| Message ID | 20220523113126.171714-3-wangkefeng.wang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Fix kcsan test_barrier fail and panic | expand |
On Mon, May 23, 2022 at 07:31:26PM +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/ > > Acked-by: Marco Elver <elver@google.com> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Having built this with GCC 12.1.0 and LLVM 14.0.0, I think this patch itself doesn't introduce any new problems, and logically makes sense. With that in mind: Acked-by: Mark Rutland <mark.rutland@arm.com> As an aside, having scanned the resulting vmlinux with objdump, there are plenty of latent issues where we get KCSAN instrumentation where we don't want it (e.g. early/late in arm64's entry-common.o). The bulk of those are due to missing `nonistr` or `__always_inline`, which we'll need to fix up. Thanks, Mark. > --- > arch/arm64/include/asm/barrier.h | 12 ++++++------ > 1 file changed, 6 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() > > -- > 2.35.3 >
Hi Will and Catalin, kindly ping... On 2022/5/23 22:16, Mark Rutland wrote: > On Mon, May 23, 2022 at 07:31:26PM +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/ >> >> Acked-by: Marco Elver <elver@google.com> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > Having built this with GCC 12.1.0 and LLVM 14.0.0, I think this patch itself > doesn't introduce any new problems, and logically makes sense. With that in > mind: > > Acked-by: Mark Rutland <mark.rutland@arm.com> > > As an aside, having scanned the resulting vmlinux with objdump, there are > plenty of latent issues where we get KCSAN instrumentation where we don't want > it (e.g. early/late in arm64's entry-common.o). The bulk of those are due to > missing `nonistr` or `__always_inline`, which we'll need to fix up. > > Thanks, > Mark. > >> --- >> arch/arm64/include/asm/barrier.h | 12 ++++++------ >> 1 file changed, 6 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() >> >> -- >> 2.35.3 >> > .
On Mon, May 23, 2022 at 07:31:26PM +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/ > > Acked-by: Marco Elver <elver@google.com> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> I'll leave the series to Will to queue for 5.20. Thanks.
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()
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/ Acked-by: Marco Elver <elver@google.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- arch/arm64/include/asm/barrier.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)