Re: [PATCH 6.6 000/129] 6.6.90-rc2 review

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, May 08, 2025 at 06:16:12PM +0530, Naresh Kamboju wrote:
> On Thu, 8 May 2025 at 17:00, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > This is the start of the stable review cycle for the 6.6.90 release.
> > There are 129 patches in this series, all will be posted as a response
> > to this one.  If anyone has any issues with these being applied, please
> > let me know.
> >
> > Responses should be made by Sat, 10 May 2025 11:25:47 +0000.
> > Anything received after that time might be too late.
> >
> > The whole patch series can be found in one patch at:
> >         https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.6.90-rc2.gz
> > or in the git tree and branch at:
> >         git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.6.y
> > and the diffstat can be found below.
> >
> > thanks,
> >
> > greg k-h
> 
> Regressions on riscv with allyesconfig and allmodconfig builds failed with
> clang-20 and gcc-13 toolchain on the stable-rc 6.6.90-rc1 and 6.6.90-rc2
> 
> * riscv, build
>   - clang-20-allmodconfig
>   - gcc-13-allmodconfig
>   - gcc-13-allyesconfig
> 
> Regression Analysis:
>  - New regression? Yes
>  - Reproducibility? Yes
> 
> Build regression: riscv uprobes.c unused variable 'start'
> 
> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
> 
> ## Build error riscv
> arch/riscv/kernel/probes/uprobes.c: In function 'arch_uprobe_copy_ixol':
> arch/riscv/kernel/probes/uprobes.c:170:23: error: unused variable
> 'start' [-Werror=unused-variable]
>   170 |         unsigned long start = (unsigned long)dst;
>       |                       ^~~~~
> cc1: all warnings being treated as errors

Oh that's wierd.  riscv defines flush_icache_range() as "empty" so then
this patch does nothing in these older kernels.  Ah, it's an inline
function in newer kernel trees as well so that the build warning isn't
there anymore.

As this change feels odd for 6.6 and older kernels, AND it's causing
build warnings, I'm just going to drop it and if the riscv maintainers
really want it applied to these trees, will take a working backport from
them.

thanks,

greg k-h