Hi Eric, On 23/06/21 9:02 am, Eric W. Biederman wrote:
Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes: So I was more thinking of the debug patch for m68k to catch all the _regular_ cases, and all the other random cases of ptrace_event() or ptrace_notify(). Although maybe we've really caught them all. The exit case was clearly missing, and the thread fork case was scrogged. There are patches for the known problems. The patches I really don't like are the verification ones to find any unknown ones.. We still have nios2 which copied the m68k logic at some point. I think that is a processor that is still ``shipping'' and that people might still be using in new designs. I haven't looked closely enough to see what the other architectures with caller saved registers are doing. The challenging ones are /proc/pid/syscall and seccomp which want to see all of the system call arguments. I think every architecture always saves the system call arguments unconditionally, so those cases are probably not as interesting. But they certain look like they could be trouble.
Seccomp hasn't yet been implemented on m68k, though I'm working on that with Adrian. The sole secure_computing() call will happen in syscall_trace_enter(), so all system call arguments have been saved on the stack.
Haven't looked at /proc/pid/syscall yet ... Cheers, Michael
Eric
