Re: [GIT PULL] non-MM updates for 6.19-rc1

[Joseph Qi <joseph.qi@linux.alibaba.com>]

On 2025/12/7 07:40, Linus Torvalds wrote:
> On Sat, 6 Dec 2025 at 11:15, Andrew Morton <akpm@linux-foundation.org> wrote:
>>
>> Dmitry Antipov (8):
>>       ocfs2: annotate flexible array members with __counted_by_le()
> 
> This causes the build to fail for me with gcc 15.2.1:
> 
>   In function ‘fortify_memset_chk’,
>       inlined from ‘ocfs2_reflink_xattr_header’ at fs/ocfs2/xattr.c:6365:5:
>   include/linux/fortify-string.h:480:25: error: call to
> ‘__write_overflow_field’ declared with attribute warning: detected
> write beyond size of field (1st parameter); maybe use struct_group()?
> [-Werror=attribute-warning]
> 
> And the reason appears to likely be a bug this exposes, rather than a
> bug in the annotation. But I really don't know the ocfs2 code at all,
> so I'm going by "the error message is horrendous, but I can follow the
> logic in the code, and I think the code was actually wrong".
> 
> I have "fixed" things.
> 
> And I put that "fixed' in quotes, because my fix looks sane to me, and
> makes the array counting logic happy, and my fix may well be the
> RightThing(tm), but somebody who actually knows the ocfs2 code needs
> to check it out.
> 
> See commit c06c303832ec ("ocfs2: fix xattr array entry __counted_by
> error") which simply makes the 'last' pointer point to the actual last
> entry, rather than point to one _past_ the last entry.  So now the
> memmove() and memset() in the "possibly remove entry" loop below might
> actually work right, in addition to building cleanly.
> 
> But again: I did this without knowing anything about the code, just by
> looking at the logic.
> 
> I _think_ the code used to copy one entry too much, and cleared an
> entry past the end. It probably worked fine, because the code also
> decrements xh_count, so even if it cleared the wrong entry, it was
> past the counted end.
> 
> I'm a bit unhappy that this didn't show up in linux-next and that I
> had to chase this down. I don't think my gcc version is that odd.
> 
> Anyway, it's building for me, but I really really want some ocfs2
> person to take a look. Please?
> 

It looks fine to me.
Sorry for the noise and thank you for pointing out my mistake.

Thanks,
Joseph