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-Wframe-larger-than= in block/blk-cgroup.c #99

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tpimh opened this issue Sep 17, 2018 · 2 comments
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-Wframe-larger-than= in block/blk-cgroup.c #99

tpimh opened this issue Sep 17, 2018 · 2 comments
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@tpimh
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tpimh commented Sep 17, 2018

Close this if can be merged with #39

block/blk-cgroup.c:942:12: warning: stack frame size of 2296 bytes in function 'blkcg_print_stat' [-Wframe-larger-than=]
static int blkcg_print_stat(struct seq_file *sf, void *v)
           ^
1 warning generated.

@tpimh tpimh added [BUG] linux A bug that should be fixed in the mainline kernel. low priority This bug is not critical and not a priority labels Sep 17, 2018
@nickdesaulniers
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please verify if this are still seen without CONFIG_KASAN

@tpimh
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tpimh commented Sep 18, 2018

Same as #100: Without CONFIG_KASAN all instances of -Wframe-larger-than= are gone

@nickdesaulniers nickdesaulniers added duplicate This issue or pull request already exists and removed [BUG] linux A bug that should be fixed in the mainline kernel. low priority This bug is not critical and not a priority labels Sep 19, 2018
nathanchance pushed a commit that referenced this issue Jan 21, 2019
…ror handling

The current code in __mdiobus_register() doesn't properly handle
failures returned by the devm_gpiod_get_optional() call: it returns
immediately, without unregistering the device that was added by the
call to device_register() earlier in the function.

This leaves a stale device, which then causes a NULL pointer
dereference in the code that handles deferred probing:

[    1.489982] Unable to handle kernel NULL pointer dereference at virtual address 00000074
[    1.498110] pgd = (ptrval)
[    1.500838] [00000074] *pgd=00000000
[    1.504432] Internal error: Oops: 17 [#1] SMP ARM
[    1.509133] Modules linked in:
[    1.512192] CPU: 1 PID: 51 Comm: kworker/1:3 Not tainted 4.20.0-00039-g3b73a4cc8b3e-dirty #99
[    1.520708] Hardware name: Xilinx Zynq Platform
[    1.525261] Workqueue: events deferred_probe_work_func
[    1.530403] PC is at klist_next+0x10/0xfc
[    1.534403] LR is at device_for_each_child+0x40/0x94
[    1.539361] pc : [<c0683fbc>]    lr : [<c0455d90>]    psr: 200e0013
[    1.545628] sp : ceeefe68  ip : 00000001  fp : ffffe000
[    1.550863] r10: 00000000  r9 : c0c66790  r8 : 00000000
[    1.556079] r7 : c0457d44  r6 : 00000000  r5 : ceeefe8c  r4 : cfa2ec78
[    1.562604] r3 : 00000064  r2 : c0457d44  r1 : ceeefe8c  r0 : 00000064
[    1.569129] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[    1.576263] Control: 18c5387d  Table: 0ed7804a  DAC: 00000051
[    1.582013] Process kworker/1:3 (pid: 51, stack limit = 0x(ptrval))
[    1.588280] Stack: (0xceeefe68 to 0xceef0000)
[    1.592630] fe60:                   cfa2ec78 c0c03c08 00000000 c0457d44 00000000 c0c66790
[    1.600814] fe80: 00000000 c0455d90 ceeefeac 00000064 00000000 0d7a542e cee9d494 cfa2ec78
[    1.608998] fea0: cfa2ec78 00000000 c0457d44 c0457d7c cee9d494 c0c03c08 00000000 c0455dac
[    1.617182] fec0: cf98ba44 cf926a00 cee9d494 0d7a542e 00000000 cf935a10 cf935a10 cf935a10
[    1.625366] fee0: c0c4e9b8 c0457d7c c0c4e80c 00000001 cf935a10 c0457df4 cf935a10 c0c4e99c
[    1.633550] ff00: c0c4e99c c045a27c c0c4e9c4 ced63f80 cfde8a80 cfdebc00 00000000 c013893c
[    1.641734] ff20: cfde8a80 cfde8a80 c07bd354 ced63f80 ced63f94 cfde8a80 00000008 c0c02d00
[    1.649936] ff40: cfde8a98 cfde8a80 ffffe000 c0139a30 ffffe000 c0c6624a c07bd354 00000000
[    1.658120] ff60: ffffe000 cee9e780 ceebfe00 00000000 ceeee000 ced63f80 c0139788 cf8cdea4
[    1.666304] ff80: cee9e79c c013e598 00000001 ceebfe00 c013e44c 00000000 00000000 00000000
[    1.674488] ffa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000
[    1.682671] ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    1.690855] ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[    1.699058] [<c0683fbc>] (klist_next) from [<c0455d90>] (device_for_each_child+0x40/0x94)
[    1.707241] [<c0455d90>] (device_for_each_child) from [<c0457d7c>] (device_reorder_to_tail+0x38/0x88)
[    1.716476] [<c0457d7c>] (device_reorder_to_tail) from [<c0455dac>] (device_for_each_child+0x5c/0x94)
[    1.725692] [<c0455dac>] (device_for_each_child) from [<c0457d7c>] (device_reorder_to_tail+0x38/0x88)
[    1.734927] [<c0457d7c>] (device_reorder_to_tail) from [<c0457df4>] (device_pm_move_to_tail+0x28/0x40)
[    1.744235] [<c0457df4>] (device_pm_move_to_tail) from [<c045a27c>] (deferred_probe_work_func+0x58/0x8c)
[    1.753746] [<c045a27c>] (deferred_probe_work_func) from [<c013893c>] (process_one_work+0x210/0x4fc)
[    1.762888] [<c013893c>] (process_one_work) from [<c0139a30>] (worker_thread+0x2a8/0x5c0)
[    1.771072] [<c0139a30>] (worker_thread) from [<c013e598>] (kthread+0x14c/0x154)
[    1.778482] [<c013e598>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
[    1.785689] Exception stack(0xceeeffb0 to 0xceeefff8)
[    1.790739] ffa0:                                     00000000 00000000 00000000 00000000
[    1.798923] ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    1.807107] ffe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    1.813724] Code: e92d47f0 e1a05000 e8900048 e1a00003 (e5937010)
[    1.819844] ---[ end trace 3c2c0c8b65399ec9 ]---

