On Wed, Jan 12, 2011 at 02:38:17PM +0000, Pawel Jakub Dawidek wrote: > Author: pjd > Date: Wed Jan 12 14:38:17 2011 > New Revision: 217308 > URL: http://svn.freebsd.org/changeset/base/217308 > > Log: > Add a note that when custom signal handler is installed for a signal, > signal action is restored to default in child after fork(2). > In this case there is no need to do anything with dummy SIGCHLD handler, > because after fork(2) it will be automatically reverted to SIG_IGN. > > Obtained from: Wheel Systems Sp. z o.o. http://www.wheelsystems.com > MFC after: 3 days > > Modified: > head/sbin/hastd/hooks.c > > Modified: head/sbin/hastd/hooks.c > ============================================================================== > --- head/sbin/hastd/hooks.c Wed Jan 12 14:35:29 2011 (r217307) > +++ head/sbin/hastd/hooks.c Wed Jan 12 14:38:17 2011 (r217308) > @@ -372,6 +372,11 @@ hook_execv(const char *path, va_list ap) > descriptors(); > PJDLOG_VERIFY(sigemptyset(&mask) == 0); > PJDLOG_VERIFY(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); > + /* > + * Dummy handler set for SIGCHLD in the parent should be > + * changed after fork(2) automatically to the default SIG_IGN, > + * so there is no need to do anything with it. > + */ > execv(path, args); > pjdlog_errno(LOG_ERR, "Unable to execute %s", path); > exit(EX_SOFTWARE); Fork does not change the disposition of the signals. Exec family of the functions indeed reset the signals with handler to default disposition.
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