[PATCH] x86: Fix bug about glibc.cpu.hwcaps.

[caiyinyu]

在 2023/3/9 上午12:56, Noah Goldstein 写道:
> On Wed, Mar 8, 2023 at 1:16 AM caiyinyu <caiyinyu@loongson.cn> wrote:
>>
>> 在 2023/3/8 上午1:23, Noah Goldstein 写道:
>>> On Tue, Mar 7, 2023 at 7:18 AM caiyinyu <caiyinyu@loongson.cn> wrote:
>>>> 在 2023/3/7 下午9:02, Xi Ruoyao 写道:
>>>>> On Tue, 2023-03-07 at 20:45 +0800, caiyinyu wrote:
>>>>>> 在 2023/3/2 下午12:22, H.J. Lu 写道:
>>>>>>> On Wed, Mar 1, 2023 at 6:36 PM caiyinyu <caiyinyu@loongson.cn>
>>>>>>> wrote:
>>>>>>>> Recorded in [BZ #30183]:
>>>>>>>>
>>>>>>>> 1. export GLIBC_TUNABLES=glibc.cpu.hwcaps=-AVX512
>>>>>>>> 2. Add  _dl_printf("p -- %s\n", p); just before switch(nl) in
>>>>>>>>        sysdeps/x86/cpu-tunables.c
>>>>>>>> 3. compiled and run ./testrun.sh /usr/bin/ls
>>>>>>>> you will get:
>>>>>>>>
>>>>>>>> p -- -AVX512
>>>>>>>> p -- LC_ADDRESS=en_US.UTF-8
>>>>>>>> p -- LC_NUMERIC=C
>>>>>>>> ...
>>>>>>>>
>>>>>>>> The function, TUNABLE_CALLBACK (set_hwcaps)
>>>>>>>> (tunable_val_t *valp), checks far more than it should and it
>>>>>>>> should stop at end of "-AVX512".
>>>>>>>> ---
>>>>>>>>      sysdeps/x86/cpu-tunables.c | 6 +++---
>>>>>>>>      1 file changed, 3 insertions(+), 3 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-
>>>>>>>> tunables.c
>>>>>>>> index d3e1367bda..772fb0c4c2 100644
>>>>>>>> --- a/sysdeps/x86/cpu-tunables.c
>>>>>>>> +++ b/sysdeps/x86/cpu-tunables.c
>>>>>>>> @@ -107,13 +107,13 @@ TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t
>>>>>>>> *valp)
>>>>>>>>           NOTE: the IFUNC selection may change over time.  Please
>>>>>>>> check all
>>>>>>>>           multiarch implementations when experimenting.  */
>>>>>>>>
>>>>>>>> -  const char *p = valp->strval;
>>>>>>>> +  const char *p = valp->strval, *c;
>>>>>>>>        struct cpu_features *cpu_features =
>>>>>>>> &GLRO(dl_x86_cpu_features);
>>>>>>>>        size_t len;
>>>>>>>>
>>>>>>>>        do
>>>>>>>>          {
>>>>>>>> -      const char *c, *n;
>>>>>>>> +      const char *n;
>>>>>>>>            bool disable;
>>>>>>>>            size_t nl;
>>>>>>>>
>>>>>>>> @@ -283,7 +283,7 @@ TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t
>>>>>>>> *valp)
>>>>>>>>             }
>>>>>>>>            p += len + 1;
>>>>>>>>          }
>>>>>>>> -  while (*p != '\0');
>>>>>>>> +  while (*c != '\0');
>>>>>>>>      }
>>>>>>>>
>>>>>>>>      # if CET_ENABLED
>>>>>>>> --
>>>>>>>> 2.31.1
>>>>>>>>
>>>>>>> OK.
>>>>>>>
>>>>>>> Thanks.
>>>>>> Could you help to push this patch?
>>>>> I guess you can push it yourself.  A port maintainer has write access to
>>>>> the entire Git repository, just use it carefully (i. e. always get a
>>>>> permission before changing other subsystems).
>>>>>
>>>> OK, thanks.
>>> did you add the tests HJ asked for?
>> Not yet.
> It also doesn't have the BZ number in the commit message. In the future please
> wait for approval before pushing.
>
Ok. There are "Recorded in [BZ #30183]:" in the commit message and I 
will append it on

the first line next time.

I mistakenly thought HJ is ok with

>>