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Sync with Linus #20

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merged 0 commits into from
Dec 22, 2014
Merged

Sync with Linus #20

merged 0 commits into from
Dec 22, 2014

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@dabrace dabrace commented Dec 22, 2014

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@dabrace dabrace merged this pull request into dabrace:master Dec 22, 2014
dabrace pushed a commit that referenced this pull request Jan 24, 2015
There are still some places in the fb helper that need to avoid
sleeping in panic context. Here's an example:

[   65.615496] bad: scheduling from the idle thread!
[   65.620747] CPU: 92 PID: 0 Comm: swapper/92 Tainted: G   M        E  3.18.0-rc4-7-default+ #20

[   65.630364] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS
BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
[   65.641923]  ffff88087f693d80 ffff88087f689878 ffffffff81566db9 0000000000000000
[   65.650226]  ffff88087f693d80 ffff88087f689898 ffffffff810871ff ffff88046eb3e0d0
[   65.658527]  ffff88087f693d80 ffff88087f6898c8 ffffffff8107c1fa 000000017f6898b8
[   65.666830] Call Trace:
[   65.669557]  <#MC>  [<ffffffff81566db9>] dump_stack+0x46/0x58
[   65.675994]  [<ffffffff810871ff>] dequeue_task_idle+0x2f/0x40
[   65.682412]  [<ffffffff8107c1fa>] dequeue_task+0x5a/0x80
[   65.688345]  [<ffffffff810804f3>] deactivate_task+0x23/0x30
[   65.694569]  [<ffffffff81569050>] __schedule+0x580/0x7f0
[   65.700502]  [<ffffffff81569739>] schedule_preempt_disabled+0x29/0x70
[   65.707696]  [<ffffffff8156abb6>] __ww_mutex_lock_slowpath+0xb8/0x162
[   65.714891]  [<ffffffff8156acb3>] __ww_mutex_lock+0x53/0x85
[   65.721125]  [<ffffffffa00b3a5d>] drm_modeset_lock+0x3d/0x110 [drm]
[   65.728132]  [<ffffffffa00b3c2a>] __drm_modeset_lock_all+0x8a/0x120 [drm]
[   65.735721]  [<ffffffffa00b3cd0>] drm_modeset_lock_all+0x10/0x30 [drm]
[   65.743015]  [<ffffffffa01af8bf>] drm_fb_helper_pan_display+0x2f/0xf0 [drm_kms_helper]
[   65.751857]  [<ffffffff8132bd21>] fb_pan_display+0xd1/0x1a0
[   65.758081]  [<ffffffff81326010>] bit_update_start+0x20/0x50
[   65.764400]  [<ffffffff813259f2>] fbcon_switch+0x3a2/0x550
[   65.770528]  [<ffffffff813a01c9>] redraw_screen+0x189/0x240
[   65.776750]  [<ffffffff81322f8a>] fbcon_blank+0x20a/0x2d0
[   65.782778]  [<ffffffff8137d359>] ? erst_writer+0x209/0x330
[   65.789002]  [<ffffffff810ba2f3>] ? internal_add_timer+0x63/0x80
[   65.795710]  [<ffffffff810bc137>] ? mod_timer+0x127/0x1e0
[   65.801740]  [<ffffffff813a0cd8>] do_unblank_screen+0xa8/0x1d0
[   65.808255]  [<ffffffff813a0e10>] unblank_screen+0x10/0x20
[   65.814381]  [<ffffffff812ca0d9>] bust_spinlocks+0x19/0x40
[   65.820508]  [<ffffffff81561ca7>] panic+0x106/0x1f5
[   65.825955]  [<ffffffff8102336c>] mce_panic+0x2ac/0x2e0
[   65.831789]  [<ffffffff812c796a>] ? delay_tsc+0x4a/0x80
[   65.837625]  [<ffffffff81024e1f>] do_machine_check+0xbaf/0xbf0
[   65.844138]  [<ffffffff813365d7>] ? intel_idle+0xc7/0x150
[   65.850166]  [<ffffffff8156f03f>] machine_check+0x1f/0x30
[   65.856195]  [<ffffffff813365d7>] ? intel_idle+0xc7/0x150
[   65.862222]  <<EOE>>  [<ffffffff814283d5>] cpuidle_enter_state+0x55/0x170
[   65.869823]  [<ffffffff814285a7>] cpuidle_enter+0x17/0x20
[   65.875852]  [<ffffffff81097b08>] cpu_startup_entry+0x2d8/0x370
[   65.882467]  [<ffffffff8102fe29>] start_secondary+0x159/0x180

There's __drm_modeset_lock_all() which Daniel Vetter introduced for this
purpose. We can leverage that without reinventing anything. This patch
works with the latest kernel.

Reviewed-by: Rob Clark <[email protected]>
Tested-by: Tony Luck <[email protected]>
Signed-off-by: Rui Wang <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>
dabrace pushed a commit that referenced this pull request Apr 15, 2015
Rather than have code which masks and then shifts, such as:

	mrc     p15, 1, r0, c0, c0, 1
ALT_SMP(ands	r3, r0, #7 << 21)
ALT_UP( ands	r3, r0, #7 << 27)
ALT_SMP(mov	r3, r3, lsr #20)
ALT_UP(	mov	r3, r3, lsr #26)

re-arrange this as a shift and then mask.  The masking is the same for
each field which we want to extract, so this allows the mask to be
shared amongst code paths:

	mrc     p15, 1, r0, c0, c0, 1
ALT_SMP(mov	r3, r0, lsr #20)
ALT_UP(	mov	r3, r0, lsr #26)
	ands	r3, r3, #7 << 1

Use this method for the LoUIS, LoUU and LoC fields.

Reviewed-by: Catalin Marinas <[email protected]>
Signed-off-by: Russell King <[email protected]>
dabrace pushed a commit that referenced this pull request Jun 17, 2015
If a device is renamed and the original name is subsequently reused
for a new device, the following warning is generated:

sysctl duplicate entry: /net/mpls/conf/veth0//input
CPU: 3 PID: 1379 Comm: ip Not tainted 4.1.0-rc4+ #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
 0000000000000000 0000000000000000 ffffffff81566aaf 0000000000000000
 ffffffff81236279 ffff88002f7d7f00 0000000000000000 ffff88000db336d8
 ffff88000db33698 0000000000000005 ffff88002e046000 ffff8800168c9280
Call Trace:
 [<ffffffff81566aaf>] ? dump_stack+0x40/0x50
 [<ffffffff81236279>] ? __register_sysctl_table+0x289/0x5a0
 [<ffffffffa051a24f>] ? mpls_dev_notify+0x1ff/0x300 [mpls_router]
 [<ffffffff8108db7f>] ? notifier_call_chain+0x4f/0x70
 [<ffffffff81470e72>] ? register_netdevice+0x2b2/0x480
 [<ffffffffa0524748>] ? veth_newlink+0x178/0x2d3 [veth]
 [<ffffffff8147f84c>] ? rtnl_newlink+0x73c/0x8e0
 [<ffffffff8147f27a>] ? rtnl_newlink+0x16a/0x8e0
 [<ffffffff81459ff2>] ? __kmalloc_reserve.isra.30+0x32/0x90
 [<ffffffff8147ccfd>] ? rtnetlink_rcv_msg+0x8d/0x250
 [<ffffffff8145b027>] ? __alloc_skb+0x47/0x1f0
 [<ffffffff8149badb>] ? __netlink_lookup+0xab/0xe0
 [<ffffffff8147cc70>] ? rtnetlink_rcv+0x30/0x30
 [<ffffffff8149e7a0>] ? netlink_rcv_skb+0xb0/0xd0
 [<ffffffff8147cc64>] ? rtnetlink_rcv+0x24/0x30
 [<ffffffff8149df17>] ? netlink_unicast+0x107/0x1a0
 [<ffffffff8149e4be>] ? netlink_sendmsg+0x50e/0x630
 [<ffffffff8145209c>] ? sock_sendmsg+0x3c/0x50
 [<ffffffff81452beb>] ? ___sys_sendmsg+0x27b/0x290
 [<ffffffff811bd258>] ? mem_cgroup_try_charge+0x88/0x110
 [<ffffffff811bd5b6>] ? mem_cgroup_commit_charge+0x56/0xa0
 [<ffffffff811d7700>] ? do_filp_open+0x30/0xa0
 [<ffffffff8145336e>] ? __sys_sendmsg+0x3e/0x80
 [<ffffffff8156c3f2>] ? system_call_fastpath+0x16/0x75

Fix this by unregistering the previous sysctl table (registered for
the path containing the original device name) and re-registering the
table for the path containing the new device name.

Fixes: 37bde79 ("mpls: Per-device enabling of packet input")
Reported-by: Scott Feldman <[email protected]>
Signed-off-by: Robert Shearman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 5, 2015
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: [email protected] # 3.9+
[[email protected]: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
dabrace pushed a commit that referenced this pull request Sep 4, 2015
The existing memory barrier macro causes a significant amount of code
to be inserted inline at every call site.  For example, in
gpio_set_irq_type(), we have this for mb():

c0344c08:       f57ff04e        dsb     st
c0344c0:       e59f8190        ldr     r8, [pc, torvalds#400]  ; c0344da4 <gpio_set_irq_type+0x230>
c0344c10:       e3590004        cmp     r9, #4
c0344c14:       e5983014        ldr     r3, [r8, #20]
c0344c18:       0a000054        beq     c0344d70 <gpio_set_irq_type+0x1fc>
c0344c1c:       e3530000        cmp     r3, #0
c0344c20:       0a000004        beq     c0344c38 <gpio_set_irq_type+0xc4>
c0344c24:       e50b2030        str     r2, [fp, #-48]  ; 0xffffffd0
c0344c28:       e50bc034        str     ip, [fp, #-52]  ; 0xffffffcc
c0344c2c:       e12fff33        blx     r3
c0344c30:       e51bc034        ldr     ip, [fp, #-52]  ; 0xffffffcc
c0344c34:       e51b2030        ldr     r2, [fp, #-48]  ; 0xffffffd0
c0344c38:       e5963004        ldr     r3, [r6, #4]

Moving the outer_cache_sync() call out of line reduces the impact of
the barrier:

c0344968:       f57ff04e        dsb     st
c034496c:       e35a0004        cmp     sl, #4
c0344970:       e50b2030        str     r2, [fp, #-48]  ; 0xffffffd0
c0344974:       0a000044        beq     c0344a8c <gpio_set_irq_type+0x1b8>
c0344978:       ebf363dd        bl      c001d8f4 <arm_heavy_mb>
c034497c:       e5953004        ldr     r3, [r5, #4]

This should reduce the cache footprint of this code.  Overall, this
results in a reduction of around 20K in the kernel size:

    text    data      bss      dec     hex filename
10773970  667392 10369656 21811018 14ccf4a ../build/imx6/vmlinux-old
10754219  667392 10369656 21791267 14c8223 ../build/imx6/vmlinux-new

Another advantage to this approach is that we can finally resolve the
issue of SoCs which have their own memory barrier requirements within
multiplatform kernels (such as OMAP.)  Here, the bus interconnects
need additional handling to ensure that writes become visible in the
correct order (eg, between dma_map() operations, writes to DMA
coherent memory, and MMIO accesses.)

