diff options
Diffstat (limited to 'scripts/tst-elf-edit.py')
| -rw-r--r-- | scripts/tst-elf-edit.py | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/scripts/tst-elf-edit.py b/scripts/tst-elf-edit.py index a514179..0e19ce1 100644 --- a/scripts/tst-elf-edit.py +++ b/scripts/tst-elf-edit.py @@ -43,9 +43,11 @@ EI_DATA=5 ELFDATA2LSB=b'\x01' ELFDATA2MSB=b'\x02' +ET_EXEC=2 ET_DYN=3 PT_LOAD=1 +PT_TLS=7 def elf_types_fmts(e_ident): endian = '<' if e_ident[EI_DATA] == ELFDATA2LSB else '>' @@ -146,8 +148,15 @@ def elf_edit_align(phdr, align): else: phdr.p_align = int(align) +def elf_edit_maximize_tls_size(phdr, elfclass): + if elfclass == ELFCLASS32: + # It is possible that the kernel can allocate half of the + # address space, so use something larger. + phdr.p_memsz = 0xfff00000 + else: + phdr.p_memsz = 1 << 63 -def elf_edit(f, align): +def elf_edit(f, opts): ei_nident_fmt = 'c' * EI_NIDENT ei_nident_len = struct.calcsize(ei_nident_fmt) @@ -172,24 +181,35 @@ def elf_edit(f, align): ehdr = Elf_Ehdr(e_ident) ehdr.read(f) - if ehdr.e_type != ET_DYN: - error('{}: not a shared library'.format(f.name)) + if ehdr.e_type not in (ET_EXEC, ET_DYN): + error('{}: not an executable or shared library'.format(f.name)) phdr = Elf_Phdr(e_ident) + maximize_tls_size_done = False for i in range(0, ehdr.e_phnum): f.seek(ehdr.e_phoff + i * phdr.len) phdr.read(f) - if phdr.p_type == PT_LOAD: - elf_edit_align(phdr, align) + if phdr.p_type == PT_LOAD and opts.align is not None: + elf_edit_align(phdr, opts.align) + f.seek(ehdr.e_phoff + i * phdr.len) + phdr.write(f) + break + if phdr.p_type == PT_TLS and opts.maximize_tls_size: + elf_edit_maximize_tls_size(phdr, e_ident[EI_CLASS]) f.seek(ehdr.e_phoff + i * phdr.len) phdr.write(f) + maximize_tls_size_done = True break + if opts.maximize_tls_size and not maximize_tls_size_done: + error('{}: TLS maximum size was not updated'.format(f.name)) def get_parser(): parser = argparse.ArgumentParser(description=__doc__) - parser.add_argument('-a', dest='align', required=True, + parser.add_argument('-a', dest='align', help='How to set the LOAD alignment') + parser.add_argument('--maximize-tls-size', action='store_true', + help='Set maximum PT_TLS size') parser.add_argument('output', help='ELF file to edit') return parser @@ -199,7 +219,7 @@ def main(argv): parser = get_parser() opts = parser.parse_args(argv) with open(opts.output, 'r+b') as fout: - elf_edit(fout, opts.align) + elf_edit(fout, opts) if __name__ == '__main__': |