Messages in this thread | ![/](/images/icornerl.gif) | | From | Björn Töpel <> | Subject | Re: [PATCH v4] riscv: patch: Fixup lockdep warning in stop_machine | Date | Wed, 15 Feb 2023 12:01:17 +0100 |
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Changbin Du <changbin.du@huawei.com> writes:
> On Wed, Feb 15, 2023 at 09:24:33AM +0800, Guo Ren wrote: >> On Wed, Feb 15, 2023 at 8:22 AM Conor Dooley <conor@kernel.org> wrote: >> > >> > Hey Changbin, >> > >> > On Thu, Feb 02, 2023 at 07:41:16PM +0800, Changbin Du wrote: >> > > The task of ftrace_arch_code_modify(_post)_prepare() caller is >> > > stop_machine, whose caller and work thread are of different tasks. The >> > > lockdep checker needs the same task context, or it's wrong. That means >> > > it's a bug here to use lockdep_assert_held because we don't guarantee >> > > the same task context. >> I'm trying to delete all stop_machine in riscv, from ftrace to kprobe. >> When I have done, we needn't this patch. >> > Which approch would you use? I looked through the riscv-spec, but didn't find any > description abount concurrent modification and execution.
CMODX is not specified for RISC-V yet, unfortunately.
This has been discussed here [1]. Maybe we can start with stating for which implementations Guo's approach work?
[1] https://lore.kernel.org/all/CAJF2gTS0s4X_uwLaEeSqKAyRmxCR2vxRuHhz7-SP2w4bBqzr+Q@mail.gmail.com/
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