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authorMarco Elver <elver@google.com>2019-07-12 06:53:56 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-12 21:05:42 +0300
commitff66135015726696568e998720d9b6afe2d04642 (patch)
tree1fc944414fb159898871708993a1f0744e84cdb9 /arch/x86/kernel
parent19a33ca6c209f5e22c73b6beb4b1974153e93050 (diff)
downloadlinux-ff66135015726696568e998720d9b6afe2d04642.tar.xz
x86: use static_cpu_has in uaccess region to avoid instrumentation
This patch is a pre-requisite for enabling KASAN bitops instrumentation; using static_cpu_has instead of boot_cpu_has avoids instrumentation of test_bit inside the uaccess region. With instrumentation, the KASAN check would otherwise be flagged by objtool. For consistency, kernel/signal.c was changed to mirror this change, however, is never instrumented with KASAN (currently unsupported under x86 32bit). Link: http://lkml.kernel.org/r/20190613125950.197667-3-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Suggested-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/signal.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 7cf508f78c8c..8eb7193e158d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -391,7 +391,7 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
put_user_ex(&frame->uc, &frame->puc);
/* Create the ucontext. */
- if (boot_cpu_has(X86_FEATURE_XSAVE))
+ if (static_cpu_has(X86_FEATURE_XSAVE))
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);