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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-08-13 07:37:34 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-08-16 11:34:53 -0700 |
| commit | 362d54c511c7668185ac6a37fb6d2042f9783567 (patch) | |
| tree | ac54842744642bf8a6ac956e7895eb93f2441af6 | |
| parent | 1760087874d21119ea4aa0f4624ea9a32fff84f9 (diff) | |
| download | glibc-hjl/pie/hidden.tar.gz | |
Add hidden visibility to internal function prototypeshjl/pie/hidden
Add hidden visibility to internal function prototypes to allow direct
access to internal functions within libc.a without using GOT when the
compiler defaults to -fPIE.
Size comparison of elf/ldconfig when the compiler defaults to -fPIE:
On x86-64:
text data bss dec hex
Before: 619646 20132 5488 645266 9d892
After : 619502 20132 5488 645122 9d802
On i686:
text data bss dec hex
Before: 550333 10748 3060 564141 89bad
After : 546453 10732 3060 560245 88c75
* include/libc-symbols.h (__hidden_proto_hiddenattr): New for
the compiler defaulting to -fPIE.
(hidden_proto): Likewise.
(hidden_tls_proto): Likewise.
(__hidden_proto): Likewise.
| -rw-r--r-- | include/libc-symbols.h | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/include/libc-symbols.h b/include/libc-symbols.h index d6a1c260f6..6c75a6f012 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -513,8 +513,20 @@ for linking") # endif #else # ifndef __ASSEMBLER__ -# define hidden_proto(name, attrs...) -# define hidden_tls_proto(name, attrs...) +# if BUILD_PIE_DEFAULT && IS_IN (libc) && !defined LIBC_NONSHARED \ + && !defined NO_HIDDEN +# define __hidden_proto_hiddenattr(attrs...) \ + __attribute__ ((visibility ("hidden"), ##attrs)) +# define hidden_proto(name, attrs...) \ + __hidden_proto (name, , name, ##attrs) +# define hidden_tls_proto(name, attrs...) \ + __hidden_proto (name, __thread, name, ##attrs) +# define __hidden_proto(name, thread, internal, attrs...) \ + extern thread __typeof (name) name __hidden_proto_hiddenattr (attrs); +# else +# define hidden_proto(name, attrs...) +# define hidden_tls_proto(name, attrs...) +# endif # else # define HIDDEN_JUMPTARGET(name) JUMPTARGET(name) # endif /* Not __ASSEMBLER__ */ |