From: "H.J. Lu" <hjl.tools@gmail.com>
To: caiyinyu <caiyinyu@loongson.cn>
Cc: libc-alpha@sourceware.org, goldstein.w.n@gmail.com
Subject: Re: [PATCH] x86: Fix bug about glibc.cpu.hwcaps.
Date: Wed, 1 Mar 2023 20:22:51 -0800 [thread overview]
Message-ID: <CAMe9rOocK8e3+fuygtuqcDyMb82pAYQMGnFonuwn9H0xjaAK3w@mail.gmail.com> (raw)
In-Reply-To: <20230302023349.3194099-1-caiyinyu@loongson.cn>
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.
--
H.J.
next prev parent reply other threads:[~2023-03-02 4:23 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-02 2:33 caiyinyu
2023-03-02 4:22 ` H.J. Lu [this message]
2023-03-07 12:45 ` caiyinyu
2023-03-07 13:02 ` Xi Ruoyao
2023-03-07 13:18 ` caiyinyu
2023-03-07 17:23 ` Noah Goldstein
2023-03-08 7:16 ` caiyinyu
2023-03-08 16:56 ` Noah Goldstein
2023-03-09 1:26 ` caiyinyu
2023-03-09 3:25 ` Xi Ruoyao
-- strict thread matches above, loose matches on Subject: below --
2023-03-01 3:22 caiyinyu
2023-03-01 4:19 ` Noah Goldstein
2023-03-01 9:10 ` caiyinyu
2023-03-01 16:42 ` Noah Goldstein
2023-03-01 17:33 ` H.J. Lu
2023-03-02 2:37 ` caiyinyu
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