diff mbox series

[v5] x86: Fallback {str|wcs}cmp RTM in the ncmp overflow case [BZ #28896]

Message ID 20220217191524.2961663-1-goldstein.w.n@gmail.com
State Committed
Commit c6272098323153db373f2986c67786ea8c85f1cf
Headers
Series [v5] x86: Fallback {str|wcs}cmp RTM in the ncmp overflow case [BZ #28896] |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

Noah Goldstein Feb. 17, 2022, 7:15 p.m. UTC 
  In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would
call strcmp-avx2 and wcsncmp-avx2 respectively. This would have
not checks around vzeroupper and would trigger spurious
aborts. This commit fixes that.

test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on
AVX2 machines with and without RTM.

Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
---
 sysdeps/x86/Makefile                        |  2 +-
 sysdeps/x86/tst-strncmp-rtm.c               | 17 ++++++++++++++++-
 sysdeps/x86_64/multiarch/strcmp-avx2.S      |  8 ++------
 sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S |  1 +
 sysdeps/x86_64/multiarch/strncmp-avx2.S     |  1 +
 sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S |  2 +-
 sysdeps/x86_64/multiarch/wcsncmp-avx2.S     |  2 +-
 7 files changed, 23 insertions(+), 10 deletions(-)

Comments

H.J. Lu Feb. 17, 2022, 7:20 p.m. UTC | #1 
On Thu, Feb 17, 2022 at 11:15 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would
> call strcmp-avx2 and wcsncmp-avx2 respectively. This would have
> not checks around vzeroupper and would trigger spurious
> aborts. This commit fixes that.
>
> test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on
> AVX2 machines with and without RTM.
>
> Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
> ---
>  sysdeps/x86/Makefile                        |  2 +-
>  sysdeps/x86/tst-strncmp-rtm.c               | 17 ++++++++++++++++-
>  sysdeps/x86_64/multiarch/strcmp-avx2.S      |  8 ++------
>  sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S |  1 +
>  sysdeps/x86_64/multiarch/strncmp-avx2.S     |  1 +
>  sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S |  2 +-
>  sysdeps/x86_64/multiarch/wcsncmp-avx2.S     |  2 +-
>  7 files changed, 23 insertions(+), 10 deletions(-)
>
> diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> index 6cf708335c..d110f7b7f2 100644
> --- a/sysdeps/x86/Makefile
> +++ b/sysdeps/x86/Makefile
> @@ -109,7 +109,7 @@ CFLAGS-tst-memset-rtm.c += -mrtm
>  CFLAGS-tst-strchr-rtm.c += -mrtm
>  CFLAGS-tst-strcpy-rtm.c += -mrtm
>  CFLAGS-tst-strlen-rtm.c += -mrtm
> -CFLAGS-tst-strncmp-rtm.c += -mrtm
> +CFLAGS-tst-strncmp-rtm.c += -mrtm -Wno-error
>  CFLAGS-tst-strrchr-rtm.c += -mrtm
>  endif
>
> diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c
> index 09ed6fa0d6..9e20abaacc 100644
> --- a/sysdeps/x86/tst-strncmp-rtm.c
> +++ b/sysdeps/x86/tst-strncmp-rtm.c
> @@ -16,6 +16,7 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>
> +#include <stdint.h>
>  #include <tst-string-rtm.h>
>
>  #define LOOP 3000
