[PATCH v5.10] arm64: fix a concurrency issue in emulation_proc_handler()

[Greg KH]

On Tue, Jan 31, 2023 at 04:23:19PM +0800, Ruan Jinjie wrote:
> 
> 
> On 2023/1/31 15:27, Greg KH wrote:
> > On Tue, Jan 31, 2023 at 02:52:11PM +0800, ruanjinjie wrote:
> >> This patch is addressing an issue in stable linux-5.10 only.
> >>
> >> In linux-6.1, the related code is refactored in 124c49b1b("arm64:
> >> armv8_deprecated: rework deprected instruction handling") and
> >> this issue was incidentally fixed. However, the patch changes a lot and
> >> is not specific to this issue.
> > 
> > Then what about 5.15.y?  You can not upgrade to that kernel and have a
> > regression, right?
> 
> This patch has a pre-dependency af483947d ("arm64: fix oops in
> concurrently setting insn_emulation sysctls"), which has not merged into
> branches except 5.10.y, so the other branches don't apply.

So there is no bug in 5.15.y?  That's confusing.

> > And nit, you need a ' ' before the '(' character.
> > 
> > But why can we just not take the original commit that fixed this issue?
> > That way almost always is the best (prevents regressions, makes
> > backports easier, is actually tested, etc.) ?
> 
> Thank you! It is ok to take the original commit to fix this issue.

Please submit it after testing.

thanks,

greg k-h