Messages in this thread | | | Date | Fri, 3 Dec 2021 10:41:02 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH v3] arm64: Enable KCSAN |
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On Fri, Dec 03, 2021 at 10:29:22AM +0800, Kefeng Wang wrote: > > On 2021/12/2 22:44, Mark Rutland wrote: > > On Thu, Dec 02, 2021 at 03:36:06PM +0100, Marco Elver wrote: > > > On Thu, 2 Dec 2021 at 15:23, Kefeng Wang <wangkefeng.wang@huawei.com> wrote: > > > > This patch enables KCSAN for arm64, with updates to build rules > > > > to not use KCSAN for several incompatible compilation units. > > > > > > > > Resent GCC version(at least GCC10) made outline-atomics as the > > > s/Resent/Recent/ > > > > > > > default option(unlike Clang), which will cause linker errors > > > > for kernel/kcsan/core.o. Disables the out-of-line atomics by > > > > no-outline-atomics to fix the linker errors. > > > > > > > > Meanwhile, as Mark said[1], there is a specific issue on arm64 > > > > about ARM64_BTI with Clang 11 if KCSAN enabled, which is fixed > > > > by Clang 12, add CLANG_VERSION check. And also some latent issues > > > > are need to be fixed which isn't just a KCSAN problem, we make > > > > the KCSAN depends on EXPERT for now. > > > > > > > > Tested selftest and kcsan_test(built with GCC11 and Clang 13), > > > > and all passed. > > > > > > > > [1] https://lkml.org/lkml/2021/12/1/354 > > > Please use lore/kernel.org permalinks. For this one it'd be: > > > https://lkml.kernel.org/r/YadiUPpJ0gADbiHQ@FVFF77S0Q05N > > > > > > (But I think if this is the final version of the patch, hopefully a > > > maintainer can amend the commit message.) > > > > > > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> > > > Acked-by: Marco Elver <elver@google.com> # kernel/kcsan > > > > > > is still valid, given nothing changed there. I leave the rest to Mark. > > I want to do some compiler / config testing before I ack this (just to > > make sure there isn't some latent issue I've forgotten about), but > > otherwise I think this should be fine. > > > > I'll try to have that done in the next few days. > > I will wait for some time, thanks Marco/Mark. > > > > > Any other review/testing would be appreciated! > > As Nathan points, commit 8cdd23c23c3d ("arm64: Restrict ARM64_BTI_KERNEL > > to clang 12.0.0 and newer"), so need to add Clang version check, which is v2 > does. > > is there some other requirement that we need this check, what's your option,
I'm not immediately aware of another reason, so I'm fine with not checking that for KCSAN -- If I discover another reason I will let you know.
Thanks, Mark.
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