Re: [PATCH v2] vmcoreinfo: make hwerr_data visible for debugging

Andrew Morton
2026-01-24T00:49:51Z

On Fri, 23 Jan 2026 01:24:17 -0800 Breno Leitao <leitao@debian.org> wrote:

> Hello Baoquan,
>
> On Fri, Jan 23, 2026 at 08:19:40AM +0800, Baoquan He wrote:
> > On 01/22/26 at 02:39am, Breno Leitao wrote:
> > > If the kernel is compiled with LTO, hwerr_data symbol might be lost, and
> > > vmcoreinfo doesn't have it dumped. This is currently seen in some
> > > production kernels with LTO enabled.
> > >
> > > Remove the static qualifier from hwerr_data so that the information is
> > > still preserved when the kernel is built with LTO. Making hwerr_data
> > > a global symbol ensures its debug info survives the LTO link process and
> > > appears in kallsyms. Also document it, so, it doesn't get removed in the
> > > future as suggested by akpm.
> > >
> > > Signed-off-by: Breno Leitao <leitao@debian.org>
> > > ---
> > > Changes in v2:
> > > - Add a comment to explain why the array is global (akpm)
> > > - Link to v1: https://patch.msgid.link/20260121-fix_vmcoreinfo-v1-1-39e96fab670e@debian.org
> > > ---
> > > kernel/vmcore_info.c | 6 +++++-
> > > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > LGTM,
> >
> > Acked-by: Baoquan He <bhe@redhat.com>
> >
> > BTW, is it worth a 'Fixes' tag?
>
> I am not sure, but, if we prefer to, this is the correct tag:
>
> Fixes: 3fa805c37dd4d ("vmcoreinfo: track and log recoverable hardware errors")

3fa805c37dd4d was added in 6.19-rc1, so this patch is a fixup against
this rc series. So yes, it should go into 6.19-rcX also.

I hadn't noticed the timing here so thanks both for pointing it out.