diff options
| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2017-11-30 15:35:54 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-12-11 19:07:07 +0100 |
| commit | 0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe (patch) | |
| tree | e3ed50888a5c91fb5d6b0e23006c916c31018968 /arch/x86 | |
| parent | f79ce87fa49da778a1ad54c7d3c6755e13cf8489 (diff) | |
x86/unwinder/guess: Prevent using CONFIG_UNWINDER_GUESS=y with CONFIG_STACKDEPOT=y
Stackdepot doesn't work well with CONFIG_UNWINDER_GUESS=y.
The 'guess' unwinder generate awfully large and inaccurate stacktraces,
thus stackdepot can't deduplicate stacktraces because they all look like
unique. Eventually stackdepot reaches its capacity limit:
WARNING: CPU: 0 PID: 545 at lib/stackdepot.c:119 depot_save_stack+0x28e/0x550
Call Trace:
? kasan_kmalloc+0x144/0x160
? depot_save_stack+0x1f5/0x550
? do_raw_spin_unlock+0xda/0xf0
? preempt_count_sub+0x13/0xc0
<...90 lines...>
? do_raw_spin_unlock+0xda/0xf0
Add a STACKDEPOT=n dependency to UNWINDER_GUESS to avoid the problem.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171130123554.4330-1-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig.debug | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 6293a8768a91..672441c008c7 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -400,6 +400,7 @@ config UNWINDER_FRAME_POINTER config UNWINDER_GUESS bool "Guess unwinder" depends on EXPERT + depends on !STACKDEPOT ---help--- This option enables the "guess" unwinder for unwinding kernel stack traces. It scans the stack and reports every kernel text address it |