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    SubjectRe: [PATCH] [RFC v2] qnx: avoid -Wstringop-overread warning, again
    On Mon, Sep 20, 2021 at 7:26 PM Linus Torvalds
    <torvalds@linux-foundation.org> wrote:
    > On Mon, Sep 20, 2021 at 5:12 AM Arnd Bergmann <arnd@kernel.org> wrote:
    > >
    > > + /*
    > > + * work around gcc-11.x using the first field it observes
    > > + * to determing the actual length
    > > + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578
    > > + */
    > > + char __empty[0];
    > > + char de_name[];
    >
    > Ugh. That looks _really_ hacky.
    >
    > It sounds like we can avoid the gcc bug if we just always use
    > "de->de_name[]". Then we don't need to depend on magical behavior
    > about one particular gcc version and a strange empty array in front of
    > it.
    >
    > IOW, something like the attached simpler thing that just does that
    > "always use de_name[]" and has a comment about why we don't do the
    > natural thing

    Yes, your patch is much nicer than my attempt. I checked it overnight
    and it addresses all the randconfig issues I found.

    > Also, just what version of gcc is the broken one? You say "gcc-11",
    > but I certainly don't see it with _my_ version of gcc-11, so can we
    > (just for that comment) document more precisely what version you have
    > (or possibly what config you use to trigger it).

    I'm using the gcc-11.1.0 that I uploaded to
    https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/11.1.0/

    The gcc bug is still open and currently targets gcc-11.3. To make it
    worse, this is definitely configuration dependent, and I do not see it
    in an allmodconfig build, but only certain randconfig builds. I originally
    had a simpler patch myself and also found that this did not fully
    address all kernel configs.
    gcc-10.x and early do not show the problem, I think the warning
    was only introduced in 11.1.

    https://pastebin.com/raw/fXmNiute is a .config for x86 that showed the
    problem for me on 5.15-rc2 but not with your new patch.

    Arnd

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