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| author | H.J. Lu <hjl.tools@gmail.com> | 2014-11-22 08:58:07 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2014-11-22 08:58:07 -0800 |
| commit | 35a14c6b54b63adc6b6ef28a4e4403bb271b9bdd (patch) | |
| tree | be0f5a56d4d72e205620f312fe0a4113754e1d08 | |
| parent | 84429e27c826c74b99791b8f1efe8dce03cfa6ca (diff) | |
| download | gdb-35a14c6b54b63adc6b6ef28a4e4403bb271b9bdd.zip gdb-35a14c6b54b63adc6b6ef28a4e4403bb271b9bdd.tar.gz gdb-35a14c6b54b63adc6b6ef28a4e4403bb271b9bdd.tar.bz2 | |
Check branch displacement overflow in x86-64 PLT entry
Displacement of branch to PLT0 in x86-64 PLT entry is signed 32-bit.
This patch adds a sanity check. We will only see the failure when PLT
size is > 2GB.
* elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Check
branch displacement overflow in PLT entry.
| -rw-r--r-- | bfd/ChangeLog | 5 | ||||
| -rw-r--r-- | bfd/elf64-x86-64.c | 12 |
2 files changed, 15 insertions, 2 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 5700c51..040576a 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,8 @@ +2014-11-22 H.J. Lu <hongjiu.lu@intel.com> + + * elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Check + branch displacement overflow in PLT entry. + 2014-11-21 Nick Clifton <nickc@redhat.com> PR binutils/17512 diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index c64ff4f..8859429 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -4906,11 +4906,19 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, /* Don't fill PLT entry for static executables. */ if (plt == htab->elf.splt) { + bfd_vma plt0_offset = h->plt.offset + plt_plt_insn_end; + /* Put relocation index. */ bfd_put_32 (output_bfd, plt_index, plt->contents + h->plt.offset + abed->plt_reloc_offset); - /* Put offset for jmp .PLT0. */ - bfd_put_32 (output_bfd, - (h->plt.offset + plt_plt_insn_end), + + /* Put offset for jmp .PLT0 and check for overflow. We don't + check relocation index for overflow since branch displacement + will overflow first. */ + if (plt0_offset > 0x80000000) + info->callbacks->einfo (_("%F%B: branch displacement overflow in PLT entry for `%s'\n"), + output_bfd, h->root.root.string); + bfd_put_32 (output_bfd, - plt0_offset, plt->contents + h->plt.offset + plt_plt_offset); } |