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author | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2013-06-12 10:21:22 -0500 |
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committer | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2013-06-12 10:21:22 -0500 |
commit | 6a97b62a5b4f18aea849d6f4d8de58d1469d2521 (patch) | |
tree | 0fdb35cb468bdb040fd3a1f01b4ddcc70b0f30dd /sysdeps/generic | |
parent | 94f2c076692a5a4beaa9a85eb10dbe4d891acb1e (diff) | |
download | glibc-6a97b62a5b4f18aea849d6f4d8de58d1469d2521.tar.gz glibc-6a97b62a5b4f18aea849d6f4d8de58d1469d2521.tar.xz glibc-6a97b62a5b4f18aea849d6f4d8de58d1469d2521.zip |
Fix unsafe compiler optimization
GCC 4.8 enables -ftree-loop-distribute-patterns at -O3 by default and this optimization may transform loops into memset/memmove calls. Without proper handling this may generate unexpected PLT calls on GLIBC. This patch fixes by create memset/memmove alias to internal GLIBC __GI_memset/__GI_memmove symbols.
Diffstat (limited to 'sysdeps/generic')
-rw-r--r-- | sysdeps/generic/symbol-hacks.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/sysdeps/generic/symbol-hacks.h b/sysdeps/generic/symbol-hacks.h index bc7b4c4441..9eaf014ff2 100644 --- a/sysdeps/generic/symbol-hacks.h +++ b/sysdeps/generic/symbol-hacks.h @@ -1 +1,6 @@ -/* Fortunately nothing to do. */ +/* Some compiler optimizations may transform loops into memset/memmove + calls and without proper declaration it may generate PLT calls. */ +#if !defined __ASSEMBLER__ && !defined NOT_IN_libc && defined SHARED +asm ("memmove = __GI_memmove"); +asm ("memset = __GI_memset"); +#endif |