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 <[email protected]> Cc: Simon Horman <[email protected]> To: [email protected] --- kexec/kexec-elf-rel.c | 10 +++++++--- 1 file 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 */ -- 2.31.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