> @@ -45,8 +46,22 @@ function (void)
>      return 1;
>  }
>
> +__attribute__ ((noinline, noclone))
> +static int
> +function_overflow (void)
> +{
> +  if (strncmp (string1, string2, SIZE_MAX) == 0)
> +    return 0;
> +  else
> +    return 1;
> +}
> +
>  static int
>  do_test (void)
>  {
> -  return do_test_1 ("strncmp", LOOP, prepare, function);
> +  int status = do_test_1 ("strncmp", LOOP, prepare, function);
> +  if (status != EXIT_SUCCESS)
> +    return status;
> +  status = do_test_1 ("strncmp", LOOP, prepare, function_overflow);
> +  return status;
>  }
> diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> index 07a5a2c889..52ff5ad724 100644
> --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
> +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> @@ -193,10 +193,10 @@ L(ret_zero):
>         .p2align 4,, 5
>  L(one_or_less):
>         jb      L(ret_zero)
> -#  ifdef USE_AS_WCSCMP
>         /* 'nbe' covers the case where length is negative (large
>            unsigned).  */
> -       jnbe    __wcscmp_avx2
> +       jnbe    OVERFLOW_STRCMP
> +#  ifdef USE_AS_WCSCMP
>         movl    (%rdi), %edx
>         xorl    %eax, %eax
>         cmpl    (%rsi), %edx
> @@ -205,10 +205,6 @@ L(one_or_less):
>         negl    %eax
>         orl     $1, %eax
>  #  else
> -       /* 'nbe' covers the case where length is negative (large
> -          unsigned).  */
> -
> -       jnbe    __strcmp_avx2
>         movzbl  (%rdi), %eax
>         movzbl  (%rsi), %ecx
>         subl    %ecx, %eax
> diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> index 37d1224bb9..68bad365ba 100644
> --- a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> +++ b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> @@ -1,3 +1,4 @@
>  #define STRCMP __strncmp_avx2_rtm
>  #define USE_AS_STRNCMP 1
> +#define OVERFLOW_STRCMP        __strcmp_avx2_rtm
>  #include "strcmp-avx2-rtm.S"
> diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2.S b/sysdeps/x86_64/multiarch/strncmp-avx2.S
> index 1678bcc235..f138e9f1fd 100644
> --- a/sysdeps/x86_64/multiarch/strncmp-avx2.S
> +++ b/sysdeps/x86_64/multiarch/strncmp-avx2.S
> @@ -1,3 +1,4 @@
>  #define STRCMP __strncmp_avx2
>  #define USE_AS_STRNCMP 1
> +#define OVERFLOW_STRCMP __strcmp_avx2
>  #include "strcmp-avx2.S"
> diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> index 4e88c70cc6..f467582cbe 100644
> --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> @@ -1,5 +1,5 @@
>  #define STRCMP __wcsncmp_avx2_rtm
>  #define USE_AS_STRNCMP 1
>  #define USE_AS_WCSCMP 1
> -
> +#define OVERFLOW_STRCMP        __wcscmp_avx2_rtm
>  #include "strcmp-avx2-rtm.S"
> diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> index 4fa1de4d3f..e9ede522b8 100644
> --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> @@ -1,5 +1,5 @@
>  #define STRCMP __wcsncmp_avx2
>  #define USE_AS_STRNCMP 1
>  #define USE_AS_WCSCMP 1
> -
> +#define OVERFLOW_STRCMP        __wcscmp_avx2
>  #include "strcmp-avx2.S"
> --
> 2.25.1
>

