| Message ID | 20191030142237.249532-8-glider@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add KernelMemorySanitizer infrastructure | expand |
On Wed, Oct 30, 2019 at 3:23 PM <glider@google.com> wrote: > > __no_sanitize_memory is a function attribute that makes KMSAN > ignore the uninitialized values coming from the function's > inputs, and initialize the function's outputs. > > Functions marked with this attribute can't be inlined into functions > not marked with it, and vice versa. > > __SANITIZE_MEMORY__ is a macro that's defined iff the file is > instrumented with KMSAN. This is not the same as CONFIG_KMSAN, which is > defined for every file. > > Signed-off-by: Alexander Potapenko <glider@google.com> > To: Alexander Potapenko <glider@google.com> > Cc: Vegard Nossum <vegard.nossum@oracle.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: linux-mm@kvack.org > > --- > > Change-Id: I1f1672652c8392f15f7ca8ac26cd4e71f9cc1e4b > --- > include/linux/compiler-clang.h | 8 ++++++++ > include/linux/compiler-gcc.h | 5 +++++ > 2 files changed, 13 insertions(+) > > diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h > index 333a6695a918..edba13a069a6 100644 > --- a/include/linux/compiler-clang.h > +++ b/include/linux/compiler-clang.h > @@ -24,6 +24,14 @@ > #define __no_sanitize_address > #endif > > +/* KMSAN is a Clang-only tool, thus putting the defines here */ > +#if __has_feature(memory_sanitizer) > +# define __SANITIZE_MEMORY__ > +# define __no_sanitize_memory __attribute__((no_sanitize("kernel-memory"))) For KASAN with Clang we ended up choosing to use no_sanitize("address") instead of no_sanitize("kernel-address") to make it match what GCC uses. Do we want to use no_sanitize("memory") here? > +#else > +# define __no_sanitize_memory > +#endif > + > /* > * Not all versions of clang implement the the type-generic versions > * of the builtin overflow checkers. Fortunately, clang implements > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > index d7ee4c6bad48..e5ebc788dde4 100644 > --- a/include/linux/compiler-gcc.h > +++ b/include/linux/compiler-gcc.h > @@ -145,6 +145,11 @@ > #define __no_sanitize_address > #endif > > +/* > + * GCC doesn't support KMSAN. > + */ > +#define __no_sanitize_memory > + > #if GCC_VERSION >= 50100 > #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 > #endif > -- > 2.24.0.rc0.303.g954a862665-goog >
On Wed, Oct 30, 2019 at 4:50 PM Andrey Konovalov <andreyknvl@google.com> wrote: > > On Wed, Oct 30, 2019 at 3:23 PM <glider@google.com> wrote: > > > > __no_sanitize_memory is a function attribute that makes KMSAN > > ignore the uninitialized values coming from the function's > > inputs, and initialize the function's outputs. > > > > Functions marked with this attribute can't be inlined into functions > > not marked with it, and vice versa. > > > > __SANITIZE_MEMORY__ is a macro that's defined iff the file is > > instrumented with KMSAN. This is not the same as CONFIG_KMSAN, which is > > defined for every file. > > > > Signed-off-by: Alexander Potapenko <glider@google.com> > > To: Alexander Potapenko <glider@google.com> > > Cc: Vegard Nossum <vegard.nossum@oracle.com> > > Cc: Dmitry Vyukov <dvyukov@google.com> > > Cc: linux-mm@kvack.org > > > > --- > > > > Change-Id: I1f1672652c8392f15f7ca8ac26cd4e71f9cc1e4b > > --- > > include/linux/compiler-clang.h | 8 ++++++++ > > include/linux/compiler-gcc.h | 5 +++++ > > 2 files changed, 13 insertions(+) > > > > diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h > > index 333a6695a918..edba13a069a6 100644 > > --- a/include/linux/compiler-clang.h > > +++ b/include/linux/compiler-clang.h > > @@ -24,6 +24,14 @@ > > #define __no_sanitize_address > > #endif > > > > +/* KMSAN is a Clang-only tool, thus putting the defines here */ > > +#if __has_feature(memory_sanitizer) > > +# define __SANITIZE_MEMORY__ > > +# define __no_sanitize_memory __attribute__((no_sanitize("kernel-memory"))) > > For KASAN with Clang we ended up choosing to use > no_sanitize("address") instead of no_sanitize("kernel-address") to > make it match what GCC uses. Do we want to use no_sanitize("memory") > here? Since GCC doesn't currently implement KMSAN instrumentation, I think we can stick to the current annotation and let GCC catch up :) > > +#else > > +# define __no_sanitize_memory > > +#endif > > + > > /* > > * Not all versions of clang implement the the type-generic versions > > * of the builtin overflow checkers. Fortunately, clang implements > > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > > index d7ee4c6bad48..e5ebc788dde4 100644 > > --- a/include/linux/compiler-gcc.h > > +++ b/include/linux/compiler-gcc.h > > @@ -145,6 +145,11 @@ > > #define __no_sanitize_address > > #endif > > > > +/* > > + * GCC doesn't support KMSAN. > > + */ > > +#define __no_sanitize_memory > > + > > #if GCC_VERSION >= 50100 > > #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 > > #endif > > -- > > 2.24.0.rc0.303.g954a862665-goog > >
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 333a6695a918..edba13a069a6 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -24,6 +24,14 @@ #define __no_sanitize_address #endif +/* KMSAN is a Clang-only tool, thus putting the defines here */ +#if __has_feature(memory_sanitizer) +# define __SANITIZE_MEMORY__ +# define __no_sanitize_memory __attribute__((no_sanitize("kernel-memory"))) +#else +# define __no_sanitize_memory +#endif + /* * Not all versions of clang implement the the type-generic versions * of the builtin overflow checkers. Fortunately, clang implements diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index d7ee4c6bad48..e5ebc788dde4 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -145,6 +145,11 @@ #define __no_sanitize_address #endif +/* + * GCC doesn't support KMSAN. + */ +#define __no_sanitize_memory + #if GCC_VERSION >= 50100 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 #endif
__no_sanitize_memory is a function attribute that makes KMSAN ignore the uninitialized values coming from the function's inputs, and initialize the function's outputs. Functions marked with this attribute can't be inlined into functions not marked with it, and vice versa. __SANITIZE_MEMORY__ is a macro that's defined iff the file is instrumented with KMSAN. This is not the same as CONFIG_KMSAN, which is defined for every file. Signed-off-by: Alexander Potapenko <glider@google.com> To: Alexander Potapenko <glider@google.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: linux-mm@kvack.org --- Change-Id: I1f1672652c8392f15f7ca8ac26cd4e71f9cc1e4b --- include/linux/compiler-clang.h | 8 ++++++++ include/linux/compiler-gcc.h | 5 +++++ 2 files changed, 13 insertions(+)