ 414.362314] start_secondary+0x235/0x2b0 [ 414.362809] secondary_startup_64_no_verify+0x18f/0x19b [ 414.363413] irq event stamp: 428794 [ 414.363825] hardirqs last enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200 [ 414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50 [ 414.365629] softirqs last enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2 [ 414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0 [ 414.367425] other info that might help us debug this: [ 414.368194] Possible unsafe locking scenario: [ 414.368900] CPU0 [ 414.369225] ---- [ 414.369548] lock(&sbq->ws[i].wait); [ 414.370000] <Interrupt> [ 414.370342] lock(&sbq->ws[i].wait); [ 414.370802] *** DEADLOCK *** [ 414.371569] 5 locks held by kworker/u10:3/1152: [ 414.372088] #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0 [ 414.373180] #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0 [ 414.374384] #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00 [ 414.375342] #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.376377] #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0 [ 414.378607] stack backtrace: [ 414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6 [ 414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 414.381177] Workqueue: writeback wb_workfn (flush-253:0) [ 414.381805] Call Trace: [ 414.382136] <TASK> [ 414.382429] dump_stack_lvl+0x91/0xf0 [ 414.382884] mark_lock_irq+0xb3b/0x1260 [ 414.383367] ? __pfx_mark_lock_irq+0x10/0x10 [ 414.383889] ? stack_trace_save+0x8e/0xc0 [ 414.384373] ? __pfx_stack_trace_save+0x10/0x10 [ 414.384903] ? graph_lock+0xcf/0x410 [ 414.385350] ? save_trace+0x3d/0xc70 [ 414.385808] mark_lock.part.20+0x56d/0xa90 [ 414.386317] mark_held_locks+0xb0/0x110 [ 414.386791] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.387320] lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.387901] ? _raw_spin_unlock_irq+0x28/0x50 [ 414.388422] trace_hardirqs_on+0x58/0x100 [ 414.388917] _raw_spin_unlock_irq+0x28/0x50 [ 414.389422] __blk_mq_tag_busy+0x1d6/0x2a0 [ 414.389920] __blk_mq_get_driver_tag+0x761/0x9f0 [ 414.390899] blk_mq_dispatch_rq_list+0x1780/0x1ee0 [ 414.391473] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [ 414.392070] ? sbitmap_get+0x2b8/0x450 [ 414.392533] ? __blk_mq_get_driver_tag+0x210/0x9f0 [ 414.393095] __blk_mq_sched_dispatch_requests+0xd99/0x1690 [ 414.393730] ? elv_attempt_insert_merge+0x1b1/0x420 [ 414.394302] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [ 414.394970] ? lock_acquire+0x18d/0x460 [ 414.395456] ? blk_mq_run_hw_queue+0x637/0xa00 [ 414.395986] ? __pfx_lock_acquire+0x10/0x10 [ 414.396499] blk_mq_sched_dispatch_requests+0x109/0x190 [ 414.397100] blk_mq_run_hw_queue+0x66e/0xa00 [ 414.397616] blk_mq_flush_plug_list.part.17+0x614/0x2030 [ 414.398244] ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10 [ 414.398897] ? writeback_sb_inodes+0x241/0xcc0 [ 414.399429] blk_mq_flush_plug_list+0x65/0x80 [ 414.399957] __blk_flush_plug+0x2f1/0x530 [ 414.400458] ? __pfx___blk_flush_plug+0x10/0x10 [ 414.400999] blk_finish_plug+0x59/0xa0 [ 414.401467] wb_writeback+0x7cc/0x920 [ 414.401935] ? __pfx_wb_writeback+0x10/0x10 [ 414.402442] ? mark_held_locks+0xb0/0x110 [ 414.402931] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.403462] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.404062] wb_workfn+0x2b3/0xcf0 [ 414.404500] ? __pfx_wb_workfn+0x10/0x10 [ 414.404989] process_scheduled_works+0x432/0x13f0 [ 414.405546] ? __pfx_process_scheduled_works+0x10/0x10 [ 414.406139] ? do_raw_spin_lock+0x101/0x2a0 [ 414.406641] ? assign_work+0x19b/0x240 [ 414.407106] ? lock_is_held_type+0x9d/0x110 [ 414.407604] worker_thread+0x6f2/0x1160 [ 414.408075] ? __kthread_parkme+0x62/0x210 [ 414.408572] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.409168] ? __kthread_parkme+0x13c/0x210 [ 414.409678] ? __pfx_worker_thread+0x10/0x10 [ 414.410191] kthread+0x33c/0x440 [ 414.410602] ? __pfx_kthread+0x10/0x10 [ 414.411068] ret_from_fork+0x4d/0x80 [ 414.411526] ? __pfx_kthread+0x10/0x10 [ 414.411993] ret_from_fork_asm+0x1b/0x30 [ 414.412489] </TASK> When interrupt is turned on while a lock holding by spin_lock_irq it throws a warning because of potential deadlock. blk_mq_prep_dispatch_rq blk_mq_get_driver_tag __blk_mq_get_driver_tag __blk_mq_alloc_driver_tag blk_mq_tag_busy -> tag is already busy // failed to get driver tag blk_mq_mark_tag_wait spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait) __add_wait_queue(wq, wait) -> wait queue active blk_mq_get_driver_tag __blk_mq_tag_busy -> 1) tag must be idle, which means there can't be inflight IO spin_lock_irq(&tags->lock) -> lock B (hctx->tags) spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally -> 2) context must be preempt by IO interrupt to trigger deadlock. As shown above, the deadlock is not possible in theory, but the warning still need to be fixed. Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq. Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'") Signed-off-by: Li Lingfeng <[email protected]> Reviewed-by: Ming Lei <[email protected]> Reviewed-by: Yu Kuai <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 86a41ea ] When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/[email protected]/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ #34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <[email protected]> Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: [email protected] CC: [email protected] Signed-off-by: James Chapman <[email protected]> Signed-off-by: Tom Parkin <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit b313a8c ] Lockdep reported a warning in Linux version 6.6: [ 414.344659] ================================ [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.356863] scsi_io_completion+0x177/0x1610 [ 414.357379] scsi_complete+0x12f/0x260 [ 414.357856] blk_complete_reqs+0xba/0xf0 [ 414.358338] __do_softirq+0x1b0/0x7a2 [ 414.358796] irq_exit_rcu+0x14b/0x1a0 [ 414.359262] sysvec_call_function_single+0xaf/0xc0 [ 414.359828] asm_sysvec_call_function_single+0x1a/0x20 [ 414.360426] default_idle+0x1e/0x30 [ 414.360873] default_idle_call+0x9b/0x1f0 [ 414.361390] do_idle+0x2d2/0x3e0 [ 414.361819] cpu_startup_entry+0x55/0x60 [ 414.362314] start_secondary+0x235/0x2b0 [ 414.362809] secondary_startup_64_no_verify+0x18f/0x19b [ 414.363413] irq event stamp: 428794 [ 414.363825] hardirqs last enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200 [ 414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50 [ 414.365629] softirqs last enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2 [ 414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0 [ 414.367425] other info that might help us debug this: [ 414.368194] Possible unsafe locking scenario: [ 414.368900] CPU0 [ 414.369225] ---- [ 414.369548] lock(&sbq->ws[i].wait); [ 414.370000] <Interrupt> [ 414.370342] lock(&sbq->ws[i].wait); [ 414.370802] *** DEADLOCK *** [ 414.371569] 5 locks held by kworker/u10:3/1152: [ 414.372088] #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0 [ 414.373180] #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0 [ 414.374384] #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00 [ 414.375342] #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.376377] #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0 [ 414.378607] stack backtrace: [ 414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6 [ 414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 414.381177] Workqueue: writeback wb_workfn (flush-253:0) [ 414.381805] Call Trace: [ 414.382136] <TASK> [ 414.382429] dump_stack_lvl+0x91/0xf0 [ 414.382884] mark_lock_irq+0xb3b/0x1260 [ 414.383367] ? __pfx_mark_lock_irq+0x10/0x10 [ 414.383889] ? stack_trace_save+0x8e/0xc0 [ 414.384373] ? __pfx_stack_trace_save+0x10/0x10 [ 414.384903] ? graph_lock+0xcf/0x410 [ 414.385350] ? save_trace+0x3d/0xc70 [ 414.385808] mark_lock.part.20+0x56d/0xa90 [ 414.386317] mark_held_locks+0xb0/0x110 [ 414.386791] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.387320] lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.387901] ? _raw_spin_unlock_irq+0x28/0x50 [ 414.388422] trace_hardirqs_on+0x58/0x100 [ 414.388917] _raw_spin_unlock_irq+0x28/0x50 [ 414.389422] __blk_mq_tag_busy+0x1d6/0x2a0 [ 414.389920] __blk_mq_get_driver_tag+0x761/0x9f0 [ 414.390899] blk_mq_dispatch_rq_list+0x1780/0x1ee0 [ 414.391473] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [ 414.392070] ? sbitmap_get+0x2b8/0x450 [ 414.392533] ? __blk_mq_get_driver_tag+0x210/0x9f0 [ 414.393095] __blk_mq_sched_dispatch_requests+0xd99/0x1690 [ 414.393730] ? elv_attempt_insert_merge+0x1b1/0x420 [ 414.394302] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [ 414.394970] ? lock_acquire+0x18d/0x460 [ 414.395456] ? blk_mq_run_hw_queue+0x637/0xa00 [ 414.395986] ? __pfx_lock_acquire+0x10/0x10 [ 414.396499] blk_mq_sched_dispatch_requests+0x109/0x190 [ 414.397100] blk_mq_run_hw_queue+0x66e/0xa00 [ 414.397616] blk_mq_flush_plug_list.part.17+0x614/0x2030 [ 414.398244] ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10 [ 414.398897] ? writeback_sb_inodes+0x241/0xcc0 [ 414.399429] blk_mq_flush_plug_list+0x65/0x80 [ 414.399957] __blk_flush_plug+0x2f1/0x530 [ 414.400458] ? __pfx___blk_flush_plug+0x10/0x10 [ 414.400999] blk_finish_plug+0x59/0xa0 [ 414.401467] wb_writeback+0x7cc/0x920 [ 414.401935] ? __pfx_wb_writeback+0x10/0x10 [ 414.402442] ? mark_held_locks+0xb0/0x110 [ 414.402931] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.403462] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.404062] wb_workfn+0x2b3/0xcf0 [ 414.404500] ? __pfx_wb_workfn+0x10/0x10 [ 414.404989] process_scheduled_works+0x432/0x13f0 [ 414.405546] ? __pfx_process_scheduled_works+0x10/0x10 [ 414.406139] ? do_raw_spin_lock+0x101/0x2a0 [ 414.406641] ? assign_work+0x19b/0x240 [ 414.407106] ? lock_is_held_type+0x9d/0x110 [ 414.407604] worker_thread+0x6f2/0x1160 [ 414.408075] ? __kthread_parkme+0x62/0x210 [ 414.408572] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.409168] ? __kthread_parkme+0x13c/0x210 [ 414.409678] ? __pfx_worker_thread+0x10/0x10 [ 414.410191] kthread+0x33c/0x440 [ 414.410602] ? __pfx_kthread+0x10/0x10 [ 414.411068] ret_from_fork+0x4d/0x80 [ 414.411526] ? __pfx_kthread+0x10/0x10 [ 414.411993] ret_from_fork_asm+0x1b/0x30 [ 414.412489] </TASK> When interrupt is turned on while a lock holding by spin_lock_irq it throws a warning because of potential deadlock. blk_mq_prep_dispatch_rq blk_mq_get_driver_tag __blk_mq_get_driver_tag __blk_mq_alloc_driver_tag blk_mq_tag_busy -> tag is already busy // failed to get driver tag blk_mq_mark_tag_wait spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait) __add_wait_queue(wq, wait) -> wait queue active blk_mq_get_driver_tag __blk_mq_tag_busy -> 1) tag must be idle, which means there can't be inflight IO spin_lock_irq(&tags->lock) -> lock B (hctx->tags) spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally -> 2) context must be preempt by IO interrupt to trigger deadlock. As shown above, the deadlock is not possible in theory, but the warning still need to be fixed. Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq. Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'") Signed-off-by: Li Lingfeng <[email protected]> Reviewed-by: Ming Lei <[email protected]> Reviewed-by: Yu Kuai <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 59a931c ] If the driver uses a page pool, it creates a page pool with page_pool_create(). The reference count of page pool is 1 as default. A page pool will be destroyed only when a reference count reaches 0. page_pool_destroy() is used to destroy page pool, it decreases a reference count. When a page pool is destroyed, ->disconnect() is called, which is mem_allocator_disconnect(). This function internally acquires mutex_lock(). If the driver uses XDP, it registers a memory model with xdp_rxq_info_reg_mem_model(). The xdp_rxq_info_reg_mem_model() internally increases a page pool reference count if a memory model is a page pool. Now the reference count is 2. To destroy a page pool, the driver should call both page_pool_destroy() and xdp_unreg_mem_model(). The xdp_unreg_mem_model() internally calls page_pool_destroy(). Only page_pool_destroy() decreases a reference count. If a driver calls page_pool_destroy() then xdp_unreg_mem_model(), we will face an invalid wait context warning. Because xdp_unreg_mem_model() calls page_pool_destroy() with rcu_read_lock(). The page_pool_destroy() internally acquires mutex_lock(). Splat looks like: ============================= [ BUG: Invalid wait context ] 6.10.0-rc6+ #4 Tainted: G W ----------------------------- ethtool/1806 is trying to lock: ffffffff90387b90 (mem_id_lock){+.+.}-{4:4}, at: mem_allocator_disconnect+0x73/0x150 other info that might help us debug this: context-{5:5} 3 locks held by ethtool/1806: stack backtrace: CPU: 0 PID: 1806 Comm: ethtool Tainted: G W 6.10.0-rc6+ #4 f916f41f172891c800f2fed Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 Call Trace: <TASK> dump_stack_lvl+0x7e/0xc0 __lock_acquire+0x1681/0x4de0 ? _printk+0x64/0xe0 ? __pfx_mark_lock.part.0+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x1b3/0x580 ? mem_allocator_disconnect+0x73/0x150 ? __wake_up_klogd.part.0+0x16/0xc0 ? __pfx_lock_acquire+0x10/0x10 ? dump_stack_lvl+0x91/0xc0 __mutex_lock+0x15c/0x1690 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_prb_read_valid+0x10/0x10 ? mem_allocator_disconnect+0x73/0x150 ? __pfx_llist_add_batch+0x10/0x10 ? console_unlock+0x193/0x1b0 ? lockdep_hardirqs_on+0xbe/0x140 ? __pfx___mutex_lock+0x10/0x10 ? tick_nohz_tick_stopped+0x16/0x90 ? __irq_work_queue_local+0x1e5/0x330 ? irq_work_queue+0x39/0x50 ? __wake_up_klogd.part.0+0x79/0xc0 ? mem_allocator_disconnect+0x73/0x150 mem_allocator_disconnect+0x73/0x150 ? __pfx_mem_allocator_disconnect+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? rcu_is_watching+0x11/0xb0 page_pool_release+0x36e/0x6d0 page_pool_destroy+0xd7/0x440 xdp_unreg_mem_model+0x1a7/0x2a0 ? __pfx_xdp_unreg_mem_model+0x10/0x10 ? kfree+0x125/0x370 ? bnxt_free_ring.isra.0+0x2eb/0x500 ? bnxt_free_mem+0x5ac/0x2500 xdp_rxq_info_unreg+0x4a/0xd0 bnxt_free_mem+0x1356/0x2500 bnxt_close_nic+0xf0/0x3b0 ? __pfx_bnxt_close_nic+0x10/0x10 ? ethnl_parse_bit+0x2c6/0x6d0 ? __pfx___nla_validate_parse+0x10/0x10 ? __pfx_ethnl_parse_bit+0x10/0x10 bnxt_set_features+0x2a8/0x3e0 __netdev_update_features+0x4dc/0x1370 ? ethnl_parse_bitset+0x4ff/0x750 ? __pfx_ethnl_parse_bitset+0x10/0x10 ? __pfx___netdev_update_features+0x10/0x10 ? mark_held_locks+0xa5/0xf0 ? _raw_spin_unlock_irqrestore+0x42/0x70 ? __pm_runtime_resume+0x7d/0x110 ethnl_set_features+0x32d/0xa20 To fix this problem, it uses rhashtable_lookup_fast() instead of rhashtable_lookup() with rcu_read_lock(). Using xa without rcu_read_lock() here is safe. xa is freed by __xdp_mem_allocator_rcu_free() and this is called by call_rcu() of mem_xa_remove(). The mem_xa_remove() is called by page_pool_destroy() if a reference count reaches 0. The xa is already protected by the reference count mechanism well in the control plane. So removing rcu_read_lock() for page_pool_destroy() is safe. Fixes: c3f812c ("page_pool: do not release pool until inflight == 0.") Signed-off-by: Taehee Yoo <[email protected]> Reviewed-by: Jakub Kicinski <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 86a41ea ] When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/[email protected]/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ #34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c597 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <[email protected]> Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: [email protected] CC: [email protected] Signed-off-by: James Chapman <[email protected]> Signed-off-by: Tom Parkin <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Oct 8, 2024
[ Upstream commit 348a198 ] Luis has been reporting an assert failure when freeing an inode cluster during inode inactivation for a while. The assert looks like: XFS: Assertion failed: bp->b_flags & XBF_DONE, file: fs/xfs/xfs_trans_buf.c, line: 241 ------------[ cut here ]------------ kernel BUG at fs/xfs/xfs_message.c:102! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 4 PID: 73 Comm: kworker/4:1 Not tainted 6.10.0-rc1 #4 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: xfs-inodegc/loop5 xfs_inodegc_worker [xfs] RIP: 0010:assfail (fs/xfs/xfs_message.c:102) xfs RSP: 0018:ffff88810188f7f0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88816e748250 RCX: 1ffffffff844b0e7 RDX: 0000000000000004 RSI: ffff88810188f558 RDI: ffffffffc2431fa0 RBP: 1ffff11020311f01 R08: 0000000042431f9f R09: ffffed1020311e9b R10: ffff88810188f4df R11: ffffffffac725d70 R12: ffff88817a3f4000 R13: ffff88812182f000 R14: ffff88810188f998 R15: ffffffffc2423f80 FS: 0000000000000000(0000) GS:ffff8881c8400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fe9d0f109c CR3: 000000014426c002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> xfs_trans_read_buf_map (fs/xfs/xfs_trans_buf.c:241 (discriminator 1)) xfs xfs_imap_to_bp (fs/xfs/xfs_trans.h:210 fs/xfs/libxfs/xfs_inode_buf.c:138) xfs xfs_inode_item_precommit (fs/xfs/xfs_inode_item.c:145) xfs xfs_trans_run_precommits (fs/xfs/xfs_trans.c:931) xfs __xfs_trans_commit (fs/xfs/xfs_trans.c:966) xfs xfs_inactive_ifree (fs/xfs/xfs_inode.c:1811) xfs xfs_inactive (fs/xfs/xfs_inode.c:2013) xfs xfs_inodegc_worker (fs/xfs/xfs_icache.c:1841 fs/xfs/xfs_icache.c:1886) xfs process_one_work (kernel/workqueue.c:3231) worker_thread (kernel/workqueue.c:3306 (discriminator 2) kernel/workqueue.c:3393 (discriminator 2)) kthread (kernel/kthread.c:389) ret_from_fork (arch/x86/kernel/process.c:147) ret_from_fork_asm (arch/x86/entry/entry_64.S:257) </TASK> And occurs when the the inode precommit handlers is attempt to look up the inode cluster buffer to attach the inode for writeback. The trail of logic that I can reconstruct is as follows. 