From 73eea4eee65f7ee7912a17673042e3d6bf781f84 Mon Sep 17 00:00:00 2001 From: jilles Date: Sun, 1 Sep 2013 19:59:54 +0000 Subject: system(): Restore behaviour for SIGINT and SIGQUIT. As mentioned in r16117 and the book "Advanced Programming in the Unix Environment" by W. Richard Stevens, we should ignore SIGINT and SIGQUIT before forking, since it is not guaranteed that the parent process starts running soon enough. To avoid calling sigaction() in the vforked child, instead block SIGINT and SIGQUIT before vfork() and keep the sigaction() to ignore after vfork(). The FreeBSD kernel discards ignored signals, even if they are blocked; therefore, it is not necessary to unblock SIGINT and SIGQUIT earlier. --- lib/libc/stdlib/system.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'lib/libc/stdlib/system.c') diff --git a/lib/libc/stdlib/system.c b/lib/libc/stdlib/system.c index 64a5447..e018e6f 100644 --- a/lib/libc/stdlib/system.c +++ b/lib/libc/stdlib/system.c @@ -59,6 +59,8 @@ __system(const char *command) (void)sigemptyset(&newsigblock); (void)sigaddset(&newsigblock, SIGCHLD); + (void)sigaddset(&newsigblock, SIGINT); + (void)sigaddset(&newsigblock, SIGQUIT); (void)_sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock); switch(pid = vfork()) { case -1: /* error */ -- cgit v1.1