Hi, On 19/09/2016 11:27, Jan Beulich wrote:
On 16.09.16 at 18:38, <konrad.w...@oracle.com> wrote:--- a/xen/arch/arm/livepatch.c +++ b/xen/arch/arm/livepatch.c @@ -117,6 +117,20 @@ bool arch_livepatch_symbol_ok(const struct livepatch_elf *elf, return true; }+bool arch_livepatch_symbol_deny(const struct livepatch_elf *elf, + const struct livepatch_elf_sym *sym) +{ +#ifdef CONFIG_ARM_32 + /* + * Xen does not use Thumb instructions - and we should not see any of + * them. If we do, abort. + */ + if ( sym->name && *sym->name == '$' && sym->name[1] == 't' )
Please use sym->name[0] for readability. Also, you may want to check the length of the symbol before checking the second character.
I'm not sure here: Are all symbols starting with $t to be rejected, or only $t but not e.g. $txyz? According to some other code I have lying around it ought to be "$t" and any symbols starting with "$t.", and would be in line with patch 6. But I guess the ARM maintainers will know best.
Only $t and $t.* should be rejected. All the others may be valid in the future.
Looking at the spec, I am wondering if we should also check the type and binding of the symbols. I have the impression that the naming is specific to STT_NOTYPE and STB_LOCAL. Any opinions?
Similar question for the previous patch (#6). Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
