shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity

[ELF] Ignore _GLOBAL_OFFSET_TABLE_ symbol in shared libs.

Browse Source 
This fixes PR26705.

Differential Revision:  http://reviews.llvm.org/D18166

llvm-svn: 263594
This commit is contained in:
Davide Italiano 2016-03-15 22:24:58 +00:00
parent 00df42459e
commit 00a7cf9ffe
2 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
lld/ELF/Driver.cpp
View File

@ -343,14 +343,15 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
Config->Rela = ELFT::Is64Bits;
if (!Config->Shared && !Config->Relocatable) {
if (Config->Entry.empty() && !Config->Shared && !Config->Relocatable &&
Config->EMachine != EM_AMDGPU)
// Add entry symbol.
//
// There is no entry symbol for AMDGPU binaries, so skip adding one to avoid
// having and undefined symbol.
if (Config->Entry.empty() && Config->EMachine != EM_AMDGPU)
Config->Entry = (Config->EMachine == EM_MIPS) ? "__start" : "_start";
Config->Entry = Config->EMachine == EM_MIPS ? "__start" : "_start";
if (!Config->Relocatable)
// In the assembly for 32 bit x86 the _GLOBAL_OFFSET_TABLE_ symbol
// is magical and is used to produce a R_386_GOTPC relocation.
// The R_386_GOTPC relocation value doesn't actually depend on the
@ -364,7 +365,6 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
// Given that the symbol is effectively unused, we just create a dummy
// hidden one to avoid the undefined symbol error.
Symtab.addIgnored("_GLOBAL_OFFSET_TABLE_");
}
if (!Config->Entry.empty()) {
// Set either EntryAddr (if S is a number) or EntrySym (otherwise).

6
lld/test/ELF/global_offset_table_shared.s Normal file
View File

@ -0,0 +1,6 @@
// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t
// RUN: ld.lld -shared %t -o %t2
// RUN: llvm-readobj -t %t2 | Filecheck %s
.long _GLOBAL_OFFSET_TABLE_
// CHECK-NOT: Name: _GLOBAL_OFFSET_TABLE_