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

Oleg Nesterov
2018-10-31T13:04:49Z

On 10/30, Kees Cook wrote:
>
> I'd like to avoid changing the return value of __secure_computing() to
> just avoid having to touch all the callers. And I'd prefer not to
> change __seccomp_filter() to a bool, since I'd like the return values
> to be consistent through the call chain.

Sure, please forget.

> I find the existing code more readable than a single-line return, just
> because it's very explicit. I don't want to have to think any harder
> when reading seccomp. ;)

Heh ;) Again, please forget, this is cosmetic.

But I simply can't resist. I asked this question exactly because I was
confused by these 2 lines:

if (__seccomp_filter(this_syscall, NULL, true))
return -1;

return 0;

to me it looks as if we need to filter out some non-zero return values and
turn them into -1. I had to spend some time (and think harder ;) to verify
that this is just the recursive call and nothing more.

nevermind, please ignore.

Oleg.