Messages in this thread | | | Date | Tue, 26 Apr 2022 23:13:27 +0800 | Subject | Re: [PATCH] arm64: kcsan: Fix kcsan test_barrier fail and panic | From | Kefeng Wang <> |
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On 2022/4/26 20:10, Marco Elver wrote: > On Tue, Apr 26, 2022 at 08:17AM +0000, Kefeng Wang wrote: >> As "kcsan: Support detecting a subset of missing memory barriers" >> introduced KCSAN_STRICT which make kcsan detects more missing memory >> barrier, but arm64 don't have KCSAN instrumentation for barriers, so >> the new selftest test_barrier() will fail, then panic. > Thanks for fixing this - did kcsan_test module pass as well?
Yes, selftest and kcsan_test passed with gcc11 & clang 14.
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>> +#ifdef __dma_mb >> +#define dma_mb() do { kcsan_mb(); __dma_mb(); } while (0) >> +#endif >> + > So it looks like arm64 is the only arch that defines dma_mb(). By adding > it to asm-generic, we'd almost be encouraging other architectures to add > it, which I don't know we want. > > Documentation/memory-barriers.txt doesn't mention dma_mb() either - so > perhaps dma_mb() doesn't belong in asm-generic/barrier.h, and you could > only change arm64's definition of dma_mb() to add the kcsan_mb(). > > Preferences? Maybe arch64 maintainers have more background on why arm64 > is an anomaly here. > . Let's wait to see aarch64 maintainers's suggestion.
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