diff options
| author | Pingfan Liu <piliu@redhat.com> | 2022-03-31 13:59:34 +0800 |
|---|---|---|
| committer | Simon Horman <horms@verge.net.au> | 2022-04-01 15:54:56 +0200 |
| commit | 2b78a27a64f097dd5d6e051c9a4b8a1b286c9ed0 (patch) | |
| tree | 44f43d7b805bc338345859a4b2d7820de81956eb | |
| parent | 1d8273d82b667d168939ba322adb5449d6171704 (diff) | |
| download | kexec-tools-2b78a27a64f097dd5d6e051c9a4b8a1b286c9ed0.tar.gz | |
kexec/elf: assign one to align if sh_addralign equals zero
According to ELF specification, if sh_addralign equals zero or one, then
the section has no alignment requirement on the start address. (I.e. it
can be aligned on 1 byte)
Since modern cpu asks the .text, .data, .bss to be aligned
on the machine word boundary at least, so in elf_rel_load(),
sh_addralign can not be zero, and
align = shdr->sh_addralign;
...
bufsz = _ALIGN(bufsz, align);
will not render a result of 'bufsz = 0'.
But it had better have a check on the case of 'sh_addralign == 0'
regardless of the assumption of machine word alignment.
This patch has no functional change.
Signed-off-by: Pingfan Liu <piliu@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
| -rw-r--r-- | kexec/kexec-elf-rel.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/kexec/kexec-elf-rel.c b/kexec/kexec-elf-rel.c index 9a6e63d..0a8b4d2 100644 --- a/kexec/kexec-elf-rel.c +++ b/kexec/kexec-elf-rel.c @@ -168,6 +168,10 @@ int build_elf_rel_info(const char *buf, off_t len, struct mem_ehdr *ehdr, return 0; } +static unsigned long get_section_addralign(struct mem_shdr *shdr) +{ + return (shdr->sh_addralign == 0) ? 1 : shdr->sh_addralign; +} int elf_rel_load(struct mem_ehdr *ehdr, struct kexec_info *info, unsigned long min, unsigned long max, int end) @@ -219,7 +223,7 @@ int elf_rel_load(struct mem_ehdr *ehdr, struct kexec_info *info, } if (shdr->sh_type != SHT_NOBITS) { unsigned long align; - align = shdr->sh_addralign; + align = get_section_addralign(shdr); /* See if I need more alignment */ if (buf_align < align) { buf_align = align; @@ -231,7 +235,7 @@ int elf_rel_load(struct mem_ehdr *ehdr, struct kexec_info *info, } else { unsigned long align; - align = shdr->sh_addralign; + align = get_section_addralign(shdr); /* See if I need more alignment */ if (bss_align < align) { bss_align = align; @@ -265,7 +269,7 @@ int elf_rel_load(struct mem_ehdr *ehdr, struct kexec_info *info, if (!(shdr->sh_flags & SHF_ALLOC)) { continue; } - align = shdr->sh_addralign; + align = get_section_addralign(shdr); if (shdr->sh_type != SHT_NOBITS) { unsigned long off; /* Adjust the address */ |