linux-stable.git/arch/arm/kernel/unwind.c, branch linux-5.4.y Linux kernel stable tree ARM: 9295/1: unwind:fix unwind abort for uleb128 case 2023-06-09T08:28:55+00:00 Haibo Li haibo.li@mediatek.com 2023-04-17T09:17:07+00:00 b950966b44f974b0a9ca832f196c0fd3d0ab97d7 [ Upstream commit fa3eeb638de0c1a9d2d860e5b48259facdd65176 ] When unwind instruction is 0xb2,the subsequent instructions are uleb128 bytes. For now,it uses only the first uleb128 byte in code. For vsp increments of 0x204~0x400,use one uleb128 byte like below: 0xc06a00e4 <unwind_test_work>: 0x80b27fac Compact model index: 0 0xb2 0x7f vsp = vsp + 1024 0xac pop {r4, r5, r6, r7, r8, r14} For vsp increments larger than 0x400,use two uleb128 bytes like below: 0xc06a00e4 <unwind_test_work>: @0xc0cc9e0c Compact model index: 1 0xb2 0x81 0x01 vsp = vsp + 1032 0xac pop {r4, r5, r6, r7, r8, r14} The unwind works well since the decoded uleb128 byte is also 0x81. For vsp increments larger than 0x600,use two uleb128 bytes like below: 0xc06a00e4 <unwind_test_work>: @0xc0cc9e0c Compact model index: 1 0xb2 0x81 0x02 vsp = vsp + 1544 0xac pop {r4, r5, r6, r7, r8, r14} In this case,the decoded uleb128 result is 0x101(vsp=0x204+(0x101<<2)). While the uleb128 used in code is 0x81(vsp=0x204+(0x81<<2)). The unwind aborts at this frame since it gets incorrect vsp. To fix this,add uleb128 decode to cover all the above case. Signed-off-by: Haibo Li <haibo.li@mediatek.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fa3eeb638de0c1a9d2d860e5b48259facdd65176 ]

When unwind instruction is 0xb2,the subsequent instructions
are uleb128 bytes.
For now,it uses only the first uleb128 byte in code.

For vsp increments of 0x204~0x400,use one uleb128 byte like below:
0xc06a00e4 <unwind_test_work>: 0x80b27fac
  Compact model index: 0
  0xb2 0x7f vsp = vsp + 1024
  0xac      pop {r4, r5, r6, r7, r8, r14}

For vsp increments larger than 0x400,use two uleb128 bytes like below:
0xc06a00e4 <unwind_test_work>: @0xc0cc9e0c
  Compact model index: 1
  0xb2 0x81 0x01 vsp = vsp + 1032
  0xac      pop {r4, r5, r6, r7, r8, r14}
The unwind works well since the decoded uleb128 byte is also 0x81.

For vsp increments larger than 0x600,use two uleb128 bytes like below:
0xc06a00e4 <unwind_test_work>: @0xc0cc9e0c
  Compact model index: 1
  0xb2 0x81 0x02 vsp = vsp + 1544
  0xac      pop {r4, r5, r6, r7, r8, r14}
In this case,the decoded uleb128 result is 0x101(vsp=0x204+(0x101<<2)).
While the uleb128 used in code is 0x81(vsp=0x204+(0x81<<2)).
The unwind aborts at this frame since it gets incorrect vsp.

To fix this,add uleb128 decode to cover all the above case.

Signed-off-by: Haibo Li <haibo.li@mediatek.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05T15:37:06+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-29T23:57:47+00:00 4505153954fdb1465d2b178288a9bf646f2a2166 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 136 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 59 temple place suite 330 boston ma 02111
  1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 136 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 8840/1: use a raw_spinlock_t in unwind 2019-02-26T11:24:51+00:00 Sebastian Andrzej Siewior bigeasy@linutronix.de 2019-02-13T16:14:42+00:00 74ffe79ae538283bbf7c155e62339f1e5c87b55a Mostly unwind is done with irqs enabled however SLUB may call it with irqs disabled while creating a new SLUB cache. I had system freeze while loading a module which called kmem_cache_create() on init. That means SLUB's __slab_alloc() disabled interrupts and then ->new_slab_objects() ->new_slab() ->setup_object() ->setup_object_debug() ->init_tracking() ->set_track() ->save_stack_trace() ->save_stack_trace_tsk() ->walk_stackframe() ->unwind_frame() ->unwind_find_idx() =>spin_lock_irqsave(&unwind_lock); Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> 
Mostly unwind is done with irqs enabled however SLUB may call it with
irqs disabled while creating a new SLUB cache.

I had system freeze while loading a module which called
kmem_cache_create() on init. That means SLUB's __slab_alloc() disabled
interrupts and then

->new_slab_objects()
 ->new_slab()
  ->setup_object()
   ->setup_object_debug()
    ->init_tracking()
     ->set_track()
      ->save_stack_trace()
       ->save_stack_trace_tsk()
        ->walk_stackframe()
         ->unwind_frame()
          ->unwind_find_idx()
           =>spin_lock_irqsave(&unwind_lock);

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
ARM: 8176/1: Use current_stack_pointer in unwind_backtrace 2014-11-13T23:58:09+00:00 Behan Webster behanw@converseincode.com 2014-09-26T23:31:10+00:00 0bf4954f248c59705470bae2210f67a4b03f8f3c Use the global current_stack_pointer to get the value of the stack pointer. This change supports being able to compile the kernel with both gcc and clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Reviewed-by: Mark Charlebois <charlebm@gmail.com> Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Use the global current_stack_pointer to get the value of the stack pointer.
This change supports being able to compile the kernel with both gcc and clang.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8152/1: Convert pr_warning to pr_warn 2014-09-26T13:39:53+00:00 Joe Perches joe@perches.com 2014-09-16T19:41:43+00:00 8b521cb2947d8811b4cf7fc6a7a6ebde35218243 Use the more common pr_warn. Other miscellanea: o Coalesce formats o Realign arguments Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Use the more common pr_warn.

