diff mbox series

[v1] x86: Fallback {str|wcs}cmp RTM in the ncmp overflow case [BZ #28896]

Message ID 20220215162751.281955-1-goldstein.w.n@gmail.com
State Superseded
Headers
Series [v1] 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. 15, 2022, 4:27 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. Note not tested on a machine that supports RTM (non
available).
---
 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 +-
 5 files changed, 6 insertions(+), 8 deletions(-)

Comments

H.J. Lu Feb. 15, 2022, 4:29 p.m. UTC | #1 
On Tue, Feb 15, 2022 at 8:28 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.

Include a testcase?

> test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all
> pass. Note not tested on a machine that supports RTM (non
> available).
> ---
>  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 +-
>  5 files changed, 6 insertions(+), 8 deletions(-)
>
> 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
>
Noah Goldstein Feb. 15, 2022, 4:51 p.m. UTC | #2 
On Tue, Feb 15, 2022 at 10:30 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Tue, Feb 15, 2022 at 8:28 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.
>
> Include a testcase?
Added test case in V2. Don't have the hardware to check it though,
can you?
>
> > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all
> > pass. Note not tested on a machine that supports RTM (non
> > available).
> > ---
> >  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 +-
> >  5 files changed, 6 insertions(+), 8 deletions(-)
> >
> > 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
> >
>
>
> --
> H.J.
H.J. Lu Feb. 15, 2022, 4:59 p.m. UTC | #3 
On Tue, Feb 15, 2022 at 8:51 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Tue, Feb 15, 2022 at 10:30 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Tue, Feb 15, 2022 at 8:28 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.
> >
> > Include a testcase?
> Added test case in V2. Don't have the hardware to check it though,
> can you?

Yes, I can.  Please V2 on a branch in gitlab.

Thanks.

> >
> > > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all
> > > pass. Note not tested on a machine that supports RTM (non
> > > available).
> > > ---
> > >  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 +-
> > >  5 files changed, 6 insertions(+), 8 deletions(-)
> > >
> > > 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
> > >
> >
> >
> > --
> > H.J.
Noah Goldstein Feb. 15, 2022, 5:06 p.m. UTC | #4 
On Tue, Feb 15, 2022 at 11:00 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Tue, Feb 15, 2022 at 8:51 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > On Tue, Feb 15, 2022 at 10:30 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> > >
> > > On Tue, Feb 15, 2022 at 8:28 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.
> > >
> > > Include a testcase?
> > Added test case in V2. Don't have the hardware to check it though,
> > can you?
>
> Yes, I can.  Please V2 on a branch in gitlab.

https://gitlab.com/x86-glibc/glibc/-/commits/users/goldsteinn/strncmp-rtm-test
>
> Thanks.
>
> > >
> > > > test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all
> > > > pass. Note not tested on a machine that supports RTM (non
> > > > available).
> > > > ---
> > > >  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 +-
> > > >  5 files changed, 6 insertions(+), 8 deletions(-)
> > > >
> > > > 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
> > > >
> > >
> > >
> > > --
> > > H.J.
>
>
>
> --
> H.J.
H.J. Lu Feb. 15, 2022, 6:49 p.m. UTC | #5 
On Tue, Feb 15, 2022 at 9:06 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> On Tue, Feb 15, 2022 at 11:00 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > On Tue, Feb 15, 2022 at 8:51 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > >
> > > On Tue, Feb 15, 2022 at 10:30 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > >
> > > > On Tue, Feb 15, 2022 at 8:28 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.
> > > >
> > > > Include a testcase?
> > > Added test case in V2. Don't have the hardware to check it though,
> > > can you?
> >
> > Yes, I can.  Please V2 on a branch in gitlab.
>
> https://gitlab.com/x86-glibc/glibc/-/commits/users/goldsteinn/strncmp-rtm-test

I updated your branch with some fixes in the testcase and the commit log.
I tested it on an AVX2 machine with RTM.  The testcase fails without your
fix.

Please submit the v2 patch.

Thanks.
Noah Goldstein Feb. 16, 2022, 8:10 a.m. UTC | #6 
On Tue, Feb 15, 2022 at 12:50 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Tue, Feb 15, 2022 at 9:06 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > On Tue, Feb 15, 2022 at 11:00 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> > >
> > > On Tue, Feb 15, 2022 at 8:51 AM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> > > >
> > > > On Tue, Feb 15, 2022 at 10:30 AM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > > >
> > > > > On Tue, Feb 15, 2022 at 8:28 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.
> > > > >
> > > > > Include a testcase?
> > > > Added test case in V2. Don't have the hardware to check it though,
> > > > can you?
> > >
> > > Yes, I can.  Please V2 on a branch in gitlab.
> >
> > https://gitlab.com/x86-glibc/glibc/-/commits/users/goldsteinn/strncmp-rtm-test
>
> I updated your branch with some fixes in the testcase and the commit log.
> I tested it on an AVX2 machine with RTM.  The testcase fails without your
> fix.
>
> Please submit the v2 patch.

It's up.

>
> Thanks.
>
> --
> H.J.
diff mbox series

Patch

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"