On Thu, February 23, 2012 20:26, Will Drewry wrote:

Seems like there's an argument for another return code,
SECCOMP_RET_CORE, that resets/unblocks the SIGSYS handler since the
existing TRAP and KILL options seem to cover the other paths (signal
handler and do_exit).

What about making SECCOMP_RET_TRAP dump core/send SIGSYS if there is
no tracer with PTRACE_O_SECCOMP set? And perhaps go for a blockable
SIGSYS? That way you only have KILL, ERRNO and TRAP, with the last
one meaning deny, but giving someone else a chance to do something.
Or is that just confusing?

I don't think there should be too many return values, or else you
put too much runtime policy into the filters.

Sending SIGSYS is useful, but it's quite a bit less useful if user
space can't handle it in a signal handler, so I don't think it's
worth it to make a unblockable version.

Greetings,

Indan