1. the inode is clean when inodegc runs, so it is not attached to a cluster buffer when precommit runs. 2. #1 implies the inode cluster buffer may be clean and not pinned by dirty inodes when inodegc runs. 3. #2 implies that the inode cluster buffer can be reclaimed by memory pressure at any time. 4. The assert failure implies that the cluster buffer was attached to the transaction, but not marked done. It had been accessed earlier in the transaction, but not marked done. 5. #4 implies the cluster buffer has been invalidated (i.e. marked stale). 6. #5 implies that the inode cluster buffer was instantiated uninitialised in the transaction in xfs_ifree_cluster(), which only instantiates the buffers to invalidate them and never marks them as done. Given factors 1-3, this issue is highly dependent on timing and environmental factors. Hence the issue can be very difficult to reproduce in some situations, but highly reliable in others. Luis has an environment where it can be reproduced easily by g/531 but, OTOH, I've reproduced it only once in ~2000 cycles of g/531. I think the fix is to have xfs_ifree_cluster() set the XBF_DONE flag on the cluster buffers, even though they may not be initialised. The reasons why I think this is safe are: 1. A buffer cache lookup hit on a XBF_STALE buffer will clear the XBF_DONE flag. Hence all future users of the buffer know they have to re-initialise the contents before use and mark it done themselves. 2. xfs_trans_binval() sets the XFS_BLI_STALE flag, which means the buffer remains locked until the journal commit completes and the buffer is unpinned. Hence once marked XBF_STALE/XFS_BLI_STALE by xfs_ifree_cluster(), the only context that can access the freed buffer is the currently running transaction. 3. #2 implies that future buffer lookups in the currently running transaction will hit the transaction match code and not the buffer cache. Hence XBF_STALE and XFS_BLI_STALE will not be cleared unless the transaction initialises and logs the buffer with valid contents again. At which point, the buffer will be marked marked XBF_DONE again, so having XBF_DONE already set on the stale buffer is a moot point. 4. #2 also implies that any concurrent access to that cluster buffer will block waiting on the buffer lock until the inode cluster has been fully freed and is no longer an active inode cluster buffer. 5. #4 + #1 means that any future user of the disk range of that buffer will always see the range of disk blocks covered by the cluster buffer as not done, and hence must initialise the contents themselves. 6. Setting XBF_DONE in xfs_ifree_cluster() then means the unlinked inode precommit code will see a XBF_DONE buffer from the transaction match as it expects. It can then attach the stale but newly dirtied inode to the stale but newly dirtied cluster buffer without unexpected failures. The stale buffer will then sail through the journal and do the right thing with the attached stale inode during unpin. Hence the fix is just one line of extra code. The explanation of why we have to set XBF_DONE in xfs_ifree_cluster, OTOH, is long and complex.... Fixes: 82842fe ("xfs: fix AGF vs inode cluster buffer deadlock") Signed-off-by: Dave Chinner <[email protected]> Tested-by: Luis Chamberlain <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Signed-off-by: Chandan Babu R <[email protected]> Signed-off-by: Leah Rumancik <[email protected]> Acked-by: Chandan Babu R <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit c3a5e3e ] When using cachefiles, lockdep may emit something similar to the circular locking dependency notice below. The problem appears to stem from the following: (1) Cachefiles manipulates xattrs on the files in its cache when called from ->writepages(). (2) The setxattr() and removexattr() system call handlers get the name (and value) from userspace after taking the sb_writers lock, putting accesses of the vma->vm_lock and mm->mmap_lock inside of that. (3) The afs filesystem uses a per-inode lock to prevent multiple revalidation RPCs and in writeback vs truncate to prevent parallel operations from deadlocking against the server on one side and local page locks on the other. Fix this by moving the getting of the name and value in {get,remove}xattr() outside of the sb_writers lock. This also has the minor benefits that we don't need to reget these in the event of a retry and we never try to take the sb_writers lock in the event we can't pull the name and value into the kernel. Alternative approaches that might fix this include moving the dispatch of a write to the cache off to a workqueue or trying to do without the validation lock in afs. Note that this might also affect other filesystems that use netfslib and/or cachefiles. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-build2+ torvalds#956 Not tainted ------------------------------------------------------ fsstress/6050 is trying to acquire lock: ffff888138fd82f0 (mapping.invalidate_lock#3){++++}-{3:3}, at: filemap_fault+0x26e/0x8b0 but task is already holding lock: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&vma->vm_lock->lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_write+0x3b/0x50 vma_start_write+0x6b/0xa0 vma_link+0xcc/0x140 insert_vm_struct+0xb7/0xf0 alloc_bprm+0x2c1/0x390 kernel_execve+0x65/0x1a0 call_usermodehelper_exec_async+0x14d/0x190 ret_from_fork+0x24/0x40 ret_from_fork_asm+0x1a/0x30 -> #3 (&mm->mmap_lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 __might_fault+0x7c/0xb0 strncpy_from_user+0x25/0x160 removexattr+0x7f/0x100 __do_sys_fremovexattr+0x7e/0xb0 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (sb_writers#14){.+.+}-{0:0}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 percpu_down_read+0x3c/0x90 vfs_iocb_iter_write+0xe9/0x1d0 __cachefiles_write+0x367/0x430 cachefiles_issue_write+0x299/0x2f0 netfs_advance_write+0x117/0x140 netfs_write_folio.isra.0+0x5ca/0x6e0 netfs_writepages+0x230/0x2f0 afs_writepages+0x4d/0x70 do_writepages+0x1e8/0x3e0 filemap_fdatawrite_wbc+0x84/0xa0 __filemap_fdatawrite_range+0xa8/0xf0 file_write_and_wait_range+0x59/0x90 afs_release+0x10f/0x270 __fput+0x25f/0x3d0 __do_sys_close+0x43/0x70 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&vnode->validate_lock){++++}-{3:3}: __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_read+0x95/0x200 afs_writepages+0x37/0x70 do_writepages+0x1e8/0x3e0 filemap_fdatawrite_wbc+0x84/0xa0 filemap_invalidate_inode+0x167/0x1e0 netfs_unbuffered_write_iter+0x1bd/0x2d0 vfs_write+0x22e/0x320 ksys_write+0xbc/0x130 do_syscall_64+0x9f/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (mapping.invalidate_lock#3){++++}-{3:3}: check_noncircular+0x119/0x160 check_prev_add+0x195/0x430 __lock_acquire+0xaf0/0xd80 lock_acquire.part.0+0x103/0x280 down_read+0x95/0x200 filemap_fault+0x26e/0x8b0 __do_fault+0x57/0xd0 do_pte_missing+0x23b/0x320 __handle_mm_fault+0x2d4/0x320 handle_mm_fault+0x14f/0x260 do_user_addr_fault+0x2a2/0x500 exc_page_fault+0x71/0x90 asm_exc_page_fault+0x22/0x30 other info that might help us debug this: Chain exists of: mapping.invalidate_lock#3 --> &mm->mmap_lock --> &vma->vm_lock->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&vma->vm_lock->lock); lock(&mm->mmap_lock); lock(&vma->vm_lock->lock); rlock(mapping.invalidate_lock#3); *** DEADLOCK *** 1 lock held by fsstress/6050: #0: ffff888113f26d18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x165/0x250 stack backtrace: CPU: 0 PID: 6050 Comm: fsstress Not tainted 6.10.0-build2+ torvalds#956 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x80 check_noncircular+0x119/0x160 ? queued_spin_lock_slowpath+0x4be/0x510 ? __pfx_check_noncircular+0x10/0x10 ? __pfx_queued_spin_lock_slowpath+0x10/0x10 ? mark_lock+0x47/0x160 ? init_chain_block+0x9c/0xc0 ? add_chain_block+0x84/0xf0 check_prev_add+0x195/0x430 __lock_acquire+0xaf0/0xd80 ? __pfx___lock_acquire+0x10/0x10 ? __lock_release.isra.0+0x13b/0x230 lock_acquire.part.0+0x103/0x280 ? filemap_fault+0x26e/0x8b0 ? __pfx_lock_acquire.part.0+0x10/0x10 ? rcu_is_watching+0x34/0x60 ? lock_acquire+0xd7/0x120 down_read+0x95/0x200 ? filemap_fault+0x26e/0x8b0 ? __pfx_down_read+0x10/0x10 ? __filemap_get_folio+0x25/0x1a0 filemap_fault+0x26e/0x8b0 ? __pfx_filemap_fault+0x10/0x10 ? find_held_lock+0x7c/0x90 ? __pfx___lock_release.isra.0+0x10/0x10 ? __pte_offset_map+0x99/0x110 __do_fault+0x57/0xd0 do_pte_missing+0x23b/0x320 __handle_mm_fault+0x2d4/0x320 ? __pfx___handle_mm_fault+0x10/0x10 handle_mm_fault+0x14f/0x260 do_user_addr_fault+0x2a2/0x500 exc_page_fault+0x71/0x90 asm_exc_page_fault+0x22/0x30 Signed-off-by: David Howells <[email protected]> Link: https://lore.kernel.org/r/[email protected] cc: Alexander Viro <[email protected]> cc: Christian Brauner <[email protected]> cc: Jan Kara <[email protected]> cc: Jeff Layton <[email protected]> cc: Gao Xiang <[email protected]> cc: Matthew Wilcox <[email protected]> cc: [email protected] cc: [email protected] cc: [email protected] [brauner: fix minor issues] Signed-off-by: