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qcom_smd-regulator: Unused regulators are not disabled after boot #16

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stephan-gh opened this issue Jul 30, 2019 · 0 comments
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@stephan-gh
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This happens because qcom_smd-regulator cannot detect if a regulator is actually enabled. So it pretends that all of them are disabled at boot, and keeps them as-is.

It might be possible to use regulator-boot-on for this, as it temporarily enables the regulator, making qcom_smd-regulator aware of the state. But at the moment regulator-boot-on is equivalent to regulator-always-on for some reason (might be regression?).

stephan-gh pushed a commit that referenced this issue Aug 12, 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]>
stephan-gh pushed a commit that referenced this issue Nov 4, 2019
We meet several NULL pointer issues if configfs_composite_unbind
and composite_setup (or composite_disconnect) are running together.
These issues occur when do the function switch stress test, the
configfs_compsoite_unbind is called from user mode by
echo "" to /sys/../UDC entry, and meanwhile, the setup interrupt
or disconnect interrupt occurs by hardware. The composite_setup
will get the cdev from get_gadget_data, but configfs_composite_unbind
will set gadget data as NULL, so the NULL pointer issue occurs.
This concurrent is hard to reproduce by native kernel, but can be
reproduced by android kernel.

In this commit, we introduce one spinlock belongs to structure
gadget_info since we can't use the same spinlock in usb_composite_dev
due to exclusive running together between composite_setup and
configfs_composite_unbind. And one bit flag 'unbind' to indicate the
code is at unbind routine, this bit is needed due to we release the
lock at during configfs_composite_unbind sometimes, and composite_setup
may be run at that time.

Several oops:

oops 1:
android_work: sent uevent USB_STATE=CONNECTED
configfs-gadget gadget: super-speed config #1: b
android_work: sent uevent USB_STATE=CONFIGURED
init: Received control message 'start' for 'adbd' from pid: 3515 (system_server)
Unable to handle kernel NULL pointer dereference at virtual address 0000002a
init: Received control message 'stop' for 'adbd' from pid: 3375 (/vendor/bin/hw/[email protected])
Mem abort info:
  Exception class = DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgd = ffff8008f1b7f000
[000000000000002a] *pgd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 4 PID: 2457 Comm: irq/125-5b11000 Not tainted 4.14.98-07846-g0b40a9b-dirty #16
Hardware name: Freescale i.MX8QM MEK (DT)
task: ffff8008f2a98000 task.stack: ffff00000b7b8000
PC is at composite_setup+0x44/0x1508
LR is at android_setup+0xb8/0x13c
pc : [<ffff0000089ffb3c>] lr : [<ffff000008a032fc>] pstate: 800001c5
sp : ffff00000b7bbb80
x29: ffff00000b7bbb80 x28: ffff8008f2a3c010
x27: 0000000000000001 x26: 0000000000000000                                                          [1232/1897]
audit: audit_lost=25791 audit_rate_limit=5 audit_backlog_limit=64
x25: 00000000ffffffa1 x24: ffff8008f2a3c010
audit: rate limit exceeded
x23: 0000000000000409 x22: ffff000009c8e000
x21: ffff8008f7a8b428 x20: ffff00000afae000
x19: ffff0000089ff000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff0000082b7c9c
x15: 0000000000000000 x14: f1866f5b952aca46
x13: e35502e30d44349c x12: 0000000000000008
x11: 0000000000000008 x10: 0000000000000a30
x9 : ffff00000b7bbd00 x8 : ffff8008f2a98a90
x7 : ffff8008f27a9c90 x6 : 0000000000000001
x5 : 0000000000000000 x4 : 0000000000000001
x3 : 0000000000000000 x2 : 0000000000000006
x1 : ffff0000089ff8d0 x0 : 732a010310b9ed00

X7: 0xffff8008f27a9c10:
9c10  00000002 00000000 00000001 00000000 13110000 ffff0000 00000002 00208040
9c30  00000000 00000000 00000000 00000000 00000000 00000005 00000029 00000000
9c50  00051778 00000001 f27a8e00 ffff8008 00000005 00000000 00000078 00000078
9c70  00000078 00000000 09031d48 ffff0000 00100000 00000000 00400000 00000000
9c90  00000001 00000000 00000000 00000000 00000000 00000000 ffefb1a0 ffff8008
9cb0  f27a9ca8 ffff8008 00000000 00000000 b9d88037 00000173 1618a3eb 00000001
9cd0  870a792a 0000002e 16188fe6 00000001 0000242b 00000000 00000000 00000000
using random self ethernet address
9cf0  019a4646 00000000 000547f3 00000000 ecfd6c33 00000002 00000000
using random host ethernet address
 00000000

X8: 0xffff8008f2a98a10:
8a10  00000000 00000000 f7788d00 ffff8008 00000001 00000000 00000000 00000000
8a30  eb218000 ffff8008 f2a98000 ffff8008 f2a98000 ffff8008 09885000 ffff0000
8a50  f34df480 ffff8008 00000000 00000000 f2a98648 ffff8008 09c8e000 ffff0000
8a70  fff2c800 ffff8008 09031d48 ffff0000 0b7bbd00 ffff0000 0b7bbd00 ffff0000
8a90  080861bc ffff0000 00000000 00000000 00000000 00000000 00000000 00000000
8ab0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8ad0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8af0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

X21: 0xffff8008f7a8b3a8:
b3a8  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b3c8  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b3e8  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b408  00000000 00000000 00000000 00000000 00000000 00000000 00000001 00000000
b428  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b448  0053004d 00540046 00300031 00010030 eb07b520 ffff8008 20011201 00000003
b468  e418d109 0104404e 00010302 00000000 eb07b558 ffff8008 eb07b558 ffff8008
b488  f7a8b488 ffff8008 f7a8b488 ffff8008 f7a8b300 ffff8008 00000000 00000000

X24: 0xffff8008f2a3bf90:
bf90  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfb0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfd0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bff0  00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
c010  00000000 00000000 f2a3c018 ffff8008 f2a3c018 ffff8008 08a067dc ffff0000
c030  f2a5a000 ffff8008 091c3650 ffff0000 f716fd18 ffff8008 f716fe30 ffff8008
c050  f2ce4a30 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
c070  f76c8010 ffff8008 f2ce4b00 ffff8008 095cac68 ffff0000 f2a5a028 ffff8008

X28: 0xffff8008f2a3bf90:
bf90  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfb0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfd0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bff0  00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
c010  00000000 00000000 f2a3c018 ffff8008 f2a3c018 ffff8008 08a067dc ffff0000
c030  f2a5a000 ffff8008 091c3650 ffff0000 f716fd18 ffff8008 f716fe30 ffff8008
c050  f2ce4a30 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
c070  f76c8010 ffff8008 f2ce4b00 ffff8008 095cac68 ffff0000 f2a5a028 ffff8008

Process irq/125-5b11000 (pid: 2457, stack limit = 0xffff00000b7b8000)
Call trace:
Exception stack(0xffff00000b7bba40 to 0xffff00000b7bbb80)
ba40: 732a010310b9ed00 ffff0000089ff8d0 0000000000000006 0000000000000000
ba60: 0000000000000001 0000000000000000 0000000000000001 ffff8008f27a9c90
ba80: ffff8008f2a98a90 ffff00000b7bbd00 0000000000000a30 0000000000000008
baa0: 0000000000000008 e35502e30d44349c f1866f5b952aca46 0000000000000000
bac0: ffff0000082b7c9c 0000000000000000 0000000000000000 ffff0000089ff000
bae0: ffff00000afae000 ffff8008f7a8b428 ffff000009c8e000 0000000000000409
bb00: ffff8008f2a3c010 00000000ffffffa1 0000000000000000 0000000000000001
bb20: ffff8008f2a3c010 ffff00000b7bbb80 ffff000008a032fc ffff00000b7bbb80
bb40: ffff0000089ffb3c 00000000800001c5 ffff00000b7bbb80 732a010310b9ed00
bb60: ffffffffffffffff ffff0000080f777c ffff00000b7bbb80 ffff0000089ffb3c
[<ffff0000089ffb3c>] composite_setup+0x44/0x1508
[<ffff000008a032fc>] android_setup+0xb8/0x13c
[<ffff0000089bd9a8>] cdns3_ep0_delegate_req+0x44/0x70
[<ffff0000089bdff4>] cdns3_check_ep0_interrupt_proceed+0x33c/0x654
[<ffff0000089bca44>] cdns3_device_thread_irq_handler+0x4b0/0x4bc
[<ffff0000089b77b4>] cdns3_thread_irq+0x48/0x68
[<ffff000008145bf0>] irq_thread_fn+0x28/0x88
[<ffff000008145e38>] irq_thread+0x13c/0x228
[<ffff0000080fed70>] kthread+0x104/0x130
[<ffff000008085064>] ret_from_fork+0x10/0x18

oops2:
composite_disconnect: Calling disconnect on a Gadget that is                      not connected
android_work: did not send uevent (0 0           (null))
init: Received control message 'stop' for 'adbd' from pid: 3359 (/vendor/bin/hw/[email protected])
init: Sending signal 9 to service 'adbd' (pid 22343) process group...
------------[ cut here ]------------
audit: audit_lost=180038 audit_rate_limit=5 audit_backlog_limit=64
audit: rate limit exceeded
WARNING: CPU: 0 PID: 3468 at kernel_imx/drivers/usb/gadget/composite.c:2009 composite_disconnect+0x80/0x88
Modules linked in:
CPU: 0 PID: 3468 Comm: HWC-UEvent-Thre Not tainted 4.14.98-07846-g0b40a9b-dirty #16
Hardware name: Freescale i.MX8QM MEK (DT)
task: ffff8008f2349c00 task.stack: ffff00000b0a8000
PC is at composite_disconnect+0x80/0x88
LR is at composite_disconnect+0x80/0x88
pc : [<ffff0000089ff9b0>] lr : [<ffff0000089ff9b0>] pstate: 600001c5
sp : ffff000008003dd0
x29: ffff000008003dd0 x28: ffff8008f2349c00
x27: ffff000009885018 x26: ffff000008004000
Timeout for IPC response!
x25: ffff000009885018 x24: ffff000009c8e280
x23: ffff8008f2d98010 x22: 00000000000001c0
x21: ffff8008f2d98394 x20: ffff8008f2d98010
x19: 0000000000000000 x18: 0000e3956f4f075a
fxos8700 4-001e: i2c block read acc failed
x17: 0000e395735727e8 x16: ffff00000829f4d4
x15: ffffffffffffffff x14: 7463656e6e6f6320
x13: 746f6e2009090920 x12: 7369207461687420
x11: 7465676461472061 x10: 206e6f207463656e
x9 : 6e6f637369642067 x8 : ffff000009c8e280
x7 : ffff0000086ca6cc x6 : ffff000009f15e78
x5 : 0000000000000000 x4 : 0000000000000000
x3 : ffffffffffffffff x2 : c3f28b86000c3900
x1 : c3f28b86000c3900 x0 : 000000000000004e

X20: 0xffff8008f2d97f90:
7f90  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fb0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
libprocessgroup: Failed to kill process cgroup uid 0 pid 22343 in 215ms, 1 processes remain
7fd0
Timeout for IPC response!
 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
using random self ethernet address
7ff0  00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
8010  00000100 00000000 f2d98018 ffff8008 f2d98018 ffff8008 08a067dc
using random host ethernet address
 ffff0000
8030  f206d800 ffff8008 091c3650 ffff0000 f7957b18 ffff8008 f7957730 ffff8008
8050  f716a630 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
8070  f76c8010 ffff8008 f716a800 ffff8008 095cac68 ffff0000 f206d828 ffff8008

X21: 0xffff8008f2d98314:
8314  ffff8008 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8334  00000000 00000000 00000000 00000000 00000000 08a04cf4 ffff0000 00000000
8354  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8374  00000000 00000000 00000000 00001001 00000000 00000000 00000000 00000000
8394  e4bbe4bb 0f230000 ffff0000 0afae000 ffff0000 ae001000 00000000 f206d400
Timeout for IPC response!
83b4  ffff8008 00000000 00000000 f7957b18 ffff8008 f7957718 ffff8008 f7957018
83d4  ffff8008 f7957118 ffff8008 f7957618 ffff8008 f7957818 ffff8008 f7957918
83f4  ffff8008 f7957d18 ffff8008 00000000 00000000 00000000 00000000 00000000

X23: 0xffff8008f2d97f90:
7f90  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fb0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fd0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7ff0  00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
8010  00000100 00000000 f2d98018 ffff8008 f2d98018 ffff8008 08a067dc ffff0000
8030  f206d800 ffff8008 091c3650 ffff0000 f7957b18 ffff8008 f7957730 ffff8008
8050  f716a630 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
8070  f76c8010 ffff8008 f716a800 ffff8008 095cac68 ffff0000 f206d828 ffff8008

X28: 0xffff8008f2349b80:
9b80  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9ba0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9bc0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9be0  00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9c00  00000022 00000000 ffffffff ffffffff 00010001 00000000 00000000 00000000
9c20  0b0a8000 ffff0000 00000002 00404040 00000000 00000000 00000000 00000000
9c40  00000001 00000000 00000001 00000000 001ebd44 00000001 f390b800 ffff8008
9c60  00000000 00000001 00000070 00000070 00000070 00000000 09031d48 ffff0000

