The following commit has been merged into the locking/kcsan branch of tip: Commit-ID: f487a549ea30ee894055d8d20e81c1996a6e10a0 Gitweb: https://git.kernel.org/tip/f487a549ea30ee894055d8d20e81c1996a6e10a0 Author: Marco Elver <[email protected]> AuthorDate: Thu, 21 May 2020 16:20:41 +02:00 Committer: Borislav Petkov <[email protected]> CommitterDate: Fri, 22 May 2020 15:12:39 +02:00
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 <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Will Deacon <[email protected]> Link: https://lkml.kernel.org/r/canpmjnnopjk0tprxkb_deinav_ummorf1-2uajlhnlwqq1h...@mail.gmail.com Link: https://lkml.kernel.org/r/[email protected] --- include/linux/compiler.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index e24cc3a..17c98b2 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -276,11 +276,9 @@ 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
