x86/uaccess: instrument copy_from_user_nmi()

Make sure usercopy hooks from linux/instrumented.h are invoked for
copy_from_user_nmi().  This fixes KMSAN false positives reported when
dumping opcodes for a stack trace.

Link: https://lkml.kernel.org/r/20221102110611.1085175-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alexander Potapenko 2022-11-02 12:06:08 +01:00 committed by Andrew Morton
parent cbadaf71f7
commit 11385b2612

View File

@ -6,6 +6,7 @@
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/instrumented.h>
#include <asm/tlbflush.h>
@ -44,7 +45,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
* called from other contexts.
*/
pagefault_disable();
instrument_copy_from_user_before(to, from, n);
ret = raw_copy_from_user(to, from, n);
instrument_copy_from_user_after(to, from, n, ret);
pagefault_enable();
return ret;