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llvm-project/lld/test/ELF/aarch64-got-relocations.s

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Don't omit dynamic relocations for the GOT. Where Clang's AArch64 backend seems to differ from the X86 backend is that it tends to use the GOT more aggressively. After getting CloudABI PIEs working on x86-64, I noticed that accessing global variables would still crash on aarch64. Tracing it down, it turns out that the GOT was filled with entries assuming the base address was zero. It turns out that we skip generating relocations for GOT entries in case the relocation pointing towards the GOT is relative. Whether the thing pointing to the GOT is absolute or relative shouldn't make any difference; the GOT entry itself should contain the absolute address, thus needs a relocation regardless. Approved by: rafael Differential Revision: http://reviews.llvm.org/D18739 llvm-svn: 265453
2016-04-06 04:17:33 +08:00
# REQUIRES: aarch64
# RUN: llvm-mc -filetype=obj -triple=aarch64-unknown-cloudabi %s -o %t.o
[ELF] - Do --hash-style=both by default. Its PR34712, GNU linkers recently changed default values to "both" of "sysv". Patch do the same for all targets except MIPS, where .gnu.hash section is not yet supported. Code suggested by Rui Ueyama. Differential revision: https://reviews.llvm.org/D38407 llvm-svn: 315051
2017-10-06 17:37:44 +08:00
# RUN: ld.lld --hash-style=sysv -pie %t.o -o %t
Don't omit dynamic relocations for the GOT. Where Clang's AArch64 backend seems to differ from the X86 backend is that it tends to use the GOT more aggressively. After getting CloudABI PIEs working on x86-64, I noticed that accessing global variables would still crash on aarch64. Tracing it down, it turns out that the GOT was filled with entries assuming the base address was zero. It turns out that we skip generating relocations for GOT entries in case the relocation pointing towards the GOT is relative. Whether the thing pointing to the GOT is absolute or relative shouldn't make any difference; the GOT entry itself should contain the absolute address, thus needs a relocation regardless. Approved by: rafael Differential Revision: http://reviews.llvm.org/D18739 llvm-svn: 265453
2016-04-06 04:17:33 +08:00
# RUN: llvm-readobj -r %t | FileCheck %s
# If we're addressing a global relatively through the GOT, we still need to
# emit a relocation for the entry in the GOT itself.
# CHECK: Relocations [
# CHECK: Section (4) .rela.dyn {
# CHECK: 0x{{[0-9A-F]+}} R_AARCH64_RELATIVE - 0x{{[0-9A-F]+}}
# CHECK: }
# CHECK: ]
.globl _start
.type _start,@function
_start:
adrp x8, :got:i
ldr x8, [x8, :got_lo12:i]
.type i,@object
.comm i,4,4