[PATCH] [stable 4.14 patch] x86: fix KMEMCHECK warning about FRAME_POINTER

[PATCH] [stable 4.14 patch] x86: fix KMEMCHECK warning about FRAME_POINTER

[Arnd Bergmann]

When KMEMCHECK is enabled without UNWINDER_FRAME_POINTER, we get a
Kconfig warning, presumably harmless:

warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK && LOCKDEP && UNWINDER_FRAME_POINTER) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS || !UNWINDER_ORC && !UNWINDER_GUESS)

In newer mainline kernels, the KMEMCHECK option has been removed, so
this no longer happens. Adding the unwinder as a direct dependency
for KMEMCHECK works for 4.14-stable as well and documents the
dependency better.

Fixes: 81d387190039 ("x86/kconfig: Consolidate unwinders into multiple choice selection")
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 17de6acc0eab..3fc58c1a166b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -111,7 +111,7 @@ config X86
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_KASAN			if X86_64
 	select HAVE_ARCH_KGDB
-	select HAVE_ARCH_KMEMCHECK
+	select HAVE_ARCH_KMEMCHECK		if !UNWINDER_ORC && !UNWINDER_GUESS
 	select HAVE_ARCH_MMAP_RND_BITS		if MMU
 	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
 	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
-- 
2.9.0

Re: [PATCH] [stable 4.14 patch] x86: fix KMEMCHECK warning about FRAME_POINTER

[Greg Kroah-Hartman]

On Fri, Feb 16, 2018 at 04:29:10PM +0100, Arnd Bergmann wrote:
> When KMEMCHECK is enabled without UNWINDER_FRAME_POINTER, we get a
> Kconfig warning, presumably harmless:
> 
> warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK && LOCKDEP && UNWINDER_FRAME_POINTER) selects FRAME_POINTER which has unmet direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || SUPERH || BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS || !UNWINDER_ORC && !UNWINDER_GUESS)
> 
> In newer mainline kernels, the KMEMCHECK option has been removed, so
> this no longer happens. Adding the unwinder as a direct dependency
> for KMEMCHECK works for 4.14-stable as well and documents the
> dependency better.

4.14.y now has that option removed as well, as I just removed all of
kmemcheck as it was "getting in the way" of other patches, so this isn't
needed anymore.

thanks,

greg k-h