public inbox for libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: "H.J. Lu" <hjl.tools@gmail.com>
To: Noah Goldstein <goldstein.w.n@gmail.com>
Cc: GNU C Library <libc-alpha@sourceware.org>,
	"Carlos O'Donell" <carlos@systemhalted.org>
Subject: Re: [PATCH v1] elf: Replace `strcpy` call with `memcpy` [BZ #29454]
Date: Mon, 8 Aug 2022 07:23:56 -0700	[thread overview]
Message-ID: <CAMe9rOoBW4x==YSLeonNQLczAO8XLeXf4BEk_gAuz6TCD3+oRw@mail.gmail.com> (raw)
In-Reply-To: <20220808032622.3804534-2-goldstein.w.n@gmail.com>

On Sun, Aug 7, 2022 at 8:26 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>
> GCC normally does this optimization for us in
> strlen_pass::handle_builtin_strcpy but only for optimized
> build. To avoid needing to include strcpy.S in the rtld build to
> support the debug build, just do the optimization by hand.
> ---
>  elf/dl-cache.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/elf/dl-cache.c b/elf/dl-cache.c
> index 8bbf110d02..b97c17b3a9 100644
> --- a/elf/dl-cache.c
> +++ b/elf/dl-cache.c
> @@ -509,8 +509,9 @@ _dl_load_cache_lookup (const char *name)
>       we are accessing. Therefore we must make the copy of the
>       mapping data without using malloc.  */
>    char *temp;
> -  temp = alloca (strlen (best) + 1);
> -  strcpy (temp, best);
> +  size_t best_len = strlen (best) + 1;
> +  temp = alloca (best_len);
> +  memcpy (temp, best, best_len);
>    return __strdup (temp);
>  }
>
> --
> 2.34.1
>

LGTM.

Thanks.

-- 
H.J.

  parent reply	other threads:[~2022-08-08 14:24 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-08  3:26 [PATCH v1] x86: Fix `#define STRCPY` guard in strcpy-sse2.S Noah Goldstein
2022-08-08  3:26 ` [PATCH v1] elf: Replace `strcpy` call with `memcpy` [BZ #29454] Noah Goldstein
2022-08-08 10:19   ` Yann Droneaud
2022-08-08 14:23   ` H.J. Lu [this message]
2022-08-10  3:29     ` Noah Goldstein
2022-08-08 14:21 ` [PATCH v1] x86: Fix `#define STRCPY` guard in strcpy-sse2.S H.J. Lu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAMe9rOoBW4x==YSLeonNQLczAO8XLeXf4BEk_gAuz6TCD3+oRw@mail.gmail.com' \
    --to=hjl.tools@gmail.com \
    --cc=carlos@systemhalted.org \
    --cc=goldstein.w.n@gmail.com \
    --cc=libc-alpha@sourceware.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).