Acked-by: Tony Lindgren <[email protected]>
Acked-by: Richard Woodruff <[email protected]>
Signed-off-by: Russell King <[email protected]>
dabrace pushed a commit that referenced this pull request Jan 15, 2016
When we're using LZ4 multi compression streams for zram swap, we found
out page allocation failure message in system running test.  That was
not only once, but a few(2 - 5 times per test).  Also, some failure
cases were continually occurring to try allocation order 3.

In order to make parallel compression private data, we should call
kzalloc() with order 2/3 in runtime(lzo/lz4).  But if there is no order
2/3 size memory to allocate in that time, page allocation fails.  This
patch makes to use vmalloc() as fallback of kmalloc(), this prevents
page alloc failure warning.

After using this, we never found warning message in running test, also
It could reduce process startup latency about 60-120ms in each case.

For reference a call trace :

    Binder_1: page allocation failure: order:3, mode:0x10c0d0
    CPU: 0 PID: 424 Comm: Binder_1 Tainted: GW 3.10.49-perf-g991d02b-dirty #20
    Call trace:
      dump_backtrace+0x0/0x270
      show_stack+0x10/0x1c
      dump_stack+0x1c/0x28
      warn_alloc_failed+0xfc/0x11c
      __alloc_pages_nodemask+0x724/0x7f0
      __get_free_pages+0x14/0x5c
      kmalloc_order_trace+0x38/0xd8
      zcomp_lz4_create+0x2c/0x38
      zcomp_strm_alloc+0x34/0x78
      zcomp_strm_multi_find+0x124/0x1ec
      zcomp_strm_find+0xc/0x18
      zram_bvec_rw+0x2fc/0x780
      zram_make_request+0x25c/0x2d4
      generic_make_request+0x80/0xbc
      submit_bio+0xa4/0x15c
      __swap_writepage+0x218/0x230
      swap_writepage+0x3c/0x4c
      shrink_page_list+0x51c/0x8d0
      shrink_inactive_list+0x3f8/0x60c
      shrink_lruvec+0x33c/0x4cc
      shrink_zone+0x3c/0x100
      try_to_free_pages+0x2b8/0x54c
      __alloc_pages_nodemask+0x514/0x7f0
      __get_free_pages+0x14/0x5c
      proc_info_read+0x50/0xe4
      vfs_read+0xa0/0x12c
      SyS_read+0x44/0x74
    DMA: 3397*4kB (MC) 26*8kB (RC) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB
         0*512kB 0*1024kB 0*2048kB 0*4096kB = 13796kB

[[email protected]: change vmalloc gfp and adding comment about gfp]
[[email protected]: tweak comments and styles]
Signed-off-by: Kyeongdon Kim <[email protected]>
Signed-off-by: Minchan Kim <[email protected]>
Acked-by: Sergey Senozhatsky <[email protected]>
Sergey Senozhatsky <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 24, 2016
commit 5634cc2 ("writeback: update writeback
tracepoints to report cgroup") made writeback tracepoints print out cgroup
path when CGROUP_WRITEBACK is enabled, but it may trigger the below bug on -rt
kernel since kernfs_path and kernfs_path_len are called by tracepoints, which
acquire spin lock that is sleepable on -rt kernel.

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:930
in_atomic(): 1, irqs_disabled(): 0, pid: 625, name: kworker/u16:3
INFO: lockdep is turned off.
Preemption disabled at:[<ffffffc000374a5c>] wb_writeback+0xec/0x830

CPU: 7 PID: 625 Comm: kworker/u16:3 Not tainted 4.4.1-rt5 #20
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Workqueue: writeback wb_workfn (flush-7:0)
Call trace:
[<ffffffc00008d708>] dump_backtrace+0x0/0x200
[<ffffffc00008d92c>] show_stack+0x24/0x30
[<ffffffc0007b0f40>] dump_stack+0x88/0xa8
[<ffffffc000127d74>] ___might_sleep+0x2ec/0x300
[<ffffffc000d5d550>] rt_spin_lock+0x38/0xb8
[<ffffffc0003e0548>] kernfs_path_len+0x30/0x90
[<ffffffc00036b360>] trace_event_raw_event_writeback_work_class+0xe8/0x2e8
[<ffffffc000374f90>] wb_writeback+0x620/0x830
[<ffffffc000376224>] wb_workfn+0x61c/0x950
[<ffffffc000110adc>] process_one_work+0x3ac/0xb30
[<ffffffc0001112fc>] worker_thread+0x9c/0x7a8
[<ffffffc00011a9e8>] kthread+0x190/0x1b0
[<ffffffc000086ca0>] ret_from_fork+0x10/0x30

With unlocked kernfs_* functions, synchronize_sched() has to be called in
kernfs_rename which could be called in syscall path, but it is problematic.
So, print out cgroup ino instead of path name, which could be converted to
path name by userland.

Withouth CGROUP_WRITEBACK enabled, it just prints out root dir. But, root
dir ino vary from different filesystems, so printing out -1U to indicate
an invalid cgroup ino.

Link: http://lkml.kernel.org/r/[email protected]

Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Yang Shi <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
dabrace pushed a commit that referenced this pull request Oct 10, 2016
Function ib_create_qp() was failing to return an error when
rdma_rw_init_mrs() fails, causing a crash further down in ib_create_qp()
when trying to dereferece the qp pointer which was actually a negative
errno.

The crash:

crash> log|grep BUG
[  136.458121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
crash> bt
PID: 3736   TASK: ffff8808543215c0  CPU: 2   COMMAND: "kworker/u64:2"
 #0 [ffff88084d323340] machine_kexec at ffffffff8105fbb0
 #1 [ffff88084d3233b0] __crash_kexec at ffffffff81116758
 #2 [ffff88084d323480] crash_kexec at ffffffff8111682d
 #3 [ffff88084d3234b0] oops_end at ffffffff81032bd6
 #4 [ffff88084d3234e0] no_context at ffffffff8106e431
 #5 [ffff88084d323530] __bad_area_nosemaphore at ffffffff8106e610
 #6 [ffff88084d323590] bad_area_nosemaphore at ffffffff8106e6f4
 #7 [ffff88084d3235a0] __do_page_fault at ffffffff8106ebdc
 #8 [ffff88084d323620] do_page_fault at ffffffff8106f057
 #9 [ffff88084d323660] page_fault at ffffffff816e3148
    [exception RIP: ib_create_qp+427]
    RIP: ffffffffa02554fb  RSP: ffff88084d323718  RFLAGS: 00010246
    RAX: 0000000000000004  RBX: fffffffffffffff4  RCX: 000000018020001f
    RDX: ffff880830997fc0  RSI: 0000000000000001  RDI: ffff88085f407200
    RBP: ffff88084d323778   R8: 0000000000000001   R9: ffffea0020bae210
    R10: ffffea0020bae218  R11: 0000000000000001  R12: ffff88084d3237c8
    R13: 00000000fffffff4  R14: ffff880859fa5000  R15: ffff88082eb89800
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
#10 [ffff88084d323780] rdma_create_qp at ffffffffa0782681 [rdma_cm]
#11 [ffff88084d3237b0] nvmet_rdma_create_queue_ib at ffffffffa07c43f3 [nvmet_rdma]
#12 [ffff88084d323860] nvmet_rdma_alloc_queue at ffffffffa07c5ba9 [nvmet_rdma]
#13 [ffff88084d323900] nvmet_rdma_queue_connect at ffffffffa07c5c96 [nvmet_rdma]
#14 [ffff88084d323980] nvmet_rdma_cm_handler at ffffffffa07c6450 [nvmet_rdma]
#15 [ffff88084d3239b0] iw_conn_req_handler at ffffffffa0787480 [rdma_cm]
#16 [ffff88084d323a60] cm_conn_req_handler at ffffffffa0775f06 [iw_cm]
#17 [ffff88084d323ab0] process_event at ffffffffa0776019 [iw_cm]
#18 [ffff88084d323af0] cm_work_handler at ffffffffa0776170 [iw_cm]
#19 [ffff88084d323cb0] process_one_work at ffffffff810a1483
#20 [ffff88084d323d90] worker_thread at ffffffff810a211d
#21 [ffff88084d323ec0] kthread at ffffffff810a6c5c
#22 [ffff88084d323f50] ret_from_fork at ffffffff816e1ebf

Fixes: 632bc3f ("IB/core, RDMA RW API: Do not exceed QP SGE send limit")
Signed-off-by: Steve Wise <[email protected]>
Cc: [email protected]
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Doug Ledford <[email protected]>
dabrace pushed a commit that referenced this pull request Dec 15, 2016
There have been several reports over the years of NULL pointer
dereferences in xfs_trans_log_inode during xfs_fsr processes,
when the process is doing an fput and tearing down extents
on the temporary inode, something like:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
PID: 29439  TASK: ffff880550584fa0  CPU: 6   COMMAND: "xfs_fsr"
    [exception RIP: xfs_trans_log_inode+0x10]
 #9 [ffff8800a57bbbe0] xfs_bunmapi at ffffffffa037398e [xfs]
#10 [ffff8800a57bbce8] xfs_itruncate_extents at ffffffffa0391b29 [xfs]
#11 [ffff8800a57bbd88] xfs_inactive_truncate at ffffffffa0391d0c [xfs]
#12 [ffff8800a57bbdb8] xfs_inactive at ffffffffa0392508 [xfs]
#13 [ffff8800a57bbdd8] xfs_fs_evict_inode at ffffffffa035907e [xfs]
#14 [ffff8800a57bbe00] evict at ffffffff811e1b67
#15 [ffff8800a57bbe28] iput at ffffffff811e23a5
#16 [ffff8800a57bbe58] dentry_kill at ffffffff811dcfc8
#17 [ffff8800a57bbe88] dput at ffffffff811dd06c
#18 [ffff8800a57bbea8] __fput at ffffffff811c823b
#19 [ffff8800a57bbef0] ____fput at ffffffff811c846e
#20 [ffff8800a57bbf00] task_work_run at ffffffff81093b27
#21 [ffff8800a57bbf30] do_notify_resume at ffffffff81013b0c
#22 [ffff8800a57bbf50] int_signal at ffffffff8161405d

As it turns out, this is because the i_itemp pointer, along
with the d_ops pointer, has been overwritten with zeros
when we tear down the extents during truncate.  When the in-core
inode fork on the temporary inode used by xfs_fsr was originally
set up during the extent swap, we mistakenly looked at di_nextents
to determine whether all extents fit inline, but this misses extents
generated by speculative preallocation; we should be using if_bytes
instead.

