On Wed, Oct 24, 2018 at 3:30 PM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > Enke Chen <enkechen@xxxxxxxxx> writes: > > For simplicity and consistency, this patch provides an implementation > > for signal-based fault notification prior to the coredump of a child > > process. A new prctl command, PR_SET_PREDUMP_SIG, is defined that can > > be used by an application to express its interest and to specify the > > signal (SIGCHLD or SIGUSR1 or SIGUSR2) for such a notification. A new > > signal code (si_code), CLD_PREDUMP, is also defined for SIGCHLD. > > > > Changes to prctl(2): > > > > PR_SET_PREDUMP_SIG (since Linux 4.20.x) > > Set the child pre-coredump signal of the calling process to > > arg2 (either SIGUSR1, or SIUSR2, or SIGCHLD, or 0 to clear). > > This is the signal that the calling process will get prior to > > the coredump of a child process. This value is cleared across > > execve(2), or for the child of a fork(2). > > > > When SIGCHLD is specified, the signal code will be set to > > CLD_PREDUMP in such an SIGCHLD signal. [...] > Ugh. Your test case is even using signalfd. So you don't even want > this signal to be delivered as a signal. Just to make sure everyone's on the same page: You're suggesting that it might make sense to deliver the pre-dump notification via a new type of file instead (along the lines of signalfd, timerfd, eventfd and so on)?
