Commit-ID: 0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe Gitweb: https://git.kernel.org/tip/0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe Author: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> AuthorDate: Thu, 30 Nov 2017 15:35:54 +0300 Committer: Ingo Molnar <mingo@xxxxxxxxxx> 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.ye@xxxxxxxxx> Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Acked-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20171130123554.4330-1-aryabinin@xxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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