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| author | Marco Elver <elver@google.com> | 2020-05-21 16:20:41 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 20:04:02 +0200 |
| commit | e3b779d9ebe82b4be0121f25f27632844bb86d96 (patch) | |
| tree | 9a048c9bdd97e3158f18591e8cf9e1f31d2fbf95 /include/linux/compiler.h | |
| parent | d31d4d6bb256c3e784709e4aaf075de87c3390fc (diff) | |
| download | lwn-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.h | 6 |
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 |