From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 19 May 2016 08:59:46 +0000 (+0200)
Subject: uloop: revert signalfd support for now
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=1257a38a6e64511207bb3b077ca7e8e1a3338fc1;p=oweals%2Flibubox.git

uloop: revert signalfd support for now

It hasn't fixed the reported race condition and it introduced some new
issues.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

diff --git a/uloop-epoll.c b/uloop-epoll.c
index 2d1c4a7..bb652fd 100644
--- a/uloop-epoll.c
+++ b/uloop-epoll.c
@@ -16,8 +16,6 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include <sys/signalfd.h>
-
 /**
  * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
  */
@@ -25,79 +23,8 @@
 #define EPOLLRDHUP 0x2000
 #endif
 
-static void
-uloop_signal_fd_cb(struct uloop_fd *fd, unsigned int events)
-{
-	struct signalfd_siginfo fdsi;
-	struct sigaction act;
-	int ret;
-
-retry:
-	ret = read(fd->fd, &fdsi, sizeof(fdsi));
-	if (ret < 0 && errno == EINTR)
-		goto retry;
-
-	if (ret != sizeof(fdsi))
-		return;
-
-	switch (fdsi.ssi_signo) {
-	case SIGQUIT:
-	case SIGINT:
-	case SIGTERM:
-		sigaction(fdsi.ssi_signo, NULL, &act);
-		if (act.sa_handler != SIG_IGN &&
-			act.sa_handler != SIG_DFL) {
-			act.sa_handler(fdsi.ssi_signo);
-			break;
-		}
-
-		/* fall through */
-	default:
-		uloop_handle_signal(fdsi.ssi_signo);
-		break;
-	}
-}
-
-static bool
-uloop_setup_signalfd(bool add)
-{
-	static struct uloop_fd sfd = {
-		.cb = uloop_signal_fd_cb
-	};
-	static sigset_t prev_mask;
-	sigset_t mask;
-
-	if (signal_fd < 0)
-		return false;
-
-	sigemptyset(&mask);
-
-	if (!add) {
-		uloop_fd_delete(&sfd);
-		sigprocmask(SIG_BLOCK, &prev_mask, NULL);
-	} else {
-		sigaddset(&mask, SIGQUIT);
-		sigaddset(&mask, SIGINT);
-		sigaddset(&mask, SIGTERM);
-		sigaddset(&mask, SIGCHLD);
-		sigprocmask(SIG_BLOCK, &mask, &prev_mask);
-
-		sfd.fd = signal_fd;
-		uloop_fd_add(&sfd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
-	}
-
-	if (signalfd(signal_fd, &mask, SFD_NONBLOCK | SFD_CLOEXEC) < 0) {
-		sigprocmask(SIG_BLOCK, &prev_mask, NULL);
-		return false;
-	}
-
-	return true;
-}
-
 int uloop_init(void)
 {
-	sigset_t mask;
-
 	if (poll_fd >= 0)
 		return 0;
 
@@ -106,10 +33,6 @@ int uloop_init(void)
 		return -1;
 
 	fcntl(poll_fd, F_SETFD, fcntl(poll_fd, F_GETFD) | FD_CLOEXEC);
-
-	sigemptyset(&mask);
-	signal_fd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
-
 	return 0;
 }
 
diff --git a/uloop-kqueue.c b/uloop-kqueue.c
index e93bc82..0cb1c14 100644
--- a/uloop-kqueue.c
+++ b/uloop-kqueue.c
@@ -15,13 +15,6 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
-
-static bool
-uloop_setup_signalfd(bool add)
-{
-	return false;
-}
-
 int uloop_init(void)
 {
 	struct timespec timeout = { 0, 0 };
diff --git a/uloop.c b/uloop.c
index af84737..cd3de85 100644
--- a/uloop.c
+++ b/uloop.c
@@ -56,7 +56,6 @@ static struct uloop_fd_stack *fd_stack = NULL;
 static struct list_head timeouts = LIST_HEAD_INIT(timeouts);
 static struct list_head processes = LIST_HEAD_INIT(processes);
 
-static int signal_fd = -1;
 static int poll_fd = -1;
 bool uloop_cancelled = false;
 static bool do_sigchld = false;
@@ -64,8 +63,6 @@ static bool do_sigchld = false;
 static struct uloop_fd_event cur_fds[ULOOP_MAX_EVENTS];
 static int cur_fd, cur_nfds;
 
-static void uloop_handle_signal(int signo);
-
 #ifdef USE_KQUEUE
 #include "uloop-kqueue.c"
 #endif
@@ -331,17 +328,14 @@ static void uloop_handle_processes(void)
 
 }
 
-static void uloop_handle_signal(int signo)
+static void uloop_handle_sigint(int signo)
 {
-	switch (signo) {
-	case SIGINT:
-	case SIGQUIT:
-	case SIGTERM:
-		uloop_cancelled = true;
-		break;
-	case SIGCHLD:
-		do_sigchld = true;
-	}
+	uloop_cancelled = true;
+}
+
+static void uloop_sigchld(int signo)
+{
+	do_sigchld = true;
 }
 
 static void uloop_install_handler(int signum, void (*handler)(int), struct sigaction* old, bool add)
@@ -392,14 +386,11 @@ static void uloop_ignore_signal(int signum, bool ignore)
 
 static void uloop_setup_signals(bool add)
 {
-	static struct sigaction old_sigint, old_sigchld, old_sigterm, old_sigquit;
-
-	uloop_setup_signalfd(add);
+	static struct sigaction old_sigint, old_sigchld, old_sigterm;
 
-	uloop_install_handler(SIGINT, uloop_handle_signal, &old_sigint, add);
-	uloop_install_handler(SIGTERM, uloop_handle_signal, &old_sigterm, add);
-	uloop_install_handler(SIGQUIT, uloop_handle_signal, &old_sigquit, add);
-	uloop_install_handler(SIGCHLD, uloop_handle_signal, &old_sigchld, add);
+	uloop_install_handler(SIGINT, uloop_handle_sigint, &old_sigint, add);
+	uloop_install_handler(SIGTERM, uloop_handle_sigint, &old_sigterm, add);
+	uloop_install_handler(SIGCHLD, uloop_sigchld, &old_sigchld, add);
 
 	uloop_ignore_signal(SIGPIPE, add);
 }
@@ -486,11 +477,6 @@ void uloop_run(void)
 
 void uloop_done(void)
 {
-	if (signal_fd >= 0) {
-		close(signal_fd);
-		signal_fd = -1;
-	}
-
 	if (poll_fd < 0)
 		return;