[Bug string/29234] Bug in rawmemchr-avx2 can return incorrect result

["carlos at redhat dot com" <sourceware-bugzilla@sourceware.org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=29234

Carlos O'Donell <carlos at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |2.36
         Resolution|---                         |FIXED
                 CC|                            |carlos at redhat dot com
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from Carlos O'Donell <carlos at redhat dot com> ---
Fixed already.

commit 2c9af8421d2b4a7fcce163e7bc81a118d22fd346
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Wed Jun 8 14:34:59 2022 -0700

    x86: Fix page cross case in rawmemchr-avx2 [BZ #29234]

    commit 6dcbb7d95dded20153b12d76d2f4e0ef0cda4f35
    Author: Noah Goldstein <goldstein.w.n@gmail.com>
    Date:   Mon Jun 6 21:11:33 2022 -0700

        x86: Shrink code size of memchr-avx2.S

    Changed how the page cross case aligned string (rdi) in
    rawmemchr. This was incompatible with how
    `L(cross_page_continue)` expected the pointer to be aligned and
    would cause rawmemchr to read data start started before the
    beginning of the string. What it would read was in valid memory
    but could count CHAR matches resulting in an incorrect return
    value.

    This commit fixes that issue by essentially reverting the changes to
    the L(page_cross) case as they didn't really matter.

    Test cases added and all pass with the new code (and where confirmed
    to fail with the old code).
    Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

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