This mistake corrupts the in-memory inode, and code in
xfs_iext_remove_inline eventually gets bad inputs, causing
it to memmove and memset incorrect ranges; this became apparent
because the two values in ifp->if_u2.if_inline_ext[1] contained
what should have been in d_ops and i_itemp; they were memmoved due
to incorrect array indexing and then the original locations
were zeroed with memset, again due to an array overrun.

Fix this by properly using i_df.if_bytes to determine the number
of extents, not di_nextents.

Thanks to dchinner for looking at this with me and spotting the
root cause.

Cc: [email protected]
Signed-off-by: Eric Sandeen <[email protected]>
Reviewed-by: Brian Foster <[email protected]>
Signed-off-by: Dave Chinner <[email protected]>
dabrace pushed a commit that referenced this pull request Feb 28, 2017
Remove spinlock and use the "rtc->ops_lock" from RTC subsystem instead.
spin_lock_irqsave() is not needed here because we do not have hard IRQs.

This patch fixes the following issue:

root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
[   82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855
[   82.113660]  lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1
[   82.121329] CPU: 0 PID: 855 Comm: hwclock Not tainted 4.8.0-00042-g09d5410-dirty #20
[   82.129078] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[   82.135609] Backtrace:
[   82.138090] [<8010d378>] (dump_backtrace) from [<8010d5c0>] (show_stack+0x20/0x24)
[   82.145664]  r7:ec936000 r6:600a0013 r5:00000000 r4:81031680
[   82.151402] [<8010d5a0>] (show_stack) from [<80401518>] (dump_stack+0xb4/0xe8)
[   82.158636] [<80401464>] (dump_stack) from [<8017b8b0>] (spin_dump+0x84/0xcc)
[   82.165775]  r10:00000000 r9:ec936000 r8:81056090 r7:600a0013 r6:edb4899c r5:edb4899c
[   82.173691]  r4:e5033e00 r3:00000000
[   82.177308] [<8017b82c>] (spin_dump) from [<8017bcb0>] (do_raw_spin_unlock+0x108/0x130)
[   82.185314]  r5:edb4899c r4:edb4899c
[   82.188938] [<8017bba8>] (do_raw_spin_unlock) from [<8094b93c>] (_raw_spin_unlock_irqrestore+0x34/0x54)
[   82.198333]  r5:edb4899c r4:600a0013
[   82.201953] [<8094b908>] (_raw_spin_unlock_irqrestore) from [<8065b090>] (rx8010_set_time+0x14c/0x188)
[   82.211261]  r5:00000020 r4:edb48990
[   82.214882] [<8065af44>] (rx8010_set_time) from [<80653fe4>] (rtc_set_time+0x70/0x104)
[   82.222801]  r7:00000051 r6:edb39da0 r5:edb39c00 r4:ec937e8c
[   82.228535] [<80653f74>] (rtc_set_time) from [<80655774>] (rtc_dev_ioctl+0x3c4/0x674)
[   82.236368]  r7:00000051 r6:7ecf1b74 r5:00000000 r4:edb39c00
[   82.242106] [<806553b0>] (rtc_dev_ioctl) from [<80284034>] (do_vfs_ioctl+0xa4/0xa6c)
[   82.249851]  r8:00000003 r7:80284a40 r6:ed1e9c80 r5:edb44e60 r4:7ecf1b74
[   82.256642] [<80283f90>] (do_vfs_ioctl) from [<80284a40>] (SyS_ioctl+0x44/0x6c)
[   82.263953]  r10:00000000 r9:ec936000 r8:7ecf1b74 r7:4024700a r6:ed1e9c80 r5:00000003
[   82.271869]  r4:ed1e9c80
[   82.274432] [<802849fc>] (SyS_ioctl) from [<80108520>] (ret_fast_syscall+0x0/0x1c)
[   82.282005]  r9:ec936000 r8:801086c4 r7:00000036 r6:00000000 r5:00000003 r4:0008e1bc
root@GE004097290448 b850v3:~#
Message from syslogd@GE004097290448 at Dec  3 11:17:08 ...
 kernel:[   82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855

Message from syslogd@GE004097290448 at Dec  3 11:17:08 ...
 kernel:[   82.113660]  lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1
hwclock --systohc
root@GE004097290448 b850v3:~#

Signed-off-by: Fabien Lahoudere <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 15, 2017
As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb3320 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <[email protected]>
Cc: Hannes Sowa <[email protected]>
Signed-off-by: Jon Maxwell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Apr 12, 2017
Commit 57e5568 ("sata_via: Implement hotplug for VT6421") adds
hotplug IRQ handler for VT6421 but enables hotplug on all chips. This
is a bug because it causes "irq xx: nobody cared" error on VT6420 when
hot-(un)plugging a drive:

[  381.839948] irq 20: nobody cared (try booting with the "irqpoll" option)
[  381.840014] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-rc5+ #148
[  381.840066] Hardware name:          P4VM800/P4VM800, BIOS P1.60 05/29/2006
[  381.840117] Call Trace:
[  381.840167]  <IRQ>
[  381.840225]  ? dump_stack+0x44/0x58
[  381.840278]  ? __report_bad_irq+0x14/0x97
[  381.840327]  ? handle_edge_irq+0xa5/0xa5
[  381.840376]  ? note_interrupt+0x155/0x1cf
[  381.840426]  ? handle_edge_irq+0xa5/0xa5
[  381.840474]  ? handle_irq_event_percpu+0x32/0x38
[  381.840524]  ? handle_irq_event+0x1f/0x38
[  381.840573]  ? handle_fasteoi_irq+0x69/0xb8
[  381.840625]  ? handle_irq+0x4f/0x5d
[  381.840672]  </IRQ>
[  381.840726]  ? do_IRQ+0x2e/0x8b
[  381.840782]  ? common_interrupt+0x2c/0x34
[  381.840836]  ? mwait_idle+0x60/0x82
[  381.840892]  ? arch_cpu_idle+0x6/0x7
[  381.840949]  ? do_idle+0x96/0x18e
[  381.841002]  ? cpu_startup_entry+0x16/0x1a
[  381.841057]  ? start_kernel+0x319/0x31c
[  381.841111]  ? startup_32_smp+0x166/0x168
[  381.841165] handlers:
[  381.841219] [<c12a7263>] ata_bmdma_interrupt
[  381.841274] Disabling IRQ #20

Seems that VT6420 can do hotplug too (there's no documentation) but the
comments say that SCR register access (required for detecting hotplug
events) can cause problems on these chips.

For now, just keep hotplug disabled on anything other than VT6421.

Signed-off-by: Ondrej Zary <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
dabrace pushed a commit that referenced this pull request May 16, 2017
cifs_relock_file() can perform a down_write() on the inode's lock_sem even
though it was already performed in cifs_strict_readv().  Lockdep complains
about this.  AFAICS, there is no problem here, and lockdep just needs to be
told that this nesting is OK.

 =============================================
 [ INFO: possible recursive locking detected ]
 4.11.0+ #20 Not tainted
 ---------------------------------------------
 cat/701 is trying to acquire lock:
  (&cifsi->lock_sem){++++.+}, at: cifs_reopen_file+0x7a7/0xc00

 but task is already holding lock:
  (&cifsi->lock_sem){++++.+}, at: cifs_strict_readv+0x177/0x310

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&cifsi->lock_sem);
   lock(&cifsi->lock_sem);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 1 lock held by cat/701:
  #0:  (&cifsi->lock_sem){++++.+}, at: cifs_strict_readv+0x177/0x310

 stack backtrace:
 CPU: 0 PID: 701 Comm: cat Not tainted 4.11.0+ #20
 Call Trace:
  dump_stack+0x85/0xc2
  __lock_acquire+0x17dd/0x2260
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  ? preempt_schedule_irq+0x6b/0x80
  lock_acquire+0xcc/0x260
  ? lock_acquire+0xcc/0x260
  ? cifs_reopen_file+0x7a7/0xc00
  down_read+0x2d/0x70
  ? cifs_reopen_file+0x7a7/0xc00
  cifs_reopen_file+0x7a7/0xc00
  ? printk+0x43/0x4b
  cifs_readpage_worker+0x327/0x8a0
  cifs_readpage+0x8c/0x2a0
  generic_file_read_iter+0x692/0xd00
  cifs_strict_readv+0x29f/0x310
  generic_file_splice_read+0x11c/0x1c0
  do_splice_to+0xa5/0xc0
  splice_direct_to_actor+0xfa/0x350
  ? generic_pipe_buf_nosteal+0x10/0x10
  do_splice_direct+0xb5/0xe0
  do_sendfile+0x278/0x3a0
  SyS_sendfile64+0xc4/0xe0
  entry_SYSCALL_64_fastpath+0x1f/0xbe

Signed-off-by: Rabin Vincent <[email protected]>
Acked-by: Pavel Shilovsky <[email protected]>
Signed-off-by: Steve French <[email protected]>
dabrace pushed a commit that referenced this pull request Jun 12, 2017
This prevents a deadlock that somehow results from the suspend() ->
forbid() -> resume() callchain.