LGTM.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Thanks.
Sunil Pandey May 25, 2022, 7:51 p.m. UTC | #2 
On Thu, Feb 17, 2022 at 11:21 AM H.J. Lu via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>
> On Thu, Feb 17, 2022 at 11:15 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would
> > call strcmp-avx2 and wcsncmp-avx2 respectively. This would have
> > not checks around vzeroupper and would trigger spurious
> > aborts. This commit fixes that.
> >
> > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on
> > AVX2 machines with and without RTM.
> >
> > Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
> > ---
> >  sysdeps/x86/Makefile                        |  2 +-
> >  sysdeps/x86/tst-strncmp-rtm.c               | 17 ++++++++++++++++-
> >  sysdeps/x86_64/multiarch/strcmp-avx2.S      |  8 ++------
> >  sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S |  1 +
> >  sysdeps/x86_64/multiarch/strncmp-avx2.S     |  1 +
> >  sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S |  2 +-
> >  sysdeps/x86_64/multiarch/wcsncmp-avx2.S     |  2 +-
> >  7 files changed, 23 insertions(+), 10 deletions(-)
> >
> > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> > index 6cf708335c..d110f7b7f2 100644
> > --- a/sysdeps/x86/Makefile
> > +++ b/sysdeps/x86/Makefile
> > @@ -109,7 +109,7 @@ CFLAGS-tst-memset-rtm.c += -mrtm
> >  CFLAGS-tst-strchr-rtm.c += -mrtm
> >  CFLAGS-tst-strcpy-rtm.c += -mrtm
> >  CFLAGS-tst-strlen-rtm.c += -mrtm
> > -CFLAGS-tst-strncmp-rtm.c += -mrtm
> > +CFLAGS-tst-strncmp-rtm.c += -mrtm -Wno-error
> >  CFLAGS-tst-strrchr-rtm.c += -mrtm
> >  endif
> >
> > diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c
> > index 09ed6fa0d6..9e20abaacc 100644
> > --- a/sysdeps/x86/tst-strncmp-rtm.c
> > +++ b/sysdeps/x86/tst-strncmp-rtm.c
> > @@ -16,6 +16,7 @@
> >     License along with the GNU C Library; if not, see
> >     <https://www.gnu.org/licenses/>.  */
> >
> > +#include <stdint.h>
> >  #include <tst-string-rtm.h>
> >
> >  #define LOOP 3000
> > @@ -45,8 +46,22 @@ function (void)
> >      return 1;
> >  }
> >
> > +__attribute__ ((noinline, noclone))
> > +static int
> > +function_overflow (void)
> > +{
> > +  if (strncmp (string1, string2, SIZE_MAX) == 0)
> > +    return 0;
> > +  else
> > +    return 1;
> > +}
> > +
> >  static int
> >  do_test (void)
> >  {
> > -  return do_test_1 ("strncmp", LOOP, prepare, function);
> > +  int status = do_test_1 ("strncmp", LOOP, prepare, function);
> > +  if (status != EXIT_SUCCESS)
> > +    return status;
> > +  status = do_test_1 ("strncmp", LOOP, prepare, function_overflow);
> > +  return status;
> >  }
> > diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > index 07a5a2c889..52ff5ad724 100644
> > --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > @@ -193,10 +193,10 @@ L(ret_zero):
> >         .p2align 4,, 5
> >  L(one_or_less):
> >         jb      L(ret_zero)
> > -#  ifdef USE_AS_WCSCMP
> >         /* 'nbe' covers the case where length is negative (large
> >            unsigned).  */
> > -       jnbe    __wcscmp_avx2
> > +       jnbe    OVERFLOW_STRCMP
> > +#  ifdef USE_AS_WCSCMP
> >         movl    (%rdi), %edx
> >         xorl    %eax, %eax
> >         cmpl    (%rsi), %edx
> > @@ -205,10 +205,6 @@ L(one_or_less):
> >         negl    %eax
> >         orl     $1, %eax
> >  #  else
> > -       /* 'nbe' covers the case where length is negative (large
> > -          unsigned).  */
> > -
> > -       jnbe    __strcmp_avx2
> >         movzbl  (%rdi), %eax
> >         movzbl  (%rsi), %ecx
> >         subl    %ecx, %eax
> > diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> > index 37d1224bb9..68bad365ba 100644
> > --- a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> > +++ b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> > @@ -1,3 +1,4 @@
> >  #define STRCMP __strncmp_avx2_rtm
> >  #define USE_AS_STRNCMP 1
> > +#define OVERFLOW_STRCMP        __strcmp_avx2_rtm
> >  #include "strcmp-avx2-rtm.S"
> > diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2.S b/sysdeps/x86_64/multiarch/strncmp-avx2.S
> > index 1678bcc235..f138e9f1fd 100644
> > --- a/sysdeps/x86_64/multiarch/strncmp-avx2.S
> > +++ b/sysdeps/x86_64/multiarch/strncmp-avx2.S
> > @@ -1,3 +1,4 @@
> >  #define STRCMP __strncmp_avx2
> >  #define USE_AS_STRNCMP 1
> > +#define OVERFLOW_STRCMP __strcmp_avx2
> >  #include "strcmp-avx2.S"
> > diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> > index 4e88c70cc6..f467582cbe 100644
> > --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> > +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> > @@ -1,5 +1,5 @@
> >  #define STRCMP __wcsncmp_avx2_rtm
> >  #define USE_AS_STRNCMP 1
> >  #define USE_AS_WCSCMP 1
> > -
> > +#define OVERFLOW_STRCMP        __wcscmp_avx2_rtm
> >  #include "strcmp-avx2-rtm.S"
> > diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> > index 4fa1de4d3f..e9ede522b8 100644
> > --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> > +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> > @@ -1,5 +1,5 @@
> >  #define STRCMP __wcsncmp_avx2
> >  #define USE_AS_STRNCMP 1
> >  #define USE_AS_WCSCMP 1
> > -
> > +#define OVERFLOW_STRCMP        __wcscmp_avx2
> >  #include "strcmp-avx2.S"
> > --
> > 2.25.1
> >
>
> LGTM.
>
> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
>
> Thanks.
>
> --
> H.J.

