diff options
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 /bfd/elfcode.h | |
parent | fa2b501cdcbb7e9e8437f1dfb4b1e939dcb07264 (diff) | |
download | binutils-96cc7918c18cdb7bd0331d836fa7f05341732580.zip binutils-96cc7918c18cdb7bd0331d836fa7f05341732580.tar.gz binutils-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 'bfd/elfcode.h')
-rw-r--r-- | bfd/elfcode.h | 36 |
1 files changed, 26 insertions, 10 deletions
diff --git a/bfd/elfcode.h b/bfd/elfcode.h index e4e29f0..495e498 100644 --- a/bfd/elfcode.h +++ b/bfd/elfcode.h @@ -266,6 +266,7 @@ elf_swap_ehdr_out (bfd *abfd, { unsigned int tmp; int signed_vma = get_elf_backend_data (abfd)->sign_extend_vma; + bool no_section_header = (abfd->flags & BFD_NO_SECTION_HEADER) != 0; memcpy (dst->e_ident, src->e_ident, EI_NIDENT); /* note that all elements of dst are *arrays of unsigned char* already... */ H_PUT_16 (abfd, src->e_type, dst->e_type); @@ -276,7 +277,10 @@ elf_swap_ehdr_out (bfd *abfd, else H_PUT_WORD (abfd, src->e_entry, dst->e_entry); H_PUT_WORD (abfd, src->e_phoff, dst->e_phoff); - H_PUT_WORD (abfd, src->e_shoff, dst->e_shoff); + if (no_section_header) + H_PUT_WORD (abfd, 0, dst->e_shoff); + else + H_PUT_WORD (abfd, src->e_shoff, dst->e_shoff); H_PUT_32 (abfd, src->e_flags, dst->e_flags); H_PUT_16 (abfd, src->e_ehsize, dst->e_ehsize); H_PUT_16 (abfd, src->e_phentsize, dst->e_phentsize); @@ -284,15 +288,24 @@ elf_swap_ehdr_out (bfd *abfd, if (tmp > PN_XNUM) tmp = PN_XNUM; H_PUT_16 (abfd, tmp, dst->e_phnum); - H_PUT_16 (abfd, src->e_shentsize, dst->e_shentsize); - tmp = src->e_shnum; - if (tmp >= (SHN_LORESERVE & 0xffff)) - tmp = SHN_UNDEF; - H_PUT_16 (abfd, tmp, dst->e_shnum); - tmp = src->e_shstrndx; - if (tmp >= (SHN_LORESERVE & 0xffff)) - tmp = SHN_XINDEX & 0xffff; - H_PUT_16 (abfd, tmp, dst->e_shstrndx); + if (no_section_header) + { + H_PUT_16 (abfd, 0, dst->e_shentsize); + H_PUT_16 (abfd, 0, dst->e_shnum); + H_PUT_16 (abfd, 0, dst->e_shstrndx); + } + else + { + H_PUT_16 (abfd, src->e_shentsize, dst->e_shentsize); + tmp = src->e_shnum; + if (tmp >= (SHN_LORESERVE & 0xffff)) + tmp = SHN_UNDEF; + H_PUT_16 (abfd, tmp, dst->e_shnum); + tmp = src->e_shstrndx; + if (tmp >= (SHN_LORESERVE & 0xffff)) + tmp = SHN_XINDEX & 0xffff; + H_PUT_16 (abfd, tmp, dst->e_shstrndx); + } } /* Translate an ELF section header table entry in external format into an @@ -1077,6 +1090,9 @@ elf_write_shdrs_and_ehdr (bfd *abfd) || bfd_bwrite (&x_ehdr, amt, abfd) != amt) return false; + if ((abfd->flags & BFD_NO_SECTION_HEADER) != 0) + return true; + /* Some fields in the first section header handle overflow of ehdr fields. */ if (i_ehdrp->e_phnum >= PN_XNUM) |