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author | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-07-06 15:22:35 +0200 |
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committer | Stefan Liebler <stli@linux.vnet.ibm.com> | 2016-07-06 15:22:35 +0200 |
commit | dd8f8da99d7a0d93f517a07e150d8abd47386d7c (patch) | |
tree | 6ef2b2ed5ea18773028cbc06939f5dad6aab070d /sysdeps/s390/linkmap.h | |
parent | b95a6ebb931a8df8604ef3b52eea8f324bc08e92 (diff) | |
download | glibc-dd8f8da99d7a0d93f517a07e150d8abd47386d7c.zip glibc-dd8f8da99d7a0d93f517a07e150d8abd47386d7c.tar.gz glibc-dd8f8da99d7a0d93f517a07e150d8abd47386d7c.tar.bz2 |
S390: Use DT_JUMPREL in prelink undo code.
On s390, the current prelink undo code in elf_machine_lazy_rel()
has the requirement, that the plt stubs use the first got slots
after the 3 reserved ones.
In case of undoing prelink, the plt got slots are reset to the correct
addresses whithin the corresponding plt-stub. Therefore the address
is calculated by the address of the first plt-stub-address which
was written by prelink (see l->l_mach.plt) to got[1] and index of
current relocation multiplied with 32 (=size of one plt slot).
The index was calculated with ¤t-got-slot - &got[3].
This patch removes the requirement, that the plt-got-slots are
starting at got[3]. The index is now calculated with
¤t-reloc - &reloc[0]. The first struct Elf64_Rela is stored
at DT_JMPREL.
This patch is needed to prepare for partial relro support.
Ulrich Weigand suggested this approach to use DT_JMPREL - Thanks.
ChangeLog:
* sysdeps/s390/linkmap.h (struct link_map_machine):
Remove member gotplt and add member jmprel.
* sysdeps/s390/s390-32/dl-machine.h
(elf_machine_runtime_setup): Setup member jmprel with DT_JMPREL
instead of gotplt with &got[3].
(elf_machine_lazy_rel): Calculate address with reloc and jmprel.
* sysdeps/s390/s390-64/dl-machine.h: Likewise.
Diffstat (limited to 'sysdeps/s390/linkmap.h')
-rw-r--r-- | sysdeps/s390/linkmap.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/s390/linkmap.h b/sysdeps/s390/linkmap.h index fc1fba3..283615b 100644 --- a/sysdeps/s390/linkmap.h +++ b/sysdeps/s390/linkmap.h @@ -2,12 +2,12 @@ struct link_map_machine { Elf64_Addr plt; /* Address of .plt + 0x2e */ - Elf64_Addr gotplt; /* Address of .got + 0x18 */ + const Elf64_Rela *jmprel; /* Address of first JMP_SLOT reloc */ }; #else struct link_map_machine { Elf32_Addr plt; /* Address of .plt + 0x2c */ - Elf32_Addr gotplt; /* Address of .got + 0x0c */ + const Elf32_Rela *jmprel; /* Address of first JMP_SLOT reloc */ }; #endif |