Re: [PATCH v8 1/2] seccomp: add a return code to trap to userspace

Oleg Nesterov
2018-10-30T16:39:32Z

On 10/30, Oleg Nesterov wrote:
>
> On 10/30, Tycho Andersen wrote:
> >
> > @@ -828,6 +823,11 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
> > */
> > rmb();
> >
> > + if (!sd) {
> > + populate_seccomp_data(&sd_local);
> > + sd = &sd_local;
> > + }
> > +
>
> To me it would be more clean to remove the "if (!sd)" check, case(SECCOMP_RET_TRACE)
> in __seccomp_filter() can simply do populate_seccomp_data(&sd_local) unconditionally
> and pass &sd_local to __seccomp_filter().

Ah, please ignore, emulate_vsyscall() does secure_computing(NULL).

Btw. why __seccomp_filter() doesn't return a boolean?

Or at least, why can't case(SECCOMP_RET_TRACE) simply do

return __seccomp_filter(this_syscall, NULL, true);

?

Oleg.