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I2c : do not rename added devices, and a minor dtsi fix #49

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mdmillerii
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The documentation says you can't rename devices once they are added.

The commit log is a bit wide because I didn't wrap the cut & pasted comments from the code.

The code is a bit ugly looking for properties in the child to determine the name.

But there are rules!

Comments and alternatives welcome.

Also is a separate patch for the dtsi which I noticed while looking at the tree structure.

milton

Changing the name of a device with dev_set_name after device_add
is not allowed.

However, of_create_device takes a bus_id parameter that specifies
the name of the platform device being added.

This does mean the bus property has to be retrieved multiple times.
Creation is skiped if there is trouble retrieving or formatting
the name.

The documentation for kobject_set_name (non-vargs) says:
 * This sets the name of the kobject.  If you have already added the
 * kobject to the system, you must call kobject_rename() in order to
 * change the name of the kobject.

As the kernel doc for device_rename says:
 * Make up a "real" name in the driver before you register anything, or add
 * some other attributes for userspace to find the device, or use udev to add
 * symlinks -- but never rename kernel devices later, it's a complete mess. We
 * don't even want to get into that and try to implement the missing pieces in
 * the core. We really have other pieces to fix in the driver core mess. :)

before:
1e78a000.i2c/1e78a1c0.i2c-bus/i2c-6/i2c-dev/i2c-6
1e78a000.i2c/1e78a180.i2c-bus/i2c-5/i2c-dev/i2c-5
1e78a000.i2c/1e78a140.i2c-bus/i2c-4/i2c-dev/i2c-4
1e78a000.i2c/1e78a100.i2c-bus/i2c-3/i2c-dev/i2c-3
1e78a000.i2c/1e78a100.i2c-bus/i2c-3/3-0050
1e78a000.i2c/1e78a0c0.i2c-bus/i2c-2/i2c-dev/i2c-2
1e78a000.i2c/1e78a0c0.i2c-bus/i2c-2/2-004c/hwmon/hwmon0
1e78a000.i2c/1e78a080.i2c-bus/i2c-1/i2c-dev/i2c-1
1e78a000.i2c/1e78a040.i2c-bus/i2c-0/i2c-dev/i2c-0
1e78a000.i2c/1e78a040.i2c-bus/i2c-0/0-0050
1e78a000.i2c/1e78a040.i2c-bus/i2c-0/0-0068/rtc/rtc0
1e78a000.i2c/1e78a340.i2c-bus/i2c-8/i2c-dev/i2c-8

after:
1e78a000.i2c/i2c-0/i2c-0/i2c-dev/i2c-0
1e78a000.i2c/i2c-0/i2c-0/0-0050
1e78a000.i2c/i2c-0/i2c-0/0-0068/rtc/rtc0
1e78a000.i2c/i2c-1/i2c-1/i2c-dev/i2c-1
1e78a000.i2c/i2c-2/i2c-2/i2c-dev/i2c-2
1e78a000.i2c/i2c-2/i2c-2/2-004c/hwmon/hwmon0
1e78a000.i2c/i2c-3/i2c-3/i2c-dev/i2c-3
1e78a000.i2c/i2c-3/i2c-3/3-0050
1e78a000.i2c/i2c-4/i2c-4/i2c-dev/i2c-4
1e78a000.i2c/i2c-5/i2c-5/i2c-dev/i2c-5
1e78a000.i2c/i2c-6/i2c-6/i2c-dev/i2c-6
1e78a000.i2c/i2c-7/i2c-7/i2c-dev/i2c-7

1e62000.fmc                   1e78e000.serial
1e62000.fmc:flash@0           1e78f000.serial
1e630000.spi                   ahb
1e630000.spi:flash             ahb:apb
1e660000.ethernet              alarmtimer
1e6c0080.interrupt-controller  i2c-0
1e6e2000.syscon                i2c-1
1e720000.sram                  i2c-2
1e780000.gpio                  i2c-3
1e782000.timer                 i2c-4
1e783000.serial                i2c-5
1e784000.serial                i2c-6
1e785000.wdt                   i2c-7
1e787000.vuart                 i2c-8
1e789140.ibt                   leds
1e78a000.i2c                   serial8250
1e78d000.serial

Signed-off-by: Milton Miller <[email protected]>
The implied format for most bus bindings implies the uname-address
part of the unit-name should be in hex without a leading 0x.

Fix the one i2c bus that did not follow this convention.

Signed-off-by: Milton Miller <[email protected]>
@shenki
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shenki commented Feb 22, 2016

Thanks, merged as 794044d.

@shenki shenki closed this Feb 22, 2016
@mdmillerii mdmillerii deleted the i2c-name-v2 branch March 10, 2016 16:56
amboar pushed a commit to amboar/linux that referenced this pull request Jul 12, 2016
Asynchronous wb switching of inodes takes an additional ref count on an
inode to make sure inode remains valid until switchover is completed.

