| commit | e03a2ef180013c861d9a9c0e473c7abc12c270e1 | [log] [tgz] |
|---|---|---|
| author | Ulrich Weigand <ulrich.weigand@de.ibm.com> | Wed Feb 14 18:26:38 2024 +0100 |
| committer | Copybara-Service <copybara-worker@google.com> | Wed Feb 14 09:41:56 2024 -0800 |
| tree | 8dceea1b49ad40c05b378933ca4cad494f91d79d | |
| parent | 161a43c38ce0150dacbd53aee95ce50402f486d0 [diff] |
[lld/ELF] Avoid unnecessary TPOFF relocations in GOT for -pie (#81739)
With the new SystemZ port we noticed that -pie executables generated
from files containing R_390_TLS_IEENT relocations will have unnecessary
relocations in their GOT:
9e8d8: R_390_TLS_TPOFF *ABS*+0x18
This is caused by the config->isPic conditon in addTpOffsetGotEntry:
static void addTpOffsetGotEntry(Symbol &sym) {
in.got->addEntry(sym);
uint64_t off = sym.getGotOffset();
if (!sym.isPreemptible && !config->isPic) {
in.got->addConstant({R_TPREL, target->symbolicRel, off, 0, &sym});
return;
}
It is correct that we need to retain a TPOFF relocation if the target
symbol is preemptible or if we're building a shared library. But when
building a -pie executable, those values are fixed at link time and
there's no need for any remaining dynamic relocation.
Note that the equivalent MIPS-specific code in MipsGotSection::build
checks for config->shared instead of config->isPic; we should use the
same check here. (Note also that on many other platforms we're not even
using addTpOffsetGotEntry in this case as an IE->LE relaxation is
applied before; we don't have this type of relaxation on SystemZ.)
GitOrigin-RevId: 6f907733e65d24edad65f763fb14402464bd578b
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