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author | H.J. Lu <hjl.tools@gmail.com> | 2022-01-03 06:50:20 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2022-01-12 06:04:29 -0800 |
commit | 6a91be866619c592762cd7e9b034a9f7ad27ef37 (patch) | |
tree | 0e6f3c1cb84ecdee20857f3ba3f2087bf0425e06 /ld/emulparams | |
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 'ld/emulparams')
-rw-r--r-- | ld/emulparams/dt-relr.sh | 18 | ||||
-rw-r--r-- | ld/emulparams/elf32_x86_64.sh | 1 | ||||
-rw-r--r-- | ld/emulparams/elf_i386.sh | 1 | ||||
-rw-r--r-- | ld/emulparams/elf_x86_64.sh | 1 |
4 files changed, 21 insertions, 0 deletions
diff --git a/ld/emulparams/dt-relr.sh b/ld/emulparams/dt-relr.sh new file mode 100644 index 0000000..b2b403c --- /dev/null +++ b/ld/emulparams/dt-relr.sh @@ -0,0 +1,18 @@ +HAVE_DT_RELR=yes +PARSE_AND_LIST_OPTIONS_PACK_RELATIVE_RELOCS=' + fprintf (file, _("\ + -z pack-relative-relocs Pack relative relocations\n")); + fprintf (file, _("\ + -z nopack-relative-relocs Do not pack relative relocations (default)\n")); +' + +PARSE_AND_LIST_ARGS_CASE_Z_PACK_RELATIVE_RELOCS=' + else if (strcmp (optarg, "pack-relative-relocs") == 0) + link_info.enable_dt_relr = true; + else if (strcmp (optarg, "nopack-relative-relocs") == 0) + link_info.enable_dt_relr = false; +' + + +PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_PACK_RELATIVE_RELOCS" +PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_PACK_RELATIVE_RELOCS" diff --git a/ld/emulparams/elf32_x86_64.sh b/ld/emulparams/elf32_x86_64.sh index ac0a7aa..4bff412 100644 --- a/ld/emulparams/elf32_x86_64.sh +++ b/ld/emulparams/elf32_x86_64.sh @@ -7,6 +7,7 @@ source_sh ${srcdir}/emulparams/cet.sh source_sh ${srcdir}/emulparams/x86-report-relative.sh source_sh ${srcdir}/emulparams/x86-64-level.sh source_sh ${srcdir}/emulparams/static.sh +source_sh ${srcdir}/emulparams/dt-relr.sh SCRIPT_NAME=elf ELFSIZE=32 OUTPUT_FORMAT="elf32-x86-64" diff --git a/ld/emulparams/elf_i386.sh b/ld/emulparams/elf_i386.sh index 98532e5..ae17bb4 100644 --- a/ld/emulparams/elf_i386.sh +++ b/ld/emulparams/elf_i386.sh @@ -6,6 +6,7 @@ source_sh ${srcdir}/emulparams/cet.sh source_sh ${srcdir}/emulparams/x86-report-relative.sh source_sh ${srcdir}/emulparams/x86-64-level.sh source_sh ${srcdir}/emulparams/static.sh +source_sh ${srcdir}/emulparams/dt-relr.sh SCRIPT_NAME=elf OUTPUT_FORMAT="elf32-i386" NO_RELA_RELOCS=yes diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh index 48d0974..5f2743e 100644 --- a/ld/emulparams/elf_x86_64.sh +++ b/ld/emulparams/elf_x86_64.sh @@ -8,6 +8,7 @@ source_sh ${srcdir}/emulparams/x86-report-relative.sh source_sh ${srcdir}/emulparams/x86-64-level.sh source_sh ${srcdir}/emulparams/x86-64-lam.sh source_sh ${srcdir}/emulparams/static.sh +source_sh ${srcdir}/emulparams/dt-relr.sh SCRIPT_NAME=elf ELFSIZE=64 OUTPUT_FORMAT="elf64-x86-64" |