However, anyone calling ihold() must already have a ref count on inode,
but in this case inode->i_count may already be zero:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 917 at fs/inode.c:397 ihold+0x2b/0x30
CPU: 1 PID: 917 Comm: kworker/u4:5 Not tainted 4.7.0-rc2+ openbmc#49
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
Workqueue: writeback wb_workfn (flush-8:16)
 0000000000000000 ffff88007ca0fb58 ffffffff805990af 0000000000000000
 0000000000000000 ffff88007ca0fb98 ffffffff80268702 0000018d000004e2
 ffff88007cef40e8 ffff88007c9b89a8 ffff880079e3a740 0000000000000003
Call Trace:
 [<ffffffff805990af>] dump_stack+0x4d/0x6e
 [<ffffffff80268702>] __warn+0xc2/0xe0
 [<ffffffff802687d8>] warn_slowpath_null+0x18/0x20
 [<ffffffff8035b4ab>] ihold+0x2b/0x30
 [<ffffffff80367ecc>] inode_switch_wbs+0x11c/0x180
 [<ffffffff80369110>] wbc_detach_inode+0x170/0x1a0
 [<ffffffff80369abc>] writeback_sb_inodes+0x21c/0x530
 [<ffffffff80369f7e>] wb_writeback+0xee/0x1e0
 [<ffffffff8036a147>] wb_workfn+0xd7/0x280
 [<ffffffff80287531>] ? try_to_wake_up+0x1b1/0x2b0
 [<ffffffff8027bb09>] process_one_work+0x129/0x300
 [<ffffffff8027be06>] worker_thread+0x126/0x480
 [<ffffffff8098cde7>] ? __schedule+0x1c7/0x561
 [<ffffffff8027bce0>] ? process_one_work+0x300/0x300
 [<ffffffff80280ff4>] kthread+0xc4/0xe0
 [<ffffffff80335578>] ? kfree+0xc8/0x100
 [<ffffffff809903cf>] ret_from_fork+0x1f/0x40
 [<ffffffff80280f30>] ? __kthread_parkme+0x70/0x70
---[ end trace aaefd2fd9f306bc4 ]---

Signed-off-by: Tahsin Erdogan <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
amboar pushed a commit to amboar/linux that referenced this pull request Dec 23, 2016
This was reported by syzkaller:

    [ INFO: possible recursive locking detected ]
    4.9.0-rc4+ openbmc#49 Not tainted
    ---------------------------------------------
    kworker/2:1/5658 is trying to acquire lock:
     ([ 1644.769018] (&work->work)
    [<     inline     >] list_empty include/linux/compiler.h:243
    [<ffffffff8128dd60>] flush_work+0x0/0x660 kernel/workqueue.c:1511

    but task is already holding lock:
     ([ 1644.769018] (&work->work)
    [<ffffffff812916ab>] process_one_work+0x94b/0x1900 kernel/workqueue.c:2093

    stack backtrace:
    CPU: 2 PID: 5658 Comm: kworker/2:1 Not tainted 4.9.0-rc4+ openbmc#49
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Workqueue: events async_pf_execute
     ffff8800676ff630 ffffffff81c2e46b ffffffff8485b930 ffff88006b1fc480
     0000000000000000 ffffffff8485b930 ffff8800676ff7e0 ffffffff81339b27
     ffff8800676ff7e8 0000000000000046 ffff88006b1fcce8 ffff88006b1fccf0
    Call Trace:
    ...
    [<ffffffff8128ddf3>] flush_work+0x93/0x660 kernel/workqueue.c:2846
    [<ffffffff812954ea>] __cancel_work_timer+0x17a/0x410 kernel/workqueue.c:2916
    [<ffffffff81295797>] cancel_work_sync+0x17/0x20 kernel/workqueue.c:2951
    [<ffffffff81073037>] kvm_clear_async_pf_completion_queue+0xd7/0x400 virt/kvm/async_pf.c:126
    [<     inline     >] kvm_free_vcpus arch/x86/kvm/x86.c:7841
    [<ffffffff810b728d>] kvm_arch_destroy_vm+0x23d/0x620 arch/x86/kvm/x86.c:7946
    [<     inline     >] kvm_destroy_vm virt/kvm/kvm_main.c:731
    [<ffffffff8105914e>] kvm_put_kvm+0x40e/0x790 virt/kvm/kvm_main.c:752
    [<ffffffff81072b3d>] async_pf_execute+0x23d/0x4f0 virt/kvm/async_pf.c:111
    [<ffffffff8129175c>] process_one_work+0x9fc/0x1900 kernel/workqueue.c:2096
    [<ffffffff8129274f>] worker_thread+0xef/0x1480 kernel/workqueue.c:2230
    [<ffffffff812a5a94>] kthread+0x244/0x2d0 kernel/kthread.c:209
    [<ffffffff831f102a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433

The reason is that kvm_put_kvm is causing the destruction of the VM, but
the page fault is still on the ->queue list.  The ->queue list is owned
by the VCPU, not by the work items, so we cannot just add list_del to
the work item.

