[FFmpeg-devel] [PATCH] avutil: [LA] use getauxval to do runtime check.

[Steven Liu]

Steven Liu <lingjiujianke at gmail.com> 于2023年2月27日周一 10:47写道：
>
> Shiyou Yin <yinshiyou-hf at loongson.cn> 于2023年2月27日周一 09:03写道：
> >
> >
> >
> > > 2023年2月23日 15:48，Steven Liu <lingjiujianke at gmail.com> 写道：
> > >
> > > Shiyou Yin <yinshiyou-hf at loongson.cn> 于2023年2月14日周二 20:26写道：
> > >>
> > >> Replace cpucfg with getauxval to avoid crash in case of
> > >> some processor capabilities are not supportted by kernel used.
> > >> ---
> > >> libavutil/loongarch/cpu.c | 24 ++++++++----------------
> > >> 1 file changed, 8 insertions(+), 16 deletions(-)
> > >>
> > >> diff --git a/libavutil/loongarch/cpu.c b/libavutil/loongarch/cpu.c
> > >> index e4b240bc44..cad8504fde 100644
> > >> --- a/libavutil/loongarch/cpu.c
> > >> +++ b/libavutil/loongarch/cpu.c
> > >> @@ -21,26 +21,18 @@
> > >>
> > >> #include <stdint.h>
> > >> #include "cpu.h"
> > >> +#include <sys/auxv.h>
> > >>
> > >> -#define LOONGARCH_CFG2 0x2
> > >> -#define LOONGARCH_CFG2_LSX    (1 << 6)
> > >> -#define LOONGARCH_CFG2_LASX   (1 << 7)
> > >> -
> > >> -static int cpu_flags_cpucfg(void)
> > >> +#define LA_HWCAP_LSX    (1<<4)
> > >> +#define LA_HWCAP_LASX   (1<<5)
> > >> +static int cpu_flags_getauxval(void)
> > >> {
> > >>     int flags = 0;
> > >> -    uint32_t cfg2 = 0;
> > >> -
> > >> -    __asm__ volatile(
> > >> -        "cpucfg %0, %1 \n\t"
> > >> -        : "+&r"(cfg2)
> > >> -        : "r"(LOONGARCH_CFG2)
> > >> -    );
> > >> +    int flag  = (int)getauxval(AT_HWCAP);
> > >>
> > >> -    if (cfg2 & LOONGARCH_CFG2_LSX)
> > >> +    if (flag & LA_HWCAP_LSX)
> > >>         flags |= AV_CPU_FLAG_LSX;
> > >> -
> > >> -    if (cfg2 & LOONGARCH_CFG2_LASX)
> > >> +    if (flag & LA_HWCAP_LASX)
> > >>         flags |= AV_CPU_FLAG_LASX;
> > >>
> > >>     return flags;
> > >> @@ -49,7 +41,7 @@ static int cpu_flags_cpucfg(void)
> > >> int ff_get_cpu_flags_loongarch(void)
> > >> {
> > >> #if defined __linux__
> > >> -    return cpu_flags_cpucfg();
> > >> +    return cpu_flags_getauxval();
> > >> #else
> > >>     /* Assume no SIMD ASE supported */
> > >>     return 0;
> > >> --
> > >> 2.20.1
> > >>
> > >> _______________________________________________
> > >> ffmpeg-devel mailing list
> > >> ffmpeg-devel at ffmpeg.org
> > >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > >>
> > >> To unsubscribe, visit link above, or email
> > >> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> > >
> > >
> > > LGTM
> > >
> > > Thanks
> > > Steven
> > > _______________________________________________
> >
> > Could you please help to merge this patch.
>
>
> I have no permission now, maybe there have some problem?
>
> (base) adeMacBook-Pro:project liuqi$ git clone git at source.ffmpeg.org:ffmpeg
> 正克隆到 'ffmpeg'...
> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
> Someone could be eavesdropping on you right now (man-in-the-middle attack)!
> It is also possible that a host key has just been changed.
> The fingerprint for the ED25519 key sent by the remote host is
> SHA256:dUNFtMwS3Z25nnzFF8UPYWsE0WiUR4majWLbWrsHBXU.
> Please contact your system administrator.

Fixed

>
>
> Thanks
> Steven
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".