From: Sunil Pandey <skpgkp2@gmail.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: Noah Goldstein <goldstein.w.n@gmail.com>,
GNU C Library <libc-alpha@sourceware.org>,
Libc-stable Mailing List <libc-stable@sourceware.org>
Subject: Re: [PATCH v3 2/7] x86: Fix __wcsncmp_evex in strcmp-evex.S [BZ# 28755]
Date: Fri, 29 Apr 2022 15:05:53 -0700 [thread overview]
Message-ID: <CAMAf5_eRTk88bxuP1c5WSsBTVepS2xDHHpq2b7PcXmC2wZmZmQ@mail.gmail.com> (raw)
In-Reply-To: <CAMe9rOq4Kykvmc5QLRvvRFdecqn6F8-N+uuR4WerNUb5Xb+M9g@mail.gmail.com>
On Wed, Jan 26, 2022 at 2:06 PM H.J. Lu via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> On Mon, Jan 10, 2022 at 6:15 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Mon, Jan 10, 2022 at 1:36 PM Noah Goldstein via Libc-alpha
> > <libc-alpha@sourceware.org> wrote:
> > >
> > > Fixes [BZ# 28755] for wcsncmp by redirecting length >= 2^56 to
> > > __wcscmp_evex. For x86_64 this covers the entire address range so any
> > > length larger could not possibly be used to bound `s1` or `s2`.
> > >
> > > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass.
> > >
> > > Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
> > > ---
> > > sysdeps/x86_64/multiarch/strcmp-evex.S | 10 ++++++++++
> > > 1 file changed, 10 insertions(+)
> > >
> > > diff --git a/sysdeps/x86_64/multiarch/strcmp-evex.S b/sysdeps/x86_64/multiarch/strcmp-evex.S
> > > index 1d971f3889..0cd939d5af 100644
> > > --- a/sysdeps/x86_64/multiarch/strcmp-evex.S
> > > +++ b/sysdeps/x86_64/multiarch/strcmp-evex.S
> > > @@ -104,6 +104,16 @@ ENTRY (STRCMP)
> > > je L(char0)
> > > jb L(zero)
> > > # ifdef USE_AS_WCSCMP
> > > +# ifndef __ILP32__
> > > + movq %rdx, %rcx
> > > + /* Check if length could overflow when multiplied by
> > > + sizeof(wchar_t). Checking top 8 bits will cover all potential
> > > + overflow cases as well as redirect cases where its impossible to
> > > + length to bound a valid memory region. In these cases just use
> > > + 'wcscmp'. */
> > > + shrq $56, %rcx
> > > + jnz __wcscmp_evex
> > > +# endif
> > > /* Convert units: from wide to byte char. */
> > > shl $2, %RDX_LP
> > > # endif
> > > --
> > > 2.25.1
> > >
> >
> > LGTM.
> >
> > Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
> >
> > Thanks.
> >
> > --
> > H.J.
>
> I am backporting this to 2.34 branch.
>
> --
> H.J.
I would like to backport this patch to release branches.
Any comments or objections?
