Commit-ID: 0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe Gitweb: https://git.kernel.org/tip/0a373d4fc248cb707821d7dad54ce6d5bcb0cdfe Author: Andrey Ryabinin <[email protected]> AuthorDate: Thu, 30 Nov 2017 15:35:54 +0300 Committer: Ingo Molnar <[email protected]> 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 <[email protected]> Reported-by: Fengguang Wu <[email protected]> Signed-off-by: Andrey Ryabinin <[email protected]> Acked-by: Dmitry Vyukov <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- 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
