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| author | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2015-01-23 11:16:49 -0500 |
|---|---|---|
| committer | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2015-01-24 08:38:39 -0500 |
| commit | 0e87343e204b44468ffad0ec5dc8c8d6068f1227 (patch) | |
| tree | 9d8fec4386efad530b94e129c8549ff4342cc959 | |
| parent | 972af9e8ddd870cabf8aad39b28a6e352c9cc79c (diff) | |
| download | glibc-0e87343e204b44468ffad0ec5dc8c8d6068f1227.tar.gz | |
powerpc: Fix ifuncmain6pie failure with GCC 4.9
This patch fix the elf/ifuncmain6pie failure when building with GCC
4.9+. For some reason, the compiler removes the branch taken code at
resolve_ifunc (sysdeps/powerpc/powerpc64/dl-machine.h) as dead-code
and thus the testcase fails because the ifunc resolves branches to an
invalid memory location. It fixes by explicit adding a dependency of
value based on odp variable to avoid compiler optimization.
It fixes BZ#17868.
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | NEWS | 2 | ||||
| -rw-r--r-- | sysdeps/powerpc/powerpc64/dl-machine.h | 4 |
3 files changed, 10 insertions, 2 deletions
@@ -1,3 +1,9 @@ +2015-01-24 Adhemerval Zanellla <azanella@linux.vnet.ibm.com> + + [BZ #17868] + * sysdeps/powerpc/powerpc64/dl-machine.h (resolve_ifunc): Force value + set dependency from opd value. + 2015-01-23 H.J. Lu <hongjiu.lu@intel.com> * sysdeps/x86_64/multiarch/init-arch.c (__init_cpu_features): @@ -18,7 +18,7 @@ Version 2.21 17664, 17665, 17668, 17682, 17702, 17717, 17719, 17722, 17723, 17724, 17725, 17732, 17733, 17744, 17745, 17746, 17747, 17748, 17775, 17777, 17780, 17781, 17782, 17791, 17793, 17796, 17797, 17803, 17806, 17834, - 17844, 17848, 17870 + 17844, 17848, 17868, 17870 * A new semaphore algorithm has been implemented in generic C code for all machines. Previous custom assembly implementations of semaphore were diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h index 944871223f..47bb5a7cb7 100644 --- a/sysdeps/powerpc/powerpc64/dl-machine.h +++ b/sysdeps/powerpc/powerpc64/dl-machine.h @@ -623,7 +623,9 @@ resolve_ifunc (Elf64_Addr value, opd.fd_func = func->fd_func + sym_map->l_addr; opd.fd_toc = func->fd_toc + sym_map->l_addr; opd.fd_aux = func->fd_aux; - value = (Elf64_Addr) &opd; + /* GCC 4.9+ eliminates the branch as dead code, force the odp set + dependency. */ + asm ("" : "=r" (value) : "0" (&opd), "X" (opd)); } #endif #endif |