Christian Brauner <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 89a906d ] Floating point instructions in userspace can crash some arm kernels built with clang/LLD 17.0.6: BUG: unsupported FP instruction in kernel mode FPEXC == 0xc0000780 Internal error: Oops - undefined instruction: 0 [#1] ARM CPU: 0 PID: 196 Comm: vfp-reproducer Not tainted 6.10.0 #1 Hardware name: BCM2835 PC is at vfp_support_entry+0xc8/0x2cc LR is at do_undefinstr+0xa8/0x250 pc : [<c0101d50>] lr : [<c010a80c>] psr: a0000013 sp : dc8d1f68 ip : 60000013 fp : bedea19c r10: ec532b17 r9 : 00000010 r8 : 0044766c r7 : c0000780 r6 : ec532b17 r5 : c1c13800 r4 : dc8d1fb0 r3 : c10072c4 r2 : c0101c88 r1 : ec532b17 r0 : 0044766c Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 00c5387d Table: 0251c008 DAC: 00000051 Register r0 information: non-paged memory Register r1 information: vmalloc memory Register r2 information: non-slab/vmalloc memory Register r3 information: non-slab/vmalloc memory Register r4 information: 2-page vmalloc region Register r5 information: slab kmalloc-cg-2k Register r6 information: vmalloc memory Register r7 information: non-slab/vmalloc memory Register r8 information: non-paged memory Register r9 information: zero-size pointer Register r10 information: vmalloc memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process vfp-reproducer (pid: 196, stack limit = 0x61aaaf8b) Stack: (0xdc8d1f68 to 0xdc8d2000) 1f60: 0000081f b6f69300 0000000f c10073f4 c10072c4 dc8d1fb0 1f80: ec532b17 0c532b17 0044766c b6f9ccd8 00000000 c010a80c 00447670 60000010 1fa0: ffffffff c1c13800 00c5387d c0100f10 b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff 00000000 00000000 Call trace: [<c0101d50>] (vfp_support_entry) from [<c010a80c>] (do_undefinstr+0xa8/0x250) [<c010a80c>] (do_undefinstr) from [<c0100f10>] (__und_usr+0x70/0x80) Exception stack(0xdc8d1fb0 to 0xdc8d1ff8) 1fa0: b6f68af8 00448fc0 00000000 bedea188 1fc0: bedea314 00000001 00448ebc b6f9d000 00447608 b6f9ccd8 00000000 bedea19c 1fe0: bede9198 bedea188 b6e1061c 0044766c 60000010 ffffffff Code: 0a000061 e3877202 e594003c e3a09010 (eef16a10) ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception in interrupt ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- This is a minimal userspace reproducer on a Raspberry Pi Zero W: #include <stdio.h> #include <math.h> int main(void) { double v = 1.0; printf("%fn", NAN + *(volatile double *)&v); return 0; } Another way to consistently trigger the oops is: calvin@raspberry-pi-zero-w ~$ python -c "import json" The bug reproduces only when the kernel is built with DYNAMIC_DEBUG=n, because the pr_debug() calls act as barriers even when not activated. This is the output from the same kernel source built with the same compiler and DYNAMIC_DEBUG=y, where the userspace reproducer works as expected: VFP: bounce: trigger ec532b17 fpexc c0000780 VFP: emulate: INST=0xee377b06 SCR=0x00000000 VFP: bounce: trigger eef1fa10 fpexc c0000780 VFP: emulate: INST=0xeeb40b40 SCR=0x00000000 VFP: raising exceptions 30000000 calvin@raspberry-pi-zero-w ~$ ./vfp-reproducer nan Crudely grepping for vmsr/vmrs instructions in the otherwise nearly idential text for vfp_support_entry() makes the problem obvious: vmlinux.llvm.good [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.good [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101d20] <+152>: vmsr fpexc, r7 vmlinux.llvm.good [0xc0101d38] <+176>: vmrs r4, fpexc vmlinux.llvm.good [0xc0101d6c] <+228>: vmrs r0, fpscr vmlinux.llvm.good [0xc0101dc4] <+316>: vmsr fpexc, r0 vmlinux.llvm.good [0xc0101dc8] <+320>: vmrs r0, fpsid vmlinux.llvm.good [0xc0101dcc] <+324>: vmrs r6, fpscr vmlinux.llvm.good [0xc0101e10] <+392>: vmrs r10, fpinst vmlinux.llvm.good [0xc0101eb8] <+560>: vmrs r10, fpinst2 vmlinux.llvm.bad [0xc0101cb8] <+48>: vmrs r7, fpexc vmlinux.llvm.bad [0xc0101cd8] <+80>: vmsr fpexc, r0 vmlinux.llvm.bad [0xc0101d20] <+152>: vmsr fpexc, r7 vmlinux.llvm.bad [0xc0101d30] <+168>: vmrs r0, fpscr vmlinux.llvm.bad [0xc0101d50] <+200>: vmrs r6, fpscr <== BOOM! vmlinux.llvm.bad [0xc0101d6c] <+228>: vmsr fpexc, r0 vmlinux.llvm.bad [0xc0101d70] <+232>: vmrs r0, fpsid vmlinux.llvm.bad [0xc0101da4] <+284>: vmrs r10, fpinst vmlinux.llvm.bad [0xc0101df8] <+368>: vmrs r4, fpexc vmlinux.llvm.bad [0xc0101e5c] <+468>: vmrs r10, fpinst2 I think LLVM's reordering is valid as the code is currently written: the compiler doesn't know the instructions have side effects in hardware. Fix by using "asm volatile" in