[  125.266960] [drm] Initialized nouveau 1.3.1 20120801 for 0000:02:00.0 on minor 1
[  370.120872] INFO: task kworker/4:1:77 blocked for more than 120 seconds.
[  370.120920]       Tainted: G           O    4.12.0-rc3 #20
[  370.120947] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  370.120982] kworker/4:1     D13808    77      2 0x00000000
[  370.120998] Workqueue: pm pm_runtime_work
[  370.121004] Call Trace:
[  370.121018]  __schedule+0x2bf/0xb40
[  370.121025]  ? mark_held_locks+0x5f/0x90
[  370.121038]  schedule+0x3d/0x90
[  370.121044]  rpm_resume+0x107/0x870
[  370.121052]  ? finish_wait+0x90/0x90
[  370.121065]  ? pci_pm_runtime_resume+0xa0/0xa0
[  370.121070]  pm_runtime_forbid+0x4c/0x60
[  370.121129]  nouveau_pmops_runtime_suspend+0xaf/0xc0 [nouveau]
[  370.121139]  pci_pm_runtime_suspend+0x5f/0x170
[  370.121147]  ? pci_pm_runtime_resume+0xa0/0xa0
[  370.121152]  __rpm_callback+0xb9/0x1e0
[  370.121159]  ? pci_pm_runtime_resume+0xa0/0xa0
[  370.121166]  rpm_callback+0x24/0x80
[  370.121171]  ? pci_pm_runtime_resume+0xa0/0xa0
[  370.121176]  rpm_suspend+0x138/0x6e0
[  370.121192]  pm_runtime_work+0x7b/0xc0
[  370.121199]  process_one_work+0x253/0x6a0
[  370.121216]  worker_thread+0x4d/0x3b0
[  370.121229]  kthread+0x133/0x150
[  370.121234]  ? process_one_work+0x6a0/0x6a0
[  370.121238]  ? kthread_create_on_node+0x70/0x70
[  370.121246]  ret_from_fork+0x2a/0x40
[  370.121283]
               Showing all locks held in the system:
[  370.121291] 2 locks held by kworker/4:1/77:
[  370.121298]  #0:  ("pm"){.+.+.+}, at: [<ffffffffac0d3530>] process_one_work+0x1d0/0x6a0
[  370.121315]  #1:  ((&dev->power.work)){+.+.+.}, at: [<ffffffffac0d3530>] process_one_work+0x1d0/0x6a0
[  370.121330] 1 lock held by khungtaskd/81:
[  370.121333]  #0:  (tasklist_lock){.+.+..}, at: [<ffffffffac10fc8d>] debug_show_all_locks+0x3d/0x1a0
[  370.121355] 1 lock held by dmesg/1639:
[  370.121358]  #0:  (&user->lock){+.+.+.}, at: [<ffffffffac124b6d>] devkmsg_read+0x4d/0x360

[  370.121377] =============================================

Signed-off-by: Ben Skeggs <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 14, 2017
This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0
regression, that was introduced by

  commit 01d4d67
  Author: Nicholas Bellinger <[email protected]>
  Date:   Wed Dec 7 12:55:54 2016 -0800

which originally had the proper list_del_init() usage, but was
dropped during list review as it was thought unnecessary by HCH.

However, list_del_init() usage is required during the special
generate_node_acls = 1 + cache_dynamic_acls = 0 case when
transport_free_session() does a list_del(&se_nacl->acl_list),
followed by target_complete_nacl() doing the same thing.

This was manifesting as a general protection fault as reported
by Justin:

kernel: general protection fault: 0000 [#1] SMP
kernel: Modules linked in:
kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20
kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014
kernel: task: ffff88026939e800 task.stack: ffffc90007884000
kernel: RIP: 0010:target_put_nacl+0x49/0xb0
kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246
kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000
kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028
kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000
kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020
kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540
kernel: FS:  0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: Call Trace:
kernel:  transport_free_session+0x67/0x140
kernel:  transport_deregister_session+0x7a/0xc0
kernel:  iscsit_close_session+0x92/0x210
kernel:  iscsit_close_connection+0x5f9/0x840
kernel:  iscsit_take_action_for_connection_exit+0xfe/0x110
kernel:  iscsi_target_tx_thread+0x140/0x1e0
kernel:  ? wait_woken+0x90/0x90
kernel:  kthread+0x124/0x160
kernel:  ? iscsit_thread_get_cpumask+0x90/0x90
kernel:  ? kthread_create_on_node+0x40/0x40
kernel:  ret_from_fork+0x22/0x30
kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c
89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89
ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20
kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70
kernel: ---[ end trace f12821adbfd46fed ]---

To address this, go ahead and use proper list_del_list() for all
cases of se_nacl->acl_list deletion.

Reported-by: Justin Maggard <[email protected]>
Tested-by: Justin Maggard <[email protected]>
Cc: Justin Maggard <[email protected]>
Cc: [email protected] # 4.1+
Signed-off-by: Nicholas Bellinger <[email protected]>
dabrace pushed a commit that referenced this pull request Sep 5, 2017
syzkaller reported a refcount_t warning [1]

Issue here is that noop_qdisc refcnt was never really considered as
a true refcount, since qdisc_destroy() found TCQ_F_BUILTIN set :

if (qdisc->flags & TCQ_F_BUILTIN ||
    !refcount_dec_and_test(&qdisc->refcnt)))
	return;

Meaning that all atomic_inc() we did on noop_qdisc.refcnt were not
really needed, but harmless until refcount_t came.

To fix this problem, we simply need to not increment noop_qdisc.refcnt,
since we never decrement it.

[1]
refcount_t: increment on 0; use-after-free.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 21754 at lib/refcount.c:152 refcount_inc+0x47/0x50 lib/refcount.c:152
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 21754 Comm: syz-executor7 Not tainted 4.13.0-rc6+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x417 kernel/panic.c:180
 __warn+0x1c4/0x1d9 kernel/panic.c:541
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190
 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:273
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323
 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:846
RIP: 0010:refcount_inc+0x47/0x50 lib/refcount.c:152
RSP: 0018:ffff8801c43477a0 EFLAGS: 00010282
RAX: 000000000000002b RBX: ffffffff86093c14 RCX: 0000000000000000
RDX: 000000000000002b RSI: ffffffff8159314e RDI: ffffed0038868ee8
RBP: ffff8801c43477a8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff86093ac0
R13: 0000000000000001 R14: ffff8801d0f3bac0 R15: dffffc0000000000
 attach_default_qdiscs net/sched/sch_generic.c:792 [inline]
 dev_activate+0x7d3/0xaa0 net/sched/sch_generic.c:833
 __dev_open+0x227/0x330 net/core/dev.c:1380
 __dev_change_flags+0x695/0x990 net/core/dev.c:6726
 dev_change_flags+0x88/0x140 net/core/dev.c:6792
 dev_ifsioc+0x5a6/0x930 net/core/dev_ioctl.c:256
 dev_ioctl+0x2bc/0xf90 net/core/dev_ioctl.c:554
 sock_do_ioctl+0x94/0xb0 net/socket.c:968
 sock_ioctl+0x2c2/0x440 net/socket.c:1058
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691

Fixes: 7b93640 ("net, sched: convert Qdisc.refcnt from atomic_t to refcount_t")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: Dmitry Vyukov <[email protected]>
Cc: Reshetova, Elena <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 9, 2017
…-text symbols"

This reverts commit 83e840c ("powerpc64/elfv1: Only dereference
function descriptor for non-text symbols").

Chandan reported that on newer kernels, trying to enable function_graph
tracer on ppc64 (BE) locks up the system with the following trace:

  Unable to handle kernel paging request for data at address 0x600000002fa30010
  Faulting instruction address: 0xc0000000001f1300
  Thread overran stack, or stack corrupted
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE SMP NR_CPUS=2048 DEBUG_PAGEALLOC NUMA pSeries
  Modules linked in:
  CPU: 1 PID: 6586 Comm: bash Not tainted 4.14.0-rc3-00162-g6e51f1f-dirty #20
  task: c000000625c07200 task.stack: c000000625c07310
  NIP:  c0000000001f1300 LR: c000000000121cac CTR: c000000000061af8
  REGS: c000000625c088c0 TRAP: 0380   Not tainted  (4.14.0-rc3-00162-g6e51f1f-dirty)
  MSR:  8000000000001032 <SF,ME,IR,DR,RI>  CR: 28002848  XER: 00000000
  CFAR: c0000000001f1320 SOFTE: 0
  ...
  NIP [c0000000001f1300] .__is_insn_slot_addr+0x30/0x90
  LR [c000000000121cac] .kernel_text_address+0x18c/0x1c0
  Call Trace:
  [c000000625c08b40] [c0000000001bd040] .is_module_text_address+0x20/0x40 (unreliable)
  [c000000625c08bc0] [c000000000121cac] .kernel_text_address+0x18c/0x1c0
  [c000000625c08c50] [c000000000061960] .prepare_ftrace_return+0x50/0x130
  [c000000625c08cf0] [c000000000061b10] .ftrace_graph_caller+0x14/0x34
  [c000000625c08d60] [c000000000121b40] .kernel_text_address+0x20/0x1c0
  [c000000625c08df0] [c000000000061960] .prepare_ftrace_return+0x50/0x130
  ...
  [c000000625c0ab30] [c000000000061960] .prepare_ftrace_return+0x50/0x130
  [c000000625c0abd0] [c000000000061b10] .ftrace_graph_caller+0x14/0x34
  [c000000625c0ac40] [c000000000121b40] .kernel_text_address+0x20/0x1c0
  [c000000625c0acd0] [c000000000061960] .prepare_ftrace_return+0x50/0x130
  [c000000625c0ad70] [c000000000061b10] .ftrace_graph_caller+0x14/0x34
  [c000000625c0ade0] [c000000000121b40] .kernel_text_address+0x20/0x1c0

This is because ftrace is using ppc_function_entry() for obtaining the
address of return_to_handler() in prepare_ftrace_return(). The call to
kernel_text_address() itself gets traced and we end up in a recursive
loop.