--Sunil
next prev parent reply other threads:[~2022-04-29 22:06 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-09 12:29 [PATCH v1 1/5] x86: Optimize strcmp-avx2.S and fix for " Noah Goldstein
2022-01-09 12:29 ` [PATCH v1 2/5] x86: Optimize strcmp-evex.S " Noah Goldstein
2022-01-09 12:29 ` [PATCH v1 3/5] string: remove stupid_[strcmp, strncmp, wcscmp, wcsncmp] Noah Goldstein
2022-01-09 12:29 ` [PATCH v1 4/5] string: Improve coverage in test-strcmp.c and test-strncmp.c Noah Goldstein
2022-01-09 12:29 ` [PATCH v1 5/5] benchtests: Add more coverage for strcmp and strncmp benchmarks Noah Goldstein
2022-01-09 12:35 ` [PATCH v1 1/5] x86: Optimize strcmp-avx2.S and fix for [BZ# 28755] Noah Goldstein
2022-01-09 14:07 ` H.J. Lu
2022-01-10 0:29 ` Noah Goldstein
2022-01-10 0:27 ` [PATCH v2 1/7] x86: Fix __wcsncmp_avx2 in strcmp-avx2.S " Noah Goldstein
2022-01-10 0:27 ` [PATCH v2 2/7] x86: Fix __wcsncmp_evex in strcmp-evex.S " Noah Goldstein
2022-01-10 0:35 ` H.J. Lu
2022-01-10 0:27 ` [PATCH v2 3/7] string/test-str*cmp: remove stupid_[strcmp, strncmp, wcscmp, wcsncmp] Noah Goldstein
2022-01-10 0:37 ` H.J. Lu
2022-01-10 0:27 ` [PATCH v2 4/7] string: Improve coverage in test-strcmp.c and test-strncmp.c Noah Goldstein
2022-01-10 0:38 ` H.J. Lu
2022-01-10 2:51 ` Noah Goldstein
2022-01-10 0:27 ` [PATCH v2 5/7] x86: Optimize strcmp-avx2.S Noah Goldstein
2022-01-10 0:41 ` H.J. Lu
2022-01-10 1:06 ` Noah Goldstein
2022-01-10 1:58 ` H.J. Lu
2022-01-10 2:54 ` Noah Goldstein
2022-01-10 0:27 ` [PATCH v2 6/7] x86: Optimize strcmp-evex.S Noah Goldstein
2022-01-10 0:41 ` H.J. Lu
2022-01-10 0:27 ` [PATCH v2 7/7] benchtests: Add more coverage for strcmp and strncmp benchmarks Noah Goldstein
2022-01-10 0:34 ` [PATCH v2 1/7] x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755] H.J. Lu
2022-01-10 21:35 ` [PATCH v3 " Noah Goldstein
2022-01-10 21:35 ` [PATCH v3 2/7] x86: Fix __wcsncmp_evex in strcmp-evex.S " Noah Goldstein
2022-01-11 2:15 ` H.J. Lu
2022-01-26 22:04 ` H.J. Lu
2022-04-29 22:05 ` Sunil Pandey [this message]
2022-01-10 21:35 ` [PATCH v3 3/7] string/test-str*cmp: remove stupid_[strcmp, strncmp, wcscmp, wcsncmp] Noah Goldstein
2022-01-10 21:35 ` [PATCH v3 4/7] string: Improve coverage in test-strcmp.c and test-strncmp.c Noah Goldstein
2022-01-10 21:35 ` [PATCH v3 5/7] x86: Optimize strcmp-avx2.S Noah Goldstein
2022-02-14 14:10 ` Andreas Schwab
2022-02-14 18:23 ` H.J. Lu
2022-02-14 19:16 ` Andreas Schwab
2022-02-14 19:30 ` H.J. Lu
2022-02-14 19:35 ` Andreas Schwab
2022-02-14 20:59 ` H.J. Lu
2022-02-14 21:10 ` H.J. Lu
2022-02-15 11:11 ` Andreas Schwab
2022-02-15 12:55 ` Andreas Schwab
2022-02-15 12:58 ` Noah Goldstein
2022-02-15 13:09 ` Noah Goldstein
2022-02-15 13:32 ` Noah Goldstein
2022-02-15 13:37 ` Noah Goldstein
2022-02-15 16:33 ` Noah Goldstein
2022-02-14 23:42 ` Noah Goldstein
2022-02-15 10:43 ` Andreas Schwab
2022-02-15 11:22 ` Andreas Schwab
2022-02-15 11:28 ` Noah Goldstein
2022-02-15 12:24 ` Andreas Schwab
2022-01-10 21:35 ` [PATCH v3 6/7] x86: Optimize strcmp-evex.S Noah Goldstein
2022-01-10 21:35 ` [PATCH v3 7/7] benchtests: Add more coverage for strcmp and strncmp benchmarks Noah Goldstein
2022-01-11 2:15 ` [PATCH v3 1/7] x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755] H.J. Lu
2022-01-26 22:05 ` H.J. Lu
2022-01-27 4:29 ` H.J. Lu
2022-01-27 5:10 ` H.J. Lu
2022-01-27 5:52 ` Noah Goldstein
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