Call trace:
Exception stack(0xffff000008003c90 to 0xffff000008003dd0)
3c80:                                   000000000000004e c3f28b86000c3900
3ca0: c3f28b86000c3900 ffffffffffffffff 0000000000000000 0000000000000000
3cc0: ffff000009f15e78 ffff0000086ca6cc ffff000009c8e280 6e6f637369642067
3ce0: 206e6f207463656e 7465676461472061 7369207461687420 746f6e2009090920
3d00: 7463656e6e6f6320 ffffffffffffffff ffff00000829f4d4 0000e395735727e8
3d20: 0000e3956f4f075a 0000000000000000 ffff8008f2d98010 ffff8008f2d98394
3d40: 00000000000001c0 ffff8008f2d98010 ffff000009c8e280 ffff000009885018
3d60: ffff000008004000 ffff000009885018 ffff8008f2349c00 ffff000008003dd0
3d80: ffff0000089ff9b0 ffff000008003dd0 ffff0000089ff9b0 00000000600001c5
3da0: ffff8008f33f2cd8 0000000000000000 0000ffffffffffff 0000000000000000
init: Received control message 'start' for 'adbd' from pid: 3359 (/vendor/bin/hw/[email protected])
3dc0: ffff000008003dd0 ffff0000089ff9b0
[<ffff0000089ff9b0>] composite_disconnect+0x80/0x88
[<ffff000008a044d4>] android_disconnect+0x3c/0x68
[<ffff0000089ba9f8>] cdns3_device_irq_handler+0xfc/0x2c8
[<ffff0000089b84c0>] cdns3_irq+0x44/0x94
[<ffff00000814494c>] __handle_irq_event_percpu+0x60/0x24c
[<ffff000008144c0c>] handle_irq_event+0x58/0xc0
[<ffff00000814873c>] handle_fasteoi_irq+0x98/0x180
[<ffff000008143a10>] generic_handle_irq+0x24/0x38
[<ffff000008144170>] __handle_domain_irq+0x60/0xac
[<ffff0000080819c4>] gic_handle_irq+0xd4/0x17c

Signed-off-by: Peter Chen <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>
stephan-gh pushed a commit that referenced this issue Mar 30, 2020
When experimenting with bpf_send_signal() helper in our production
environment (5.2 based), we experienced a deadlock in NMI mode:
   #5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24
   #6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012
   #7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd
   #8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55
   #9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602
  #10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a
  #11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227
  #12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140
  #13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf
  #14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09
  #15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47
  #16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d
  #17 [ffffc9002219fc90] schedule at ffffffff81a3e219
  #18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9
  #19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529
  #20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc
  #21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c
  #22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602
  #23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068

The above call stack is actually very similar to an issue
reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with
rq_lock in bpf_get_stack()") by Song Liu. The only difference is
bpf_send_signal() helper instead of bpf_get_stack() helper.

The above deadlock is triggered with a perf_sw_event.
Similar to Commit eac9153, the below almost identical reproducer
used tracepoint point sched/sched_switch so the issue can be easily caught.
  /* stress_test.c */
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/mman.h>
  #include <pthread.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>

  #define THREAD_COUNT 1000
  char *filename;
  void *worker(void *p)
  {
        void *ptr;
        int fd;
        char *pptr;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return NULL;
        while (1) {
                struct timespec ts = {0, 1000 + rand() % 2000};

                ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
                usleep(1);
                if (ptr == MAP_FAILED) {
                        printf("failed to mmap\n");
                        break;
                }
                munmap(ptr, 4096 * 64);
                usleep(1);
                pptr = malloc(1);
                usleep(1);
                pptr[0] = 1;
                usleep(1);
                free(pptr);
                usleep(1);
                nanosleep(&ts, NULL);
        }
        close(fd);
        return NULL;
  }

  int main(int argc, char *argv[])
  {
        void *ptr;
        int i;
        pthread_t threads[THREAD_COUNT];

        if (argc < 2)
                return 0;

        filename = argv[1];

        for (i = 0; i < THREAD_COUNT; i++) {
                if (pthread_create(threads + i, NULL, worker, NULL)) {
                        fprintf(stderr, "Error creating thread\n");
                        return 0;
                }
        }

        for (i = 0; i < THREAD_COUNT; i++)
                pthread_join(threads[i], NULL);
        return 0;
  }
and the following command:
  1. run `stress_test /bin/ls` in one windown
  2. hack bcc trace.py with the following change:
     --- a/tools/trace.py
     +++ b/tools/trace.py
     @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s);
              __data.tgid = __tgid;
              __data.pid = __pid;
              bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
     +        bpf_send_signal(10);
      %s
      %s
              %s.perf_submit(%s, &__data, sizeof(__data));
  3. in a different window run
     ./trace.py -p $(pidof stress_test) t:sched:sched_switch

The deadlock can be reproduced in our production system.

Similar to Song's fix, the fix is to delay sending signal if
irqs is disabled to avoid deadlocks involving with rq_lock.
With this change, my above stress-test in our production system
won't cause deadlock any more.

I also implemented a scale-down version of reproducer in the
selftest (a subsequent commit). With latest bpf-next,
it complains for the following potential deadlock.
  [   32.832450] -> #1 (&p->pi_lock){-.-.}:
  [   32.833100]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.833696]        task_rq_lock+0x2c/0xa0
  [   32.834182]        task_sched_runtime+0x59/0xd0
  [   32.834721]        thread_group_cputime+0x250/0x270
  [   32.835304]        thread_group_cputime_adjusted+0x2e/0x70
  [   32.835959]        do_task_stat+0x8a7/0xb80
  [   32.836461]        proc_single_show+0x51/0xb0
  ...
  [   32.839512] -> #0 (&(&sighand->siglock)->rlock){....}:
  [   32.840275]        __lock_acquire+0x1358/0x1a20
  [   32.840826]        lock_acquire+0xc7/0x1d0
  [   32.841309]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.841916]        __lock_task_sighand+0x79/0x160
  [   32.842465]        do_send_sig_info+0x35/0x90
  [   32.842977]        bpf_send_signal+0xa/0x10
  [   32.843464]        bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000
  [   32.844301]        trace_call_bpf+0x115/0x270
  [   32.844809]        perf_trace_run_bpf_submit+0x4a/0xc0
  [   32.845411]        perf_trace_sched_switch+0x10f/0x180
  [   32.846014]        __schedule+0x45d/0x880
  [   32.846483]        schedule+0x5f/0xd0
  ...

  [   32.853148] Chain exists of:
  [   32.853148]   &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock
  [   32.853148]
  [   32.854451]  Possible unsafe locking scenario:
  [   32.854451]
  [   32.855173]        CPU0                    CPU1
  [   32.855745]        ----                    ----
  [   32.856278]   lock(&rq->lock);
  [   32.856671]                                lock(&p->pi_lock);
  [   32.857332]                                lock(&rq->lock);
  [   32.857999]   lock(&(&sighand->siglock)->rlock);

  Deadlock happens on CPU0 when it tries to acquire &sighand->siglock
  but it has been held by CPU1 and CPU1 tries to grab &rq->lock
  and cannot get it.

  This is not exactly the callstack in our production environment,
  but sympotom is similar and both locks are using spin_lock_irqsave()
  to acquire the lock, and both involves rq_lock. The fix to delay
  sending signal when irq is disabled also fixed this issue.

Signed-off-by: Yonghong Song <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Cc: Song Liu <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
stephan-gh pushed a commit that referenced this issue Sep 14, 2020
…s metrics" test

Linux 5.9 introduced perf test case "Parse and process metrics" and
on s390 this test case always dumps core:

  [root@t35lp67 perf]# ./perf test -vvvv -F 67
  67: Parse and process metrics                             :
  --- start ---
  metric expr inst_retired.any / cpu_clk_unhalted.thread for IPC
  parsing metric: inst_retired.any / cpu_clk_unhalted.thread
  Segmentation fault (core dumped)
  [root@t35lp67 perf]#

I debugged this core dump and gdb shows this call chain:

  (gdb) where
   #0  0x000003ffabc3192a in __strnlen_c_1 () from /lib64/libc.so.6
   #1  0x000003ffabc293de in strcasestr () from /lib64/libc.so.6
   #2  0x0000000001102ba2 in match_metric(list=0x1e6ea20 "inst_retired.any",
            n=<optimized out>)
       at util/metricgroup.c:368
   #3  find_metric (map=<optimized out>, map=<optimized out>,
           metric=0x1e6ea20 "inst_retired.any")
      at util/metricgroup.c:765
   #4  __resolve_metric (ids=0x0, map=<optimized out>, metric_list=0x0,
           metric_no_group=<optimized out>, m=<optimized out>)
      at util/metricgroup.c:844
   #5  resolve_metric (ids=0x0, map=0x0, metric_list=0x0,
          metric_no_group=<optimized out>)
      at util/metricgroup.c:881
   #6  metricgroup__add_metric (metric=<optimized out>,
        metric_no_group=metric_no_group@entry=false, events=<optimized out>,
        events@entry=0x3ffd84fb878, metric_list=0x0,
        metric_list@entry=0x3ffd84fb868, map=0x0)
      at util/metricgroup.c:943
   #7  0x00000000011034ae in metricgroup__add_metric_list (map=0x13f9828 <map>,
        metric_list=0x3ffd84fb868, events=0x3ffd84fb878,
        metric_no_group=<optimized out>, list=<optimized out>)
      at util/metricgroup.c:988
   #8  parse_groups (perf_evlist=perf_evlist@entry=0x1e70260,
          str=str@entry=0x12f34b2 "IPC", metric_no_group=<optimized out>,
          metric_no_merge=<optimized out>,
          fake_pmu=fake_pmu@entry=0x1462f18 <perf_pmu.fake>,
          metric_events=0x3ffd84fba58, map=0x1)
      at util/metricgroup.c:1040
   #9  0x0000000001103eb2 in metricgroup__parse_groups_test(
  	evlist=evlist@entry=0x1e70260, map=map@entry=0x13f9828 <map>,
  	str=str@entry=0x12f34b2 "IPC",
  	metric_no_group=metric_no_group@entry=false,
  	metric_no_merge=metric_no_merge@entry=false,
  	metric_events=0x3ffd84fba58)
      at util/metricgroup.c:1082
   #10 0x00000000010c84d8 in __compute_metric (ratio2=0x0, name2=0x0,
          ratio1=<synthetic pointer>, name1=0x12f34b2 "IPC",
  	vals=0x3ffd84fbad8, name=0x12f34b2 "IPC")
      at tests/parse-metric.c:159
   #11 compute_metric (ratio=<synthetic pointer>, vals=0x3ffd84fbad8,
  	name=0x12f34b2 "IPC")
      at tests/parse-metric.c:189
   #12 test_ipc () at tests/parse-metric.c:208
.....
..... omitted many more lines

This test case was added with
commit 218ca91 ("perf tests: Add parse metric test for frontend metric").

When I compile with make DEBUG=y it works fine and I do not get a core dump.

It turned out that the above listed function call chain worked on a struct
pmu_event array which requires a trailing element with zeroes which was
missing. The marco map_for_each_event() loops over that array tests for members
metric_expr/metric_name/metric_group being non-NULL. Adding this element fixes
the issue.

Output after:

  [root@t35lp46 perf]# ./perf test 67
  67: Parse and process metrics                             : Ok
  [root@t35lp46 perf]#

Committer notes:

As Ian remarks, this is not s390 specific:

<quote Ian>
  This also shows up with address sanitizer on all architectures
  (perhaps change the patch title) and perhaps add a "Fixes: <commit>"
  tag.

