[PATCH v1] elf: Replace `strcpy` call with `memcpy` [BZ #29454]
Yann Droneaud
ydroneaud@opteya.com
Mon Aug 8 10:19:43 GMT 2022
Hi,
Le 08/08/2022 à 05:26, Noah Goldstein via Libc-alpha a écrit :
> 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.
It does fixes this build issue I had when using -Og (using gcc 11.2, on amd64):
gcc -nostdlib -nostartfiles -shared -o .../build/elf/ld.so.new \
-Wl,-z,relro -Wl,-z,defs \
-Wl,-z,pack-relative-relocs \
.../build/elf/librtld.os -Wl,--version-script=.../build/ld.map \
-Wl,-soname=ld-linux-x86-64.so.2
/usr/bin/ld: .../build/elf/librtld.os: in function `_dl_load_cache_lookup':
.../elf/dl-cache.c:513: undefined reference to `strcpy'
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile:1347: .../build/elf/ld.so] Error 1
make[2]: Leaving directory '.../elf'
make[1]: *** [Makefile:484: elf/subdir_lib] Error 2
make[1]: Leaving directory '...'
make: *** [Makefile:9: all] Error 2
Thanks.
> ---
> 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);
> }
>
Regards.
--
Yann Droneaud
OPTEYA
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