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author | Kaylee Blake <klkblake@gmail.com> | 2020-03-04 19:18:07 +1030 |
---|---|---|
committer | H.J. Lu <hjl.tools@gmail.com> | 2023-06-29 10:29:46 -0700 |
commit | 96cc7918c18cdb7bd0331d836fa7f05341732580 (patch) | |
tree | 906a911fb1b123f4ae238f8504671b1aeecbbe89 /ld | |
parent | fa2b501cdcbb7e9e8437f1dfb4b1e939dcb07264 (diff) | |
download | gdb-96cc7918c18cdb7bd0331d836fa7f05341732580.zip gdb-96cc7918c18cdb7bd0331d836fa7f05341732580.tar.gz gdb-96cc7918c18cdb7bd0331d836fa7f05341732580.tar.bz2 |
ELF: Strip section header in ELF objects
Section header isn't mandatory on ELF executable nor shared library.
This patch adds a new linker option, -z nosectionheader, to omit ELF
section header, a new objcopy and strip option, --strip-section-headers,
to remove ELF section headers.
bfd/
2023-06-06 H.J. Lu <hongjiu.lu@intel.com>
Kaylee Blake <klkblake@gmail.com>
PR ld/25617
* bfd.c (BFD_NO_SECTION_HEADER): New.
(BFD_FLAGS_SAVED): Add BFD_NO_SECTION_HEADER.
(BFD_FLAGS_FOR_BFD_USE_MASK): Likewise.
* elfcode.h (elf_swap_ehdr_out): Omit section header with
BFD_NO_SECTION_HEADER.
(elf_write_shdrs_and_ehdr): Likewise.
* elfxx-target.h (TARGET_BIG_SYM): Add BFD_NO_SECTION_HEADER
to object_flags.
(TARGET_LITTLE_SYM): Likewise.
* bfd-in2.h: Regenerated.
binutils/
2023-06-06 H.J. Lu <hongjiu.lu@intel.com>
PR ld/25617
* NEWS: Mention --strip-section-headers for objcopy and strip.
* objcopy.c (strip_section_headers): New.
(command_line_switch): Add OPTION_STRIP_SECTION_HEADERS.
(strip_options): Add --strip-section-headers.
(copy_options): Likewise.
(copy_usage): Add --strip-section-headers.
(strip_usage): Likewise.
(copy_object): Handle --strip-section-headers for ELF files.
(strip_main): Handle OPTION_STRIP_SECTION_HEADERS.
(copy_main): Likewise.
* doc/binutils.texi: Document --strip-section-headers for objcopy
and strip.
ld/
2023-06-06 H.J. Lu <hongjiu.lu@intel.com>
Kaylee Blake <klkblake@gmail.com>
PR ld/25617
* NEWS: Mention -z nosectionheader.
* emultempl/elf.em: Support -z sectionheader and
-z nosectionheader.
* ld.h (ld_config_type): Add no_section_header.
* ld.texi: Document -z sectionheader and -z nosectionheader.
* ldlang.c (ldlang_open_output): Handle
config.no_section_header.
* lexsup.c (parse_args): Enable --strip-all with
-z nosectionheader. Disallow -r with -z nosectionheader.
(elf_static_list_options): Add -z sectionheader and
-z nosectionheader.
Diffstat (limited to 'ld')
-rw-r--r-- | ld/NEWS | 3 | ||||
-rw-r--r-- | ld/emultempl/elf.em | 4 | ||||
-rw-r--r-- | ld/ld.h | 3 | ||||
-rw-r--r-- | ld/ld.texi | 5 | ||||
-rw-r--r-- | ld/ldlang.c | 4 | ||||
-rw-r--r-- | ld/lexsup.c | 13 |
6 files changed, 32 insertions, 0 deletions
@@ -15,6 +15,9 @@ * The linker script syntax has a new command for output sections: ASCIZ "string" This will insert a zero-terminated string at the current location. +* Add command-line option, -z nosectionheader, to omit ELF section + header. + Changes in 2.40: * The linker has a new command line option to suppress the generation of any diff --git a/ld/emultempl/elf.em b/ld/emultempl/elf.em index e367299..3f67f8b 100644 --- a/ld/emultempl/elf.em +++ b/ld/emultempl/elf.em @@ -807,6 +807,10 @@ fragment <<EOF "must be default, internal, hidden, or protected"), optarg); } + else if (strcmp (optarg, "sectionheader") == 0) + config.no_section_header = false; + else if (strcmp (optarg, "nosectionheader") == 0) + config.no_section_header = true; EOF if test x"$GENERATE_SHLIB_SCRIPT" = xyes; then @@ -280,6 +280,9 @@ typedef struct /* If set, code and non-code sections should never be in one segment. */ bool separate_code; + /* If set, generation of ELF section header should be suppressed. */ + bool no_section_header; + /* The rpath separation character. Usually ':'. */ char rpath_separator; @@ -1544,6 +1544,11 @@ Don't create an ELF @code{PT_GNU_RELRO} segment if @samp{norelro}. Report dynamic relative relocations generated by linker. Supported for Linux/i386 and Linux/x86_64. +@item sectionheader +@itemx nosectionheader +Generate section header. Don't generate section header if +@samp{nosectionheader} is used. @option{sectionheader} is the default. + @item separate-code @itemx noseparate-code Create separate code @code{PT_LOAD} segment header in the object. This diff --git a/ld/ldlang.c b/ld/ldlang.c index e359a89..f4a8b72 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -3434,6 +3434,10 @@ ldlang_open_output (lang_statement_union_type *statement) link_info.output_bfd->flags |= BFD_TRADITIONAL_FORMAT; else link_info.output_bfd->flags &= ~BFD_TRADITIONAL_FORMAT; + if (config.no_section_header) + link_info.output_bfd->flags |= BFD_NO_SECTION_HEADER; + else + link_info.output_bfd->flags &= ~BFD_NO_SECTION_HEADER; break; case lang_target_statement_enum: diff --git a/ld/lexsup.c b/ld/lexsup.c index 4e20e93..fe87223 100644 --- a/ld/lexsup.c +++ b/ld/lexsup.c @@ -1998,6 +1998,15 @@ parse_args (unsigned argc, char **argv) break; } + /* -z nosectionheader implies --strip-all. */ + if (config.no_section_header) + { + if (bfd_link_relocatable (&link_info)) + einfo (_("%F%P: -r and -z nosectionheader may not be used together\n")); + + link_info.strip = strip_all; + } + if (!bfd_link_dll (&link_info)) { if (command_line.filter_shlib) @@ -2272,6 +2281,10 @@ elf_static_list_options (FILE *file) fprintf (file, _("\ -z start-stop-visibility=V Set visibility of built-in __start/__stop symbols\n\ to DEFAULT, PROTECTED, HIDDEN or INTERNAL\n")); + fprintf (file, _("\ + -z sectionheader Generate section header (default)\n")); + fprintf (file, _("\ + -z nosectionheader Do not generate section header\n")); } static void |