]> git.baikalelectronics.ru Git - kernel.git/commit
x86/uaccess, kasan: Fix KASAN vs SMAP
authorPeter Zijlstra <peterz@infradead.org>
Wed, 3 Apr 2019 07:39:50 +0000 (09:39 +0200)
committerIngo Molnar <mingo@kernel.org>
Wed, 3 Apr 2019 09:02:24 +0000 (11:02 +0200)
commit57b78a62e7f23c4686fe54091cdc3d12e60d6513
treed8ac655da75b7a72365c7226b93e78c06d0c9204
parenta936af8ea3580855adcc80daa8e01c0196afeb15
x86/uaccess, kasan: Fix KASAN vs SMAP

KASAN inserts extra code for every LOAD/STORE emitted by te compiler.
Much of this code is simple and safe to run with AC=1, however the
kasan_report() function, called on error, is most certainly not safe
to call with AC=1.

Therefore wrap kasan_report() in user_access_{save,restore}; which for
x86 SMAP, saves/restores EFLAGS and clears AC before calling the real
function.

Also ensure all the functions are without __fentry__ hook. The
function tracer is also not safe.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mm/kasan/Makefile
mm/kasan/common.c
mm/kasan/report.c