| Message ID | 20200325161249.55095-11-glider@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add KernelMemorySanitizer infrastructure | expand |
On Wed, Mar 25, 2020 at 5:13 PM <glider@google.com> wrote: > > READ_ONCE_NOCHECK() is already used by KASAN to ignore memory accesses > from e.g. stack unwinders. > Define READ_ONCE_NOCHECK() for KMSAN so that it returns initialized > values. This helps defeat false positives from leftover stack contents. > > Signed-off-by: Alexander Potapenko <glider@google.com> > To: Alexander Potapenko <glider@google.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Vegard Nossum <vegard.nossum@oracle.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Marco Elver <elver@google.com> > Cc: Andrey Konovalov <andreyknvl@google.com> > Cc: linux-mm@kvack.org Reviewed-by: Andrey Konovalov <andreyknvl@google.com> > --- > v3: > - removed unnecessary #ifdef as requested by Mark Rutland > v4: > - added an #include as requested by Marco Elver > > Change-Id: Ib38369ba038ab3b581d8e45b81036c3304fb79cb > --- > include/linux/compiler.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/linux/compiler.h b/include/linux/compiler.h > index f504edebd5d71..c6c67729729e3 100644 > --- a/include/linux/compiler.h > +++ b/include/linux/compiler.h > @@ -279,6 +279,7 @@ void __write_once_size(volatile void *p, void *res, int size) > */ > #include <asm/barrier.h> > #include <linux/kasan-checks.h> > +#include <linux/kmsan-checks.h> > > #define __READ_ONCE(x, check) \ > ({ \ > @@ -294,9 +295,9 @@ void __write_once_size(volatile void *p, void *res, int size) > > /* > * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need > - * to hide memory access from KASAN. > + * to hide memory access from KASAN or KMSAN. > */ > -#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0) > +#define READ_ONCE_NOCHECK(x) KMSAN_INIT_VALUE(__READ_ONCE(x, 0)) > > static __no_kasan_or_inline > unsigned long read_word_at_a_time(const void *addr) > -- > 2.25.1.696.g5e7596f4ac-goog >
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index f504edebd5d71..c6c67729729e3 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -279,6 +279,7 @@ void __write_once_size(volatile void *p, void *res, int size) */ #include <asm/barrier.h> #include <linux/kasan-checks.h> +#include <linux/kmsan-checks.h> #define __READ_ONCE(x, check) \ ({ \ @@ -294,9 +295,9 @@ void __write_once_size(volatile void *p, void *res, int size) /* * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need - * to hide memory access from KASAN. + * to hide memory access from KASAN or KMSAN. */ -#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0) +#define READ_ONCE_NOCHECK(x) KMSAN_INIT_VALUE(__READ_ONCE(x, 0)) static __no_kasan_or_inline unsigned long read_word_at_a_time(const void *addr)
READ_ONCE_NOCHECK() is already used by KASAN to ignore memory accesses from e.g. stack unwinders. Define READ_ONCE_NOCHECK() for KMSAN so that it returns initialized values. This helps defeat false positives from leftover stack contents. Signed-off-by: Alexander Potapenko <glider@google.com> To: Alexander Potapenko <glider@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: linux-mm@kvack.org --- v3: - removed unnecessary #ifdef as requested by Mark Rutland v4: - added an #include as requested by Marco Elver Change-Id: Ib38369ba038ab3b581d8e45b81036c3304fb79cb --- include/linux/compiler.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)