On Sat, Apr 27, 2013 at 9:21 PM, Eric Dumazet <eric.duma...@gmail.com> wrote:
> I would feel more comfortable if you added :
>
> if (seen & SEEN_DATAREF) {
> pr_err_once("SECCOMP_LD_W assertion failed\n"):
> goto out;
> }
>
> This way, if BPF is changed in the future, but not the x86 JIT, we
> can have a working kernel.
>
> Ideally, we should add a SEEN_SKBREF to make sure rdi value can be
> scratched, or you just push %rdi/pop %rdi, its only one byte
> instructions.
Adding SEEN_SKBREF sounds like a good idea. :)
> Or completely optimize the thing and not call seccomp_bpf_load() at all.
This would be cool.
> (current would be loaded once in r9, task_pt_regs() would be loaded once
> in r8)
Both syscall_get_arch() and syscall_get_arguments() need to test for
the TS_COMPAT bit (in task_thread_info(current)->status); we should
load that once, too.
Thanks for the comments. Will try a v3.
- xi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