Fixes: 83e840c ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols")
Cc: [email protected] # v4.13+
Reported-by: Chandan Rajendra <[email protected]>
Signed-off-by: Naveen N. Rao <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 13, 2017
When a GSO skb of truesize O is segmented into 2 new skbs of truesize N1
and N2, we want to transfer socket ownership to the new fresh skbs.

In order to avoid expensive atomic operations on a cache line subject to
cache bouncing, we replace the sequence :

refcount_add(N1, &sk->sk_wmem_alloc);
refcount_add(N2, &sk->sk_wmem_alloc); // repeated by number of segments

refcount_sub(O, &sk->sk_wmem_alloc);

by a single

refcount_add(sum_of(N) - O, &sk->sk_wmem_alloc);

Problem is :

In some pathological cases, sum(N) - O might be a negative number, and
syzkaller bot was apparently able to trigger this trace [1]

atomic_t was ok with this construct, but we need to take care of the
negative delta with refcount_t

[1]
refcount_t: saturated; leaking memory.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8404 at lib/refcount.c:77 refcount_add_not_zero+0x198/0x200 lib/refcount.c:77
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 8404 Comm: syz-executor2 Not tainted 4.14.0-rc5-mm1+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1c4/0x1e0 kernel/panic.c:546
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:177
 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:260
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:refcount_add_not_zero+0x198/0x200 lib/refcount.c:77
RSP: 0018:ffff8801c606e3a0 EFLAGS: 00010282
RAX: 0000000000000026 RBX: 0000000000001401 RCX: 0000000000000000
RDX: 0000000000000026 RSI: ffffc900036fc000 RDI: ffffed0038c0dc68
RBP: ffff8801c606e430 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801d97f5eba R11: 0000000000000000 R12: ffff8801d5acf73c
R13: 1ffff10038c0dc75 R14: 00000000ffffffff R15: 00000000fffff72f
 refcount_add+0x1b/0x60 lib/refcount.c:101
 tcp_gso_segment+0x10d0/0x16b0 net/ipv4/tcp_offload.c:155
 tcp4_gso_segment+0xd4/0x310 net/ipv4/tcp_offload.c:51
 inet_gso_segment+0x60c/0x11c0 net/ipv4/af_inet.c:1271
 skb_mac_gso_segment+0x33f/0x660 net/core/dev.c:2749
 __skb_gso_segment+0x35f/0x7f0 net/core/dev.c:2821
 skb_gso_segment include/linux/netdevice.h:3971 [inline]
 validate_xmit_skb+0x4ba/0xb20 net/core/dev.c:3074
 __dev_queue_xmit+0xe49/0x2070 net/core/dev.c:3497
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3538
 neigh_hh_output include/net/neighbour.h:471 [inline]
 neigh_output include/net/neighbour.h:479 [inline]
 ip_finish_output2+0xece/0x1460 net/ipv4/ip_output.c:229
 ip_finish_output+0x85e/0xd10 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:238 [inline]
 ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:459 [inline]
 ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x8c6/0x18e0 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x1ab7/0x3840 net/ipv4/tcp_output.c:1137
 tcp_write_xmit+0x663/0x4de0 net/ipv4/tcp_output.c:2341
 __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2513
 tcp_push_pending_frames include/net/tcp.h:1722 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5050 [inline]
 tcp_rcv_established+0x8c7/0x18a0 net/ipv4/tcp_input.c:5497
 tcp_v4_do_rcv+0x2ab/0x7d0 net/ipv4/tcp_ipv4.c:1460
 sk_backlog_rcv include/net/sock.h:909 [inline]
 __release_sock+0x124/0x360 net/core/sock.c:2264
 release_sock+0xa4/0x2a0 net/core/sock.c:2776
 tcp_sendmsg+0x3a/0x50 net/ipv4/tcp.c:1462
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763
 sock_sendmsg_nosec net/socket.c:632 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:642
 ___sys_sendmsg+0x31c/0x890 net/socket.c:2048
 __sys_sendmmsg+0x1e6/0x5f0 net/socket.c:2138

Fixes: 14afee4 ("net: convert sock.sk_wmem_alloc from atomic_t to refcount_t")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Apr 5, 2018
when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
dabrace pushed a commit that referenced this pull request May 21, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
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+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Jiri Benc <[email protected]>
Reported-by: syzbot <[email protected]>
Acked-by: Jiri Benc <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
dabrace pushed a commit that referenced this pull request Jul 24, 2018
Crash dump shows following instructions

crash> bt
PID: 0      TASK: ffffffffbe412480  CPU: 0   COMMAND: "swapper/0"
 #0 [ffff891ee0003868] machine_kexec at ffffffffbd063ef1
 #1 [ffff891ee00038c8] __crash_kexec at ffffffffbd12b6f2
 #2 [ffff891ee0003998] crash_kexec at ffffffffbd12c84c
 #3 [ffff891ee00039b8] oops_end at ffffffffbd030f0a
 #4 [ffff891ee00039e0] no_context at ffffffffbd074643
 #5 [ffff891ee0003a40] __bad_area_nosemaphore at ffffffffbd07496e
 #6 [ffff891ee0003a90] bad_area_nosemaphore at ffffffffbd074a64
 #7 [ffff891ee0003aa0] __do_page_fault at ffffffffbd074b0a
 #8 [ffff891ee0003b18] do_page_fault at ffffffffbd074fc8
 #9 [ffff891ee0003b50] page_fault at ffffffffbda01925
    [exception RIP: qlt_schedule_sess_for_deletion+15]
    RIP: ffffffffc02e526f  RSP: ffff891ee0003c08  RFLAGS: 00010046
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: ffffffffc0307847
    RDX: 00000000000020e6  RSI: ffff891edbc377c8  RDI: 0000000000000000
    RBP: ffff891ee0003c18   R8: ffffffffc02f0b20   R9: 0000000000000250
    R10: 0000000000000258  R11: 000000000000b780  R12: ffff891ed9b43000
    R13: 00000000000000f0  R14: 0000000000000006  R15: ffff891edbc377c8
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #10 [ffff891ee0003c20] qla2x00_fcport_event_handler at ffffffffc02853d3 [qla2xxx]
 #11 [ffff891ee0003cf0] __dta_qla24xx_async_gnl_sp_done_333 at ffffffffc0285a1d [qla2xxx]
 #12 [ffff891ee0003de8] qla24xx_process_response_queue at ffffffffc02a2eb5 [qla2xxx]
 #13 [ffff891ee0003e88] qla24xx_msix_rsp_q at ffffffffc02a5403 [qla2xxx]
 #14 [ffff891ee0003ec0] __handle_irq_event_percpu at ffffffffbd0f4c59
 #15 [ffff891ee0003f10] handle_irq_event_percpu at ffffffffbd0f4e02
 #16 [ffff891ee0003f40] handle_irq_event at ffffffffbd0f4e90
 #17 [ffff891ee0003f68] handle_edge_irq at ffffffffbd0f8984
 #18 [ffff891ee0003f88] handle_irq at ffffffffbd0305d5
 #19 [ffff891ee0003fb8] do_IRQ at ffffffffbda02a18
 --- <IRQ stack> ---
 #20 [ffffffffbe403d30] ret_from_intr at ffffffffbda0094e
    [exception RIP: unknown or invalid address]
    RIP: 000000000000001f  RSP: 0000000000000000  RFLAGS: fff3b8c2091ebb3f
    RAX: ffffbba5a0000200  RBX: 0000be8cdfa8f9fa  RCX: 0000000000000018
    RDX: 0000000000000101  RSI: 000000000000015d  RDI: 0000000000000193
    RBP: 0000000000000083   R8: ffffffffbe403e38   R9: 0000000000000002
    R10: 0000000000000000  R11: ffffffffbe56b820  R12: ffff891ee001cf00
    R13: ffffffffbd11c0a4  R14: ffffffffbe403d60  R15: 0000000000000001
    ORIG_RAX: ffff891ee0022ac0  CS: 0000  SS: ffffffffffffffb9
 bt: WARNING: possibly bogus exception frame
 #21 [ffffffffbe403dd8] cpuidle_enter_state at ffffffffbd67c6fd
 #22 [ffffffffbe403e40] cpuidle_enter at ffffffffbd67c907
 #23 [ffffffffbe403e50] call_cpuidle at ffffffffbd0d98f3
 #24 [ffffffffbe403e60] do_idle at ffffffffbd0d9b42
 #25 [ffffffffbe403e98] cpu_startup_entry at ffffffffbd0d9da3
 #26 [ffffffffbe403ec0] rest_init at ffffffffbd81d4aa
 #27 [ffffffffbe403ed0] start_kernel at ffffffffbe67d2ca
 #28 [ffffffffbe403f28] x86_64_start_reservations at ffffffffbe67c675
 #29 [ffffffffbe403f38] x86_64_start_kernel at ffffffffbe67c6eb
 #30 [ffffffffbe403f50] secondary_startup_64 at ffffffffbd0000d5

Fixes: 040036b ("scsi: qla2xxx: Delay loop id allocation at login")
Cc: <[email protected]> # v4.17+
Signed-off-by: Chuck Anderson <[email protected]>
Signed-off-by: Himanshu Madhani <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 7, 2018
When IDLETIMER rule is added, sysfs file is created under
/sys/class/xt_idletimer/timers/
But some label name shouldn't be used.
".", "..", "power", "uevent", "subsystem", etc...
So that sysfs filename checking routine is needed.

test commands:
   %iptables -I INPUT -j IDLETIMER --timeout 1 --label "power"

splat looks like:
[95765.423132] sysfs: cannot create duplicate filename '/devices/virtual/xt_idletimer/timers/power'
[95765.433418] CPU: 0 PID: 8446 Comm: iptables Not tainted 4.19.0-rc6+ #20
[95765.449755] Call Trace:
[95765.449755]  dump_stack+0xc9/0x16b
[95765.449755]  ? show_regs_print_info+0x5/0x5
[95765.449755]  sysfs_warn_dup+0x74/0x90
[95765.449755]  sysfs_add_file_mode_ns+0x352/0x500
[95765.449755]  sysfs_create_file_ns+0x179/0x270
[95765.449755]  ? sysfs_add_file_mode_ns+0x500/0x500
[95765.449755]  ? idletimer_tg_checkentry+0x3e5/0xb1b [xt_IDLETIMER]
[95765.449755]  ? rcu_read_lock_sched_held+0x114/0x130
[95765.449755]  ? __kmalloc_track_caller+0x211/0x2b0
[95765.449755]  ? memcpy+0x34/0x50
[95765.449755]  idletimer_tg_checkentry+0x4e2/0xb1b [xt_IDLETIMER]
[ ... ]

