Commit Graph

6 Commits

Author SHA1 Message Date
Peter Smith 3d044f57d4 [ELF] Recommit 327248 with Arm using the .got for _GLOBAL_OFFSET_TABLE_
This is the same as 327248 except Arm defining _GLOBAL_OFFSET_TABLE_ to
be the base of the .got section as some existing code is relying upon it.

For most Targets the _GLOBAL_OFFSET_TABLE_ symbol is expected to be at
the start of the .got.plt section so that _GLOBAL_OFFSET_TABLE_[0] =
reserved value that is by convention the address of the dynamic section.
Previously we had defined _GLOBAL_OFFSET_TABLE_ as either the start or end
of the .got section with the intention that the .got.plt section would
follow the .got. However this does not always hold with the current
default section ordering so _GLOBAL_OFFSET_TABLE_[0] may not be consistent
with the reserved first entry of the .got.plt.

X86, X86_64 and AArch64 will use the .got.plt. Arm, Mips and Power use .got

Fixes PR36555

Differential Revision: https://reviews.llvm.org/D44259

llvm-svn: 327823
2018-03-19 06:52:51 +00:00
Peter Collingbourne 5c902845e5 Revert r327248, "For most Targets the _GLOBAL_OFFSET_TABLE_ symbol is expected to be at"
This change broke ARM code that expects to be able to add
_GLOBAL_OFFSET_TABLE_ to the result of an R_ARM_REL32.

I will provide a reproducer on llvm-commits.

llvm-svn: 327688
2018-03-16 01:01:44 +00:00
Rumeet Dhindsa 14c3a871be Update Error Message
Summary: Updates error message  for dynamic relocation attempt for read only segments.

Reviewers: ruiu

Reviewed By: ruiu

Subscribers: emaste, javed.absar, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D44453

llvm-svn: 327584
2018-03-14 22:05:12 +00:00
Peter Smith 18aa0be36e For most Targets the _GLOBAL_OFFSET_TABLE_ symbol is expected to be at
the start of the .got.plt section so that _GLOBAL_OFFSET_TABLE_[0] =
reserved value that is by convention the address of the dynamic section.
Previously we had defined _GLOBAL_OFFSET_TABLE_ as either the start or end
of the .got section with the intention that the .got.plt section would
follow the .got. However this does not always hold with the current
default section ordering so _GLOBAL_OFFSET_TABLE_[0] may not be consistent
with the reserved first entry of the .got.plt.

X86, X86_64, Arm and AArch64 will use the .got.plt. Mips and Power use .got

Fixes PR36555

Differential Revision: https://reviews.llvm.org/D44259

llvm-svn: 327248
2018-03-11 20:58:18 +00:00
Rui Ueyama be85529d2b Remove one parameter from Target::getRelExpr.
A section was passed to getRelExpr just to create an error message.
But if there's an invalid relocation, we would eventually report it
in relocateOne. So we don't have to pass a section to getRelExpr.

llvm-svn: 315552
2017-10-12 03:14:06 +00:00
George Rimar e7bf968803 [ELF] - Stop producing broken output for R_386_GOT32[X] relocations.
Previously we silently produced broken output for R_386_GOT32X/R_386_GOT32 
relocations if they were used to compute the address of the symbol’s global
offset table entry without base register when position-independent code is disabled.

Situation happened because of recent ABI changes. Released ABI mentions that
R_386_GOT32X can be calculated in a two different ways (so we did not follow ABI here 
before this patch), but draft ABI also mentions R_386_GOT32 relocation here. 
We should use the same calculations for both relocations.

Problem is that we always calculated them as G + A - GOT (offset from end of GOT),
but for case when PIC is disabled, according to i386 ABI calculation should be G + A,
what should produce just an address in GOT finally.

ABI: https://github.com/hjl-tools/x86-psABI/wiki/intel386-psABI-draft.pdf (p36, p60).
llvm-svn: 299812
2017-04-08 06:14:14 +00:00