Messages in this thread | | | Date | Fri, 10 Dec 2021 14:58:27 +0800 | Subject | Re: [PATCH v3] arm64: Enable KCSAN | From | Kefeng Wang <> |
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On 2021/12/3 18:41, Mark Rutland wrote: > 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.
Hi Mark, I will send v4 to address the comments in v3, is there new update about this?
>> >>> 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.
Ok, will drop the Clang version check in v4.
Thanks.
> > Thanks, > Mark. > .
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