I would like to backport this patch to release branches.
Any comments or objections?

Patch attached, it fixes BZ# 29127.

--Sunil
H.J. Lu May 25, 2022, 7:56 p.m. UTC | #3 
On Wed, May 25, 2022 at 12:52 PM Sunil Pandey <skpgkp2@gmail.com> wrote:
>
> On Thu, Feb 17, 2022 at 11:21 AM H.J. Lu via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
> >
> > On Thu, Feb 17, 2022 at 11:15 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > >
> > > In the overflow fallback strncmp-avx2-rtm and wcsncmp-avx2-rtm would
> > > call strcmp-avx2 and wcsncmp-avx2 respectively. This would have
> > > not checks around vzeroupper and would trigger spurious
> > > aborts. This commit fixes that.
> > >
> > > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass on
> > > AVX2 machines with and without RTM.
> > >
> > > Co-authored-by: H.J. Lu <hjl.tools@gmail.com>
> > > ---
> > >  sysdeps/x86/Makefile                        |  2 +-
> > >  sysdeps/x86/tst-strncmp-rtm.c               | 17 ++++++++++++++++-
> > >  sysdeps/x86_64/multiarch/strcmp-avx2.S      |  8 ++------
> > >  sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S |  1 +
> > >  sysdeps/x86_64/multiarch/strncmp-avx2.S     |  1 +
> > >  sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S |  2 +-
> > >  sysdeps/x86_64/multiarch/wcsncmp-avx2.S     |  2 +-
> > >  7 files changed, 23 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> > > index 6cf708335c..d110f7b7f2 100644
> > > --- a/sysdeps/x86/Makefile
> > > +++ b/sysdeps/x86/Makefile
> > > @@ -109,7 +109,7 @@ CFLAGS-tst-memset-rtm.c += -mrtm
> > >  CFLAGS-tst-strchr-rtm.c += -mrtm
> > >  CFLAGS-tst-strcpy-rtm.c += -mrtm
> > >  CFLAGS-tst-strlen-rtm.c += -mrtm
> > > -CFLAGS-tst-strncmp-rtm.c += -mrtm
> > > +CFLAGS-tst-strncmp-rtm.c += -mrtm -Wno-error
> > >  CFLAGS-tst-strrchr-rtm.c += -mrtm
> > >  endif
> > >
> > > diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c
> > > index 09ed6fa0d6..9e20abaacc 100644
> > > --- a/sysdeps/x86/tst-strncmp-rtm.c
> > > +++ b/sysdeps/x86/tst-strncmp-rtm.c
> > > @@ -16,6 +16,7 @@
> > >     License along with the GNU C Library; if not, see
> > >     <https://www.gnu.org/licenses/>.  */
> > >
> > > +#include <stdint.h>
> > >  #include <tst-string-rtm.h>
> > >
> > >  #define LOOP 3000
> > > @@ -45,8 +46,22 @@ function (void)
> > >      return 1;
> > >  }
> > >
> > > +__attribute__ ((noinline, noclone))
> > > +static int
> > > +function_overflow (void)
> > > +{
> > > +  if (strncmp (string1, string2, SIZE_MAX) == 0)
> > > +    return 0;
> > > +  else
> > > +    return 1;
> > > +}
> > > +
> > >  static int
> > >  do_test (void)
> > >  {
> > > -  return do_test_1 ("strncmp", LOOP, prepare, function);
> > > +  int status = do_test_1 ("strncmp", LOOP, prepare, function);
> > > +  if (status != EXIT_SUCCESS)
> > > +    return status;
> > > +  status = do_test_1 ("strncmp", LOOP, prepare, function_overflow);
> > > +  return status;
> > >  }
> > > diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > > index 07a5a2c889..52ff5ad724 100644
