X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fprocess%2Fposix_spawn.c;h=93fb15553537f8e3f34500f6414a5d75bdcdb85a;hb=6fcd60ddd903df13402704fe6026cb1f8e780fd7;hp=e6a031ccc1dc10ce9d1f0a6fa9b19730d4ad1834;hpb=a0473a0c826016aec1181819fcd4fff5c074f042;p=musl

diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c
index e6a031cc..93fb1555 100644
--- a/src/process/posix_spawn.c
+++ b/src/process/posix_spawn.c
@@ -20,38 +20,65 @@ struct args {
 	char *const *argv, *const *envp;
 };
 
+void __get_handler_set(sigset_t *);
+
+static int __sys_dup2(int old, int new)
+{
+#ifdef SYS_dup2
+	return __syscall(SYS_dup2, old, new);
+#else
+	return __syscall(SYS_dup3, old, new, 0);
+#endif
+}
+
 static int child(void *args_vp)
 {
 	int i, ret;
-	struct sigaction sa;
+	struct sigaction sa = {0};
 	struct args *args = args_vp;
 	int p = args->p[1];
 	const posix_spawn_file_actions_t *fa = args->fa;
 	const posix_spawnattr_t *restrict attr = args->attr;
+	sigset_t hset;
 
 	close(args->p[0]);
 
 	/* All signal dispositions must be either SIG_DFL or SIG_IGN
 	 * before signals are unblocked. Otherwise a signal handler
 	 * from the parent might get run in the child while sharing
-	 * memory, with unpredictable and dangerous results. */
+	 * memory, with unpredictable and dangerous results. To
+	 * reduce overhead, sigaction has tracked for us which signals
+	 * potentially have a signal handler. */
+	__get_handler_set(&hset);
 	for (i=1; i<_NSIG; i++) {
-		__libc_sigaction(i, 0, &sa);
-		if (sa.sa_handler!=SIG_DFL && (sa.sa_handler!=SIG_IGN ||
-		    ((attr->__flags & POSIX_SPAWN_SETSIGDEF)
-		     && sigismember(&attr->__def, i) ))) {
+		if ((attr->__flags & POSIX_SPAWN_SETSIGDEF)
+		     && sigismember(&attr->__def, i)) {
 			sa.sa_handler = SIG_DFL;
-			__libc_sigaction(i, &sa, 0);
+		} else if (sigismember(&hset, i)) {
+			if (i-32<3U) {
+				sa.sa_handler = SIG_IGN;
+			} else {
+				__libc_sigaction(i, 0, &sa);
+				if (sa.sa_handler==SIG_IGN) continue;
+				sa.sa_handler = SIG_DFL;
+			}
+		} else {
+			continue;
 		}
+		__libc_sigaction(i, &sa, 0);
 	}
 
+	if (attr->__flags & POSIX_SPAWN_SETSID)
+		if ((ret=__syscall(SYS_setsid)) < 0)
+			goto fail;
+
 	if (attr->__flags & POSIX_SPAWN_SETPGROUP)
 		if ((ret=__syscall(SYS_setpgid, 0, attr->__pgrp)))
 			goto fail;
 
-	/* Use syscalls directly because pthread state because the
-	 * library functions attempt to do a multi-threaded synchronized
-	 * id-change, which would trash the parent's state. */
+	/* Use syscalls directly because the library functions attempt
+	 * to do a multi-threaded synchronized id-change, which would
+	 * trash the parent's state. */
 	if (attr->__flags & POSIX_SPAWN_RESETIDS)
 		if ((ret=__syscall(SYS_setgid, __syscall(SYS_getgid))) ||
 		    (ret=__syscall(SYS_setuid, __syscall(SYS_getuid))) )
@@ -74,19 +101,26 @@ static int child(void *args_vp)
 			}
 			switch(op->cmd) {
 			case FDOP_CLOSE:
-				if ((ret=__syscall(SYS_close, op->fd)))
-					goto fail;
+				__syscall(SYS_close, op->fd);
 				break;
 			case FDOP_DUP2:
-				if ((ret=__syscall(SYS_dup2, op->srcfd, op->fd))<0)
-					goto fail;
+				fd = op->srcfd;
+				if (fd != op->fd) {
+					if ((ret=__sys_dup2(fd, op->fd))<0)
+						goto fail;
+				} else {
+					ret = __syscall(SYS_fcntl, fd, F_GETFD);
+					ret = __syscall(SYS_fcntl, fd, F_SETFD,
+					                ret & ~FD_CLOEXEC);
+					if (ret<0)
+						goto fail;
+				}
 				break;
 			case FDOP_OPEN:
-				fd = __syscall(SYS_open, op->path,
-					op->oflag | O_LARGEFILE, op->mode);
+				fd = __sys_open(op->path, op->oflag, op->mode);
 				if ((ret=fd) < 0) goto fail;
 				if (fd != op->fd) {
-					if ((ret=__syscall(SYS_dup2, fd, op->fd))<0)
+					if ((ret=__sys_dup2(fd, op->fd))<0)
 						goto fail;
 					__syscall(SYS_close, fd);
 				}
@@ -105,11 +139,12 @@ static int child(void *args_vp)
 		? &attr->__mask : &args->oldmask, 0);
 
 	args->exec(args->path, args->argv, args->envp);
+	ret = -errno;
 
 fail:
 	/* Since sizeof errno < PIPE_BUF, the write is atomic. */
 	ret = -ret;
-	if (ret) while (write(p, &ret, sizeof ret) < 0);
+	if (ret) while (__syscall(SYS_write, p, &ret, sizeof ret) < 0);
 	_exit(127);
 }
 
@@ -121,7 +156,7 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path,
 	char *const argv[restrict], char *const envp[restrict])
 {
 	pid_t pid;
-	char stack[1024];
+	char stack[1024+PATH_MAX];
 	int ec=0, cs;
 	struct args args;
 
@@ -138,7 +173,8 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path,
 	args.envp = envp;
 	pthread_sigmask(SIG_BLOCK, SIGALL_SET, &args.oldmask);
 
-	pid = __clone(child, stack+sizeof stack, CLONE_VM|SIGCHLD, &args);
+	pid = __clone(child, stack+sizeof stack,
+		CLONE_VM|CLONE_VFORK|SIGCHLD, &args);
 	close(args.p[1]);
 
 	if (pid > 0) {
@@ -150,7 +186,7 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path,
 
 	close(args.p[0]);
 
-	if (!ec) *res = pid;
+	if (!ec && res) *res = pid;
 
 	pthread_sigmask(SIG_SETMASK, &args.oldmask, 0);
 	pthread_setcancelstate(cs, 0);