Hello, regarding the PR_SET_PDEATHSIG paragraph in prctl(2): > PR_SET_PDEATHSIG (since Linux 2.1.57) > Set the parent death signal of the calling process to arg2 > (either a signal value in the range 1..maxsig, or 0 to clear). > This is the signal that the calling process will get when its > parent dies. This value is cleared for the child of a fork(2) > and (since Linux 2.4.36 / 2.6.23) when executing a set-user-ID > or set-group-ID binary, or a binary that has associated > capabilities (see capabilities(7)). This value is preserved > across execve(2). > > Warning: the "parent" in this case is considered to be the > thread that created this process. In other words, the signal > will be sent when that thread terminates (via, for example, > pthread_exit(3)), rather than after all of the threads in the > parent process terminate. Perhaps it makes sense to add a note regarding a race condition between the child being able to call prctl() and an early exit of the parent process (after a successful fork()); i.e. when the parent death signal is installed after the parent has already died. See for example following links that may indicate that this isn't necessarily obvious: - http://lkml.iu.edu/hypermail/linux/kernel/0003.1/0769.html - http://stackoverflow.com/a/284443/427158 If you like you can include a code snippet how to use prctl(PR_SET_PDEATHSIGH, ) race condition free, cf. the snippets I've included in my answer on SO: http://stackoverflow.com/a/36945270/427158 Best regards Georg -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
