diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2022-01-03 06:50:20 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2022-01-12 06:04:29 -0800 |
| commit | 6a91be866619c592762cd7e9b034a9f7ad27ef37 (patch) | |
| tree | 0e6f3c1cb84ecdee20857f3ba3f2087bf0425e06 /bfd/elflink.c | |
| parent | e2cbf4df83fe57892a6aaedf737b84baa6321fa7 (diff) | |
| download | gdb-6a91be866619c592762cd7e9b034a9f7ad27ef37.zip gdb-6a91be866619c592762cd7e9b034a9f7ad27ef37.tar.gz gdb-6a91be866619c592762cd7e9b034a9f7ad27ef37.tar.bz2 | |
ld: Initial DT_RELR support
Add a -z pack-relative-relocs option to enable DT_RELR and create a
relr.dyn section for DT_RELR. DT_RELR is implemented with the linker
relaxation infrastructure, but it doesn't require the --relax option
enabled. -z pack-relative-relocs implies -z combreloc. -z nocombreloc
implies -z nopack-relative-relocs.
-z pack-relative-relocs is chosen over the similar option in lld,
--pack-dyn-relocs=relr, to implement a glibc binary lockout mechanism
with a special glibc version symbol, to avoid random crashes of DT_RELR
binaries with the existing glibc binaries.
bfd/
* elf-bfd.h (elf_link_hash_table): Add srelrdyn.
* elflink.c (_bfd_elf_link_create_dynamic_sections): Create a
.relr.dyn section for DT_RELR.
include/
* bfdlink.h (bfd_link_info): Add enable_dt_relr.
ld/
* News: Mention -z pack-relative-relocs and
-z nopack-relative-relocs.
* ld.texi: Document -z pack-relative-relocs and
-z nopack-relative-relocs.
* ldelf.c (ldelf_after_parse): Disable DT_RELR if not building
PIE nor shared library. Add 3 spare dynamic tags for DT_RELR,
DT_RELRSZ and DT_RELRENT.
* ldlang.c (lang_relax_sections): Also enable relaxation if
DT_RELR is enabled.
* emulparams/elf32_x86_64.sh: Source dt-relr.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_x86_64.sh: Likewise.
* emulparams/dt-relr.sh: New file.
* scripttempl/elf.sc: Support .relr.dyn.
Diffstat (limited to 'bfd/elflink.c')
| -rw-r--r-- | bfd/elflink.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/bfd/elflink.c b/bfd/elflink.c index 46bff27..17407f2 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -359,6 +359,17 @@ _bfd_elf_link_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info) elf_section_data (s)->this_hdr.sh_entsize = 4; } + if (info->enable_dt_relr) + { + s = bfd_make_section_anyway_with_flags (abfd, ".relr.dyn", + (bed->dynamic_sec_flags + | SEC_READONLY)); + if (s == NULL + || !bfd_set_section_alignment (s, bed->s->log_file_align)) + return false; + elf_hash_table (info)->srelrdyn = s; + } + /* Let the backend create the rest of the sections. This lets the backend set the right flags. The backend will normally create the .got and .plt sections. */ |