On Tue, Mar 28, 2017 at 06:15:44PM +0200, Dmitry Vyukov wrote:
> KASAN uses compiler instrumentation to intercept all memory accesses.
> But it does not see memory accesses done in assembly code.
> One notable user of assembly code is atomic operations. Frequently,
> for example, an atomic reference decrement is the last access to an
> object and a good candidate for a racy use-after-free.
>
> Add manual KASAN checks to atomic operations.
>
> Signed-off-by: Dmitry Vyukov <dvyu...@google.com>
> Cc: Mark Rutland <mark.rutl...@arm.com>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: Will Deacon <will.dea...@arm.com>,
> Cc: Andrew Morton <a...@linux-foundation.org>,
> Cc: Andrey Ryabinin <aryabi...@virtuozzo.com>,
> Cc: Ingo Molnar <mi...@redhat.com>,
> Cc: kasan-...@googlegroups.com
> Cc: linux...@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Cc: x...@kernel.org
FWIW, I think that structuring the file this way will make it easier to
add the {acquire,release,relaxed} variants (as arm64 will need),
so this looks good to me.
As a heads-up, I wanted to have a go at that, but I wasn't able to apply
patch two onwards on v4.11-rc{3,4} or next-20170329. I was not able to
cleanly revert the instrumentation patches currently in next-20170329,
since other patches built atop of them.
It would be nice to see that sorted out.
Thanks,
Mark.
> ---
> include/asm-generic/atomic-instrumented.h | 76
> +++++++++++++++++++++++++++++--
> 1 file changed, 72 insertions(+), 4 deletions(-)
>
> diff --git a/include/asm-generic/atomic-instrumented.h
> b/include/asm-generic/atomic-instrumented.h
> index fd483115d4c6..7f8eb761f896 100644
> --- a/include/asm-generic/atomic-instrumented.h
> +++ b/include/asm-generic/atomic-instrumented.h
> @@ -1,44 +1,54 @@
> #ifndef _LINUX_ATOMIC_INSTRUMENTED_H
> #define _LINUX_ATOMIC_INSTRUMENTED_H
>
> +#include <linux/kasan-checks.h>
> +
> static __always_inline int atomic_read(const atomic_t *v)
> {
> + kasan_check_read(v, sizeof(*v));
> return arch_atomic_read(v);
> }
>
> static __always_inline long long atomic64_read(const atomic64_t *v)
> {
> + kasan_check_read(v, sizeof(*v));
> return arch_atomic64_read(v);
> }
>
> static __always_inline void atomic_set(atomic_t *v, int i)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_set(v, i);
> }
>
> static __always_inline void atomic64_set(atomic64_t *v, long long i)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_set(v, i);
> }
>
> static __always_inline int atomic_xchg(atomic_t *v, int i)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_xchg(v, i);
> }
>
> static __always_inline long long atomic64_xchg(atomic64_t *v, long long i)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_xchg(v, i);
> }
>
> static __always_inline int atomic_cmpxchg(atomic_t *v, int old, int new)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_cmpxchg(v, old, new);
> }
>
> static __always_inline long long atomic64_cmpxchg(atomic64_t *v, long long
> old,
> long long new)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_cmpxchg(v, old, new);
> }
>
> @@ -46,6 +56,8 @@ static __always_inline long long
> atomic64_cmpxchg(atomic64_t *v, long long old,
> #define atomic_try_cmpxchg atomic_try_cmpxchg
> static __always_inline bool atomic_try_cmpxchg(atomic_t *v, int *old, int
> new)
> {
> + kasan_check_write(v, sizeof(*v));
> + kasan_check_read(old, sizeof(*old));
> return arch_atomic_try_cmpxchg(v, old, new);
> }
> #endif
> @@ -55,12 +67,15 @@ static __always_inline bool atomic_try_cmpxchg(atomic_t
> *v, int *old, int new)
> static __always_inline bool atomic64_try_cmpxchg(atomic64_t *v, long long
> *old,
> long long new)
> {
> + kasan_check_write(v, sizeof(*v));
> + kasan_check_read(old, sizeof(*old));
> return arch_atomic64_try_cmpxchg(v, old, new);
> }
> #endif
>
> static __always_inline int __atomic_add_unless(atomic_t *v, int a, int u)
> {
> + kasan_check_write(v, sizeof(*v));
> return __arch_atomic_add_unless(v, a, u);
> }
>
> @@ -68,242 +83,295 @@ static __always_inline int __atomic_add_unless(atomic_t
> *v, int a, int u)
> static __always_inline bool atomic64_add_unless(atomic64_t *v, long long a,
> long long u)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_add_unless(v, a, u);
> }
>
> static __always_inline void atomic_inc(atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_inc(v);
> }
>
> static __always_inline void atomic64_inc(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_inc(v);
> }
>
> static __always_inline void atomic_dec(atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_dec(v);
> }
>
> static __always_inline void atomic64_dec(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_dec(v);
> }
>
> static __always_inline void atomic_add(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_add(i, v);
> }
>
> static __always_inline void atomic64_add(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_add(i, v);
> }
>
> static __always_inline void atomic_sub(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_sub(i, v);
> }
>
> static __always_inline void atomic64_sub(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_sub(i, v);
> }
>
> static __always_inline void atomic_and(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_and(i, v);
> }
>
> static __always_inline void atomic64_and(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_and(i, v);
> }
>