> > > --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > > +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > > @@ -193,10 +193,10 @@ L(ret_zero):
> > >         .p2align 4,, 5
> > >  L(one_or_less):
> > >         jb      L(ret_zero)
> > > -#  ifdef USE_AS_WCSCMP
> > >         /* 'nbe' covers the case where length is negative (large
> > >            unsigned).  */
> > > -       jnbe    __wcscmp_avx2
> > > +       jnbe    OVERFLOW_STRCMP
> > > +#  ifdef USE_AS_WCSCMP
> > >         movl    (%rdi), %edx
> > >         xorl    %eax, %eax
> > >         cmpl    (%rsi), %edx
> > > @@ -205,10 +205,6 @@ L(one_or_less):
> > >         negl    %eax
> > >         orl     $1, %eax
> > >  #  else
> > > -       /* 'nbe' covers the case where length is negative (large
> > > -          unsigned).  */
> > > -
> > > -       jnbe    __strcmp_avx2
> > >         movzbl  (%rdi), %eax
> > >         movzbl  (%rsi), %ecx
> > >         subl    %ecx, %eax
> > > diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> > > index 37d1224bb9..68bad365ba 100644
> > > --- a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> > > +++ b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
> > > @@ -1,3 +1,4 @@
> > >  #define STRCMP __strncmp_avx2_rtm
> > >  #define USE_AS_STRNCMP 1
> > > +#define OVERFLOW_STRCMP        __strcmp_avx2_rtm
> > >  #include "strcmp-avx2-rtm.S"
> > > diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2.S b/sysdeps/x86_64/multiarch/strncmp-avx2.S
> > > index 1678bcc235..f138e9f1fd 100644
> > > --- a/sysdeps/x86_64/multiarch/strncmp-avx2.S
> > > +++ b/sysdeps/x86_64/multiarch/strncmp-avx2.S
> > > @@ -1,3 +1,4 @@
> > >  #define STRCMP __strncmp_avx2
> > >  #define USE_AS_STRNCMP 1
> > > +#define OVERFLOW_STRCMP __strcmp_avx2
> > >  #include "strcmp-avx2.S"
> > > diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> > > index 4e88c70cc6..f467582cbe 100644
> > > --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> > > +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
> > > @@ -1,5 +1,5 @@
> > >  #define STRCMP __wcsncmp_avx2_rtm
> > >  #define USE_AS_STRNCMP 1
> > >  #define USE_AS_WCSCMP 1
> > > -
> > > +#define OVERFLOW_STRCMP        __wcscmp_avx2_rtm
> > >  #include "strcmp-avx2-rtm.S"
> > > diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> > > index 4fa1de4d3f..e9ede522b8 100644
> > > --- a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> > > +++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
> > > @@ -1,5 +1,5 @@
> > >  #define STRCMP __wcsncmp_avx2
> > >  #define USE_AS_STRNCMP 1
> > >  #define USE_AS_WCSCMP 1
> > > -
> > > +#define OVERFLOW_STRCMP        __wcscmp_avx2
> > >  #include "strcmp-avx2.S"
> > > --
> > > 2.25.1
> > >
> >
> > LGTM.
> >
> > Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
> >
> > Thanks.
> >
> > --
> > H.J.
>
> I would like to backport this patch to release branches.
> Any comments or objections?
>
> Patch attached, it fixes BZ# 29127.
>
> --Sunil

LGTM.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Thanks.
diff mbox series