Fixes: 0902b46 ("netfilter: xtables: idletimer target implementation")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 12, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 #4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 #5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 #6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 #7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 #8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 #9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 #10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 #11 [9a069e78]  200 bytes  insert_work at 23fc2e
 #12 [9a069f40]  648 bytes  __queue_work at 2487c0
 #13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 #14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 #15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 #16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 #17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 #18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 #19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 #20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 #21 [9a06acf8]  320 bytes  schedule at 219e476
 #22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 #23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 #24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 #25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 #26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 #27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 #28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 #29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 #30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 #31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 #32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 #33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 #34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 #35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 #36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 #37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 #38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 #39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 #40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 #41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 #42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 #43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 #44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 #45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 #46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 #47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 #48 [9a06f388]  536 bytes  wb_workfn at a28228
 #49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 #50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 #51 [9a06fe40]  104 bytes  kthread at 26545a
 #52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
dabrace pushed a commit that referenced this pull request Dec 3, 2018
Currently on driver bringup with KASAN enabled, meson triggers an OOB
memory access as shown below:

[  117.904528] ==================================================================
[  117.904560] BUG: KASAN: global-out-of-bounds in meson_viu_set_osd_lut+0x7a0/0x890
[  117.904588] Read of size 4 at addr ffff20000a63ce24 by task systemd-udevd/498
[  117.904601]
[  118.083372] CPU: 4 PID: 498 Comm: systemd-udevd Not tainted 4.20.0-rc3Lyude-Test+ #20
[  118.091143] Hardware name: amlogic khadas-vim2/khadas-vim2, BIOS 2018.07-rc2-armbian 09/11/2018
[  118.099768] Call trace:
[  118.102181]  dump_backtrace+0x0/0x3e8
[  118.105796]  show_stack+0x14/0x20
[  118.109083]  dump_stack+0x130/0x1c4
[  118.112539]  print_address_description+0x60/0x25c
[  118.117214]  kasan_report+0x1b4/0x368
[  118.120851]  __asan_report_load4_noabort+0x18/0x20
[  118.125566]  meson_viu_set_osd_lut+0x7a0/0x890
[  118.129953]  meson_viu_init+0x10c/0x290
[  118.133741]  meson_drv_bind_master+0x474/0x748
[  118.138141]  meson_drv_bind+0x10/0x18
[  118.141760]  try_to_bring_up_master+0x3d8/0x768
[  118.146249]  component_add+0x214/0x570
[  118.149978]  meson_dw_hdmi_probe+0x18/0x20 [meson_dw_hdmi]
[  118.155404]  platform_drv_probe+0x98/0x138
[  118.159455]  really_probe+0x2a0/0xa70
[  118.163070]  driver_probe_device+0x1b4/0x2d8
[  118.167299]  __driver_attach+0x200/0x280
[  118.171189]  bus_for_each_dev+0x10c/0x1a8
[  118.175144]  driver_attach+0x38/0x50
[  118.178681]  bus_add_driver+0x330/0x608
[  118.182471]  driver_register+0x140/0x388
[  118.186361]  __platform_driver_register+0xc8/0x108
[  118.191117]  meson_dw_hdmi_platform_driver_init+0x1c/0x1000 [meson_dw_hdmi]
[  118.198022]  do_one_initcall+0x12c/0x3bc
[  118.201883]  do_init_module+0x1fc/0x638
[  118.205673]  load_module+0x4b4c/0x6808
[  118.209387]  __se_sys_init_module+0x2e8/0x3c0
[  118.213699]  __arm64_sys_init_module+0x68/0x98
[  118.218100]  el0_svc_common+0x104/0x210
[  118.221893]  el0_svc_handler+0x48/0xb8
[  118.225594]  el0_svc+0x8/0xc
[  118.228429]
[  118.229887] The buggy address belongs to the variable:
[  118.235007]  eotf_33_linear_mapping+0x84/0xc0
[  118.239301]
[  118.240752] Memory state around the buggy address:
[  118.245522]  ffff20000a63cd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  118.252695]  ffff20000a63cd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  118.259850] >ffff20000a63ce00: 00 00 00 00 04 fa fa fa fa fa fa fa 00 00 00 00
[  118.267000]                                ^
[  118.271222]  ffff20000a63ce80: 00 fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00
[  118.278393]  ffff20000a63cf00: 00 00 00 00 00 00 00 00 00 00 00 00 04 fa fa fa
[  118.285542] ==================================================================
[  118.292699] Disabling lock debugging due to kernel taint

It seems that when looping through the OSD EOTF LUT maps, we use the
same max iterator for OETF: 20. This is wrong though, since 20*2 is 40,
which means that we'll stop out of bounds on the EOTF maps.

But, this whole thing is already confusing enough to read through as-is,
so let's just replace all of the hardcoded sizes with
OSD_(OETF/EOTF)_LUT_SIZE / 2.

Signed-off-by: Lyude Paul <[email protected]>
Fixes: bbbe775 ("drm: Add support for Amlogic Meson Graphic Controller")
Cc: Neil Armstrong <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Carlo Caione <[email protected]>
Cc: Kevin Hilman <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: <[email protected]> # v4.10+
Acked-by: Neil Armstrong <[email protected]>
Signed-off-by: Neil Armstrong <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Sean Paul <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 25, 2019
…r-free issue

The evlist should be destroyed before the perf session.

Detected with gcc's ASan:

  =================================================================
  ==27350==ERROR: AddressSanitizer: heap-use-after-free on address 0x62b000002e38 at pc 0x5611da276999 bp 0x7ffce8f1d1a0 sp 0x7ffce8f1d190
  WRITE of size 8 at 0x62b000002e38 thread T0
      #0 0x5611da276998 in __list_del /home/work/linux/tools/include/linux/list.h:89
      #1 0x5611da276d4a in __list_del_entry /home/work/linux/tools/include/linux/list.h:102
      #2 0x5611da276e77 in list_del_init /home/work/linux/tools/include/linux/list.h:145
      #3 0x5611da2781cd in thread__put util/thread.c:130
      #4 0x5611da2cc0a8 in __thread__zput util/thread.h:68
      #5 0x5611da2d2dcb in hist_entry__delete util/hist.c:1148
      #6 0x5611da2cdf91 in hists__delete_entry util/hist.c:337
      #7 0x5611da2ce19e in hists__delete_entries util/hist.c:365
      #8 0x5611da2db2ab in hists__delete_all_entries util/hist.c:2639
      #9 0x5611da2db325 in hists_evsel__exit util/hist.c:2651
      #10 0x5611da1c5352 in perf_evsel__exit util/evsel.c:1304
      #11 0x5611da1c5390 in perf_evsel__delete util/evsel.c:1309
      #12 0x5611da1b35f0 in perf_evlist__purge util/evlist.c:124
      #13 0x5611da1b38e2 in perf_evlist__delete util/evlist.c:148
      #14 0x5611da069781 in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1645
      #15 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #16 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #17 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #18 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #19 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)
      #20 0x5611d9ff35c9 in _start (/home/work/linux/tools/perf/perf+0x3e95c9)

  0x62b000002e38 is located 11320 bytes inside of 27448-byte region [0x62b000000200,0x62b000006d38)
  freed by thread T0 here:
      #0 0x7fdccb04ab70 in free (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedb70)
      #1 0x5611da260df4 in perf_session__delete util/session.c:201
      #2 0x5611da063de5 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1300
      #3 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      #4 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #5 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #6 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #7 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #8 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  previously allocated by thread T0 here:
      #0 0x7fdccb04b138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5611da26010c in zalloc util/util.h:23
      #2 0x5611da260824 in perf_session__new util/session.c:118
      #3 0x5611da0633a6 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1192
      #4 0x5611da06973c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      #5 0x5611da17d038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #6 0x5611da17d577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #7 0x5611da17d97b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #8 0x5611da17e0e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #9 0x7fdcc970f09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  SUMMARY: AddressSanitizer: heap-use-after-free /home/work/linux/tools/include/linux/list.h:89 in __list_del
  Shadow bytes around the buggy address:
    0x0c567fff8570: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8580: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8590: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85a0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85b0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  =>0x0c567fff85c0: fd fd fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd
    0x0c567fff85d0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85e0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff85f0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8600: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
    0x0c567fff8610: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  ==27350==ABORTING

Signed-off-by: Changbin Du <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
dabrace pushed a commit that referenced this pull request Jul 8, 2019
Current snapshot implementation swaps two ring_buffers even though their
sizes are different from each other, that can cause an inconsistency
between the contents of buffer_size_kb file and the current buffer size.

