Re: [PATCH v2 7/9] x86/module: Use text_poke() for late relocations
From: Peter Zijlstra
Date: Fri Apr 17 2020 - 10:29:52 EST
On Fri, Apr 17, 2020 at 09:04:32AM -0500, Josh Poimboeuf wrote:
> +int apply_relocate_add(Elf64_Shdr *sechdrs,
> + const char *strtab,
> + unsigned int symindex,
> + unsigned int relsec,
> + struct module *me)
> +{
> + int ret;
> + bool early = me->state == MODULE_STATE_UNFORMED;
> + void *(*write)(void *, const void *, size_t) = memcpy;
> +
> + if (!early) {
> + write = text_poke;
> + mutex_lock(&text_mutex);
> + }
> +
> + ret = __apply_relocate_add(sechdrs, strtab, symindex, relsec, me,
> + write);
> +
> + if (!early) {
> + mutex_unlock(&text_mutex);
> + text_poke_sync();
I'm thinking text_poke_sync() wants to be inside text_mutex. Although
given that nothing should be running that text, it really doesn't
matter.
> + }
> +
> + return ret;
> +}
> +
> #endif
>
> int module_finalize(const Elf_Ehdr *hdr,
> --
> 2.21.1
>