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author | H.J. Lu <hjl.tools@gmail.com> | 2020-09-12 05:37:30 -0700 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2020-09-12 05:37:43 -0700 |
commit | 496afd17055aeb7d8f45e01715c475664f2b73bd (patch) | |
tree | 221e0db337f288cbced1e5e4189463c23733a1a1 /ld/ld.texi | |
parent | e71774ed24cc6890285b174cb95caf79a7622466 (diff) | |
download | gdb-496afd17055aeb7d8f45e01715c475664f2b73bd.zip gdb-496afd17055aeb7d8f45e01715c475664f2b73bd.tar.gz gdb-496afd17055aeb7d8f45e01715c475664f2b73bd.tar.bz2 |
elf: Add -z unique-symbol to avoid duplicated local symbol names
The symbol string table in the .symtab section is optional and cosmetic.
The contents of the .symtab section have no impact on run-time execution.
The symbol names in the symbol string table help distinguish addresses at
different locations. Add a linker option, -z unique-symbol, to avoid
duplicated local symbol names in the symbol string table.
This feature was well received by the livepatch maintainers. It not only
solves the duplicated local symbol name problem, but also would allow
livepatch to more precisely locate duplicate symbols in general for
patching.
bfd/
PR ld/26391
* elflink.c (elf_final_link_info): Add local_hash_table.
(local_hash_entry): New.
(local_hash_newfunc): Likewise.
(elf_link_output_symstrtab): Append ".COUNT" to duplicated local
symbols.
(bfd_elf_final_link): Initialize and free local_hash_table for
"-z unique-symbol".
include/
PR ld/26391
* bfdlink.h (bfd_link_info): Add unique_symbol.
ld/
PR ld/26391
* NEWS: Mention "-z unique-symbol".
* emultempl/elf.em (gld${EMULATION_NAME}_handle_option): Handle
"-z unique-symbol" and "-z nounique-symbol".
* ld.texi: Document "-z unique-symbol" and "-z nounique-symbol".
* lexsup.c (elf_static_list_options): Add "-z unique-symbol" and
"-z nounique-symbol".
* testsuite/ld-elf/elf.exp: Add PR ld/26391 tests.
* testsuite/ld-elf/pr26391.nd: New file.
* testsuite/ld-elf/pr26391.out: Likewise.
* testsuite/ld-elf/pr26391a.c: Likewise.
* testsuite/ld-elf/pr26391b.c: Likewise.
* testsuite/ld-elf/pr26391c.c: Likewise.
* testsuite/ld-elf/pr26391d.c: Likewise.
Diffstat (limited to 'ld/ld.texi')
-rw-r--r-- | ld/ld.texi | 6 |
1 files changed, 6 insertions, 0 deletions
@@ -1378,6 +1378,12 @@ specifies a memory segment that should contain only instructions and must be in wholly disjoint pages from any other data. Don't create separate code @code{PT_LOAD} segment if @samp{noseparate-code} is used. +@item unique-symbol +@itemx nounique-symbol +Avoid duplicated local symbol names in the symbol string table. Append +".@code{number}" to duplicated local symbol names if @samp{unique-symbol} +is used. @option{nounique-symbol} is the default. + @item shstk Generate GNU_PROPERTY_X86_FEATURE_1_SHSTK in .note.gnu.property section to indicate compatibility with Intel Shadow Stack. Supported for |