For example:

  # cat buffer_size_kb
  7 (expanded: 1408)
  # echo 1 > events/enable
  # grep bytes per_cpu/cpu0/stats
  bytes: 1441020
  # echo 1 > snapshot             // current:1408, spare:1408
  # echo 123 > buffer_size_kb     // current:123,  spare:1408
  # echo 1 > snapshot             // current:1408, spare:123
  # grep bytes per_cpu/cpu0/stats
  bytes: 1443700
  # cat buffer_size_kb
  123                             // != current:1408

And also, a similar per-cpu case hits the following WARNING:

Reproducer:

  # echo 1 > per_cpu/cpu0/snapshot
  # echo 123 > buffer_size_kb
  # echo 1 > per_cpu/cpu0/snapshot

WARNING:

  WARNING: CPU: 0 PID: 1946 at kernel/trace/trace.c:1607 update_max_tr_single.part.0+0x2b8/0x380
  Modules linked in:
  CPU: 0 PID: 1946 Comm: bash Not tainted 5.2.0-rc6 #20
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
  RIP: 0010:update_max_tr_single.part.0+0x2b8/0x380
  Code: ff e8 dc da f9 ff 0f 0b e9 88 fe ff ff e8 d0 da f9 ff 44 89 ee bf f5 ff ff ff e8 33 dc f9 ff 41 83 fd f5 74 96 e8 b8 da f9 ff <0f> 0b eb 8d e8 af da f9 ff 0f 0b e9 bf fd ff ff e8 a3 da f9 ff 48
  RSP: 0018:ffff888063e4fca0 EFLAGS: 00010093
  RAX: ffff888066214380 RBX: ffffffff99850fe0 RCX: ffffffff964298a8
  RDX: 0000000000000000 RSI: 00000000fffffff5 RDI: 0000000000000005
  RBP: 1ffff1100c7c9f96 R08: ffff888066214380 R09: ffffed100c7c9f9b
  R10: ffffed100c7c9f9a R11: 0000000000000003 R12: 0000000000000000
  R13: 00000000ffffffea R14: ffff888066214380 R15: ffffffff99851060
  FS:  00007f9f8173c700(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000714dc0 CR3: 0000000066fa6000 CR4: 00000000000006f0
  Call Trace:
   ? trace_array_printk_buf+0x140/0x140
   ? __mutex_lock_slowpath+0x10/0x10
   tracing_snapshot_write+0x4c8/0x7f0
   ? trace_printk_init_buffers+0x60/0x60
   ? selinux_file_permission+0x3b/0x540
   ? tracer_preempt_off+0x38/0x506
   ? trace_printk_init_buffers+0x60/0x60
   __vfs_write+0x81/0x100
   vfs_write+0x1e1/0x560
   ksys_write+0x126/0x250
   ? __ia32_sys_read+0xb0/0xb0
   ? do_syscall_64+0x1f/0x390
   do_syscall_64+0xc1/0x390
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

This patch adds resize_buffer_duplicate_size() to check if there is a
difference between current/spare buffer sizes and resize a spare buffer
if necessary.

Link: http://lkml.kernel.org/r/[email protected]

Cc: [email protected]
Fixes: ad909e2 ("tracing: Add internal tracing_snapshot() functions")
Signed-off-by: Eiichi Tsukata <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 5, 2019
Make debug exceptions visible from RCU so that synchronize_rcu()
correctly track the debug exception handler.

This also introduces sanity checks for user-mode exceptions as same
as x86's ist_enter()/ist_exit().

The debug exception can interrupt in idle task. For example, it warns
if we put a kprobe on a function called from idle task as below.
The warning message showed that the rcu_read_lock() caused this
problem. But actually, this means the RCU is lost the context which
is already in NMI/IRQ.

  /sys/kernel/debug/tracing # echo p default_idle_call >> kprobe_events
  /sys/kernel/debug/tracing # echo 1 > events/kprobes/enable
  /sys/kernel/debug/tracing # [  135.122237]
  [  135.125035] =============================
  [  135.125310] WARNING: suspicious RCU usage
  [  135.125581] 5.2.0-08445-g9187c508bdc7 #20 Not tainted
  [  135.125904] -----------------------------
  [  135.126205] include/linux/rcupdate.h:594 rcu_read_lock() used illegally while idle!
  [  135.126839]
  [  135.126839] other info that might help us debug this:
  [  135.126839]
  [  135.127410]
  [  135.127410] RCU used illegally from idle CPU!
  [  135.127410] rcu_scheduler_active = 2, debug_locks = 1
  [  135.128114] RCU used illegally from extended quiescent state!
  [  135.128555] 1 lock held by swapper/0/0:
  [  135.128944]  #0: (____ptrval____) (rcu_read_lock){....}, at: call_break_hook+0x0/0x178
  [  135.130499]
  [  135.130499] stack backtrace:
  [  135.131192] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-08445-g9187c508bdc7 #20
  [  135.131841] Hardware name: linux,dummy-virt (DT)
  [  135.132224] Call trace:
  [  135.132491]  dump_backtrace+0x0/0x140
  [  135.132806]  show_stack+0x24/0x30
  [  135.133133]  dump_stack+0xc4/0x10c
  [  135.133726]  lockdep_rcu_suspicious+0xf8/0x108
  [  135.134171]  call_break_hook+0x170/0x178
  [  135.134486]  brk_handler+0x28/0x68
  [  135.134792]  do_debug_exception+0x90/0x150
  [  135.135051]  el1_dbg+0x18/0x8c
  [  135.135260]  default_idle_call+0x0/0x44
  [  135.135516]  cpu_startup_entry+0x2c/0x30
  [  135.135815]  rest_init+0x1b0/0x280
  [  135.136044]  arch_call_rest_init+0x14/0x1c
  [  135.136305]  start_kernel+0x4d4/0x500
  [  135.136597]

So make debug exception visible to RCU can fix this warning.

Reported-by: Naresh Kamboju <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 9, 2019
A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <[email protected]>
Cc: [email protected]
Signed-off-by: Jens Axboe <[email protected]>
dabrace pushed a commit that referenced this pull request Aug 14, 2020
This patch is to fix a crash:

 #3 [ffffb6580689f898] oops_end at ffffffffa2835bc2
 #4 [ffffb6580689f8b8] no_context at ffffffffa28766e7
 #5 [ffffb6580689f920] async_page_fault at ffffffffa320135e
    [exception RIP: f2fs_is_compressed_page+34]
    RIP: ffffffffa2ba83a2  RSP: ffffb6580689f9d8  RFLAGS: 00010213
    RAX: 0000000000000001  RBX: fffffc0f50b34bc0  RCX: 0000000000002122
    RDX: 0000000000002123  RSI: 0000000000000c00  RDI: fffffc0f50b34bc0
    RBP: ffff97e815a40178   R8: 0000000000000000   R9: ffff97e83ffc9000
    R10: 0000000000032300  R11: 0000000000032380  R12: ffffb6580689fa38
    R13: fffffc0f50b34bc0  R14: ffff97e825cbd000  R15: 0000000000000c00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #6 [ffffb6580689f9d8] __is_cp_guaranteed at ffffffffa2b7ea98
 #7 [ffffb6580689f9f0] f2fs_submit_page_write at ffffffffa2b81a69
 #8 [ffffb6580689fa30] f2fs_do_write_meta_page at ffffffffa2b99777
 #9 [ffffb6580689fae0] __f2fs_write_meta_page at ffffffffa2b75f1a
 #10 [ffffb6580689fb18] f2fs_sync_meta_pages at ffffffffa2b77466
 #11 [ffffb6580689fc98] do_checkpoint at ffffffffa2b78e46
 #12 [ffffb6580689fd88] f2fs_write_checkpoint at ffffffffa2b79c29
 #13 [ffffb6580689fdd0] f2fs_sync_fs at ffffffffa2b69d95
 #14 [ffffb6580689fe20] sync_filesystem at ffffffffa2ad2574
 #15 [ffffb6580689fe30] generic_shutdown_super at ffffffffa2a9b582
 #16 [ffffb6580689fe48] kill_block_super at ffffffffa2a9b6d1
 #17 [ffffb6580689fe60] kill_f2fs_super at ffffffffa2b6abe1
 #18 [ffffb6580689fea0] deactivate_locked_super at ffffffffa2a9afb6
 #19 [ffffb6580689feb8] cleanup_mnt at ffffffffa2abcad4
 #20 [ffffb6580689fee0] task_work_run at ffffffffa28bca28
 #21 [ffffb6580689ff00] exit_to_usermode_loop at ffffffffa28050b7
 #22 [ffffb6580689ff38] do_syscall_64 at ffffffffa280560e
 #23 [ffffb6580689ff50] entry_SYSCALL_64_after_hwframe at ffffffffa320008c

This occurred when umount f2fs if enable F2FS_FS_COMPRESSION
with F2FS_IO_TRACE. Fixes it by adding IS_IO_TRACED_PAGE to check
validity of pid for page_private.

Signed-off-by: Yu Changchun <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
dabrace pushed a commit that referenced this pull request Sep 17, 2020
The test_generic_metric() missed to release entries in the pctx.  Asan
reported following leak (and more):

  Direct leak of 128 byte(s) in 1 object(s) allocated from:
    #0 0x7f4c9396980e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x55f7e748cc14 in hashmap_grow (/home/namhyung/project/linux/tools/perf/perf+0x90cc14)
    #2 0x55f7e748d497 in hashmap__insert (/home/namhyung/project/linux/tools/perf/perf+0x90d497)
    #3 0x55f7e7341667 in hashmap__set /home/namhyung/project/linux/tools/perf/util/hashmap.h:111
    #4 0x55f7e7341667 in expr__add_ref util/expr.c:120
    #5 0x55f7e7292436 in prepare_metric util/stat-shadow.c:783
    #6 0x55f7e729556d in test_generic_metric util/stat-shadow.c:858
    #7 0x55f7e712390b in compute_single tests/parse-metric.c:128
    #8 0x55f7e712390b in __compute_metric tests/parse-metric.c:180
    #9 0x55f7e712446d in compute_metric tests/parse-metric.c:196
    #10 0x55f7e712446d in test_dcache_l2 tests/parse-metric.c:295
    #11 0x55f7e712446d in test__parse_metric tests/parse-metric.c:355
    #12 0x55f7e70be09b in run_test tests/builtin-test.c:410
    #13 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
    #14 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
    #15 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
    #16 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #17 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #18 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #19 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #20 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 6d432c4 ("perf tools: Add test_generic_metric function")
Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
dabrace pushed a commit that referenced this pull request Nov 23, 2020
This fix is for a failure that occurred in the DWARF unwind perf test.

Stack unwinders may probe memory when looking for frames.

Memory sanitizer will poison and track uninitialized memory on the
stack, and on the heap if the value is copied to the heap.

This can lead to false memory sanitizer failures for the use of an
uninitialized value.

Avoid this problem by removing the poison on the copied stack.

