| Message ID | 20220520031548.175582-3-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Fix kcsan test_barrier fail and panic | expand |
On Fri, May 20, 2022 at 11:15AM +0800, Kefeng Wang wrote: > As "kcsan: Support detecting a subset of missing memory barriers"[1] > introduced KCSAN_STRICT/KCSAN_WEAK_MEMORY which make kcsan detects > more missing memory barrier, but arm64 don't have KCSAN instrumentation > for barriers, so the new selftest test_barrier() and test cases for > memory barrier instrumentation in kcsan_test module will fail, even > panic on selftest. > > Let's prefix all barriers with __ on arm64, as asm-generic/barriers.h > defined the final instrumented version of these barriers, which will > fix the above issues. > > Note, barrier instrumentation that can be disabled via __no_kcsan with > appropriate compiler-support (and not just with objtool help), see > commit bd3d5bd1a0ad ("kcsan: Support WEAK_MEMORY with Clang where no > objtool support exists"), it adds disable_sanitizer_instrumentation to > __no_kcsan attribute which will remove all sanitizer instrumentation fully > (with Clang 14.0). Meanwhile, GCC does the same thing with no_sanitize. > > [1] https://lore.kernel.org/linux-mm/20211130114433.2580590-1-elver@google.com/ > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > --- > arch/arm64/include/asm/barrier.h | 12 ++++++------ > include/asm-generic/barrier.h | 4 ++++ > 2 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h > index 9f3e2c3d2ca0..2cfc4245d2e2 100644 > --- a/arch/arm64/include/asm/barrier.h > +++ b/arch/arm64/include/asm/barrier.h > @@ -50,13 +50,13 @@ > #define pmr_sync() do {} while (0) > #endif > > -#define mb() dsb(sy) > -#define rmb() dsb(ld) > -#define wmb() dsb(st) > +#define __mb() dsb(sy) > +#define __rmb() dsb(ld) > +#define __wmb() dsb(st) > > -#define dma_mb() dmb(osh) > -#define dma_rmb() dmb(oshld) > -#define dma_wmb() dmb(oshst) > +#define __dma_mb() dmb(osh) > +#define __dma_rmb() dmb(oshld) > +#define __dma_wmb() dmb(oshst) > > #define io_stop_wc() dgh() > > diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h > index fd7e8fbaeef1..18863c50e9ce 100644 > --- a/include/asm-generic/barrier.h > +++ b/include/asm-generic/barrier.h > @@ -38,6 +38,10 @@ > #define wmb() do { kcsan_wmb(); __wmb(); } while (0) > #endif > > +#ifdef __dma_mb > +#define dma_mb() do { kcsan_mb(); __dma_mb(); } while (0) > +#endif The asm-generic changes might want to go into a separate patch, along with the generic definition of dma_mb() if there's no __dma_mb, as mentioned in the other email. Thanks, -- Marco
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 9f3e2c3d2ca0..2cfc4245d2e2 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -50,13 +50,13 @@ #define pmr_sync() do {} while (0) #endif -#define mb() dsb(sy) -#define rmb() dsb(ld) -#define wmb() dsb(st) +#define __mb() dsb(sy) +#define __rmb() dsb(ld) +#define __wmb() dsb(st) -#define dma_mb() dmb(osh) -#define dma_rmb() dmb(oshld) -#define dma_wmb() dmb(oshst) +#define __dma_mb() dmb(osh) +#define __dma_rmb() dmb(oshld) +#define __dma_wmb() dmb(oshst) #define io_stop_wc() dgh() diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index fd7e8fbaeef1..18863c50e9ce 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -38,6 +38,10 @@ #define wmb() do { kcsan_wmb(); __wmb(); } while (0) #endif +#ifdef __dma_mb +#define dma_mb() do { kcsan_mb(); __dma_mb(); } while (0) +#endif + #ifdef __dma_rmb #define dma_rmb() do { kcsan_rmb(); __dma_rmb(); } while (0) #endif
As "kcsan: Support detecting a subset of missing memory barriers"[1] introduced KCSAN_STRICT/KCSAN_WEAK_MEMORY which make kcsan detects more missing memory barrier, but arm64 don't have KCSAN instrumentation for barriers, so the new selftest test_barrier() and test cases for memory barrier instrumentation in kcsan_test module will fail, even panic on selftest. Let's prefix all barriers with __ on arm64, as asm-generic/barriers.h defined the final instrumented version of these barriers, which will fix the above issues. Note, barrier instrumentation that can be disabled via __no_kcsan with appropriate compiler-support (and not just with objtool help), see commit bd3d5bd1a0ad ("kcsan: Support WEAK_MEMORY with Clang where no objtool support exists"), it adds disable_sanitizer_instrumentation to __no_kcsan attribute which will remove all sanitizer instrumentation fully (with Clang 14.0). Meanwhile, GCC does the same thing with no_sanitize. [1] https://lore.kernel.org/linux-mm/20211130114433.2580590-1-elver@google.com/ Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- arch/arm64/include/asm/barrier.h | 12 ++++++------ include/asm-generic/barrier.h | 4 ++++ 2 files changed, 10 insertions(+), 6 deletions(-)