Other miscellanea:

o Coalesce formats
o Realign arguments

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8073/1: unwind: Use arm_get_current_stackframe 2014-07-18T11:29:16+00:00 Nikolay Borisov Nikolay.Borisov@arm.com 2014-06-03T18:49:14+00:00 c8bee0ad78b2107ffb56fa82f0ab2b762311d172 Make the unwind code use the correct API so that the frame pointer is extracted from the correct register. Signed-off-by: Nikolay Borisov <Nikolay.Borisov@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Make the unwind code use the correct API so that the frame pointer
is extracted from the correct register.

Signed-off-by: Nikolay Borisov <Nikolay.Borisov@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arm, unwind, LLVMLinux: Enable clang to be used for unwinding the stack 2014-06-07T18:44:39+00:00 Mark Charlebois charlebm@gmail.com 2014-02-12T03:26:08+00:00 e6b80757700a11315dd81b161f8d86099214c185 Patch to prevent warning of a buggy compiler when using clang and the ARM_UNWIND option. Clang defines (at least on the current trunk) GNUC, GNUC_MINOR, and GNUC_PATCHLEVEL to 4, 2, and 1 respectively. This version of GCC gets flagged as buggy, but it isn't actually an issue with clang so the patch will do what it did before unless clang is defined and then it will not report the GCC version as an issue. Signed-off-by: Mark Charlebois <charlebm@gmail.com> Signed-off-by: Behan Webster <behanw@converseincode.com> 
Patch to prevent warning of a buggy compiler when using clang and
the ARM_UNWIND option.

Clang defines (at least on the current trunk) GNUC, GNUC_MINOR, and
GNUC_PATCHLEVEL to 4, 2, and 1 respectively.

This version of GCC gets flagged as buggy, but it isn't actually an
issue with clang so the patch will do what it did before unless clang
is defined and then it will not report the GCC version as an issue.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
ARM: 8052/1: unwind: Fix handling of "Pop r4-r[4+nnn],r14" opcode 2014-05-25T22:44:26+00:00 Nikolay Borisov Nikolay.Borisov@arm.com 2014-05-08T14:54:26+00:00 8203d5b628907ae6141e4eb52f9b48e0f1f46cd2 The arm EABI states that unwind opcode 10100nnn means pop register r4-4[4+nnn],aditionally there is a similar unwind opcode: 10101nnn which means the same thing plus popping r14. Those two cases are handled by the unwind_exec_pop_r4_to_rN function which checks whether the 4th bit is set and does r14 popping. However, up until now it has been checking whether the 8th bit was set (mask & 0x80) instead of the 4th (mask & 0x8), a simple to make typo but this meant that we were always popping r14 even if we had the former opcode. This patch changes the mask so that the 2 unwind opcodes are being handled correctly. Signed-off-by: Nikolay Borisov <Nikolay.Borisov@arm.com> Reviewed-by: Anurag Aggarwal <anurag19aggarwal@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
The arm EABI states that unwind opcode 10100nnn means pop register r4-4[4+nnn],aditionally there is a similar unwind opcode: 10101nnn which means the same thing plus popping r14. Those two cases are handled by the unwind_exec_pop_r4_to_rN function which checks whether the 4th bit is set and does r14 popping.

However, up until now it has been checking whether the 8th bit was set (mask & 0x80) instead of the 4th (mask & 0x8), a simple to make typo but this meant that we were always popping r14 even if we had the former opcode.

This patch changes the mask so that the 2 unwind opcodes are being handled correctly.

Signed-off-by: Nikolay Borisov <Nikolay.Borisov@arm.com>
Reviewed-by: Anurag Aggarwal <anurag19aggarwal@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7987/1: ARM : unwinder : Prevent data abort due to stack overflow 2014-02-25T11:48:24+00:00 Anurag Aggarwal a.anurag@samsung.com 2014-02-24T10:17:36+00:00 a51345770e519552e749ff457a2a9f83171a67b5 While unwinding backtrace, stack overflow is possible. This stack overflow can sometimes lead to data abort in system if the area after stack is not mapped to physical memory. To prevent this problem from happening, execute the instructions that can cause a data abort in separate helper functions, where a check for feasibility is made before reading each word from the stack. Signed-off-by: Anurag Aggarwal <a.anurag@samsung.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
While unwinding backtrace, stack overflow is possible. This stack
overflow can sometimes lead to data abort in system if the area after
stack is not mapped to physical memory.

To prevent this problem from happening, execute the instructions that
can cause a data abort in separate helper functions, where a check for
feasibility is made before reading each word from the stack.

Signed-off-by: Anurag Aggarwal <a.anurag@samsung.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: unwinder: fix bisection to find origin in .idx section 2011-12-15T22:02:19+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2011-12-15T20:47:56+00:00 ddf5a25c5fdd4cc276edf451871c38002eec0f95 The bisection implemented in unwind_find_origin() stopped to early. If there is only a single entry left to check the original code just took the end point as origin which might be wrong. This was introduced in commit de66a979012d ("ARM: 7187/1: fix unwinding for XIP kernels"). Reported-and-tested-by: Nick Bowler <nbowler@elliptictech.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The bisection implemented in unwind_find_origin() stopped to early.  If
there is only a single entry left to check the original code just took
the end point as origin which might be wrong.

This was introduced in commit de66a979012d ("ARM: 7187/1: fix unwinding
for XIP kernels").

Reported-and-tested-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>