  =================================================================
  ==4718==ERROR: AddressSanitizer: global-buffer-overflow on address
  0x55c93b4d59e8 at pc 0x55c93a1541e2 bp 0x7ffd24327c60 sp
  0x7ffd24327c58
  READ of size 8 at 0x55c93b4d59e8 thread T0
      #0 0x55c93a1541e1 in find_metric tools/perf/util/metricgroup.c:764:2
      #1 0x55c93a153e6c in __resolve_metric tools/perf/util/metricgroup.c:844:9
      #2 0x55c93a152f18 in resolve_metric tools/perf/util/metricgroup.c:881:9
      #3 0x55c93a1528db in metricgroup__add_metric
  tools/perf/util/metricgroup.c:943:9
      #4 0x55c93a151996 in metricgroup__add_metric_list
  tools/perf/util/metricgroup.c:988:9
      #5 0x55c93a1511b9 in parse_groups tools/perf/util/metricgroup.c:1040:8
      #6 0x55c93a1513e1 in metricgroup__parse_groups_test
  tools/perf/util/metricgroup.c:1082:9
      #7 0x55c93a0108ae in __compute_metric tools/perf/tests/parse-metric.c:159:8
      #8 0x55c93a010744 in compute_metric tools/perf/tests/parse-metric.c:189:9
      #9 0x55c93a00f5ee in test_ipc tools/perf/tests/parse-metric.c:208:2
      #10 0x55c93a00f1e8 in test__parse_metric
  tools/perf/tests/parse-metric.c:345:2
      #11 0x55c939fd7202 in run_test tools/perf/tests/builtin-test.c:410:9
      #12 0x55c939fd6736 in test_and_print tools/perf/tests/builtin-test.c:440:9
      #13 0x55c939fd58c3 in __cmd_test tools/perf/tests/builtin-test.c:661:4
      #14 0x55c939fd4e02 in cmd_test tools/perf/tests/builtin-test.c:807:9
      #15 0x55c939e4763d in run_builtin tools/perf/perf.c:313:11
      #16 0x55c939e46475 in handle_internal_command tools/perf/perf.c:365:8
      #17 0x55c939e4737e in run_argv tools/perf/perf.c:409:2
      #18 0x55c939e45f7e in main tools/perf/perf.c:539:3

  0x55c93b4d59e8 is located 0 bytes to the right of global variable
  'pme_test' defined in 'tools/perf/tests/parse-metric.c:17:25'
  (0x55c93b4d54a0) of size 1352
  SUMMARY: AddressSanitizer: global-buffer-overflow
  tools/perf/util/metricgroup.c:764:2 in find_metric
  Shadow bytes around the buggy address:
    0x0ab9a7692ae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692af0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  =>0x0ab9a7692b30: 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 f9
    0x0ab9a7692b40: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b50: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
    0x0ab9a7692b60: f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
    0x0ab9a7692b70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ab9a7692b80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
  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
    Shadow gap:              cc
</quote>

I'm also adding the missing "Fixes" tag and setting just .name to NULL,
as doing it that way is more compact (the compiler will zero out
everything else) and the table iterators look for .name being NULL as
the sentinel marking the end of the table.

Fixes: 0a507af ("perf tests: Add parse metric test for ipc metric")
Signed-off-by: Thomas Richter <[email protected]>
Reviewed-by: Sumanth Korikkar <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
stephan-gh pushed a commit that referenced this issue Sep 14, 2020
__apply_to_page_range() is also used to change and/or allocate
page-table pages in the vmalloc area of the address space.  Make sure
these changes get synchronized to other page-tables in the system by
calling arch_sync_kernel_mappings() when necessary.

The impact appears limited to x86-32, where apply_to_page_range may miss
updating the PMD.  That leads to explosions in drivers like

  BUG: unable to handle page fault for address: fe036000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  *pde = 00000000
  Oops: 0002 [#1] SMP
  CPU: 3 PID: 1300 Comm: gem_concurrent_ Not tainted 5.9.0-rc1+ #16
  Hardware name:  /NUC6i3SYB, BIOS SYSKLi35.86A.0024.2015.1027.2142 10/27/2015
  EIP: __execlists_context_alloc+0x132/0x2d0 [i915]
  Code: 31 d2 89 f0 e8 2f 55 02 00 89 45 e8 3d 00 f0 ff ff 0f 87 11 01 00 00 8b 4d e8 03 4b 30 b8 5a 5a 5a 5a ba 01 00 00 00 8d 79 04 <c7> 01 5a 5a 5a 5a c7 81 fc 0f 00 00 5a 5a 5a 5a 83 e7 fc 29 f9 81
  EAX: 5a5a5a5a EBX: f60ca000 ECX: fe036000 EDX: 00000001
  ESI: f43b7340 EDI: fe036004 EBP: f6389cb8 ESP: f6389c9c
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010286
  CR0: 80050033 CR2: fe036000 CR3: 2d361000 CR4: 001506d0
  DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
  DR6: fffe0ff0 DR7: 00000400
  Call Trace:
    execlists_context_alloc+0x10/0x20 [i915]
    intel_context_alloc_state+0x3f/0x70 [i915]
    __intel_context_do_pin+0x117/0x170 [i915]
    i915_gem_do_execbuffer+0xcc7/0x2500 [i915]
    i915_gem_execbuffer2_ioctl+0xcd/0x1f0 [i915]
    drm_ioctl_kernel+0x8f/0xd0
    drm_ioctl+0x223/0x3d0
    __ia32_sys_ioctl+0x1ab/0x760
    __do_fast_syscall_32+0x3f/0x70
    do_fast_syscall_32+0x29/0x60
    do_SYSENTER_32+0x15/0x20
    entry_SYSENTER_32+0x9f/0xf2
  EIP: 0xb7f28559
  Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d 76 00 58 b8 77 00 00 00 cd 80 90 8d 76
  EAX: ffffffda EBX: 00000005 ECX: c0406469 EDX: bf95556c
  ESI: b7e68000 EDI: c0406469 EBP: 00000005 ESP: bf9554d8
  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000296
  Modules linked in: i915 x86_pkg_temp_thermal intel_powerclamp crc32_pclmul crc32c_intel intel_cstate intel_uncore intel_gtt drm_kms_helper intel_pch_thermal video button autofs4 i2c_i801 i2c_smbus fan
  CR2: 00000000fe036000

It looks like kasan, xen and i915 are vulnerable.

Actual impact is "on thinkpad X60 in 5.9-rc1, screen starts blinking
after 30-or-so minutes, and machine is unusable"

[[email protected]: ARCH_PAGE_TABLE_SYNC_MASK needs vmalloc.h]
  Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: changelog addition]
[[email protected]: changelog addition]

Fixes: 2ba3e69 ("mm/vmalloc: track which page-table levels were modified")
Fixes: 86cf69f ("x86/mm/32: implement arch_sync_kernel_mappings()")
Signed-off-by: Joerg Roedel <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Tested-by: Chris Wilson <[email protected]>	[x86-32]
Tested-by: Pavel Machek <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Cc: <[email protected]>	[5.8+]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>
stephan-gh pushed a commit that referenced this issue Sep 21, 2020
The evsel->unit borrows a pointer of pmu event or alias instead of
owns a string.  But tool event (duration_time) passes a result of
strdup() caused a leak.

It was found by ASAN during metric test:

  Direct leak of 210 byte(s) in 70 object(s) allocated from:
    #0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414
    #2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414
    #3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
    #4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
    #5 0x559fbbcc95da in __parse_events util/parse-events.c:2141
    #6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406
    #7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393
    #8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415
    #9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498
    #10 0x559fbbc0109b in run_test tests/builtin-test.c:410
    #11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
    #12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
    #13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
    #14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: f0fbb11 ("perf stat: Implement duration_time as a proper event")
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]>
stephan-gh pushed a commit that referenced this issue Sep 21, 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]>
stephan-gh pushed a commit that referenced this issue Sep 21, 2020
The metricgroup__add_metric() can find multiple match for a metric group
and it's possible to fail.  Also it can fail in the middle like in
resolve_metric() even for single metric.

In those cases, the intermediate list and ids will be leaked like:

  Direct leak of 3 byte(s) in 1 object(s) allocated from:
    #0 0x7f4c938f40b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x55f7e71c1bef in __add_metric util/metricgroup.c:683
    #2 0x55f7e71c31d0 in add_metric util/metricgroup.c:906
    #3 0x55f7e71c3844 in metricgroup__add_metric util/metricgroup.c:940
    #4 0x55f7e71c488d in metricgroup__add_metric_list util/metricgroup.c:993
    #5 0x55f7e71c488d in parse_groups util/metricgroup.c:1045
    #6 0x55f7e71c60a4 in metricgroup__parse_groups_test util/metricgroup.c:1087
    #7 0x55f7e71235ae in __compute_metric tests/parse-metric.c:164
    #8 0x55f7e7124650 in compute_metric tests/parse-metric.c:196
    #9 0x55f7e7124650 in test_recursion_fail tests/parse-metric.c:318
    #10 0x55f7e7124650 in test__parse_metric tests/parse-metric.c:356
    #11 0x55f7e70be09b in run_test tests/builtin-test.c:410
    #12 0x55f7e70be09b in test_and_print tests/builtin-test.c:440
    #13 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661
    #14 0x55f7e70c101a in cmd_test tests/builtin-test.c:807
    #15 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #16 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #17 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #18 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #19 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 83de0b7 ("perf metric: Collect referenced metrics in struct metric_ref_node")
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]>
ghost referenced this issue in msm8953-mainline/linux Nov 26, 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]>
stephan-gh pushed a commit that referenced this issue Mar 22, 2021
commit 4d14c5c upstream

Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:

 * ae5e070 ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")

 * 6f23277 ("btrfs: qgroup: don't commit transaction when we already
 hold the handle")

Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:

  PID: 6963   TASK: ffff8c7f3f94c000  CPU: 2   COMMAND: "test"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_timeout at ffffffffa52a1bdd
  #3  wait_for_completion at ffffffffa529eeea             <-- sleeps with delayed node mutex held
  #4  start_delalloc_inodes at ffffffffc0380db5
  #5  btrfs_start_delalloc_snapshot at ffffffffc0393836
  #6  try_flush_qgroup at ffffffffc03f04b2
  #7  __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6     <-- tries to reserve space and starts delalloc inodes.
  #8  btrfs_delayed_update_inode at ffffffffc03e31aa      <-- acquires delayed node mutex
  #9  btrfs_update_inode at ffffffffc0385ba8
 #10  btrfs_dirty_inode at ffffffffc038627b               <-- TRANSACTIION OPENED
 #11  touch_atime at ffffffffa4cf0000
 #12  generic_file_read_iter at ffffffffa4c1f123
 #13  new_sync_read at ffffffffa4ccdc8a
 #14  vfs_read at ffffffffa4cd0849
 #15  ksys_read at ffffffffa4cd0bd1
 #16  do_syscall_64 at ffffffffa4a052eb
 #17  entry_SYSCALL_64_after_hwframe at ffffffffa540008c

This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:

  PID: 455    TASK: ffff8c8085fa4000  CPU: 5   COMMAND: "kworker/u16:30"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_preempt_disabled at ffffffffa529e80a
  #3  __mutex_lock at ffffffffa529fdcb                    <-- goes to sleep, never wakes up.
  #4  btrfs_delayed_update_inode at ffffffffc03e3143      <-- tries to acquire the mutex
  #5  btrfs_update_inode at ffffffffc0385ba8              <-- this is the same inode that pid 6963 is holding
  #6  cow_file_range_inline.constprop.78 at ffffffffc0386be7
  #7  cow_file_range at ffffffffc03879c1
  #8  btrfs_run_delalloc_range at ffffffffc038894c
  #9  writepage_delalloc at ffffffffc03a3c8f
 #10  __extent_writepage at ffffffffc03a4c01
 #11  extent_write_cache_pages at ffffffffc03a500b
 #12  extent_writepages at ffffffffc03a6de2
 #13  do_writepages at ffffffffa4c277eb
 #14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 #15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 #16  normal_work_helper at ffffffffc03b706c
 #17  process_one_work at ffffffffa4aba4e4
 #18  worker_thread at ffffffffa4aba6fd
 #19  kthread at ffffffffa4ac0a3d
 #20  ret_from_fork at ffffffffa54001ff

To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.

Fixes: c53e965 ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: [email protected] # 5.10+
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Sudip Mukherjee <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
stephan-gh pushed a commit that referenced this issue Mar 22, 2021
[ Upstream commit dc860b8 ]

Routes are currently processed from a workqueue whereas nexthop objects
are processed in system call context. This can result in the driver not
finding a suitable nexthop group for a route and issuing a warning [1].

Fix this by ignoring such routes earlier in the process. The subsequent
deletion notification will be ignored as well.

[1]
 WARNING: CPU: 2 PID: 7754 at drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:4853 mlxsw_sp_router_fib_event_work+0x1112/0x1e00 [mlxsw_spectrum]
 [...]
 CPU: 2 PID: 7754 Comm: kworker/u8:0 Not tainted 5.11.0-rc6-cq-20210207-1 #16
 Hardware name: Mellanox Technologies Ltd. MSN2100/SA001390, BIOS 5.6.5 05/24/2018
 Workqueue: mlxsw_core_ordered mlxsw_sp_router_fib_event_work [mlxsw_spectrum]
 RIP: 0010:mlxsw_sp_router_fib_event_work+0x1112/0x1e00 [mlxsw_spectrum]

Fixes: cdd6cfc ("mlxsw: spectrum_router: Allow programming routes with nexthop objects")
Signed-off-by: Ido Schimmel <[email protected]>
Reported-by: Alex Veber <[email protected]>
Tested-by: Alex Veber <[email protected]>
Reviewed-by: Petr Machata <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
ghost referenced this issue in msm8953-mainline/linux Apr 22, 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]>
stephan-gh pushed a commit that referenced this issue May 31, 2021
When calling the 'ql_sem_spinlock', the driver has already acquired the
spin lock, so the driver should not call 'ssleep' in atomic context.

This bug can be fixed by using 'mdelay' instead of 'ssleep'.