The full msan failure with track origins looks like:

==2168==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x559ceb10755b in handle_cfi elfutils/libdwfl/frame_unwind.c:648:8
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106acf in __libdwfl_frame_reg_set elfutils/libdwfl/frame_unwind.c:77:22
    #1 0x559ceb106acf in handle_cfi elfutils/libdwfl/frame_unwind.c:627:13
    #2 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #3 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #4 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #5 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #6 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #7 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #8 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #9 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #10 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #11 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #12 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #13 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #14 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #15 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #16 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #17 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #18 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #19 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #20 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #21 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #22 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #23 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #24 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceb106a54 in handle_cfi elfutils/libdwfl/frame_unwind.c:613:9
    #1 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #2 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #3 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #4 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #5 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #6 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #7 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #8 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #9 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #10 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #11 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #12 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #13 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #14 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #15 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #16 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #17 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #18 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #19 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #20 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #21 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #22 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #23 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559ceaff8800 in memory_read tools/perf/util/unwind-libdw.c:156:10
    #1 0x559ceb10f053 in expr_eval elfutils/libdwfl/frame_unwind.c:501:13
    #2 0x559ceb1060cc in handle_cfi elfutils/libdwfl/frame_unwind.c:603:18
    #3 0x559ceb105448 in __libdwfl_frame_unwind elfutils/libdwfl/frame_unwind.c:741:4
    #4 0x559ceb0ece90 in dwfl_thread_getframes elfutils/libdwfl/dwfl_frame.c:435:7
    #5 0x559ceb0ec6b7 in get_one_thread_frames_cb elfutils/libdwfl/dwfl_frame.c:379:10
    #6 0x559ceb0ec6b7 in get_one_thread_cb elfutils/libdwfl/dwfl_frame.c:308:17
    #7 0x559ceb0ec6b7 in dwfl_getthreads elfutils/libdwfl/dwfl_frame.c:283:17
    #8 0x559ceb0ec6b7 in getthread elfutils/libdwfl/dwfl_frame.c:354:14
    #9 0x559ceb0ec6b7 in dwfl_getthread_frames elfutils/libdwfl/dwfl_frame.c:388:10
    #10 0x559ceaff6ae6 in unwind__get_entries tools/perf/util/unwind-libdw.c:236:8
    #11 0x559ceabc9dbc in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:111:8
    #12 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #13 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #14 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #15 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #16 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #17 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #18 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #19 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #20 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #21 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #22 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #23 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #24 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #25 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was stored to memory at
    #0 0x559cea9027d9 in __msan_memcpy llvm/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1558:3
    #1 0x559cea9d2185 in sample_ustack tools/perf/arch/x86/tests/dwarf-unwind.c:41:2
    #2 0x559cea9d202c in test__arch_unwind_sample tools/perf/arch/x86/tests/dwarf-unwind.c:72:9
    #3 0x559ceabc9cbd in test_dwarf_unwind__thread tools/perf/tests/dwarf-unwind.c:106:6
    #4 0x559ceabca5cf in test_dwarf_unwind__compare tools/perf/tests/dwarf-unwind.c:138:26
    #5 0x7f812a6865b0 in bsearch (libc.so.6+0x4e5b0)
    #6 0x559ceabca871 in test_dwarf_unwind__krava_3 tools/perf/tests/dwarf-unwind.c:162:2
    #7 0x559ceabca926 in test_dwarf_unwind__krava_2 tools/perf/tests/dwarf-unwind.c:169:9
    #8 0x559ceabca946 in test_dwarf_unwind__krava_1 tools/perf/tests/dwarf-unwind.c:174:9
    #9 0x559ceabcae12 in test__dwarf_unwind tools/perf/tests/dwarf-unwind.c:211:8
    #10 0x559ceabbc4ab in run_test tools/perf/tests/builtin-test.c:418:9
    #11 0x559ceabbc4ab in test_and_print tools/perf/tests/builtin-test.c:448:9
    #12 0x559ceabbac70 in __cmd_test tools/perf/tests/builtin-test.c:669:4
    #13 0x559ceabbac70 in cmd_test tools/perf/tests/builtin-test.c:815:9
    #14 0x559cea960e30 in run_builtin tools/perf/perf.c:313:11
    #15 0x559cea95fbce in handle_internal_command tools/perf/perf.c:365:8
    #16 0x559cea95fbce in run_argv tools/perf/perf.c:409:2
    #17 0x559cea95fbce in main tools/perf/perf.c:539:3

  Uninitialized value was created by an allocation of 'bf' in the stack frame of function 'perf_event__synthesize_mmap_events'
    #0 0x559ceafc5f60 in perf_event__synthesize_mmap_events tools/perf/util/synthetic-events.c:445

SUMMARY: MemorySanitizer: use-of-uninitialized-value elfutils/libdwfl/frame_unwind.c:648:8 in handle_cfi
Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: [email protected]
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sandeep Dasgupta <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 24, 2021
The evlist and the cpu/thread maps should be released together.
Otherwise following error was reported by Asan.

Note that this test still has memory leaks in DSOs so it still fails
even after this change.  I'll take a look at that too.

  # perf test -v 26
  26: Object code reading                        :
  --- start ---
  test child forked, pid 154184
  Looking at the vmlinux_path (8 entries long)
  symsrc__init: build id mismatch for vmlinux.
  symsrc__init: cannot get elf header.
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols
  Parsing event 'cycles'
  mmap size 528384B
  ...
  =================================================================
  ==154184==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 439 byte(s) in 1 object(s) allocated from:
    #0 0x7fcb66e77037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x55ad9b7e821e in dso__new_id util/dso.c:1256
    #2 0x55ad9b8cfd4a in __machine__addnew_vdso util/vdso.c:132
    #3 0x55ad9b8cfd4a in machine__findnew_vdso util/vdso.c:347
    #4 0x55ad9b845b7e in map__new util/map.c:176
    #5 0x55ad9b8415a2 in machine__process_mmap2_event util/machine.c:1787
    #6 0x55ad9b8fab16 in perf_tool__process_synth_event util/synthetic-events.c:64
    #7 0x55ad9b8fab16 in perf_event__synthesize_mmap_events util/synthetic-events.c:499
    #8 0x55ad9b8fbfdf in __event__synthesize_thread util/synthetic-events.c:741
    #9 0x55ad9b8ff3e3 in perf_event__synthesize_thread_map util/synthetic-events.c:833
    #10 0x55ad9b738585 in do_test_code_reading tests/code-reading.c:608
    #11 0x55ad9b73b25d in test__code_reading tests/code-reading.c:722
    #12 0x55ad9b6f28fb in run_test tests/builtin-test.c:428
    #13 0x55ad9b6f28fb in test_and_print tests/builtin-test.c:458
    #14 0x55ad9b6f4a53 in __cmd_test tests/builtin-test.c:679
    #15 0x55ad9b6f4a53 in cmd_test tests/builtin-test.c:825
    #16 0x55ad9b760cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #20 0x7fcb669acd09 in __libc_start_main ../csu/libc-start.c:308

    ...
  SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Object code reading: FAILED!

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
dabrace pushed a commit that referenced this pull request Apr 6, 2021
I got several memory leak reports from Asan with a simple command.  It
was because VDSO is not released due to the refcount.  Like in
__dsos_addnew_id(), it should put the refcount after adding to the list.

  $ perf record true
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.030 MB perf.data (10 samples) ]

  =================================================================
  ==692599==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 439 byte(s) in 1 object(s) allocated from:
    #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x559bce4aa8ee in dso__new_id util/dso.c:1256
    #2 0x559bce59245a in __machine__addnew_vdso util/vdso.c:132
    #3 0x559bce59245a in machine__findnew_vdso util/vdso.c:347
    #4 0x559bce50826c in map__new util/map.c:175
    #5 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787
    #6 0x559bce512f6b in machines__deliver_event util/session.c:1481
    #7 0x559bce515107 in perf_session__deliver_event util/session.c:1551
    #8 0x559bce51d4d2 in do_flush util/ordered-events.c:244
    #9 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323
    #10 0x559bce519bea in __perf_session__process_events util/session.c:2268
    #11 0x559bce519bea in perf_session__process_events util/session.c:2297
    #12 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017
    #13 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234
    #14 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026
    #15 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858
    #16 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #17 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #18 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #19 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #20 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308

  Indirect leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7fea52341037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154
    #1 0x559bce520907 in nsinfo__copy util/namespaces.c:169
    #2 0x559bce50821b in map__new util/map.c:168
    #3 0x559bce503c92 in machine__process_mmap2_event util/machine.c:1787
    #4 0x559bce512f6b in machines__deliver_event util/session.c:1481
    #5 0x559bce515107 in perf_session__deliver_event util/session.c:1551
    #6 0x559bce51d4d2 in do_flush util/ordered-events.c:244
    #7 0x559bce51d4d2 in __ordered_events__flush util/ordered-events.c:323
    #8 0x559bce519bea in __perf_session__process_events util/session.c:2268
    #9 0x559bce519bea in perf_session__process_events util/session.c:2297
    #10 0x559bce2e7a52 in process_buildids /home/namhyung/project/linux/tools/perf/builtin-record.c:1017
    #11 0x559bce2e7a52 in record__finish_output /home/namhyung/project/linux/tools/perf/builtin-record.c:1234
    #12 0x559bce2ed4f6 in __cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2026
    #13 0x559bce2ed4f6 in cmd_record /home/namhyung/project/linux/tools/perf/builtin-record.c:2858
    #14 0x559bce422db4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #15 0x559bce2acac8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #16 0x559bce2acac8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #17 0x559bce2acac8 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #18 0x7fea51e76d09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s).

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
dabrace pushed a commit that referenced this pull request Mar 17, 2022
When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

    [  755.549084] mlx5_core 0000:12:00.1: Shutdown was called
    [  756.404455] mlx5_core 0000:12:00.0: Shutdown was called
    ...
    [  757.937260] BUG: unable to handle kernel NULL pointer dereference at           (null)
    [  758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

    crash> bt
    ...
    PID: 12649  TASK: ffff8924108f2100  CPU: 1   COMMAND: "amsd"
    ...
     #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
        [exception RIP: dma_pool_alloc+0x1ab]
        RIP: ffffffff8ee11acb  RSP: ffff89240e1a3968  RFLAGS: 00010046
        RAX: 0000000000000246  RBX: ffff89243d874100  RCX: 0000000000001000
        RDX: 0000000000000000  RSI: 0000000000000246  RDI: ffff89243d874090
        RBP: ffff89240e1a39c0   R8: 000000000001f080   R9: ffff8905ffc03c00
        R10: ffffffffc04680d4  R11: ffffffff8edde9fd  R12: 00000000000080d0
        R13: ffff89243d874090  R14: ffff89243d874080  R15: 0000000000000000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
    #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
    #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
    #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
    #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
    #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
    #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
    #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
    #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
    #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
    #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
    #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
    #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
    #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
    #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
    #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
    #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

    crash> net_device.state ffff89443b0c0000
      state = 0x5  (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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