On 4/7/20 5:42 PM, Jens Axboe wrote: > Lots of system calls return -EINTR if interrupted by a signal, don't > think there's anything worth fixing there. For the wait part, the > application may want to handle the signal before we can wait again. > We can't go to sleep with a pending signal. This seems to be an unambiguous bug, at least according to the BUGS section of the ptrace man page. The behavior of epoll_wait is explicitly called out as being buggy/wrong, and we're emulating its behavior. As for the application wanting to handle the signal, in those cases, it would choose to install a signal handler, in which case I absolutely agree that returning -EINTR is the right thing to do. I'm only talking about the case where the application didn't choose to install a signal handler (and the signal would have been completely invisible to the process had it not been being traced). Joseph C. Sible
