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| author | Paul Eggert <eggert@cs.ucla.edu> | 2015-11-16 17:48:08 -0800 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2015-11-16 17:48:52 -0800 |
| commit | c9fd597a4cffcae873b25381ee8cc755f0debe95 (patch) | |
| tree | 0c924c1268813c82c6a6863a2da9149efee45772 /src/unexelf.c | |
| parent | 1cdddc1db6243cf90467e5736cc897718267f389 (diff) | |
| download | emacs-c9fd597a4cffcae873b25381ee8cc755f0debe95.tar.gz | |
ELF unexec: align section header
This ports the recent unexelf.c changes to Fedora x86-64
when configured with GCC’s -fsanitize=undefined option.
* src/unexelf.c (unexec): Align new_data2_size to a multiple
of ElfW (Shdr)’s alignment, so that NEW_SECTION_H returns a
pointer aligned appropriately for its type.
Diffstat (limited to 'src/unexelf.c')
| -rw-r--r-- | src/unexelf.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/src/unexelf.c b/src/unexelf.c index c10c7f21bf2..03e6dafe8ee 100644 --- a/src/unexelf.c +++ b/src/unexelf.c @@ -247,7 +247,7 @@ unexec (const char *new_name, const char *old_name) ElfW (Phdr) *old_bss_seg, *new_bss_seg; ElfW (Addr) old_bss_addr, new_bss_addr; - ElfW (Word) old_bss_size, new_data2_size; + ElfW (Word) old_bss_size, bss_size_growth, new_data2_size; ElfW (Off) old_bss_offset, new_data2_offset; ptrdiff_t n; @@ -331,7 +331,11 @@ unexec (const char *new_name, const char *old_name) new_break = sbrk (0); new_bss_addr = (ElfW (Addr)) new_break; - new_data2_size = new_bss_addr - old_bss_addr; + bss_size_growth = new_bss_addr - old_bss_addr; + new_data2_size = bss_size_growth; + new_data2_size += alignof (ElfW (Shdr)) - 1; + new_data2_size -= new_data2_size % alignof (ElfW (Shdr)); + new_data2_offset = old_bss_offset; #ifdef UNEXELF_DEBUG @@ -399,7 +403,8 @@ unexec (const char *new_name, const char *old_name) new_bss_seg->p_memsz = new_bss_seg->p_filesz; /* Copy over what we have in memory now for the bss area. */ - memcpy (new_base + new_data2_offset, (caddr_t) old_bss_addr, new_data2_size); + memcpy (new_base + new_data2_offset, (caddr_t) old_bss_addr, + bss_size_growth); /* Walk through all section headers, copying data and updating. */ for (n = 1; n < old_file_h->e_shnum; n++) |