> static __always_inline void atomic_or(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_or(i, v);
> }
>
> static __always_inline void atomic64_or(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_or(i, v);
> }
>
> static __always_inline void atomic_xor(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic_xor(i, v);
> }
>
> static __always_inline void atomic64_xor(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> arch_atomic64_xor(i, v);
> }
>
> static __always_inline int atomic_inc_return(atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_inc_return(v);
> }
>
> static __always_inline long long atomic64_inc_return(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_inc_return(v);
> }
>
> static __always_inline int atomic_dec_return(atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_dec_return(v);
> }
>
> static __always_inline long long atomic64_dec_return(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_dec_return(v);
> }
>
> static __always_inline long long atomic64_inc_not_zero(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_inc_not_zero(v);
> }
>
> static __always_inline long long atomic64_dec_if_positive(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_dec_if_positive(v);
> }
>
> static __always_inline bool atomic_dec_and_test(atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_dec_and_test(v);
> }
>
> static __always_inline bool atomic64_dec_and_test(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_dec_and_test(v);
> }
>
> static __always_inline bool atomic_inc_and_test(atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_inc_and_test(v);
> }
>
> static __always_inline bool atomic64_inc_and_test(atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_inc_and_test(v);
> }
>
> static __always_inline int atomic_add_return(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_add_return(i, v);
> }
>
> static __always_inline long long atomic64_add_return(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_add_return(i, v);
> }
>
> static __always_inline int atomic_sub_return(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_sub_return(i, v);
> }
>
> static __always_inline long long atomic64_sub_return(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_sub_return(i, v);
> }
>
> static __always_inline int atomic_fetch_add(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_fetch_add(i, v);
> }
>
> static __always_inline long long atomic64_fetch_add(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_fetch_add(i, v);
> }
>
> static __always_inline int atomic_fetch_sub(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_fetch_sub(i, v);
> }
>
> static __always_inline long long atomic64_fetch_sub(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_fetch_sub(i, v);
> }
>
> static __always_inline int atomic_fetch_and(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_fetch_and(i, v);
> }
>
> static __always_inline long long atomic64_fetch_and(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_fetch_and(i, v);
> }
>
> static __always_inline int atomic_fetch_or(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_fetch_or(i, v);
> }
>
> static __always_inline long long atomic64_fetch_or(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_fetch_or(i, v);
> }
>
> static __always_inline int atomic_fetch_xor(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_fetch_xor(i, v);
> }
>
> static __always_inline long long atomic64_fetch_xor(long long i, atomic64_t
> *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_fetch_xor(i, v);
> }
>
> static __always_inline bool atomic_sub_and_test(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_sub_and_test(i, v);
> }
>
> static __always_inline bool atomic64_sub_and_test(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_sub_and_test(i, v);
> }
>
> static __always_inline bool atomic_add_negative(int i, atomic_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic_add_negative(i, v);
> }
>
> static __always_inline bool atomic64_add_negative(long long i, atomic64_t *v)
> {
> + kasan_check_write(v, sizeof(*v));
> return arch_atomic64_add_negative(i, v);
> }
>
> #define cmpxchg(ptr, old, new) \
> ({ \
> + __typeof__(ptr) ___ptr = (ptr); \
> + kasan_check_write(___ptr, sizeof(*___ptr)); \
> arch_cmpxchg((ptr), (old), (new)); \
> })
>
> #define sync_cmpxchg(ptr, old, new) \
> ({ \
> - arch_sync_cmpxchg((ptr), (old), (new)); \
> + __typeof__(ptr) ___ptr = (ptr); \
> + kasan_check_write(___ptr, sizeof(*___ptr)); \
> + arch_sync_cmpxchg(___ptr, (old), (new)); \
> })
>
> #define cmpxchg_local(ptr, old, new) \
> ({ \
> - arch_cmpxchg_local((ptr), (old), (new)); \
> + __typeof__(ptr) ____ptr = (ptr); \
> + kasan_check_write(____ptr, sizeof(*____ptr)); \
> + arch_cmpxchg_local(____ptr, (old), (new)); \
> })
>
> #define cmpxchg64(ptr, old, new) \
> ({ \
> - arch_cmpxchg64((ptr), (old), (new)); \
> + __typeof__(ptr) ____ptr = (ptr); \
> + kasan_check_write(____ptr, sizeof(*____ptr)); \
> + arch_cmpxchg64(____ptr, (old), (new)); \
> })
>
> #define cmpxchg64_local(ptr, old, new) \
> ({ \
> - arch_cmpxchg64_local((ptr), (old), (new)); \
> + __typeof__(ptr) ____ptr = (ptr); \
> + kasan_check_write(____ptr, sizeof(*____ptr)); \
> + arch_cmpxchg64_local(____ptr, (old), (new)); \
> })
>
> #define cmpxchg_double(p1, p2, o1, o2, n1, n2)
> \
> --
> 2.12.2.564.g063fe858b8-goog
>