Instead, use work->vcpu to note async page faults that have been resolved
and will be processed through the done list.  There is no need to flush
those.

Cc: Dmitry Vyukov <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Radim Krčmář <[email protected]>
amboar pushed a commit to amboar/linux that referenced this pull request Dec 23, 2016
Cluster xAPIC delivery incorrectly assumed that dest_id <= 0xff.
With enabled KVM_X2APIC_API_USE_32BIT_IDS in KVM_CAP_X2APIC_API, a
userspace can send an interrupt with dest_id that results in
out-of-bounds access.

Found by syzkaller:

  BUG: KASAN: slab-out-of-bounds in kvm_irq_delivery_to_apic_fast+0x11fa/0x1210 at addr ffff88003d9ca750
  Read of size 8 by task syz-executor/22923
  CPU: 0 PID: 22923 Comm: syz-executor Not tainted 4.9.0-rc4+ openbmc#49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __dump_stack lib/dump_stack.c:15
   [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51
   [...] kasan_object_err+0x1c/0x70 mm/kasan/report.c:156
   [...] print_address_description mm/kasan/report.c:194
   [...] kasan_report_error mm/kasan/report.c:283
   [...] kasan_report+0x231/0x500 mm/kasan/report.c:303
   [...] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:329
   [...] kvm_irq_delivery_to_apic_fast+0x11fa/0x1210 arch/x86/kvm/lapic.c:824
   [...] kvm_irq_delivery_to_apic+0x132/0x9a0 arch/x86/kvm/irq_comm.c:72
   [...] kvm_set_msi+0x111/0x160 arch/x86/kvm/irq_comm.c:157
   [...] kvm_send_userspace_msi+0x201/0x280 arch/x86/kvm/../../../virt/kvm/irqchip.c:74
   [...] kvm_vm_ioctl+0xba5/0x1670 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3015
   [...] vfs_ioctl fs/ioctl.c:43
   [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
   [...] SYSC_ioctl fs/ioctl.c:694
   [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
   [...] entry_SYSCALL_64_fastpath+0x1f/0xc2

Reported-by: Dmitry Vyukov <[email protected]>
Cc: [email protected]
Fixes: e45115b ("KVM: x86: use physical LAPIC array for logical x2APIC")
Reviewed-by: Paolo Bonzini <[email protected]>
Signed-off-by: Radim Krčmář <[email protected]>
amboar pushed a commit to amboar/linux that referenced this pull request Dec 23, 2016
em_jmp_far and em_ret_far assumed that setting IP can only fail in 64
bit mode, but syzkaller proved otherwise (and SDM agrees).
Code segment was restored upon failure, but it was left uninitialized
outside of long mode, which could lead to a leak of host kernel stack.
We could have fixed that by always saving and restoring the CS, but we
take a simpler approach and just break any guest that manages to fail
as the error recovery is error-prone and modern CPUs don't need emulator
for this.

Found by syzkaller:

  WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ openbmc#49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __dump_stack lib/dump_stack.c:15
   [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51
   [...] panic+0x1b7/0x3a3 kernel/panic.c:179
   [...] __warn+0x1c4/0x1e0 kernel/panic.c:542
   [...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
   [...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217
   [...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227
   [...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294
   [...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545
   [...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116
   [...] complete_emulated_io arch/x86/kvm/x86.c:6870
   [...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934
   [...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978
   [...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557
   [...] vfs_ioctl fs/ioctl.c:43
   [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
   [...] SYSC_ioctl fs/ioctl.c:694
   [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
   [...] entry_SYSCALL_64_fastpath+0x1f/0xc2

Reported-by: Dmitry Vyukov <[email protected]>
Cc: [email protected]
Fixes: d1442d8 ("KVM: x86: Handle errors when RIP is set during far jumps")
Signed-off-by: Radim Krčmář <[email protected]>
amboar pushed a commit to amboar/linux that referenced this pull request Dec 23, 2016
KVM was using arrays of size KVM_MAX_VCPUS with vcpu_id, but ID can be
bigger that the maximal number of VCPUs, resulting in out-of-bounds
access.