fmxr() and fmrx(), so they cannot be reordered with respect to each other. The original compiler now produces working kernels on my hardware with DYNAMIC_DEBUG=n. This is the relevant piece of the diff of the vfp_support_entry() text, from the original oopsing kernel to a working kernel with this patch: vmrs r0, fpscr tst r0, #4096 bne 0xc0101d48 tst r0, #458752 beq 0xc0101ecc orr r7, r7, #536870912 ldr r0, [r4, #0x3c] mov r9, #16 -vmrs r6, fpscr orr r9, r9, #251658240 add r0, r0, #4 str r0, [r4, #0x3c] mvn r0, torvalds#159 sub r0, r0, #-1207959552 and r0, r7, r0 vmsr fpexc, r0 vmrs r0, fpsid +vmrs r6, fpscr and r0, r0, #983040 cmp r0, #65536 bne 0xc0101d88 Fixes: 4708fb0 ("ARM: vfp: Reimplement VFP exception entry in C code") Signed-off-by: Calvin Owens <[email protected]> Signed-off-by: Russell King (Oracle) <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Oct 10, 2024
commit 44d1745 upstream. Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the fairness of r/w semaphores). CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu); Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier(): cpuhp_cpufreq_online() | -> cpufreq_online() | -> cpufreq_gov_performance_limits() | -> __cpufreq_driver_target() | -> __target_index() | -> cpufreq_freq_transition_begin() | -> cpufreq_notify_transition() | -> ... __kvmclock_cpufreq_notifier() But, actually triggering such deadlocks is beyond rare due to the combination of dependencies and timings involved. E.g. the cpufreq notifier is only used on older CPUs without a constant TSC, mucking with the NX hugepage mitigation while VMs are running is very uncommon, and doing so while also onlining/offlining a CPU (necessary to generate contention on cpu_hotplug_lock) would be even more unusual. The most robust solution to the general cpu_hotplug_lock issue is likely to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq notifier doesn't to take kvm_lock. For now, settle for fixing the most blatant deadlock, as switching to an RCU-protected list is a much more involved change, but add a comment in locking.rst to call out that care needs to be taken when walking holding kvm_lock and walking vm_list. ====================================================== WARNING: possible circular locking dependency detected 6.10.0-smp--c257535a0c9d-pip torvalds#330 Tainted: G S O ------------------------------------------------------ tee/35048 is trying to acquire lock: ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm] but task is already holding lock: ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kvm_lock){+.+.}-{3:3}: __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 kvm_dev_ioctl+0x4fb/0xe50 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #2 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2e/0xb0 static_key_slow_inc+0x16/0x30 kvm_lapic_set_base+0x6a/0x1c0 [kvm] kvm_set_apic_base+0x8f/0xe0 [kvm] kvm_set_msr_common+0x9ae/0xf80 [kvm] vmx_set_msr+0xa54/0xbe0 [kvm_intel] __kvm_set_msr+0xb6/0x1a0 [kvm] kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm] kvm_vcpu_ioctl+0x485/0x5b0 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (&kvm->srcu){.+.+}-{0:0}: __synchronize_srcu+0x44/0x1a0 synchronize_srcu_expedited+0x21/0x30 kvm_swap_active_memslots+0x110/0x1c0 [kvm] kvm_set_memslot+0x360/0x620 [kvm] __kvm_set_memory_region+0x27b/0x300 [kvm] kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm] kvm_vm_ioctl+0x295/0x650 [kvm] __se_sys_ioctl+0x7b/0xd0 __x64_sys_ioctl+0x21/0x30 x64_sys_call+0x15d0/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&kvm->slots_lock){+.+.}-{3:3}: __lock_acquire+0x15ef/0x2e30 lock_acquire+0xe0/0x260 __mutex_lock+0x6a/0xb40 mutex_lock_nested+0x1f/0x30 set_nx_huge_pages+0x179/0x1e0 [kvm] param_attr_store+0x93/0x100 module_attr_store+0x22/0x40 sysfs_kf_write+0x81/0xb0 kernfs_fop_write_iter+0x133/0x1d0 vfs_write+0x28d/0x380 ksys_write+0x70/0xe0 __x64_sys_write+0x1f/0x30 x64_sys_call+0x281b/0x2e60 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e Cc: Chao Gao <[email protected]> Fixes: 0bf5049 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock") Cc: [email protected] Reviewed-by: Kai Huang <[email protected]> Acked-by: Kai Huang <[email protected]> Tested-by: Farrah Chen <[email protected]> Signed-off-by: Sean Christopherson <[email protected]> Message-ID: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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This patch applies aufs 4.2 to the odroid xu4 kernel.