Re: [RFC PATCH 1/3] rseq: Introduce feature size and alignment ELF auxiliary vector entries

From: Peter Zijlstra
Date: Sun Feb 06 2022 - 16:50:06 EST


On Thu, Feb 03, 2022 at 02:38:51PM -0500, Mathieu Desnoyers wrote:

> @@ -286,6 +287,10 @@ create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
> if (bprm->have_execfd) {
> NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
> }
> +#ifdef CONFIG_RSEQ
> + NEW_AUX_ENT(AT_RSEQ_FEATURE_SIZE, offsetof(struct rseq, end));

I've gotta ask, what's up with offsetof(, end) vs sizeof() ?

> + NEW_AUX_ENT(AT_RSEQ_ALIGN, __alignof__(struct rseq));
> +#endif