PR_SET_PDEATHSIG(2const)

NAME

PR_SET_PDEATHSIG - set the parent-death signal of the calling process

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#include <linux/prctl.h>  /* Definition of PR_* constants */
#include <sys/prctl.h>

int prctl(PR_SET_PDEATHSIG, long sig);

DESCRIPTION

Set the parent-death signal of the calling process to sig (either a signal value in the range [1, NSIG - 1], or 0 to clear). This is the signal that the calling process will get when its parent dies.

The parent-death signal is sent upon subsequent termination of the parent thread and also upon termination of each subreaper process (see PR_SET_CHILD_SUBREAPER(2const)) to which the caller is subsequently reparented. If the parent thread and all ancestor subreapers have already terminated by the time of the PR_SET_PDEATHSIG operation, then no parent-death signal is sent to the caller.

The parent-death signal is process-directed (see signal(7)) and, if the child installs a handler using the sigaction(2) SA_SIGINFO flag, the si_pid field of the siginfo_t argument of the handler contains the PID of the terminating parent process.

The parent-death signal setting is cleared for the child of a fork(2). It is also (since Linux 2.4.36 / 2.6.23) cleared when executing a set-user-ID or set-group-ID binary, or a binary that has associated capabilities (see capabilities(7)); otherwise, this value is preserved across execve(2). The parent-death signal setting is also cleared upon changes to any of the following thread credentials: effective user ID, effective group ID, filesystem user ID, or filesystem group ID.

RETURN VALUE

On success, 0 is returned. On error, -1 is returned, and errno is set to indicate the error.

ERRORS

EINVAL: sig is not a valid signal number.

STANDARDS

Linux.

HISTORY

Linux 2.1.57.

CAVEATS

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.