[PATCH 3/3] x86, kcsan: Add __no_kcsan to noinstr

From: Peter Zijlstra
Date: Tue Jun 02 2020 - 13:35:08 EST


The 'noinstr' function attribute means no-instrumentation, this should
very much include *SAN. Because lots of that is broken at present,
only include KCSAN for now, as that is limited to clang11, which has
sane function attribute behaviour.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/compiler_types.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -118,10 +118,6 @@ struct ftrace_likely_data {
#define notrace __attribute__((__no_instrument_function__))
#endif

-/* Section for code which can't be instrumented at all */
-#define noinstr \
- noinline notrace __attribute((__section__(".noinstr.text")))
-
/*
* it doesn't make sense on ARM (currently the only user of __naked)
* to trace naked functions because then mcount is called without
@@ -200,6 +196,10 @@ struct ftrace_likely_data {
#define __no_sanitize_or_inline __always_inline
#endif

+/* Section for code which can't be instrumented at all */
+#define noinstr \
+ noinline notrace __attribute((__section__(".noinstr.text"))) __no_kcsan
+
#endif /* __KERNEL__ */

#endif /* __ASSEMBLY__ */