summaryrefslogtreecommitdiff
path: root/include/linux/compiler.h
diff options
context:
space:
mode:
authorMarco Elver <elver@google.com>2020-05-21 16:20:41 +0200
committerThomas Gleixner <tglx@linutronix.de>2020-06-11 20:04:02 +0200
commite3b779d9ebe82b4be0121f25f27632844bb86d96 (patch)
tree9a048c9bdd97e3158f18591e8cf9e1f31d2fbf95 /include/linux/compiler.h
parentd31d4d6bb256c3e784709e4aaf075de87c3390fc (diff)
downloadlwn-e3b779d9ebe82b4be0121f25f27632844bb86d96.tar.gz
lwn-e3b779d9ebe82b4be0121f25f27632844bb86d96.zip
kcsan: Remove 'noinline' from __no_kcsan_or_inline
Some compilers incorrectly inline small __no_kcsan functions, which then results in instrumenting the accesses. For this reason, the 'noinline' attribute was added to __no_kcsan_or_inline. All known versions of GCC are affected by this. Supported versions of Clang are unaffected, and never inline a no_sanitize function. However, the attribute 'noinline' in __no_kcsan_or_inline causes unexpected code generation in functions that are __no_kcsan and call a __no_kcsan_or_inline function. In certain situations it is expected that the __no_kcsan_or_inline function is actually inlined by the __no_kcsan function, and *no* calls are emitted. By removing the 'noinline' attribute, give the compiler the ability to inline and generate the expected code in __no_kcsan functions. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/CANpmjNNOpJk0tprXKB_deiNAv_UmmORf1-2uajLhnLWQQ1hvoA@mail.gmail.com Link: https://lkml.kernel.org/r/20200521142047.169334-6-elver@google.com
Diffstat (limited to 'include/linux/compiler.h')
-rw-r--r--include/linux/compiler.h6
1 files changed, 2 insertions, 4 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f09ebbf16562..6d307c0aa4b4 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -329,11 +329,9 @@ do { \
#ifdef __SANITIZE_THREAD__
/*
* Rely on __SANITIZE_THREAD__ instead of CONFIG_KCSAN, to avoid not inlining in
- * compilation units where instrumentation is disabled. The attribute 'noinline'
- * is required for older compilers, where implicit inlining of very small
- * functions renders __no_sanitize_thread ineffective.
+ * compilation units where instrumentation is disabled.
*/
-# define __no_kcsan_or_inline __no_kcsan noinline notrace __maybe_unused
+# define __no_kcsan_or_inline __no_kcsan notrace __maybe_unused
# define __no_sanitize_or_inline __no_kcsan_or_inline
#else
# define __no_kcsan_or_inline __always_inline