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author | H.J. Lu <hjl.tools@gmail.com> | 2018-02-05 08:38:16 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2018-02-05 08:38:16 -0800 |
commit | cd04836359da82ae1dc67e5a05565536f4427b51 (patch) | |
tree | fc72f6593a58e26174caadbfe9515204901fb318 /bfd/elfxx-x86.c | |
parent | b8df6ca79e69678a07d3216b9b2b552fce27cda8 (diff) | |
download | gdb-cd04836359da82ae1dc67e5a05565536f4427b51.zip gdb-cd04836359da82ae1dc67e5a05565536f4427b51.tar.gz gdb-cd04836359da82ae1dc67e5a05565536f4427b51.tar.bz2 |
x86: Remove the unused _GLOBAL_OFFSET_TABLE_
Since _GLOBAL_OFFSET_TABLE_ may be referenced implicitly on x86,
checking ref_regular_nonweak leaves the unused _GLOBAL_OFFSET_TABLE_
in output. This patch checks explicit GOT references instead.
ld-i386/discarded1.s and ld-x86-64/discarded1.s are updated to avoid
linker optimization which removes GOT references.
bfd/
PR ld/22782
* elf32-i386.c (elf_i386_check_relocs): Set got_referenced if
_GLOBAL_OFFSET_TABLE_ is referenced or GOT is needed to resolve
undefined weak symbol to 0.
* elf64-x86-64.c (elf_x86_64_check_relocs): Set got_referenced
if _GLOBAL_OFFSET_TABLE_ is referenced.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Check
got_referenced instead of ref_regular_nonweak. Remove the
unused _GLOBAL_OFFSET_TABLE_ from symbol table.
* elfxx-x86.h (elf_x86_link_hash_table): Add got_referenced.
ld/
PR ld/22782
* testsuite/ld-i386/discarded1.s: Replace mov with div.
* testsuite/ld-x86-64/discarded1.s: Likewise.
* testsuite/ld-i386/i386.exp: Run pr22782.
* testsuite/ld-i386/load1-nacl.d: Updated for removing
_GLOBAL_OFFSET_TABLE_ from output.
* testsuite/ld-i386/load1.d: Likewise.
* testsuite/ld-x86-64/load1a-nacl.d: Likewise.
* testsuite/ld-x86-64/load1a.d: Likewise.
* testsuite/ld-x86-64/load1b-nacl.d: Likewise.
* testsuite/ld-x86-64/load1b.d: Likewise.
* testsuite/ld-i386/pr22782.d: New file.
* testsuite/ld-i386/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782a.d: Likewise.
* testsuite/ld-x86-64/pr22782b.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr22782a and pr22782b.
Diffstat (limited to 'bfd/elfxx-x86.c')
-rw-r--r-- | bfd/elfxx-x86.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c index a7db5d9..dbda542 100644 --- a/bfd/elfxx-x86.c +++ b/bfd/elfxx-x86.c @@ -1086,7 +1086,7 @@ _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd, /* Don't allocate .got.plt section if there are no GOT nor PLT entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */ if ((htab->elf.hgot == NULL - || !htab->elf.hgot->ref_regular_nonweak) + || !htab->got_referenced) && (htab->elf.sgotplt->size == bed->got_header_size) && (htab->elf.splt == NULL || htab->elf.splt->size == 0) @@ -1096,7 +1096,20 @@ _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd, || htab->elf.iplt->size == 0) && (htab->elf.igotplt == NULL || htab->elf.igotplt->size == 0)) - htab->elf.sgotplt->size = 0; + { + htab->elf.sgotplt->size = 0; + if (htab->elf.hgot != NULL) + { + /* Remove the unused _GLOBAL_OFFSET_TABLE_ from symbol + table. */ + htab->elf.hgot->root.type = bfd_link_hash_undefined; + htab->elf.hgot->root.u.undef.abfd + = htab->elf.hgot->root.u.def.section->owner; + htab->elf.hgot->root.linker_def = 0; + htab->elf.hgot->ref_regular = 0; + htab->elf.hgot->def_regular = 0; + } + } } if (_bfd_elf_eh_frame_present (info)) |