The KASAN's log reveals it:

[    3.238124 ] BUG: scheduling while atomic: swapper/0/1/0x00000002
[    3.238748 ] 2 locks held by swapper/0/1:
[    3.239151 ]  #0: ffff88810177b240 (&dev->mutex){....}-{3:3}, at:
__device_driver_lock+0x41/0x60
[    3.240026 ]  #1: ffff888107c60e28 (&qdev->hw_lock){....}-{2:2}, at:
ql3xxx_probe+0x2aa/0xea0
[    3.240873 ] Modules linked in:
[    3.241187 ] irq event stamp: 460854
[    3.241541 ] hardirqs last  enabled at (460853): [<ffffffff843051bf>]
_raw_spin_unlock_irqrestore+0x4f/0x70
[    3.242245 ] hardirqs last disabled at (460854): [<ffffffff843058ca>]
_raw_spin_lock_irqsave+0x2a/0x70
[    3.242245 ] softirqs last  enabled at (446076): [<ffffffff846002e4>]
__do_softirq+0x2e4/0x4b1
[    3.242245 ] softirqs last disabled at (446069): [<ffffffff811ba5e0>]
irq_exit_rcu+0x100/0x110
[    3.242245 ] Preemption disabled at:
[    3.242245 ] [<ffffffff828ca5ba>] ql3xxx_probe+0x2aa/0xea0
[    3.242245 ] Kernel panic - not syncing: scheduling while atomic
[    3.242245 ] CPU: 2 PID: 1 Comm: swapper/0 Not tainted
5.13.0-rc1-00145
-gee7dc339169-dirty #16
[    3.242245 ] Call Trace:
[    3.242245 ]  dump_stack+0xba/0xf5
[    3.242245 ]  ? ql3xxx_probe+0x1f0/0xea0
[    3.242245 ]  panic+0x15a/0x3f2
[    3.242245 ]  ? vprintk+0x76/0x150
[    3.242245 ]  ? ql3xxx_probe+0x2aa/0xea0
[    3.242245 ]  __schedule_bug+0xae/0xe0
[    3.242245 ]  __schedule+0x72e/0xa00
[    3.242245 ]  schedule+0x43/0xf0
[    3.242245 ]  schedule_timeout+0x28b/0x500
[    3.242245 ]  ? del_timer_sync+0xf0/0xf0
[    3.242245 ]  ? msleep+0x2f/0x70
[    3.242245 ]  msleep+0x59/0x70
[    3.242245 ]  ql3xxx_probe+0x307/0xea0
[    3.242245 ]  ? _raw_spin_unlock_irqrestore+0x3a/0x70
[    3.242245 ]  ? pci_device_remove+0x110/0x110
[    3.242245 ]  local_pci_probe+0x45/0xa0
[    3.242245 ]  pci_device_probe+0x12b/0x1d0
[    3.242245 ]  really_probe+0x2a9/0x610
[    3.242245 ]  driver_probe_device+0x90/0x1d0
[    3.242245 ]  ? mutex_lock_nested+0x1b/0x20
[    3.242245 ]  device_driver_attach+0x68/0x70
[    3.242245 ]  __driver_attach+0x124/0x1b0
[    3.242245 ]  ? device_driver_attach+0x70/0x70
[    3.242245 ]  bus_for_each_dev+0xbb/0x110
[    3.242245 ]  ? rdinit_setup+0x45/0x45
[    3.242245 ]  driver_attach+0x27/0x30
[    3.242245 ]  bus_add_driver+0x1eb/0x2a0
[    3.242245 ]  driver_register+0xa9/0x180
[    3.242245 ]  __pci_register_driver+0x82/0x90
[    3.242245 ]  ? yellowfin_init+0x25/0x25
[    3.242245 ]  ql3xxx_driver_init+0x23/0x25
[    3.242245 ]  do_one_initcall+0x7f/0x3d0
[    3.242245 ]  ? rdinit_setup+0x45/0x45
[    3.242245 ]  ? rcu_read_lock_sched_held+0x4f/0x80
[    3.242245 ]  kernel_init_freeable+0x2aa/0x301
[    3.242245 ]  ? rest_init+0x2c0/0x2c0
[    3.242245 ]  kernel_init+0x18/0x190
[    3.242245 ]  ? rest_init+0x2c0/0x2c0
[    3.242245 ]  ? rest_init+0x2c0/0x2c0
[    3.242245 ]  ret_from_fork+0x1f/0x30
[    3.242245 ] Dumping ftrace buffer:
[    3.242245 ]    (ftrace buffer empty)
[    3.242245 ] Kernel Offset: disabled
[    3.242245 ] Rebooting in 1 seconds.

Reported-by: Zheyu Ma <[email protected]>
Signed-off-by: Zheyu Ma <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
stephan-gh pushed a commit that referenced this issue Jun 21, 2021
There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled.
The reason is that nsfs tries to access ns->ops but the proc_ns_operations
is not implemented in this case.

[7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010
[7.670268] pgd = 32b54000
[7.670544] [00000010] *pgd=00000000
[7.671861] Internal error: Oops: 5 [#1] SMP ARM
[7.672315] Modules linked in:
[7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16
[7.673309] Hardware name: Generic DT based system
[7.673642] PC is at nsfs_evict+0x24/0x30
[7.674486] LR is at clear_inode+0x20/0x9c

The same to tun SIOCGSKNS command.

To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is
disabled. Meanwhile move it to right place net/core/net_namespace.c.

Signed-off-by: Changbin Du <[email protected]>
Fixes: c62cce2 ("net: add an ioctl to get a socket network namespace")
Cc: Cong Wang <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: David Laight <[email protected]>
Cc: Christian Brauner <[email protected]>
Suggested-by: Jakub Kicinski <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
stephan-gh pushed a commit that referenced this issue Sep 20, 2021
It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  #1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  #2  0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  #3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  #4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  #5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  #6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38)
      at util/hist.c:1056
  #7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056
  #8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  #9  0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0)
      at builtin-top.c:842
  #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202
  #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  #13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339
  #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  #17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  #18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame #2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan <[email protected]>
CC: Milian Wolff <[email protected]>
Cc: Jiri Olsa <[email protected]>
Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/[email protected]
Reported-by: Juri Lelli <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
stephan-gh pushed a commit that referenced this issue Oct 20, 2021
[BUG]
There is a bug report that injected ENOMEM error could leave a tree
block locked while we return to user-space:

  BTRFS info (device loop0): enabling ssd optimizations
  FAULT_INJECTION: forcing a failure.
  name failslab, interval 1, probability 0, space 0, times 0
  CPU: 0 PID: 7579 Comm: syz-executor Not tainted 5.15.0-rc1 #16
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
  Call Trace:
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106
   fail_dump lib/fault-inject.c:52 [inline]
   should_fail+0x13c/0x160 lib/fault-inject.c:146
   should_failslab+0x5/0x10 mm/slab_common.c:1328
   slab_pre_alloc_hook.constprop.99+0x4e/0xc0 mm/slab.h:494
   slab_alloc_node mm/slub.c:3120 [inline]
   slab_alloc mm/slub.c:3214 [inline]
   kmem_cache_alloc+0x44/0x280 mm/slub.c:3219
   btrfs_alloc_delayed_extent_op fs/btrfs/delayed-ref.h:299 [inline]
   btrfs_alloc_tree_block+0x38c/0x670 fs/btrfs/extent-tree.c:4833
   __btrfs_cow_block+0x16f/0x7d0 fs/btrfs/ctree.c:415
   btrfs_cow_block+0x12a/0x300 fs/btrfs/ctree.c:570
   btrfs_search_slot+0x6b0/0xee0 fs/btrfs/ctree.c:1768
   btrfs_insert_empty_items+0x80/0xf0 fs/btrfs/ctree.c:3905
   btrfs_new_inode+0x311/0xa60 fs/btrfs/inode.c:6530
   btrfs_create+0x12b/0x270 fs/btrfs/inode.c:6783
   lookup_open+0x660/0x780 fs/namei.c:3282
   open_last_lookups fs/namei.c:3352 [inline]
   path_openat+0x465/0xe20 fs/namei.c:3557
   do_filp_open+0xe3/0x170 fs/namei.c:3588
   do_sys_openat2+0x357/0x4a0 fs/open.c:1200
   do_sys_open+0x87/0xd0 fs/open.c:1216
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  RIP: 0033:0x46ae99
  Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48
  89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d
  01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f46711b9c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
  RAX: ffffffffffffffda RBX: 000000000078c0a0 RCX: 000000000046ae99
  RDX: 0000000000000000 RSI: 00000000000000a1 RDI: 0000000020005800
  RBP: 00007f46711b9c80 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000017
  R13: 0000000000000000 R14: 000000000078c0a0 R15: 00007ffc129da6e0

  ================================================
  WARNING: lock held when returning to user space!
  5.15.0-rc1 #16 Not tainted
  ------------------------------------------------
  syz-executor/7579 is leaving the kernel with locks still held!
  1 lock held by syz-executor/7579:
   #0: ffff888104b73da8 (btrfs-tree-01/1){+.+.}-{3:3}, at:
  __btrfs_tree_lock+0x2e/0x1a0 fs/btrfs/locking.c:112

[CAUSE]
In btrfs_alloc_tree_block(), after btrfs_init_new_buffer(), the new
extent buffer @buf is locked, but if later operations like adding
delayed tree ref fail, we just free @buf without unlocking it,
resulting above warning.

[FIX]
Unlock @buf in out_free_buf: label.

Reported-by: Hao Sun <[email protected]>
Link: https://lore.kernel.org/linux-btrfs/CACkBjsZ9O6Zr0KK1yGn=1rQi6Crh1yeCRdTSBxx9R99L4xdn-Q@mail.gmail.com/
CC: [email protected] # 5.4+
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
TravMurav pushed a commit that referenced this issue Feb 27, 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]>
TravMurav pushed a commit that referenced this issue Feb 27, 2022
In current async pagefault logic, when a page is ready, KVM relies on
kvm_arch_can_dequeue_async_page_present() to determine whether to deliver
a READY event to the Guest. This function test token value of struct
kvm_vcpu_pv_apf_data, which must be reset to zero by Guest kernel when a
READY event is finished by Guest. If value is zero meaning that a READY
event is done, so the KVM can deliver another.
But the kvm_arch_setup_async_pf() may produce a valid token with zero
value, which is confused with previous mention and may lead the loss of
this READY event.

This bug may cause task blocked forever in Guest:
 INFO: task stress:7532 blocked for more than 1254 seconds.
       Not tainted 5.10.0 #16
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:stress          state:D stack:    0 pid: 7532 ppid:  1409
 flags:0x00000080
 Call Trace:
  __schedule+0x1e7/0x650
  schedule+0x46/0xb0
  kvm_async_pf_task_wait_schedule+0xad/0xe0
  ? exit_to_user_mode_prepare+0x60/0x70
  __kvm_handle_async_pf+0x4f/0xb0
  ? asm_exc_page_fault+0x8/0x30
  exc_page_fault+0x6f/0x110
  ? asm_exc_page_fault+0x8/0x30
  asm_exc_page_fault+0x1e/0x30
 RIP: 0033:0x402d00
 RSP: 002b:00007ffd31912500 EFLAGS: 00010206
 RAX: 0000000000071000 RBX: ffffffffffffffff RCX: 00000000021a32b0
 RDX: 000000000007d011 RSI: 000000000007d000 RDI: 00000000021262b0
 RBP: 00000000021262b0 R08: 0000000000000003 R09: 0000000000000086
 R10: 00000000000000eb R11: 00007fefbdf2baa0 R12: 0000000000000000
 R13: 0000000000000002 R14: 000000000007d000 R15: 0000000000001000

Signed-off-by: Liang Zhang <[email protected]>
Message-Id: <[email protected]>
Cc: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>
stephan-gh pushed a commit that referenced this issue May 8, 2022
kernfs_remove supported NULL kernfs_node param to bail out but revent
per-fs lock change introduced regression that dereferencing the
param without NULL check so kernel goes crash.

This patch checks the NULL kernfs_node in kernfs_remove and if so,
just return.

Quote from bug report by Jirka

```
The bug is triggered by running NAS Parallel benchmark suite on
SuperMicro servers with 2x Xeon(R) Gold 6126 CPU. Here is the error
log:

[  247.035564] BUG: kernel NULL pointer dereference, address: 0000000000000008
[  247.036009] #PF: supervisor read access in kernel mode
[  247.036009] #PF: error_code(0x0000) - not-present page
[  247.036009] PGD 0 P4D 0
[  247.036009] Oops: 0000 [#1] PREEMPT SMP PTI
[  247.058060] CPU: 1 PID: 6546 Comm: umount Not tainted
5.16.0393c3714081a53795bbff0e985d24146def6f57f+ #16
[  247.058060] Hardware name: Supermicro Super Server/X11DDW-L, BIOS
2.0b 03/07/2018
[  247.058060] RIP: 0010:kernfs_remove+0x8/0x50
[  247.058060] Code: 4c 89 e0 5b 5d 41 5c 41 5d 41 5e c3 49 c7 c4 f4
ff ff ff eb b2 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00 00
41 54 55 <48> 8b 47 08 48 89 fd 48 85 c0 48 0f 44 c7 4c 8b 60 50 49 83
c4 60
[  247.058060] RSP: 0018:ffffbbfa48a27e48 EFLAGS: 00010246
[  247.058060] RAX: 0000000000000001 RBX: ffffffff89e31f98 RCX: 0000000080200018
[  247.058060] RDX: 0000000080200019 RSI: fffff6760786c900 RDI: 0000000000000000
[  247.058060] RBP: ffffffff89e31f98 R08: ffff926b61b24d00 R09: 0000000080200018
[  247.122048] R10: ffff926b61b24d00 R11: ffff926a8040c000 R12: ffff927bd09a2000
[  247.122048] R13: ffffffff89e31fa0 R14: dead000000000122 R15: dead000000000100
[  247.122048] FS:  00007f01be0a8c40(0000) GS:ffff926fa8e40000(0000)
knlGS:0000000000000000
[  247.122048] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  247.122048] CR2: 0000000000000008 CR3: 00000001145c6003 CR4: 00000000007706e0
[  247.122048] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  247.122048] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  247.122048] PKRU: 55555554
[  247.122048] Call Trace:
[  247.122048]  <TASK>
[  247.122048]  rdt_kill_sb+0x29d/0x350
[  247.122048]  deactivate_locked_super+0x36/0xa0
[  247.122048]  cleanup_mnt+0x131/0x190
[  247.122048]  task_work_run+0x5c/0x90
[  247.122048]  exit_to_user_mode_prepare+0x229/0x230
[  247.122048]  syscall_exit_to_user_mode+0x18/0x40
[  247.122048]  do_syscall_64+0x48/0x90
[  247.122048]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  247.122048] RIP: 0033:0x7f01be2d735b
```

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215696
Link: https://lore.kernel.org/lkml/CAE4VaGDZr_4wzRn2___eDYRtmdPaGGJdzu_LCSkJYuY9BEO3cw@mail.gmail.com/
Fixes: 393c371 (kernfs: switch global kernfs_rwsem lock to per-fs lock)
Cc: [email protected]
Reported-by: Jirka Hladky <[email protected]>
Tested-by: Jirka Hladky <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Minchan Kim <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
stephan-gh pushed a commit that referenced this issue Dec 11, 2022
We use "unsigned long" to store a PFN in the kernel and phys_addr_t to
store a physical address.