Found by syzkaller:

  BUG: KASAN: slab-out-of-bounds in __apic_accept_irq+0xb33/0xb50 at addr [...]
  Write of size 1 by task a.out/27101
  CPU: 1 PID: 27101 Comm: a.out Not tainted 4.9.0-rc5+ openbmc#49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __apic_accept_irq+0xb33/0xb50 arch/x86/kvm/lapic.c:905
   [...] kvm_apic_set_irq+0x10e/0x180 arch/x86/kvm/lapic.c:495
   [...] kvm_irq_delivery_to_apic+0x732/0xc10 arch/x86/kvm/irq_comm.c:86
   [...] ioapic_service+0x41d/0x760 arch/x86/kvm/ioapic.c:360
   [...] ioapic_set_irq+0x275/0x6c0 arch/x86/kvm/ioapic.c:222
   [...] kvm_ioapic_inject_all arch/x86/kvm/ioapic.c:235
   [...] kvm_set_ioapic+0x223/0x310 arch/x86/kvm/ioapic.c:670
   [...] kvm_vm_ioctl_set_irqchip arch/x86/kvm/x86.c:3668
   [...] kvm_arch_vm_ioctl+0x1a08/0x23c0 arch/x86/kvm/x86.c:3999
   [...] kvm_vm_ioctl+0x1fa/0x1a70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3099

Reported-by: Dmitry Vyukov <[email protected]>
Cc: [email protected]
Fixes: af1bae5 ("KVM: x86: bump KVM_MAX_VCPU_ID to 1023")
Reviewed-by: Paolo Bonzini <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Signed-off-by: Radim Krčmář <[email protected]>
shenki pushed a commit that referenced this pull request Nov 19, 2018
[ Upstream commit da71577 ]

When an FDB entry is configured, the address is validated to have the
length of an Ethernet address, but the device for which the address is
configured can be of any type.

The above can result in the use of uninitialized memory when the address
is later compared against existing addresses since 'dev->addr_len' is
used and it may be greater than ETH_ALEN, as with ip6tnl devices.

Fix this by making sure that FDB entries are only configured for
Ethernet devices.

BUG: KMSAN: uninit-value in memcmp+0x11d/0x180 lib/string.c:863
CPU: 1 PID: 4318 Comm: syz-executor998 Not tainted 4.19.0-rc3+ #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x14b/0x190 lib/dump_stack.c:113
  kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:956
  __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:645
  memcmp+0x11d/0x180 lib/string.c:863
  dev_uc_add_excl+0x165/0x7b0 net/core/dev_addr_lists.c:464
  ndo_dflt_fdb_add net/core/rtnetlink.c:3463 [inline]
  rtnl_fdb_add+0x1081/0x1270 net/core/rtnetlink.c:3558
  rtnetlink_rcv_msg+0xa0b/0x1530 net/core/rtnetlink.c:4715
  netlink_rcv_skb+0x36e/0x5f0 net/netlink/af_netlink.c:2454
  rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4733
  netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
  netlink_unicast+0x1638/0x1720 net/netlink/af_netlink.c:1343
  netlink_sendmsg+0x1205/0x1290 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:621 [inline]
  sock_sendmsg net/socket.c:631 [inline]
  ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114
  __sys_sendmsg net/socket.c:2152 [inline]
  __do_sys_sendmsg net/socket.c:2161 [inline]
  __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159
  __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159
  do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
  entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x440ee9
Code: e8 cc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff6a93b518 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440ee9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 000000000000b4b0
R13: 0000000000401ec0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
  kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:181
  kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:91
  kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:100
  slab_post_alloc_hook mm/slab.h:446 [inline]
  slab_alloc_node mm/slub.c:2718 [inline]
  __kmalloc_node_track_caller+0x9e7/0x1160 mm/slub.c:4351
  __kmalloc_reserve net/core/skbuff.c:138 [inline]
  __alloc_skb+0x2f5/0x9e0 net/core/skbuff.c:206
  alloc_skb include/linux/skbuff.h:996 [inline]
  netlink_alloc_large_skb net/netlink/af_netlink.c:1189 [inline]
  netlink_sendmsg+0xb49/0x1290 net/netlink/af_netlink.c:1883
  sock_sendmsg_nosec net/socket.c:621 [inline]
  sock_sendmsg net/socket.c:631 [inline]
  ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114
  __sys_sendmsg net/socket.c:2152 [inline]
  __do_sys_sendmsg net/socket.c:2161 [inline]
  __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159
  __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159
  do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
  entry_SYSCALL_64_after_hwframe+0x63/0xe7

v2:
* Make error message more specific (David)

Fixes: 090096b ("net: generic fdb support for drivers without ndo_fdb_<op>")
Signed-off-by: Ido Schimmel <[email protected]>
Reported-and-tested-by: [email protected]
Reported-and-tested-by: [email protected]
Cc: Vlad Yasevich <[email protected]>
Cc: David Ahern <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
shenki pushed a commit that referenced this pull request Aug 9, 2019
[ Upstream commit e198987 ]

gtp_encap_enable_socket() and gtp_encap_destroy() are not protected
by rcu_read_lock(). and it's not safe to write sk->sk_user_data.
This patch make these functions to use lock_sock() instead of
rcu_dereference_sk_user_data().

