Commit-ID: 0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe Gitweb: https://git.kernel.org/tip/0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe Author: Andrey Ryabinin <aryabi...@virtuozzo.com> AuthorDate: Thu, 30 Nov 2017 15:35:54 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 11 Dec 2017 19:07:07 +0100
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...@intel.com> Reported-by: Fengguang Wu <fengguang...@intel.com> Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> Acked-by: Dmitry Vyukov <dvyu...@google.com> Acked-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Alexander Potapenko <gli...@google.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/20171130123554.4330-1-aryabi...@virtuozzo.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/Kconfig.debug | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 6293a87..672441c 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