On a 64bit system, both are 64bit wide.  However, on a 32bit system, the
latter might be 64bit wide.  This is, for example, the case on x86 with
PAE: phys_addr_t and PTEs are 64bit wide, while "unsigned long" only spans
32bit.

The current definition of SWP_PFN_BITS without MAX_PHYSMEM_BITS misses
that case, and assumes that the maximum PFN is limited by an 32bit
phys_addr_t.  This implies, that SWP_PFN_BITS will currently only be able
to cover 4 GiB - 1 on any 32bit system with 4k page size, which is wrong.

Let's rely on the number of bits in phys_addr_t instead, but make sure to
not exceed the maximum swap offset, to not make the BUILD_BUG_ON() in
is_pfn_swap_entry() unhappy.  Note that swp_entry_t is effectively an
unsigned long and the maximum swap offset shares that value with the swap
type.

For example, on an 8 GiB x86 PAE system with a kernel config based on
Debian 11.5 (-> CONFIG_FLATMEM=y, CONFIG_X86_PAE=y), we will currently
fail removing migration entries (remove_migration_ptes()), because
mm/page_vma_mapped.c:check_pte() will fail to identify a PFN match as
swp_offset_pfn() wrongly masks off PFN bits.  For example,
split_huge_page_to_list()->...->remap_page() will leave migration entries
in place and continue to unlock the page.

Later, when we stumble over these migration entries (e.g., via
/proc/self/pagemap), pfn_swap_entry_to_page() will BUG_ON() because these
migration entries shouldn't exist anymore and the page was unlocked.

[   33.067591] kernel BUG at include/linux/swapops.h:497!
[   33.067597] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[   33.067602] CPU: 3 PID: 742 Comm: cow Tainted: G            E      6.1.0-rc8+ #16
[   33.067605] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
[   33.067606] EIP: pagemap_pmd_range+0x644/0x650
[   33.067612] Code: 00 00 00 00 66 90 89 ce b9 00 f0 ff ff e9 ff fb ff ff 89 d8 31 db e8 48 c6 52 00 e9 23 fb ff ff e8 61 83 56 00 e9 b6 fe ff ff <0f> 0b bf 00 f0 ff ff e9 38 fa ff ff 3e 8d 74 26 00 55 89 e5 57 31
[   33.067615] EAX: ee394000 EBX: 00000002 ECX: ee394000 EDX: 00000000
[   33.067617] ESI: c1b0ded4 EDI: 00024a00 EBP: c1b0ddb4 ESP: c1b0dd68
[   33.067619] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010246
[   33.067624] CR0: 80050033 CR2: b7a00000 CR3: 01bbbd20 CR4: 00350ef0
[   33.067625] Call Trace:
[   33.067628]  ? madvise_free_pte_range+0x720/0x720
[   33.067632]  ? smaps_pte_range+0x4b0/0x4b0
[   33.067634]  walk_pgd_range+0x325/0x720
[   33.067637]  ? mt_find+0x1d6/0x3a0
[   33.067641]  ? mt_find+0x1d6/0x3a0
[   33.067643]  __walk_page_range+0x164/0x170
[   33.067646]  walk_page_range+0xf9/0x170
[   33.067648]  ? __kmem_cache_alloc_node+0x2a8/0x340
[   33.067653]  pagemap_read+0x124/0x280
[   33.067658]  ? default_llseek+0x101/0x160
[   33.067662]  ? smaps_account+0x1d0/0x1d0
[   33.067664]  vfs_read+0x90/0x290
[   33.067667]  ? do_madvise.part.0+0x24b/0x390
[   33.067669]  ? debug_smp_processor_id+0x12/0x20
[   33.067673]  ksys_pread64+0x58/0x90
[   33.067675]  __ia32_sys_ia32_pread64+0x1b/0x20
[   33.067680]  __do_fast_syscall_32+0x4c/0xc0
[   33.067683]  do_fast_syscall_32+0x29/0x60
[   33.067686]  do_SYSENTER_32+0x15/0x20
[   33.067689]  entry_SYSENTER_32+0x98/0xf1

Decrease the indentation level of SWP_PFN_BITS and SWP_PFN_MASK to keep it
readable and consistent.

[[email protected]: rely on sizeof(phys_addr_t) and min_t() instead]
  Link: https://lkml.kernel.org/r/[email protected]
[[email protected]: use "int" for comparison, as we're only comparing numbers < 64]
  Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 0d206b5 ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry")
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Peter Xu <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
stephan-gh pushed a commit that referenced this issue Feb 7, 2023
Set kprobe at 'jalr 1140(ra)' of vfs_write results in the following
crash:

[   32.092235] Unable to handle kernel access to user memory without uaccess routines at virtual address 00aaaaaad77b1170
[   32.093115] Oops [#1]
[   32.093251] Modules linked in:
[   32.093626] CPU: 0 PID: 135 Comm: ftracetest Not tainted 6.2.0-rc2-00013-gb0aa5e5df0cb-dirty #16
[   32.093985] Hardware name: riscv-virtio,qemu (DT)
[   32.094280] epc : ksys_read+0x88/0xd6
[   32.094855]  ra : ksys_read+0xc0/0xd6
[   32.095016] epc : ffffffff801cda80 ra : ffffffff801cdab8 sp : ff20000000d7bdc0
[   32.095227]  gp : ffffffff80f14000 tp : ff60000080f9cb40 t0 : ffffffff80f13e80
[   32.095500]  t1 : ffffffff8000c29c t2 : ffffffff800dbc54 s0 : ff20000000d7be60
[   32.095716]  s1 : 0000000000000000 a0 : ffffffff805a64ae a1 : ffffffff80a83708
[   32.095921]  a2 : ffffffff80f160a0 a3 : 0000000000000000 a4 : f229b0afdb165300
[   32.096171]  a5 : f229b0afdb165300 a6 : ffffffff80eeebd0 a7 : 00000000000003ff
[   32.096411]  s2 : ff6000007ff76800 s3 : fffffffffffffff7 s4 : 00aaaaaad77b1170
[   32.096638]  s5 : ffffffff80f160a0 s6 : ff6000007ff76800 s7 : 0000000000000030
[   32.096865]  s8 : 00ffffffc3d97be0 s9 : 0000000000000007 s10: 00aaaaaad77c9410
[   32.097092]  s11: 0000000000000000 t3 : ffffffff80f13e48 t4 : ffffffff8000c29c
[   32.097317]  t5 : ffffffff8000c29c t6 : ffffffff800dbc54
[   32.097505] status: 0000000200000120 badaddr: 00aaaaaad77b1170 cause: 000000000000000d
[   32.098011] [<ffffffff801cdb72>] ksys_write+0x6c/0xd6
[   32.098222] [<ffffffff801cdc06>] sys_write+0x2a/0x38
[   32.098405] [<ffffffff80003c76>] ret_from_syscall+0x0/0x2

Since the rs1 and rd might be the same one, such as 'jalr 1140(ra)',
hence it requires obtaining the target address from rs1 followed by
updating rd.

Fixes: c22b0bc ("riscv: Add kprobes supported")
Signed-off-by: Liao Chang <[email protected]>
Reviewed-by: Guo Ren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[Palmer: Pick Guo's cleanup]
Signed-off-by: Palmer Dabbelt <[email protected]>
stephan-gh pushed a commit that referenced this issue Apr 11, 2023
When a system with E810 with existing VFs gets rebooted the following
hang may be observed.

 Pid 1 is hung in iavf_remove(), part of a network driver:
 PID: 1        TASK: ffff965400e5a340  CPU: 24   COMMAND: "systemd-shutdow"
  #0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb
  #1 [ffffaad04005fae8] schedule at ffffffff8b323e2d
  #2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc
  #3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930
  #4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf]
  #5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513
  #6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa
  #7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc
  #8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e
  #9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429
 #10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4
 #11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice]
 #12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice]
 #13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice]
 #14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1
 #15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386
 #16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870
 #17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6
 #18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159
 #19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc
 #20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d
 #21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169
 #22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b
     RIP: 00007f1baa5c13d7  RSP: 00007fffbcc55a98  RFLAGS: 00000202
     RAX: ffffffffffffffda  RBX: 0000000000000000  RCX: 00007f1baa5c13d7
     RDX: 0000000001234567  RSI: 0000000028121969  RDI: 00000000fee1dead
     RBP: 00007fffbcc55ca0   R8: 0000000000000000   R9: 00007fffbcc54e90
     R10: 00007fffbcc55050  R11: 0000000000000202  R12: 0000000000000005
     R13: 0000000000000000  R14: 00007fffbcc55af0  R15: 0000000000000000
     ORIG_RAX: 00000000000000a9  CS: 0033  SS: 002b

During reboot all drivers PM shutdown callbacks are invoked.
In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE.
In ice_shutdown() the call chain above is executed, which at some point
calls iavf_remove(). However iavf_remove() expects the VF to be in one
of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If
that's not the case it sleeps forever.
So if iavf_shutdown() gets invoked before iavf_remove() the system will
hang indefinitely because the adapter is already in state __IAVF_REMOVE.

Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE,
as we already went through iavf_shutdown().

Fixes: 9745780 ("iavf: Add waiting so the port is initialized in remove")
Fixes: a841733 ("iavf: Fix race condition between iavf_shutdown and iavf_remove")
Reported-by: Marius Cornea <[email protected]>
Signed-off-by: Stefan Assmann <[email protected]>
Reviewed-by: Michal Kubiak <[email protected]>
Tested-by: Rafal Romanowski <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
stephan-gh pushed a commit that referenced this issue May 22, 2023
For a similar reason as commit f2c7ca8 ("drm/atomic-helper: Don't
set deadline for modesets"), we need the crtc to be already active in
order to compute a target vblank time for an async commit.  Otherwise
we get this splat reminding us that we are doing it wrong:

   ------------[ cut here ]------------
   msm_dpu ae01000.mdp: drm_WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev))
   WARNING: CPU: 7 PID: 1923 at drivers/gpu/drm/drm_vblank.c:728 drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x148/0x370
   Modules linked in: snd_seq_dummy snd_seq snd_seq_device bridge stp llc tun vhost_vsock vhost vhost_iotlb vmw_vsock_virtio_transport_common vsock uinput rfcomm algif_hash algif_skcipher af_alg veth venus_dec venus_enc cros_ec_typec typec qcom_spmi_temp_alarm qcom_spmi_adc_tm5 qcom_spmi_adc5 xt_cgroup qcom_vadc_common qcom_stats hci_uart btqca xt_MASQUERADE venus_core 8021q coresight_tmc coresight_funnel coresight_etm4x coresight_replicator snd_soc_lpass_sc7180 coresight snd_soc_sc7180 ip6table_nat fuse ath10k_snoc ath10k_core ath mac80211 iio_trig_sysfs bluetooth cfg80211 cros_ec_sensors cros_ec_sensors_core ecdh_generic industrialio_triggered_buffer ecc kfifo_buf cros_ec_sensorhub r8153_ecm cdc_ether usbnet r8152 mii lzo_rle lzo_compress zram hid_vivaldi hid_google_hammer hid_vivaldi_common joydev
   CPU: 7 PID: 1923 Comm: DrmThread Not tainted 5.15.107-18853-g3be267609a0b-dirty #16 a1ffc1a66e79c21c3536d8c9a42e819236e39714
   Hardware name: Google Wormdingler rev1+ BOE panel board (DT)
   pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
   pc : drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x148/0x370
   lr : drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x144/0x370
   sp : ffffffc012e2b800
   x29: ffffffc012e2b840 x28: ffffff8083676094 x27: ffffffc012e2bb28
   x26: ffffff8084539800 x25: 0000000000000000 x24: ffffff8083676000
   x23: ffffffd3c8cdc5a0 x22: ffffff80845b9d00 x21: ffffffc012e2b8b4
   x20: ffffffc012e2b910 x19: 0000000000000001 x18: 0000000000000000
   x17: 0000000000000000 x16: 0000000000000010 x15: ffffffd3c8451a88
   x14: 0000000000000003 x13: 0000000000000004 x12: 0000000000000001
   x11: c0000000ffffdfff x10: ffffffd3c973ef58 x9 : 8ea3526b3cc95900
   x8 : 8ea3526b3cc95900 x7 : 0000000000000000 x6 : 000000000000003a
   x5 : ffffffd3c99676cd x4 : 0000000000000000 x3 : ffffffc012e2b4b8
   x2 : ffffffc012e2b4c0 x1 : 00000000ffffdfff x0 : 0000000000000000
   Call trace:
    drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x148/0x370
    drm_crtc_vblank_helper_get_vblank_timestamp+0x20/0x30
    drm_crtc_get_last_vbltimestamp+0x68/0xb0
    drm_crtc_next_vblank_start+0x5c/0xa8
    msm_atomic_commit_tail+0x264/0x664
    commit_tail+0xac/0x160
    drm_atomic_helper_commit+0x160/0x168
    drm_atomic_commit+0xfc/0x128
    drm_atomic_helper_disable_plane+0x8c/0x110
    __setplane_atomic+0x10c/0x138
    drm_mode_cursor_common+0x3a8/0x410
    drm_mode_cursor_ioctl+0x48/0x70
    drm_ioctl_kernel+0xe0/0x158
    drm_ioctl+0x25c/0x4d8
    __arm64_sys_ioctl+0x98/0xd0
    invoke_syscall+0x4c/0x100
    el0_svc_common+0x98/0x104
    do_el0_svc+0x30/0x90
    el0_svc+0x20/0x50
    el0t_64_sync_handler+0x78/0x108
    el0t_64_sync+0x1a4/0x1a8
   ---[ end trace a0f587e1ab9589e8 ]---

Fixes: 52ff0d3 ("drm/msm/atomic: Switch to vblank_start helper")
Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/532727/
Link: https://lore.kernel.org/r/[email protected]
affenull2345 pushed a commit to affenull2345/linux that referenced this issue Jul 31, 2023
The cited commit adds a compeletion to remove dependency on rtnl
lock. But it causes a deadlock for multiple encapsulations:

 crash> bt ffff8aece8a64000
 PID: 1514557  TASK: ffff8aece8a64000  CPU: 3    COMMAND: "tc"
  #0 [ffffa6d14183f368] __schedule at ffffffffb8ba7f45
  msm8916-mainline#1 [ffffa6d14183f3f8] schedule at ffffffffb8ba8418
  msm8916-mainline#2 [ffffa6d14183f418] schedule_preempt_disabled at ffffffffb8ba8898
  msm8916-mainline#3 [ffffa6d14183f428] __mutex_lock at ffffffffb8baa7f8
  msm8916-mainline#4 [ffffa6d14183f4d0] mutex_lock_nested at ffffffffb8baabeb
  msm8916-mainline#5 [ffffa6d14183f4e0] mlx5e_attach_encap at ffffffffc0f48c17 [mlx5_core]
  msm8916-mainline#6 [ffffa6d14183f628] mlx5e_tc_add_fdb_flow at ffffffffc0f39680 [mlx5_core]
  msm8916-mainline#7 [ffffa6d14183f688] __mlx5e_add_fdb_flow at ffffffffc0f3b636 [mlx5_core]
  msm8916-mainline#8 [ffffa6d14183f6f0] mlx5e_tc_add_flow at ffffffffc0f3bcdf [mlx5_core]
  msm8916-mainline#9 [ffffa6d14183f728] mlx5e_configure_flower at ffffffffc0f3c1d1 [mlx5_core]
 msm8916-mainline#10 [ffffa6d14183f790] mlx5e_rep_setup_tc_cls_flower at ffffffffc0f3d529 [mlx5_core]
 msm8916-mainline#11 [ffffa6d14183f7a0] mlx5e_rep_setup_tc_cb at ffffffffc0f3d714 [mlx5_core]
 msm8916-mainline#12 [ffffa6d14183f7b0] tc_setup_cb_add at ffffffffb8931bb8
 msm8916-mainline#13 [ffffa6d14183f810] fl_hw_replace_filter at ffffffffc0dae901 [cls_flower]
 msm8916-mainline#14 [ffffa6d14183f8d8] fl_change at ffffffffc0db5c57 [cls_flower]
 msm8916-mainline#15 [ffffa6d14183f970] tc_new_tfilter at ffffffffb8936047
 msm8916-mainline#16 [ffffa6d14183fac8] rtnetlink_rcv_msg at ffffffffb88c7c31
 msm8916-mainline#17 [ffffa6d14183fb50] netlink_rcv_skb at ffffffffb8942853
 msm8916-mainline#18 [ffffa6d14183fbc0] rtnetlink_rcv at ffffffffb88c1835
 msm8916-mainline#19 [ffffa6d14183fbd0] netlink_unicast at ffffffffb8941f27
 msm8916-mainline#20 [ffffa6d14183fc18] netlink_sendmsg at ffffffffb8942245
 msm8916-mainline#21 [ffffa6d14183fc98] sock_sendmsg at ffffffffb887d482
 msm8916-mainline#22 [ffffa6d14183fcb8] ____sys_sendmsg at ffffffffb887d81a
 msm8916-mainline#23 [ffffa6d14183fd38] ___sys_sendmsg at ffffffffb88806e2
 msm8916-mainline#24 [ffffa6d14183fe90] __sys_sendmsg at ffffffffb88807a2
 msm8916-mainline#25 [ffffa6d14183ff28] __x64_sys_sendmsg at ffffffffb888080f
 msm8916-mainline#26 [ffffa6d14183ff38] do_syscall_64 at ffffffffb8b9b6a8
 msm8916-mainline#27 [ffffa6d14183ff50] entry_SYSCALL_64_after_hwframe at ffffffffb8c0007c
 crash> bt 0xffff8aeb07544000
 PID: 1110766  TASK: ffff8aeb07544000  CPU: 0    COMMAND: "kworker/u20:9"
  #0 [ffffa6d14e6b7bd8] __schedule at ffffffffb8ba7f45
  msm8916-mainline#1 [ffffa6d14e6b7c68] schedule at ffffffffb8ba8418
  msm8916-mainline#2 [ffffa6d14e6b7c88] schedule_timeout at ffffffffb8baef88
  msm8916-mainline#3 [ffffa6d14e6b7d10] wait_for_completion at ffffffffb8ba968b
  msm8916-mainline#4 [ffffa6d14e6b7d60] mlx5e_take_all_encap_flows at ffffffffc0f47ec4 [mlx5_core]
  msm8916-mainline#5 [ffffa6d14e6b7da0] mlx5e_rep_update_flows at ffffffffc0f3e734 [mlx5_core]
  msm8916-mainline#6 [ffffa6d14e6b7df8] mlx5e_rep_neigh_update at ffffffffc0f400bb [mlx5_core]
  msm8916-mainline#7 [ffffa6d14e6b7e50] process_one_work at ffffffffb80acc9c
  msm8916-mainline#8 [ffffa6d14e6b7ed0] worker_thread at ffffffffb80ad012
  msm8916-mainline#9 [ffffa6d14e6b7f10] kthread at ffffffffb80b615d
 msm8916-mainline#10 [ffffa6d14e6b7f50] ret_from_fork at ffffffffb8001b2f

After the first encap is attached, flow will be added to encap
entry's flows list. If neigh update is running at this time, the
following encaps of the flow can't hold the encap_tbl_lock and
sleep. If neigh update thread is waiting for that flow's init_done,
deadlock happens.

Fix it by holding lock outside of the for loop. If neigh update is
running, prevent encap flows from offloading. Since the lock is held
outside of the for loop, concurrent creation of encap entries is not
allowed. So remove unnecessary wait_for_completion call for res_ready.

Fixes: 95435ad ("net/mlx5e: Only access fully initialized flows in neigh update")
Signed-off-by: Chris Mi <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Reviewed-by: Vlad Buslov <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
affenull2345 pushed a commit to affenull2345/linux that referenced this issue Jul 31, 2023
Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.

Here is an example:

  PID: 59693    TASK: ffff0005f4f51500  CPU: 0    COMMAND: "ovs-vswitchd"
   #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
   msm8916-mainline#1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
   msm8916-mainline#2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
   msm8916-mainline#3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
   msm8916-mainline#4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
   msm8916-mainline#5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
   msm8916-mainline#6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
   msm8916-mainline#7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
   ...

  PID: 58682    TASK: ffff0005b2f0bf00  CPU: 0    COMMAND: "kworker/0:3"
   #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
   msm8916-mainline#1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
   msm8916-mainline#2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
   msm8916-mainline#3 [ffff80000a5d3120] die at ffffb70f0628234c
   msm8916-mainline#4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
   msm8916-mainline#5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
   msm8916-mainline#6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
   msm8916-mainline#7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
   msm8916-mainline#8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
   msm8916-mainline#9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
  msm8916-mainline#10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
  msm8916-mainline#11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
  msm8916-mainline#12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
  msm8916-mainline#13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
  msm8916-mainline#14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
  msm8916-mainline#15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
  msm8916-mainline#16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
  msm8916-mainline#17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90

We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.

Fixes: 95637d9 ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets")
Signed-off-by: Eelco Chaudron <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Acked-by: Aaron Conole <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
stephan-gh pushed a commit that referenced this issue Aug 7, 2023
The cited commit holds encap tbl lock unconditionally when setting
up dests. But it may cause the following deadlock:

 PID: 1063722  TASK: ffffa062ca5d0000  CPU: 13   COMMAND: "handler8"
  #0 [ffffb14de05b7368] __schedule at ffffffffa1d5aa91
  #1 [ffffb14de05b7410] schedule at ffffffffa1d5afdb
  #2 [ffffb14de05b7430] schedule_preempt_disabled at ffffffffa1d5b528
  #3 [ffffb14de05b7440] __mutex_lock at ffffffffa1d5d6cb
  #4 [ffffb14de05b74e8] mutex_lock_nested at ffffffffa1d5ddeb
  #5 [ffffb14de05b74f8] mlx5e_tc_tun_encap_dests_set at ffffffffc12f2096 [mlx5_core]
  #6 [ffffb14de05b7568] post_process_attr at ffffffffc12d9fc5 [mlx5_core]
  #7 [ffffb14de05b75a0] mlx5e_tc_add_fdb_flow at ffffffffc12de877 [mlx5_core]
  #8 [ffffb14de05b75f0] __mlx5e_add_fdb_flow at ffffffffc12e0eef [mlx5_core]
  #9 [ffffb14de05b7660] mlx5e_tc_add_flow at ffffffffc12e12f7 [mlx5_core]
 #10 [ffffb14de05b76b8] mlx5e_configure_flower at ffffffffc12e1686 [mlx5_core]
 #11 [ffffb14de05b7720] mlx5e_rep_indr_offload at ffffffffc12e3817 [mlx5_core]
 #12 [ffffb14de05b7730] mlx5e_rep_indr_setup_tc_cb at ffffffffc12e388a [mlx5_core]
 #13 [ffffb14de05b7740] tc_setup_cb_add at ffffffffa1ab2ba8
 #14 [ffffb14de05b77a0] fl_hw_replace_filter at ffffffffc0bdec2f [cls_flower]
 #15 [ffffb14de05b7868] fl_change at ffffffffc0be6caa [cls_flower]
 #16 [ffffb14de05b7908] tc_new_tfilter at ffffffffa1ab71f0

[1031218.028143]  wait_for_completion+0x24/0x30
[1031218.028589]  mlx5e_update_route_decap_flows+0x9a/0x1e0 [mlx5_core]
[1031218.029256]  mlx5e_tc_fib_event_work+0x1ad/0x300 [mlx5_core]
[1031218.029885]  process_one_work+0x24e/0x510

Actually no need to hold encap tbl lock if there is no encap action.
Fix it by checking if encap action exists or not before holding
encap tbl lock.