Test commands:
    gtp-link add gtp1

Splat looks like:
[   83.238315] =============================
[   83.239127] WARNING: suspicious RCU usage
[   83.239702] 5.2.0-rc6+ #49 Not tainted
[   83.240268] -----------------------------
[   83.241205] drivers/net/gtp.c:799 suspicious rcu_dereference_check() usage!
[   83.243828]
[   83.243828] other info that might help us debug this:
[   83.243828]
[   83.246325]
[   83.246325] rcu_scheduler_active = 2, debug_locks = 1
[   83.247314] 1 lock held by gtp-link/1008:
[   83.248523]  #0: 0000000017772c7f (rtnl_mutex){+.+.}, at: __rtnl_newlink+0x5f5/0x11b0
[   83.251503]
[   83.251503] stack backtrace:
[   83.252173] CPU: 0 PID: 1008 Comm: gtp-link Not tainted 5.2.0-rc6+ #49
[   83.253271] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   83.254562] Call Trace:
[   83.254995]  dump_stack+0x7c/0xbb
[   83.255567]  gtp_encap_enable_socket+0x2df/0x360 [gtp]
[   83.256415]  ? gtp_find_dev+0x1a0/0x1a0 [gtp]
[   83.257161]  ? memset+0x1f/0x40
[   83.257843]  gtp_newlink+0x90/0xa21 [gtp]
[   83.258497]  ? __netlink_ns_capable+0xc3/0xf0
[   83.259260]  __rtnl_newlink+0xb9f/0x11b0
[   83.260022]  ? rtnl_link_unregister+0x230/0x230
[ ... ]

Fixes: 1e3a3ab ("gtp: make GTP sockets in gtp_newlink optional")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
shenki pushed a commit that referenced this pull request May 5, 2020
…LAG_DETACH is set

commit 8305f72 upstream.

During system resume from suspend, this can be observed on ASM1062 PMP
controller:

ata10.01: SATA link down (SStatus 0 SControl 330)
ata10.02: hard resetting link
ata10.02: SATA link down (SStatus 0 SControl 330)
ata10.00: configured for UDMA/133
Kernel panic - not syncing: stack-protector: Kernel
 in: sata_pmp_eh_recover+0xa2b/0xa40

CPU: 2 PID: 230 Comm: scsi_eh_9 Tainted: P OE
#49-Ubuntu
Hardware name: System manufacturer System Product
 1001 12/10/2017
Call Trace:
dump_stack+0x63/0x8b
panic+0xe4/0x244
? sata_pmp_eh_recover+0xa2b/0xa40
__stack_chk_fail+0x19/0x20
sata_pmp_eh_recover+0xa2b/0xa40
? ahci_do_softreset+0x260/0x260 [libahci]
? ahci_do_hardreset+0x140/0x140 [libahci]
? ata_phys_link_offline+0x60/0x60
? ahci_stop_engine+0xc0/0xc0 [libahci]
sata_pmp_error_handler+0x22/0x30
ahci_error_handler+0x45/0x80 [libahci]
ata_scsi_port_error_handler+0x29b/0x770
? ata_scsi_cmd_error_handler+0x101/0x140
ata_scsi_error+0x95/0xd0
? scsi_try_target_reset+0x90/0x90
scsi_error_handler+0xd0/0x5b0
kthread+0x121/0x140
? scsi_eh_get_sense+0x200/0x200
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x22/0x40
Kernel Offset: 0xcc00000 from 0xffffffff81000000
(relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Since sata_pmp_eh_recover_pmp() doens't set rc when ATA_DFLAG_DETACH is
set, sata_pmp_eh_recover() continues to run. During retry it triggers
the stack protector.

Set correct rc in sata_pmp_eh_recover_pmp() to let sata_pmp_eh_recover()
jump to pmp_fail directly.

BugLink: https://bugs.launchpad.net/bugs/1821434
Cc: [email protected]
Signed-off-by: Kai-Heng Feng <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
shenki pushed a commit that referenced this pull request Jun 24, 2020
commit fe8d33b upstream.

