Don't use Zend signal handling in pcntl

The deferred signal delivery provided by Zend signal handling is not used anywhere now,
so there is no need to go through `zend_sigaction` in pcntl.

Since `zend_sigaction` did have the effect of unblocking the signal whose handler has
been set, add that in pcntl to avoid changing behavior.

The one thing which will change is that Zend signal handling ignored the signal mask
provided by pcntl and used its own. Now the signal mask requested by pcntl will
actually be used.

Author: alexdowad

ext/pcntl/pcntl.c

@@ -936,7 +936,7 @@ PHP_FUNCTION(pcntl_signal)
 			php_error_docref(NULL, E_WARNING, "Invalid value for handle argument specified");
 			RETURN_FALSE;
 		}
-		if (php_signal(signo, (Sigfunc *) Z_LVAL_P(handle), (int) restart_syscalls) == (void *)SIG_ERR) {
+		if (php_signal(signo, (Sigfunc *) Z_LVAL_P(handle), (int) restart_syscalls) == FAILURE) {
 			PCNTL_G(last_error) = errno;
 			php_error_docref(NULL, E_WARNING, "Error assigning signal");
 			RETURN_FALSE;
@@ -959,7 +959,7 @@ PHP_FUNCTION(pcntl_signal)
 	handle = zend_hash_index_update(&PCNTL_G(php_signal_table), signo, handle);
 	Z_TRY_ADDREF_P(handle);
 
-	if (php_signal4(signo, pcntl_signal_handler, (int) restart_syscalls, 1) == (void *)SIG_ERR) {
+	if (php_signal4(signo, pcntl_signal_handler, (int) restart_syscalls, 1) == FAILURE) {
 		PCNTL_G(last_error) = errno;
 		php_error_docref(NULL, E_WARNING, "Error assigning signal");
 		RETURN_FALSE;

ext/pcntl/php_signal.c

@@ -17,13 +17,19 @@
 #include "TSRM.h"
 #include "php_signal.h"
 #include "Zend/zend.h"
-#include "Zend/zend_signal.h"
+
+#ifdef ZTS
+# define php_sigprocmask(how, set, oldset) tsrm_sigmask((how), (set), (oldset))
+#else
+# define php_sigprocmask(how, set, oldset) sigprocmask((how), (set), (oldset))
+#endif
 
 /* php_signal using sigaction is derived from Advanced Programming
  * in the Unix Environment by W. Richard Stevens p 298. */
-Sigfunc *php_signal4(int signo, Sigfunc *func, int restart, int mask_all)
+int php_signal4(int signo, Sigfunc *func, int restart, int mask_all)
 {
-	struct sigaction act,oact;
+	struct sigaction act;
+	sigset_t sigset;
 
 #ifdef HAVE_STRUCT_SIGINFO_T
 	act.sa_sigaction = func;
@@ -48,18 +54,19 @@ Sigfunc *php_signal4(int signo, Sigfunc *func, int restart, int mask_all)
 		act.sa_flags |= SA_RESTART; /* SVR4, 4.3+BSD */
 #endif
 	}
-	if (zend_sigaction(signo, &act, &oact) < 0) {
-		return (void*)SIG_ERR;
+	if (sigaction(signo, &act, NULL) < 0) {
+		return FAILURE;
 	}
 
-#ifdef HAVE_STRUCT_SIGINFO_T
-	return oact.sa_sigaction;
-#else
-	return oact.sa_handler;
-#endif
+	/* Ensure this signal is not blocked */
+	sigemptyset(&sigset);
+	sigaddset(&sigset, signo);
+	php_sigprocmask(SIG_UNBLOCK, &sigset, NULL);
+
+	return SUCCESS;
 }
 
-Sigfunc *php_signal(int signo, Sigfunc *func, int restart)
+int php_signal(int signo, Sigfunc *func, int restart)
 {
 	return php_signal4(signo, func, restart, 0);
 }

ext/pcntl/php_signal.h

@@ -23,7 +23,7 @@ typedef void Sigfunc(int, siginfo_t*, void*);
 #else
 typedef void Sigfunc(int);
 #endif
-Sigfunc *php_signal(int signo, Sigfunc *func, int restart);
-Sigfunc *php_signal4(int signo, Sigfunc *func, int restart, int mask_all);
+int php_signal(int signo, Sigfunc *func, int restart);
+int php_signal4(int signo, Sigfunc *func, int restart, int mask_all);
 
 #endif