The actual error that we had from devm_gpiod_get_optional() was
-EPROBE_DEFER, due to the GPIO being provided by a driver that is
probed later than the Ethernet controller driver.

To fix this, we simply add the missing device_del() invocation in the
error path.

Fixes: 6922689 ("mdio_bus: Issue GPIO RESET to PHYs")
Signed-off-by: Thomas Petazzoni <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
nathanchance pushed a commit that referenced this issue Jul 28, 2019
When arch_stack_walk_user() is called from atomic contexts, access_ok() can
trigger the following warning if compiled with CONFIG_DEBUG_ATOMIC_SLEEP=y.

Reproducer:

  // CONFIG_DEBUG_ATOMIC_SLEEP=y
  # cd /sys/kernel/debug/tracing
  # echo 1 > options/userstacktrace
  # echo 1 > events/irq/irq_handler_entry/enable

  WARNING: CPU: 0 PID: 2649 at arch/x86/kernel/stacktrace.c:103 arch_stack_walk_user+0x6e/0xf6
  CPU: 0 PID: 2649 Comm: bash Not tainted 5.3.0-rc1+ #99
  RIP: 0010:arch_stack_walk_user+0x6e/0xf6
  Call Trace:
   <IRQ>
   stack_trace_save_user+0x10a/0x16d
   trace_buffer_unlock_commit_regs+0x185/0x240
   trace_event_buffer_commit+0xec/0x330
   trace_event_raw_event_irq_handler_entry+0x159/0x1e0
   __handle_irq_event_percpu+0x22d/0x440
   handle_irq_event_percpu+0x70/0x100
   handle_irq_event+0x5a/0x8b
   handle_edge_irq+0x12f/0x3f0
   handle_irq+0x34/0x40
   do_IRQ+0xa6/0x1f0
   common_interrupt+0xf/0xf
   </IRQ>

Fix it by calling __range_not_ok() directly instead of access_ok() as
copy_from_user_nmi() does. This is fine here because the actual copy is
inside a pagefault disabled region.

Reported-by: Juri Lelli <[email protected]>
Signed-off-by: Eiichi Tsukata <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
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