| Message ID | 20170911195950.3077184-1-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
| Series | x86/kconfig: hide unwinder menu for KMEMCHECK | expand |
On Mon, Sep 11, 2017 at 09:59:36PM +0200, Arnd Bergmann wrote: > When KMEMCHECK is enabled, we always build with frame pointers, > which is incompatible with ORC_UNWINDER and GUESS_UNWINDER, as > Kconfig points out: > > warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK && LOCKDEP && FRAME_POINTER_UNWINDER) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS || !ORC_UNWINDER && !GUESS_UNWINDER) > > This works around it by making those two unwinders depend on > !KMEMCHECK. The other three options that enable frame pointers > (FAULT_INJECTION_STACKTRACE_FILTER, LATENCYTOP and LOCKDEP) only > do that on some architectures but not on x86. > > It's possible that KMEMCHECK doesn't actually require frame pointers > but only requires some unwinder. If that is the case, we should drop > the 'select FRAME_POINTER' there. KMEMCHECK is currenly used only > on x86. KMEMCHECK should work with *any* of the unwinders because it uses the unwinder-agnostic save_stack_trace() interface. So removing the 'select FRAME_POINTER' sounds like the right fix. -- Josh
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 71a48a30fc84..79f0f563d525 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -381,7 +381,7 @@ config FRAME_POINTER_UNWINDER config ORC_UNWINDER bool "ORC unwinder" - depends on X86_64 + depends on X86_64 && !KMEMCHECK select STACK_VALIDATION ---help--- This option enables the ORC (Oops Rewind Capability) unwinder for @@ -397,7 +397,7 @@ config ORC_UNWINDER config GUESS_UNWINDER bool "Guess unwinder" - depends on EXPERT + depends on EXPERT && !KMEMCHECK ---help--- This option enables the "guess" unwinder for unwinding kernel stack traces. It scans the stack and reports every kernel text address it
When KMEMCHECK is enabled, we always build with frame pointers, which is incompatible with ORC_UNWINDER and GUESS_UNWINDER, as Kconfig points out: warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK && LOCKDEP && FRAME_POINTER_UNWINDER) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS || !ORC_UNWINDER && !GUESS_UNWINDER) This works around it by making those two unwinders depend on !KMEMCHECK. The other three options that enable frame pointers (FAULT_INJECTION_STACKTRACE_FILTER, LATENCYTOP and LOCKDEP) only do that on some architectures but not on x86. It's possible that KMEMCHECK doesn't actually require frame pointers but only requires some unwinder. If that is the case, we should drop the 'select FRAME_POINTER' there. KMEMCHECK is currenly used only on x86. Fixes: 81d387190039 ("x86/kconfig: Consolidate unwinders into multiple choice selection") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/x86/Kconfig.debug | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.9.0