Turning on CONFIG_DMA_API_DEBUG_SG results in the following warning:
WARNING: CPU: 1 PID: 20 at kernel/dma/debug.c:500 add_dma_entry+0x16c/0x17c
DMA-API: exceeded 7 overlapping mappings of cacheline 0x031d2645
Modules linked in:
CPU: 1 PID: 20 Comm: kworker/1:1 Not tainted 5.5.0-rc2-00021-gdeda30999c2b-dirty #49
Hardware name: STM32 (Device Tree Support)
Workqueue: events_freezable mmc_rescan
[<c03138c0>] (unwind_backtrace) from [<c030d760>] (show_stack+0x10/0x14)
[<c030d760>] (show_stack) from [<c0f2eb28>] (dump_stack+0xc0/0xd4)
[<c0f2eb28>] (dump_stack) from [<c034a14c>] (__warn+0xd0/0xf8)
[<c034a14c>] (__warn) from [<c034a530>] (warn_slowpath_fmt+0x94/0xb8)
[<c034a530>] (warn_slowpath_fmt) from [<c03bca0c>] (add_dma_entry+0x16c/0x17c)
[<c03bca0c>] (add_dma_entry) from [<c03bdf54>] (debug_dma_map_sg+0xe4/0x3d4)
[<c03bdf54>] (debug_dma_map_sg) from [<c0d09244>] (sdmmc_idma_prep_data+0x94/0xf8)
[<c0d09244>] (sdmmc_idma_prep_data) from [<c0d05a2c>] (mmci_prep_data+0x2c/0xb0)
[<c0d05a2c>] (mmci_prep_data) from [<c0d073ec>] (mmci_start_data+0x134/0x2f0)
[<c0d073ec>] (mmci_start_data) from [<c0d078d0>] (mmci_request+0xe8/0x154)
[<c0d078d0>] (mmci_request) from [<c0cecb44>] (mmc_start_request+0x94/0xbc)

DMA api debug brings to light leaking dma-mappings, dma_map_sg and
dma_unmap_sg are not correctly balanced.

If a request is prepared, the dma_map/unmap are done in asynchronous call
pre_req (prep_data) and post_req (unprep_data). In this case the
dma-mapping is right balanced.

But if the request was not prepared, the data->host_cookie is define to
zero and the dma_map/unmap must be done in the request.  The dma_map is
called by mmci_dma_start (prep_data), but there is no dma_unmap in this
case.

This patch adds dma_unmap_sg when the dma is finalized and the data cookie
is zero (request not prepared).

Signed-off-by: Ludovic Barre <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Fixes: 46b723d ("mmc: mmci: add stm32 sdmmc variant")
Cc: [email protected]
Signed-off-by: Ulf Hansson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
shenki pushed a commit that referenced this pull request May 24, 2021
[ Upstream commit 0f20615 ]

Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable
bitfields. Missing breaks in a switch caused 8-byte reads always. This can
confuse libbpf because it does strict checks that memory load size corresponds
to the original size of the field, which in this case quite often would be
wrong.

After fixing that, we run into another problem, which quite subtle, so worth
documenting here. The issue is in Clang optimization and CO-RE relocation
interactions. Without that asm volatile construct (also known as
barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and
will apply BYTE_OFFSET 4 times for each switch case arm. This will result in
the same error from libbpf about mismatch of memory load size and original
field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *),
*(u32 *), and *(u64 *) memory loads, three of which will fail. Using
barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to
calculate p, after which value of p is used without relocation in each of
switch case arms, doing appropiately-sized memory load.

Here's the list of relevant relocations and pieces of generated BPF code
before and after this patch for test_core_reloc_bitfields_direct selftests.

BEFORE
=====
 #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32
 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32

     157:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     159:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     160:       b7 02 00 00 04 00 00 00 r2 = 4
; BYTE_SIZE relocation here                 ^^^
     161:       66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63>
     162:       16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65>
     163:       16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66>
     164:       05 00 12 00 00 00 00 00 goto +18 <LBB0_69>

0000000000000528 <LBB0_66>:
     165:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     167:       69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     168:       05 00 0e 00 00 00 00 00 goto +14 <LBB0_69>

0000000000000548 <LBB0_63>:
     169:       16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67>
     170:       16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68>
     171:       05 00 0b 00 00 00 00 00 goto +11 <LBB0_69>

0000000000000560 <LBB0_68>:
     172:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     174:       79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     175:       05 00 07 00 00 00 00 00 goto +7 <LBB0_69>

0000000000000580 <LBB0_65>:
     176:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     178:       71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8)
; BYTE_OFFSET relo here w/ WRONG size        ^^^^^^^^^^^^^^^^
     179:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

00000000000005a0 <LBB0_67>:
     180:       18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll
     182:       61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8)
; BYTE_OFFSET relo here w/ RIGHT size        ^^^^^^^^^^^^^^^^

00000000000005b8 <LBB0_69>:
     183:       67 01 00 00 20 00 00 00 r1 <<= 32
     184:       b7 02 00 00 00 00 00 00 r2 = 0
     185:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     186:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     187:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000005e0 <LBB0_71>:
     188:       77 01 00 00 20 00 00 00 r1 >>= 32

AFTER
=====

 #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32
 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32

     129:       18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll
     131:       7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1
     132:       b7 01 00 00 08 00 00 00 r1 = 8
; BYTE_OFFSET relo here                     ^^^
; no size check for non-memory dereferencing instructions
     133:       0f 12 00 00 00 00 00 00 r2 += r1
     134:       b7 03 00 00 04 00 00 00 r3 = 4
; BYTE_SIZE relocation here                 ^^^
     135:       66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63>
     136:       16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65>
     137:       16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66>
     138:       05 00 0a 00 00 00 00 00 goto +10 <LBB0_69>