Fixes: 37c3b9f ("net/mlx5e: Prevent encap offload when neigh update is running")
Signed-off-by: Chris Mi <[email protected]>
Reviewed-by: Vlad Buslov <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
stephan-gh pushed a commit that referenced this issue Aug 7, 2023
Christoph Biedl reported early OOM on recent kernels:

    swapper: page allocation failure: order:0, mode:0x100(__GFP_ZERO),
nodemask=(null)
    CPU: 0 PID: 0 Comm: swapper Not tainted 6.3.0-rc4+ #16
    Hardware name: 9000/785/C3600
    Backtrace:
     [<10408594>] show_stack+0x48/0x5c
     [<10e152d8>] dump_stack_lvl+0x48/0x64
     [<10e15318>] dump_stack+0x24/0x34
     [<105cf7f8>] warn_alloc+0x10c/0x1c8
     [<105d068c>] __alloc_pages+0xbbc/0xcf8
     [<105d0e4c>] __get_free_pages+0x28/0x78
     [<105ad10c>] __pte_alloc_kernel+0x30/0x98
     [<10406934>] set_fixmap+0xec/0xf4
     [<10411ad4>] patch_map.constprop.0+0xa8/0xdc
     [<10411bb0>] __patch_text_multiple+0xa8/0x208
     [<10411d78>] patch_text+0x30/0x48
     [<1041246c>] arch_jump_label_transform+0x90/0xcc
     [<1056f734>] jump_label_update+0xd4/0x184
     [<1056fc9c>] static_key_enable_cpuslocked+0xc0/0x110
     [<1056fd08>] static_key_enable+0x1c/0x2c
     [<1011362c>] init_mem_debugging_and_hardening+0xdc/0xf8
     [<1010141c>] start_kernel+0x5f0/0xa98
     [<10105da8>] start_parisc+0xb8/0xe4

    Mem-Info:
    active_anon:0 inactive_anon:0 isolated_anon:0
     active_file:0 inactive_file:0 isolated_file:0
     unevictable:0 dirty:0 writeback:0
     slab_reclaimable:0 slab_unreclaimable:0
     mapped:0 shmem:0 pagetables:0
     sec_pagetables:0 bounce:0
     kernel_misc_reclaimable:0
     free:0 free_pcp:0 free_cma:0
    Node 0 active_anon:0kB inactive_anon:0kB active_file:0kB
inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB
mapped:0kB dirty:0kB writeback:0kB shmem:0kB
+writeback_tmp:0kB kernel_stack:0kB pagetables:0kB sec_pagetables:0kB
all_unreclaimable? no
    Normal free:0kB boost:0kB min:0kB low:0kB high:0kB
reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB
inactive_file:0kB unevictable:0kB writepending:0kB
+present:1048576kB managed:1039360kB mlocked:0kB bounce:0kB free_pcp:0kB
local_pcp:0kB free_cma:0kB
    lowmem_reserve[]: 0 0
    Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB
0*1024kB 0*2048kB 0*4096kB = 0kB
    0 total pagecache pages
    0 pages in swap cache
    Free swap  = 0kB
    Total swap = 0kB
    262144 pages RAM
    0 pages HighMem/MovableOnly
    2304 pages reserved
    Backtrace:
     [<10411d78>] patch_text+0x30/0x48
     [<1041246c>] arch_jump_label_transform+0x90/0xcc
     [<1056f734>] jump_label_update+0xd4/0x184
     [<1056fc9c>] static_key_enable_cpuslocked+0xc0/0x110
     [<1056fd08>] static_key_enable+0x1c/0x2c
     [<1011362c>] init_mem_debugging_and_hardening+0xdc/0xf8
     [<1010141c>] start_kernel+0x5f0/0xa98
     [<10105da8>] start_parisc+0xb8/0xe4

    Kernel Fault: Code=15 (Data TLB miss fault) at addr 0f7fe3c0
    CPU: 0 PID: 0 Comm: swapper Not tainted 6.3.0-rc4+ #16
    Hardware name: 9000/785/C3600

This happens because patching static key code temporarily maps it via
fixmap and if it happens before page allocator is initialized set_fixmap()
cannot allocate memory using pte_alloc_kernel().

Make sure that fixmap page tables are preallocated early so that
pte_offset_kernel() in set_fixmap() never resorts to pte allocation.

Signed-off-by: Mike Rapoport (IBM) <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Signed-off-by: Helge Deller <[email protected]>
Tested-by: Christoph Biedl <[email protected]>
Tested-by: John David Anglin <[email protected]>
Cc: <[email protected]> # v6.4+
stephan-gh pushed a commit that referenced this issue Sep 18, 2023
The following processes run into a deadlock. CPU 41 was waiting for CPU 29
to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29
was hung by that spinlock with IRQs disabled.

  PID: 17360    TASK: ffff95c1090c5c40  CPU: 41  COMMAND: "mrdiagd"
  !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0
  !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0
  !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0
   # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0
   # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0
   # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0
   # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0
   # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0
   # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0
   # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0
   #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0
   #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0
   #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0
   #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0
   #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0
   #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0
   #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0
   #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0
   #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0
   #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

  PID: 17355    TASK: ffff95c1090c3d80  CPU: 29  COMMAND: "mrdiagd"
  !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0
  !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0
   # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0
   # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0
   # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0
   # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0
   # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0
   # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0
   # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0
   # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0
   #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0
   #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0
   #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0
   #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0
   #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0
   #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0
   #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0
   #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0

The lock is used to synchronize different sysfs operations, it doesn't
protect any resource that will be touched by an interrupt. Consequently
it's not required to disable IRQs. Replace the spinlock with a mutex to fix
the deadlock.

Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Cc: [email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
wonderfulShrineMaidenOfParadise pushed a commit to wonderfulShrineMaidenOfParadise/linux that referenced this issue Sep 18, 2023
[ Upstream commit 99d4850 ]

Found by leak sanitizer:
```
==1632594==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 21 byte(s) in 1 object(s) allocated from:
    #0 0x7f2953a7077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439
    #1 0x556701d6fbbf in perf_env__read_cpuid util/env.c:369
    msm8916-mainline#2 0x556701d70589 in perf_env__cpuid util/env.c:465
    msm8916-mainline#3 0x55670204bba2 in x86__is_amd_cpu arch/x86/util/env.c:14
    msm8916-mainline#4 0x5567020487a2 in arch__post_evsel_config arch/x86/util/evsel.c:83
    msm8916-mainline#5 0x556701d8f78b in evsel__config util/evsel.c:1366
    msm8916-mainline#6 0x556701ef5872 in evlist__config util/record.c:108
    msm8916-mainline#7 0x556701cd6bcd in test__PERF_RECORD tests/perf-record.c:112
    msm8916-mainline#8 0x556701cacd07 in run_test tests/builtin-test.c:236
    msm8916-mainline#9 0x556701cacfac in test_and_print tests/builtin-test.c:265
    msm8916-mainline#10 0x556701cadddb in __cmd_test tests/builtin-test.c:402
    msm8916-mainline#11 0x556701caf2aa in cmd_test tests/builtin-test.c:559
    msm8916-mainline#12 0x556701d3b557 in run_builtin tools/perf/perf.c:323
    msm8916-mainline#13 0x556701d3bac8 in handle_internal_command tools/perf/perf.c:377
    msm8916-mainline#14 0x556701d3be90 in run_argv tools/perf/perf.c:421
    msm8916-mainline#15 0x556701d3c3f8 in main tools/perf/perf.c:537
    msm8916-mainline#16 0x7f2952a46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

SUMMARY: AddressSanitizer: 21 byte(s) leaked in 1 allocation(s).
```

Fixes: f7b58cb ("perf mem/c2c: Add load store event mappings for AMD")
Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Ravi Bangoria <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
K9100ii pushed a commit to K9100ii/msm8916-mainline-linux that referenced this issue Oct 2, 2023
Fix an error detected by memory sanitizer:
```
==4033==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6
    msm8916-mainline#1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2
    msm8916-mainline#2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9
    msm8916-mainline#3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32
    msm8916-mainline#4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6
    msm8916-mainline#5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8
    msm8916-mainline#6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8
    msm8916-mainline#7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9
    msm8916-mainline#8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8
    msm8916-mainline#9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15
    msm8916-mainline#10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9
    msm8916-mainline#11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8
    msm8916-mainline#12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5
    msm8916-mainline#13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9
    msm8916-mainline#14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11
    msm8916-mainline#15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8
    msm8916-mainline#16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2
    msm8916-mainline#17 0x55fb0f941dab in main tools/perf/perf.c:535:3
```

Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs")
Signed-off-by: Ian Rogers <[email protected]>
Cc: James Clark <[email protected]>
Cc: Kan Liang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>
K9100ii pushed a commit to K9100ii/msm8916-mainline-linux that referenced this issue Oct 2, 2023
…alid

If smb2 request from client is invalid, The following kernel oops could
happen. The patch e2b76ab: "ksmbd: add support for read compound"
leads this issue. When request is invalid, It doesn't set anything in
the response buffer. This patch add missing set invalid parameter error
response.

[  673.085542] ksmbd: cli req too short, len 184 not 142. cmd:5 mid:109
[  673.085580] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  673.085591] #PF: supervisor read access in kernel mode
[  673.085600] #PF: error_code(0x0000) - not-present page
[  673.085608] PGD 0 P4D 0
[  673.085620] Oops: 0000 [msm8916-mainline#1] PREEMPT SMP NOPTI
[  673.085631] CPU: 3 PID: 1039 Comm: kworker/3:0 Not tainted 6.6.0-rc2-tmt msm8916-mainline#16
[  673.085643] Hardware name: AZW U59/U59, BIOS JTKT001 05/05/2022
[  673.085651] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd]
[  673.085719] RIP: 0010:ksmbd_conn_write+0x68/0xc0 [ksmbd]
[  673.085808] RAX: 0000000000000000 RBX: ffff88811ade4f00 RCX: 0000000000000000
[  673.085817] RDX: 0000000000000000 RSI: ffff88810c2a9780 RDI: ffff88810c2a9ac0
[  673.085826] RBP: ffffc900005e3e00 R08: 0000000000000000 R09: 0000000000000000
[  673.085834] R10: ffffffffa3168160 R11: 63203a64626d736b R12: ffff8881057c8800
[  673.085842] R13: ffff8881057c8820 R14: ffff8882781b2380 R15: ffff8881057c8800
[  673.085852] FS:  0000000000000000(0000) GS:ffff888278180000(0000) knlGS:0000000000000000
[  673.085864] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  673.085872] CR2: 0000000000000000 CR3: 000000015b63c000 CR4: 0000000000350ee0
[  673.085883] Call Trace:
[  673.085890]  <TASK>
[  673.085900]  ? show_regs+0x6a/0x80
[  673.085916]  ? __die+0x25/0x70
[  673.085926]  ? page_fault_oops+0x154/0x4b0
[  673.085938]  ? tick_nohz_tick_stopped+0x18/0x50
[  673.085954]  ? __irq_work_queue_local+0xba/0x140
[  673.085967]  ? do_user_addr_fault+0x30f/0x6c0
[  673.085979]  ? exc_page_fault+0x79/0x180
[  673.085992]  ? asm_exc_page_fault+0x27/0x30
[  673.086009]  ? ksmbd_conn_write+0x68/0xc0 [ksmbd]
[  673.086067]  ? ksmbd_conn_write+0x46/0xc0 [ksmbd]
[  673.086123]  handle_ksmbd_work+0x28d/0x4b0 [ksmbd]
[  673.086177]  process_one_work+0x178/0x350
[  673.086193]  ? __pfx_worker_thread+0x10/0x10
[  673.086202]  worker_thread+0x2f3/0x420
[  673.086210]  ? _raw_spin_unlock_irqrestore+0x27/0x50
[  673.086222]  ? __pfx_worker_thread+0x10/0x10
[  673.086230]  kthread+0x103/0x140
[  673.086242]  ? __pfx_kthread+0x10/0x10
[  673.086253]  ret_from_fork+0x39/0x60
[  673.086263]  ? __pfx_kthread+0x10/0x10
[  673.086274]  ret_from_fork_asm+0x1b/0x30

Fixes: e2b76ab ("ksmbd: add support for read compound")
Reported-by: Tom Talpey <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>
K9100ii pushed a commit to K9100ii/msm8916-mainline-linux that referenced this issue Oct 10, 2023
The following call trace shows a deadlock issue due to recursive locking of
mutex "device_mutex". First lock acquire is in target_for_each_device() and
second in target_free_device().

 PID: 148266   TASK: ffff8be21ffb5d00  CPU: 10   COMMAND: "iscsi_ttx"
  #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f
  msm8916-mainline#1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224
  msm8916-mainline#2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee
  msm8916-mainline#3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7
  msm8916-mainline#4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3
  msm8916-mainline#5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c
  msm8916-mainline#6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod]
  msm8916-mainline#7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod]
  msm8916-mainline#8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f
  msm8916-mainline#9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583
 msm8916-mainline#10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod]
 msm8916-mainline#11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc
 msm8916-mainline#12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod]
 msm8916-mainline#13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod]
 msm8916-mainline#14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod]
 msm8916-mainline#15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod]
 msm8916-mainline#16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07
 msm8916-mainline#17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod]
 msm8916-mainline#18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod]
 msm8916-mainline#19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080
 msm8916-mainline#20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364

Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion")
Signed-off-by: Junxiao Bi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
K9100ii pushed a commit to K9100ii/msm8916-mainline-linux that referenced this issue Dec 22, 2023
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a
cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when
removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be
dereferenced as wrong struct in irdma_free_pending_cqp_request().