Patch

diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 6cf708335c..d110f7b7f2 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -109,7 +109,7 @@  CFLAGS-tst-memset-rtm.c += -mrtm
 CFLAGS-tst-strchr-rtm.c += -mrtm
 CFLAGS-tst-strcpy-rtm.c += -mrtm
 CFLAGS-tst-strlen-rtm.c += -mrtm
-CFLAGS-tst-strncmp-rtm.c += -mrtm
+CFLAGS-tst-strncmp-rtm.c += -mrtm -Wno-error
 CFLAGS-tst-strrchr-rtm.c += -mrtm
 endif
 
diff --git a/sysdeps/x86/tst-strncmp-rtm.c b/sysdeps/x86/tst-strncmp-rtm.c
index 09ed6fa0d6..9e20abaacc 100644
--- a/sysdeps/x86/tst-strncmp-rtm.c
+++ b/sysdeps/x86/tst-strncmp-rtm.c
@@ -16,6 +16,7 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <stdint.h>
 #include <tst-string-rtm.h>
 
 #define LOOP 3000
@@ -45,8 +46,22 @@  function (void)
     return 1;
 }
 
+__attribute__ ((noinline, noclone))
+static int
+function_overflow (void)
+{
+  if (strncmp (string1, string2, SIZE_MAX) == 0)
+    return 0;
+  else
+    return 1;
+}
+
 static int
 do_test (void)
 {
-  return do_test_1 ("strncmp", LOOP, prepare, function);
+  int status = do_test_1 ("strncmp", LOOP, prepare, function);
+  if (status != EXIT_SUCCESS)
+    return status;
+  status = do_test_1 ("strncmp", LOOP, prepare, function_overflow);
+  return status;
 }
diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
index 07a5a2c889..52ff5ad724 100644
--- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
@@ -193,10 +193,10 @@  L(ret_zero):
 	.p2align 4,, 5
 L(one_or_less):
 	jb	L(ret_zero)
-#  ifdef USE_AS_WCSCMP
 	/* 'nbe' covers the case where length is negative (large
 	   unsigned).  */
-	jnbe	__wcscmp_avx2
+	jnbe	OVERFLOW_STRCMP
+#  ifdef USE_AS_WCSCMP
 	movl	(%rdi), %edx
 	xorl	%eax, %eax
 	cmpl	(%rsi), %edx
@@ -205,10 +205,6 @@  L(one_or_less):
 	negl	%eax
 	orl	$1, %eax
 #  else
-	/* 'nbe' covers the case where length is negative (large
-	   unsigned).  */
-
-	jnbe	__strcmp_avx2
 	movzbl	(%rdi), %eax
 	movzbl	(%rsi), %ecx
 	subl	%ecx, %eax
diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
index 37d1224bb9..68bad365ba 100644
--- a/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
+++ b/sysdeps/x86_64/multiarch/strncmp-avx2-rtm.S
@@ -1,3 +1,4 @@ 
 #define STRCMP	__strncmp_avx2_rtm
 #define USE_AS_STRNCMP 1
+#define OVERFLOW_STRCMP	__strcmp_avx2_rtm
 #include "strcmp-avx2-rtm.S"
diff --git a/sysdeps/x86_64/multiarch/strncmp-avx2.S b/sysdeps/x86_64/multiarch/strncmp-avx2.S
index 1678bcc235..f138e9f1fd 100644
--- a/sysdeps/x86_64/multiarch/strncmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/strncmp-avx2.S
@@ -1,3 +1,4 @@ 
 #define STRCMP	__strncmp_avx2
 #define USE_AS_STRNCMP 1
+#define OVERFLOW_STRCMP __strcmp_avx2
 #include "strcmp-avx2.S"
diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
index 4e88c70cc6..f467582cbe 100644
--- a/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
+++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2-rtm.S
@@ -1,5 +1,5 @@ 
 #define STRCMP __wcsncmp_avx2_rtm
 #define USE_AS_STRNCMP 1
 #define USE_AS_WCSCMP 1
-
+#define OVERFLOW_STRCMP	__wcscmp_avx2_rtm
 #include "strcmp-avx2-rtm.S"
diff --git a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
index 4fa1de4d3f..e9ede522b8 100644
--- a/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
+++ b/sysdeps/x86_64/multiarch/wcsncmp-avx2.S
@@ -1,5 +1,5 @@ 
 #define STRCMP __wcsncmp_avx2
 #define USE_AS_STRNCMP 1
 #define USE_AS_WCSCMP 1
-
+#define OVERFLOW_STRCMP	__wcscmp_avx2
 #include "strcmp-avx2.S"