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author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2021-01-06 11:31:04 +0000 |
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committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2021-01-20 14:42:46 +0000 |
commit | d7eb5cfd6953e9689c0306d808e234bd00741e6e (patch) | |
tree | 79de8c2f0521178cb8319b470ca02e64b328b6ef /nptl/tst-execstack.c | |
parent | b5dbaa167f4317c312e22fb761036d3570e6614a (diff) | |
download | glibc-nsz/bug27072.tar.gz glibc-nsz/bug27072.tar.xz glibc-nsz/bug27072.zip |
Make libc symbols hidden in static PIE nsz/bug27072
Hidden visibility can avoid indirections and RELATIVE relocs in static PIE libc. The check should use IS_IN_LIB instead of IS_IN(libc) since all symbols are defined locally in static PIE and the optimization is useful in all libraries not just libc. However the test system links objects from libcrypt.a into dynamic linked test binaries where hidden visibility does not work. I think mixing static and shared libc components in the same binary should not be supported usage, but to be safe only use hidden in libc.a. On some targets (i386) this optimization cannot be applied because hidden visibility PIE ifunc functions don't work, so it is gated by NO_HIDDEN_EXTERN_FUNC_IN_PIE. From -static-pie linked 'int main(){}' this shaves off 71 relative relocs on aarch64 and reduces code size by about 2k.
Diffstat (limited to 'nptl/tst-execstack.c')
0 files changed, 0 insertions, 0 deletions