0000000000000458 <LBB0_66>:
     139:       69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     140:       05 00 08 00 00 00 00 00 goto +8 <LBB0_69>

0000000000000468 <LBB0_63>:
     141:       16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67>
     142:       16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68>
     143:       05 00 05 00 00 00 00 00 goto +5 <LBB0_69>

0000000000000480 <LBB0_68>:
     144:       79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     145:       05 00 03 00 00 00 00 00 goto +3 <LBB0_69>

0000000000000490 <LBB0_65>:
     146:       71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^
     147:       05 00 01 00 00 00 00 00 goto +1 <LBB0_69>

00000000000004a0 <LBB0_67>:
     148:       61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0)
; NO CO-RE relocation here                   ^^^^^^^^^^^^^^^^

00000000000004a8 <LBB0_69>:
     149:       67 01 00 00 20 00 00 00 r1 <<= 32
     150:       b7 02 00 00 00 00 00 00 r2 = 0
     151:       16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71>
     152:       c7 01 00 00 20 00 00 00 r1 s>>= 32
     153:       05 00 01 00 00 00 00 00 goto +1 <LBB0_72>

00000000000004d0 <LBB0_71>:
     154:       77 01 00 00 20 00 00 00 r1 >>= 323

Fixes: ee26dad ("libbpf: Add support for relocatable bitfields")
Signed-off-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Lorenz Bauer <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
shenki pushed a commit that referenced this pull request May 24, 2021
[ Upstream commit d5027ca ]

Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Acked-By: Anton Ivanov <[email protected]>
Tested-By: Ritesh Raj Sarraf <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
shenki pushed a commit that referenced this pull request Jun 19, 2023
[ Upstream commit c308e9e ]

SMCRv1 has a similar issue to SMCRv2 (see link below) that may access
invalid MRs of RMBs when construct LLC ADD LINK CONT messages.

 BUG: kernel NULL pointer dereference, address: 0000000000000014
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 5 PID: 48 Comm: kworker/5:0 Kdump: loaded Tainted: G W   E      6.4.0-rc3+ #49
 Workqueue: events smc_llc_add_link_work [smc]
 RIP: 0010:smc_llc_add_link_cont+0x160/0x270 [smc]
 RSP: 0018:ffffa737801d3d50 EFLAGS: 00010286
 RAX: ffff964f82144000 RBX: ffffa737801d3dd8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff964f81370c30
 RBP: ffffa737801d3dd4 R08: ffff964f81370000 R09: ffffa737801d3db0
 R10: 0000000000000001 R11: 0000000000000060 R12: ffff964f82e70000
 R13: ffff964f81370c38 R14: ffffa737801d3dd3 R15: 0000000000000001
 FS:  0000000000000000(0000) GS:ffff9652bfd40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000014 CR3: 000000008fa20004 CR4: 00000000003706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  smc_llc_srv_rkey_exchange+0xa7/0x190 [smc]
  smc_llc_srv_add_link+0x3ae/0x5a0 [smc]
  smc_llc_add_link_work+0xb8/0x140 [smc]
  process_one_work+0x1e5/0x3f0
  worker_thread+0x4d/0x2f0
  ? __pfx_worker_thread+0x10/0x10
  kthread+0xe5/0x120
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x2c/0x50
  </TASK>

When an alernate RNIC is available in system, SMC will try to add a new
link based on the RNIC for resilience. All the RMBs in use will be mapped
to the new link. Then the RMBs' MRs corresponding to the new link will
be filled into LLC messages. For SMCRv1, they are ADD LINK CONT messages.

However smc_llc_add_link_cont() may mistakenly access to unused RMBs which
haven't been mapped to the new link and have no valid MRs, thus causing a
crash. So this patch fixes it.

Fixes: 87f88cd ("net/smc: rkey processing for a new link as SMC client")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Wen Gu <[email protected]>
Reviewed-by: Wenjia Zhang <[email protected]>
Reviewed-by: Tony Lu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
amboar pushed a commit to amboar/linux that referenced this pull request May 1, 2024
If stack_depot_save_flags() allocates memory it always drops
__GFP_NOLOCKDEP flag.  So when KASAN tries to track __GFP_NOLOCKDEP
allocation we may end up with lockdep splat like bellow:

======================================================
 WARNING: possible circular locking dependency detected
 6.9.0-rc3+ openbmc#49 Not tainted
 ------------------------------------------------------
 kswapd0/149 is trying to acquire lock:
 ffff88811346a920
(&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_reclaim_inode+0x3ac/0x590
[xfs]

 but task is already holding lock:
 ffffffff8bb33100 (fs_reclaim){+.+.}-{0:0}, at:
balance_pgdat+0x5d9/0xad0

