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csu: Avoid weak ref for __ehdr_start in static PIE

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All linkers support __ehdr_start that support static PIE linking,
so there is no need to check for its presence via a weak reference.

This avoids a RELATIVE relocation in static PIE startup code on some
targets.

With non-PIE static linking the weak ref check is kept in case the
linker does not support __ehdr_start.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
Szabolcs Nagy
2021-01-06 14:28:02 +00:00
parent 374cef32ac
commit 04af1eb313
1 changed files with 4 additions and 0 deletions
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4
csu/libc-start.c
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@ -175,8 +175,12 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
information from auxv. */ information from auxv. */
extern const ElfW(Ehdr) __ehdr_start extern const ElfW(Ehdr) __ehdr_start
# if BUILD_PIE_DEFAULT
__attribute__ ((visibility ("hidden")));
# else
__attribute__ ((weak, visibility ("hidden"))); __attribute__ ((weak, visibility ("hidden")));
if (&__ehdr_start != NULL) if (&__ehdr_start != NULL)
# endif
{ {
assert (__ehdr_start.e_phentsize == sizeof *GL(dl_phdr)); assert (__ehdr_start.e_phentsize == sizeof *GL(dl_phdr));
GL(dl_phdr) = (const void *) &__ehdr_start + __ehdr_start.e_phoff; GL(dl_phdr) = (const void *) &__ehdr_start + __ehdr_start.e_phoff;