  PID: 3669   TASK: ffff88aef892c000  CPU: 28  COMMAND: "kworker/28:0"
   #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34
   msm8916-mainline#1 [fffffe0000549e40] nmi_handle at ffffffff810788b2
   msm8916-mainline#2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f
   msm8916-mainline#3 [fffffe0000549eb8] do_nmi at ffffffff81079582
   msm8916-mainline#4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4
      [exception RIP: native_queued_spin_lock_slowpath+1291]
      RIP: ffffffff8127e72b  RSP: ffff88aa841ef778  RFLAGS: 00000046
      RAX: 0000000000000000  RBX: ffff88b01f849700  RCX: ffffffff8127e47e
      RDX: 0000000000000000  RSI: 0000000000000004  RDI: ffffffff83857ec0
      RBP: ffff88afe3e4efc8   R8: ffffed15fc7c9dfa   R9: ffffed15fc7c9dfa
      R10: 0000000000000001  R11: ffffed15fc7c9df9  R12: 0000000000740000
      R13: ffff88b01f849708  R14: 0000000000000003  R15: ffffed1603f092e1
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
  -- <NMI exception stack> --
   msm8916-mainline#5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b
   msm8916-mainline#6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4
   msm8916-mainline#7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363
   msm8916-mainline#8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma]
   msm8916-mainline#9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma]
   msm8916-mainline#10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma]
   msm8916-mainline#11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma]
   msm8916-mainline#12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb
   msm8916-mainline#13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6
   msm8916-mainline#14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278
   msm8916-mainline#15 [ffff88aa841efb88] device_del at ffffffff82179d23
   msm8916-mainline#16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice]
   msm8916-mainline#17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice]
   msm8916-mainline#18 [ffff88aa841efde8] process_one_work at ffffffff811c589a
   msm8916-mainline#19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff
   msm8916-mainline#20 [ffff88aa841eff10] kthread at ffffffff811d87a0
   msm8916-mainline#21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f

Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions")
Link: https://lore.kernel.org/r/[email protected]
Suggested-by: "Ismail, Mustafa" <[email protected]>
Signed-off-by: Shifeng Li <[email protected]>
Reviewed-by: Shiraz Saleem <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
wonderfulShrineMaidenOfParadise pushed a commit to wonderfulShrineMaidenOfParadise/linux that referenced this issue Feb 2, 2024
[ Upstream commit 55a8210 ]

When processing a packed profile in unpack_profile() described like

 "profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}"

a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then
passed to aa_splitn_fqname().

aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace.
Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later
aa_alloc_profile() crashes as the new profile name is NULL now.

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty msm8916-mainline#16
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:strlen+0x1e/0xa0
Call Trace:
 <TASK>
 ? strlen+0x1e/0xa0
 aa_policy_init+0x1bb/0x230
 aa_alloc_profile+0xb1/0x480
 unpack_profile+0x3bc/0x4960
 aa_unpack+0x309/0x15e0
 aa_replace_profiles+0x213/0x33c0
 policy_update+0x261/0x370
 profile_replace+0x20e/0x2a0
 vfs_write+0x2af/0xe00
 ksys_write+0x126/0x250
 do_syscall_64+0x46/0xf0
 entry_SYSCALL_64_after_hwframe+0x6e/0x76
 </TASK>
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x1e/0xa0

It seems such behaviour of aa_splitn_fqname() is expected and checked in
other places where it is called (e.g. aa_remove_profiles). Well, there
is an explicit comment "a ns name without a following profile is allowed"
inside.

AFAICS, nothing can prevent unpacked "name" to be in form like
":samba-dcerpcd" - it is passed from userspace.

Deny the whole profile set replacement in such case and inform user with
EPROTO and an explaining message.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 04dc715 ("apparmor: audit policy ns specified in policy load")
Signed-off-by: Fedor Pchelkin <[email protected]>
Signed-off-by: John Johansen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
TravMurav pushed a commit that referenced this issue Apr 29, 2024
vhost_worker will call tun call backs to receive packets. If too many
illegal packets arrives, tun_do_read will keep dumping packet contents.
When console is enabled, it will costs much more cpu time to dump
packet and soft lockup will be detected.

net_ratelimit mechanism can be used to limit the dumping rate.

PID: 33036    TASK: ffff949da6f20000  CPU: 23   COMMAND: "vhost-32980"
 #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253
 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3
 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e
 #3 [fffffe00003fced0] do_nmi at ffffffff8922660d
 #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663
    [exception RIP: io_serial_in+20]
    RIP: ffffffff89792594  RSP: ffffa655314979e8  RFLAGS: 00000002
    RAX: ffffffff89792500  RBX: ffffffff8af428a0  RCX: 0000000000000000
    RDX: 00000000000003fd  RSI: 0000000000000005  RDI: ffffffff8af428a0
    RBP: 0000000000002710   R8: 0000000000000004   R9: 000000000000000f
    R10: 0000000000000000  R11: ffffffff8acbf64f  R12: 0000000000000020
    R13: ffffffff8acbf698  R14: 0000000000000058  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594
 #6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470
 #7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6
 #8 [ffffa65531497a20] uart_console_write at ffffffff8978b605
 #9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558
 #10 [ffffa65531497ac8] console_unlock at ffffffff89316124
 #11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07
 #12 [ffffa65531497b68] printk at ffffffff89318306
 #13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765
 #14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun]
 #15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun]
 #16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net]
 #17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost]
 #18 [ffffa65531497f10] kthread at ffffffff892d2e72
 #19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f

Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors")
Signed-off-by: Lei Chen <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Acked-by: Jason Wang <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
TravMurav pushed a commit that referenced this issue May 19, 2024
With BPF_PROBE_MEM, BPF allows de-referencing an untrusted pointer. To
thwart invalid memory accesses, the JITs add an exception table entry
for all such accesses. But in case the src_reg + offset is a userspace
address, the BPF program might read that memory if the user has
mapped it.

Make the verifier add guard instructions around such memory accesses and
skip the load if the address falls into the userspace region.

The JITs need to implement bpf_arch_uaddress_limit() to define where
the userspace addresses end for that architecture or TASK_SIZE is taken
as default.

The implementation is as follows:

REG_AX =  SRC_REG
if(offset)
	REG_AX += offset;
REG_AX >>= 32;
if (REG_AX <= (uaddress_limit >> 32))
	DST_REG = 0;
else
	DST_REG = *(size *)(SRC_REG + offset);

Comparing just the upper 32 bits of the load address with the upper
32 bits of uaddress_limit implies that the values are being aligned down
to a 4GB boundary before comparison.

The above means that all loads with address <= uaddress_limit + 4GB are
skipped. This is acceptable because there is a large hole (much larger
than 4GB) between userspace and kernel space memory, therefore a
correctly functioning BPF program should not access this 4GB memory
above the userspace.

Let's analyze what this patch does to the following fentry program
dereferencing an untrusted pointer:

  SEC("fentry/tcp_v4_connect")
  int BPF_PROG(fentry_tcp_v4_connect, struct sock *sk)
  {
                *(volatile long *)sk;
                return 0;
  }

    BPF Program before              |           BPF Program after
    ------------------              |           -----------------

  0: (79) r1 = *(u64 *)(r1 +0)          0: (79) r1 = *(u64 *)(r1 +0)
  -----------------------------------------------------------------------
  1: (79) r1 = *(u64 *)(r1 +0) --\      1: (bf) r11 = r1
  ----------------------------\   \     2: (77) r11 >>= 32
  2: (b7) r0 = 0               \   \    3: (b5) if r11 <= 0x8000 goto pc+2
  3: (95) exit                  \   \-> 4: (79) r1 = *(u64 *)(r1 +0)
                                 \      5: (05) goto pc+1
                                  \     6: (b7) r1 = 0
                                   \--------------------------------------
                                        7: (b7) r0 = 0
                                        8: (95) exit

As you can see from above, in the best case (off=0), 5 extra instructions
are emitted.

Now, we analyze the same program after it has gone through the JITs of
ARM64 and RISC-V architectures. We follow the single load instruction
that has the untrusted pointer and see what instrumentation has been
added around it.

                                x86-64 JIT
                                ==========
     JIT's Instrumentation
          (upstream)
     ---------------------

   0:   nopl   0x0(%rax,%rax,1)
   5:   xchg   %ax,%ax
   7:   push   %rbp
   8:   mov    %rsp,%rbp
   b:   mov    0x0(%rdi),%rdi
  ---------------------------------
   f:   movabs $0x800000000000,%r11
  19:   cmp    %r11,%rdi
  1c:   jb     0x000000000000002a
  1e:   mov    %rdi,%r11
  21:   add    $0x0,%r11
  28:   jae    0x000000000000002e
  2a:   xor    %edi,%edi
  2c:   jmp    0x0000000000000032
  2e:   mov    0x0(%rdi),%rdi
  ---------------------------------
  32:   xor    %eax,%eax
  34:   leave
  35:   ret

The x86-64 JIT already emits some instructions to protect against user
memory access. This patch doesn't make any changes for the x86-64 JIT.

                                  ARM64 JIT
                                  =========

        No Intrumentation                       Verifier's Instrumentation
           (upstream)                                  (This patch)
        -----------------                       --------------------------

   0:   add     x9, x30, #0x0                0:   add     x9, x30, #0x0
   4:   nop                                  4:   nop
   8:   paciasp                              8:   paciasp
   c:   stp     x29, x30, [sp, #-16]!        c:   stp     x29, x30, [sp, #-16]!
  10:   mov     x29, sp                     10:   mov     x29, sp
  14:   stp     x19, x20, [sp, #-16]!       14:   stp     x19, x20, [sp, #-16]!
  18:   stp     x21, x22, [sp, #-16]!       18:   stp     x21, x22, [sp, #-16]!
  1c:   stp     x25, x26, [sp, #-16]!       1c:   stp     x25, x26, [sp, #-16]!
  20:   stp     x27, x28, [sp, #-16]!       20:   stp     x27, x28, [sp, #-16]!
  24:   mov     x25, sp                     24:   mov     x25, sp
  28:   mov     x26, #0x0                   28:   mov     x26, #0x0
  2c:   sub     x27, x25, #0x0              2c:   sub     x27, x25, #0x0
  30:   sub     sp, sp, #0x0                30:   sub     sp, sp, #0x0
  34:   ldr     x0, [x0]                    34:   ldr     x0, [x0]
--------------------------------------------------------------------------------
  38:   ldr     x0, [x0] ----------\        38:   add     x9, x0, #0x0
-----------------------------------\\       3c:   lsr     x9, x9, #32
  3c:   mov     x7, #0x0            \\      40:   cmp     x9, #0x10, lsl #12
  40:   mov     sp, sp               \\     44:   b.ls    0x0000000000000050
  44:   ldp     x27, x28, [sp], #16   \\--> 48:   ldr     x0, [x0]
  48:   ldp     x25, x26, [sp], #16    \    4c:   b       0x0000000000000054
  4c:   ldp     x21, x22, [sp], #16     \   50:   mov     x0, #0x0
  50:   ldp     x19, x20, [sp], #16      \---------------------------------------
  54:   ldp     x29, x30, [sp], #16         54:   mov     x7, #0x0
  58:   add     x0, x7, #0x0                58:   mov     sp, sp
  5c:   autiasp                             5c:   ldp     x27, x28, [sp], #16
  60:   ret                                 60:   ldp     x25, x26, [sp], #16
  64:   nop                                 64:   ldp     x21, x22, [sp], #16
  68:   ldr     x10, 0x0000000000000070     68:   ldp     x19, x20, [sp], #16
  6c:   br      x10                         6c:   ldp     x29, x30, [sp], #16
                                            70:   add     x0, x7, #0x0
                                            74:   autiasp
                                            78:   ret
                                            7c:   nop
                                            80:   ldr     x10, 0x0000000000000088
                                            84:   br      x10

There are 6 extra instructions added in ARM64 in the best case. This will
become 7 in the worst case (off != 0).

                           RISC-V JIT (RISCV_ISA_C Disabled)
                           ==========

        No Intrumentation           Verifier's Instrumentation
           (upstream)                      (This patch)
        -----------------           --------------------------

   0:   nop                            0:   nop
   4:   nop                            4:   nop
   8:   li      a6, 33                 8:   li      a6, 33
   c:   addi    sp, sp, -16            c:   addi    sp, sp, -16
  10:   sd      s0, 8(sp)             10:   sd      s0, 8(sp)
  14:   addi    s0, sp, 16            14:   addi    s0, sp, 16
  18:   ld      a0, 0(a0)             18:   ld      a0, 0(a0)
---------------------------------------------------------------
  1c:   ld      a0, 0(a0) --\         1c:   mv      t0, a0
--------------------------\  \        20:   srli    t0, t0, 32
  20:   li      a5, 0      \  \       24:   lui     t1, 4096
  24:   ld      s0, 8(sp)   \  \      28:   sext.w  t1, t1
  28:   addi    sp, sp, 16   \  \     2c:   bgeu    t1, t0, 12
  2c:   sext.w  a0, a5        \  \--> 30:   ld      a0, 0(a0)
  30:   ret                    \      34:   j       8
                                \     38:   li      a0, 0
                                 \------------------------------
                                      3c:   li      a5, 0
                                      40:   ld      s0, 8(sp)
                                      44:   addi    sp, sp, 16
                                      48:   sext.w  a0, a5
                                      4c:   ret

There are 7 extra instructions added in RISC-V.

Fixes: 8008342 ("bpf, arm64: Add BPF exception tables")
Reported-by: Breno Leitao <[email protected]>
Suggested-by: Alexei Starovoitov <[email protected]>
Acked-by: Ilya Leoshkevich <[email protected]>
Signed-off-by: Puranjay Mohan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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