On Wed, Jul 16, 2014 at 1:21 PM, Kees Cook <[email protected]> wrote: > On Tue, Jul 15, 2014 at 12:32 PM, Andy Lutomirski <[email protected]> wrote: >> >> + >> + ret = seccomp_phase1(&sd); >> + if (ret == SECCOMP_PHASE1_SKIP) { >> + regs->orig_ax = -ENOSYS; > > Before, seccomp didn't touch orig_ax on a skip. I don't see any > problem with this, and it's probably more clear this way, but are you > sure there aren't unexpected side-effects from this?
It's necessary to cause the syscall to be skipped -- see syscall_trace_enter. That being said, setting it to -ENOSYS is nonsense and probably confused you at least as much as it confused me. It should be regs->orig_ax = -1. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