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:
 -> openbmc#1 (fs_reclaim){+.+.}-{0:0}:
        __lock_acquire+0x7da/0x1030
        lock_acquire+0x15d/0x400
        fs_reclaim_acquire+0xb5/0x100
 prepare_alloc_pages.constprop.0+0xc5/0x230
        __alloc_pages+0x12a/0x3f0
        alloc_pages_mpol+0x175/0x340
        stack_depot_save_flags+0x4c5/0x510
        kasan_save_stack+0x30/0x40
        kasan_save_track+0x10/0x30
        __kasan_slab_alloc+0x83/0x90
        kmem_cache_alloc+0x15e/0x4a0
        __alloc_object+0x35/0x370
        __create_object+0x22/0x90
 __kmalloc_node_track_caller+0x477/0x5b0
        krealloc+0x5f/0x110
        xfs_iext_insert_raw+0x4b2/0x6e0 [xfs]
        xfs_iext_insert+0x2e/0x130 [xfs]
        xfs_iread_bmbt_block+0x1a9/0x4d0 [xfs]
        xfs_btree_visit_block+0xfb/0x290 [xfs]
        xfs_btree_visit_blocks+0x215/0x2c0 [xfs]
        xfs_iread_extents+0x1a2/0x2e0 [xfs]
 xfs_buffered_write_iomap_begin+0x376/0x10a0 [xfs]
        iomap_iter+0x1d1/0x2d0
 iomap_file_buffered_write+0x120/0x1a0
        xfs_file_buffered_write+0x128/0x4b0 [xfs]
        vfs_write+0x675/0x890
        ksys_write+0xc3/0x160
        do_syscall_64+0x94/0x170
 entry_SYSCALL_64_after_hwframe+0x71/0x79

Always preserve __GFP_NOLOCKDEP to fix this.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: cd11016 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB")
Signed-off-by: Andrey Ryabinin <[email protected]>
Reported-by: Xiubo Li <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Reported-by: Damien Le Moal <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Suggested-by: Dave Chinner <[email protected]>
Tested-by: Xiubo Li <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
amboar pushed a commit that referenced this pull request May 3, 2024
commit 6fe6046 upstream.

If stack_depot_save_flags() allocates memory it always drops
__GFP_NOLOCKDEP flag.  So when KASAN tries to track __GFP_NOLOCKDEP
allocation we may end up with lockdep splat like bellow:

======================================================
 WARNING: possible circular locking dependency detected
 6.9.0-rc3+ #49 Not tainted
 ------------------------------------------------------
 kswapd0/149 is trying to acquire lock:
 ffff88811346a920
(&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_reclaim_inode+0x3ac/0x590
[xfs]

 but task is already holding lock:
 ffffffff8bb33100 (fs_reclaim){+.+.}-{0:0}, at:
balance_pgdat+0x5d9/0xad0

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:
 -> #1 (fs_reclaim){+.+.}-{0:0}:
        __lock_acquire+0x7da/0x1030
        lock_acquire+0x15d/0x400
        fs_reclaim_acquire+0xb5/0x100
 prepare_alloc_pages.constprop.0+0xc5/0x230
        __alloc_pages+0x12a/0x3f0
        alloc_pages_mpol+0x175/0x340
        stack_depot_save_flags+0x4c5/0x510
        kasan_save_stack+0x30/0x40
        kasan_save_track+0x10/0x30
        __kasan_slab_alloc+0x83/0x90
        kmem_cache_alloc+0x15e/0x4a0
        __alloc_object+0x35/0x370
        __create_object+0x22/0x90
 __kmalloc_node_track_caller+0x477/0x5b0
        krealloc+0x5f/0x110
        xfs_iext_insert_raw+0x4b2/0x6e0 [xfs]
        xfs_iext_insert+0x2e/0x130 [xfs]
        xfs_iread_bmbt_block+0x1a9/0x4d0 [xfs]
        xfs_btree_visit_block+0xfb/0x290 [xfs]
        xfs_btree_visit_blocks+0x215/0x2c0 [xfs]
        xfs_iread_extents+0x1a2/0x2e0 [xfs]
 xfs_buffered_write_iomap_begin+0x376/0x10a0 [xfs]
        iomap_iter+0x1d1/0x2d0
 iomap_file_buffered_write+0x120/0x1a0
        xfs_file_buffered_write+0x128/0x4b0 [xfs]
        vfs_write+0x675/0x890
        ksys_write+0xc3/0x160
        do_syscall_64+0x94/0x170
 entry_SYSCALL_64_after_hwframe+0x71/0x79

Always preserve __GFP_NOLOCKDEP to fix this.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: cd11016 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB")
Signed-off-by: Andrey Ryabinin <[email protected]>
Reported-by: Xiubo Li <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Reported-by: Damien Le Moal <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Suggested-by: Dave Chinner <[email protected]>
Tested-by: Xiubo Li <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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