| Message ID | 20190626142014.141844-2-elver@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/kasan: Add object validation in ksize() | expand |
On Wed, Jun 26, 2019 at 04:20:10PM +0200, Marco Elver wrote: > This introduces __kasan_check_{read,write}. __kasan_check functions may > be used from anywhere, even compilation units that disable > instrumentation selectively. > > This change eliminates the need for the __KASAN_INTERNAL definition. > > Signed-off-by: Marco Elver <elver@google.com> > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Alexander Potapenko <glider@google.com> > Cc: Andrey Konovalov <andreyknvl@google.com> > Cc: Christoph Lameter <cl@linux.com> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: David Rientjes <rientjes@google.com> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: kasan-dev@googlegroups.com > Cc: linux-kernel@vger.kernel.org > Cc: linux-mm@kvack.org Logically this makes sense to me, so FWIW: Acked-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark. > --- > v3: > * Fix Formatting and split introduction of __kasan_check_* and returning > bool into 2 patches. > --- > include/linux/kasan-checks.h | 31 ++++++++++++++++++++++++++++--- > mm/kasan/common.c | 10 ++++------ > 2 files changed, 32 insertions(+), 9 deletions(-) > > diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h > index a61dc075e2ce..19a0175d2452 100644 > --- a/include/linux/kasan-checks.h > +++ b/include/linux/kasan-checks.h > @@ -2,9 +2,34 @@ > #ifndef _LINUX_KASAN_CHECKS_H > #define _LINUX_KASAN_CHECKS_H > > -#if defined(__SANITIZE_ADDRESS__) || defined(__KASAN_INTERNAL) > -void kasan_check_read(const volatile void *p, unsigned int size); > -void kasan_check_write(const volatile void *p, unsigned int size); > +/* > + * __kasan_check_*: Always available when KASAN is enabled. This may be used > + * even in compilation units that selectively disable KASAN, but must use KASAN > + * to validate access to an address. Never use these in header files! > + */ > +#ifdef CONFIG_KASAN > +void __kasan_check_read(const volatile void *p, unsigned int size); > +void __kasan_check_write(const volatile void *p, unsigned int size); > +#else > +static inline void __kasan_check_read(const volatile void *p, unsigned int size) > +{ } > +static inline void __kasan_check_write(const volatile void *p, unsigned int size) > +{ } > +#endif > + > +/* > + * kasan_check_*: Only available when the particular compilation unit has KASAN > + * instrumentation enabled. May be used in header files. > + */ > +#ifdef __SANITIZE_ADDRESS__ > +static inline void kasan_check_read(const volatile void *p, unsigned int size) > +{ > + __kasan_check_read(p, size); > +} > +static inline void kasan_check_write(const volatile void *p, unsigned int size) > +{ > + __kasan_check_read(p, size); > +} > #else > static inline void kasan_check_read(const volatile void *p, unsigned int size) > { } > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > index 242fdc01aaa9..6bada42cc152 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -14,8 +14,6 @@ > * > */ > > -#define __KASAN_INTERNAL > - > #include <linux/export.h> > #include <linux/interrupt.h> > #include <linux/init.h> > @@ -89,17 +87,17 @@ void kasan_disable_current(void) > current->kasan_depth--; > } > > -void kasan_check_read(const volatile void *p, unsigned int size) > +void __kasan_check_read(const volatile void *p, unsigned int size) > { > check_memory_region((unsigned long)p, size, false, _RET_IP_); > } > -EXPORT_SYMBOL(kasan_check_read); > +EXPORT_SYMBOL(__kasan_check_read); > > -void kasan_check_write(const volatile void *p, unsigned int size) > +void __kasan_check_write(const volatile void *p, unsigned int size) > { > check_memory_region((unsigned long)p, size, true, _RET_IP_); > } > -EXPORT_SYMBOL(kasan_check_write); > +EXPORT_SYMBOL(__kasan_check_write); > > #undef memset > void *memset(void *addr, int c, size_t len) > -- > 2.22.0.410.gd8fdbe21b5-goog >
diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h index a61dc075e2ce..19a0175d2452 100644 --- a/include/linux/kasan-checks.h +++ b/include/linux/kasan-checks.h @@ -2,9 +2,34 @@ #ifndef _LINUX_KASAN_CHECKS_H #define _LINUX_KASAN_CHECKS_H -#if defined(__SANITIZE_ADDRESS__) || defined(__KASAN_INTERNAL) -void kasan_check_read(const volatile void *p, unsigned int size); -void kasan_check_write(const volatile void *p, unsigned int size); +/* + * __kasan_check_*: Always available when KASAN is enabled. This may be used + * even in compilation units that selectively disable KASAN, but must use KASAN + * to validate access to an address. Never use these in header files! + */ +#ifdef CONFIG_KASAN +void __kasan_check_read(const volatile void *p, unsigned int size); +void __kasan_check_write(const volatile void *p, unsigned int size); +#else +static inline void __kasan_check_read(const volatile void *p, unsigned int size) +{ } +static inline void __kasan_check_write(const volatile void *p, unsigned int size) +{ } +#endif + +/* + * kasan_check_*: Only available when the particular compilation unit has KASAN + * instrumentation enabled. May be used in header files. + */ +#ifdef __SANITIZE_ADDRESS__ +static inline void kasan_check_read(const volatile void *p, unsigned int size) +{ + __kasan_check_read(p, size); +} +static inline void kasan_check_write(const volatile void *p, unsigned int size) +{ + __kasan_check_read(p, size); +} #else static inline void kasan_check_read(const volatile void *p, unsigned int size) { } diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 242fdc01aaa9..6bada42cc152 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -14,8 +14,6 @@ * */ -#define __KASAN_INTERNAL - #include <linux/export.h> #include <linux/interrupt.h> #include <linux/init.h> @@ -89,17 +87,17 @@ void kasan_disable_current(void) current->kasan_depth--; } -void kasan_check_read(const volatile void *p, unsigned int size) +void __kasan_check_read(const volatile void *p, unsigned int size) { check_memory_region((unsigned long)p, size, false, _RET_IP_); } -EXPORT_SYMBOL(kasan_check_read); +EXPORT_SYMBOL(__kasan_check_read); -void kasan_check_write(const volatile void *p, unsigned int size) +void __kasan_check_write(const volatile void *p, unsigned int size) { check_memory_region((unsigned long)p, size, true, _RET_IP_); } -EXPORT_SYMBOL(kasan_check_write); +EXPORT_SYMBOL(__kasan_check_write); #undef memset void *memset(void *addr, int c, size_t len)
This introduces __kasan_check_{read,write}. __kasan_check functions may be used from anywhere, even compilation units that disable instrumentation selectively. This change eliminates the need for the __KASAN_INTERNAL definition. Signed-off-by: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: kasan-dev@googlegroups.com Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org --- v3: * Fix Formatting and split introduction of __kasan_check_* and returning bool into 2 patches. --- include/linux/kasan-checks.h | 31 ++++++++++++++++++++++++++++--- mm/kasan/common.c | 10 ++++------ 2 files changed, 32 insertions(+), 9 deletions(-)