4 files changed, 110 insertions, 56 deletions

diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c
index 8a6ff6db..e8557487 100644
--- a/src/process/posix_spawn.c
+++ b/src/process/posix_spawn.c
@@ -4,6 +4,7 @@
 #include <stdint.h>
 #include <fcntl.h>
 #include "syscall.h"
+#include "pthread_impl.h"
 #include "fdop.h"
 #include "libc.h"
 
@@ -30,7 +31,7 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path,
 
 	if (!attr) attr = &dummy_attr;
 
-	sigprocmask(SIG_BLOCK, (void *)(uint64_t []){-1}, &oldmask);
+	sigprocmask(SIG_BLOCK, SIGALL_SET, &oldmask);
 
 	__acquire_ptc();
 	pid = __vfork();
@@ -43,14 +44,14 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path,
 		return 0;
 	}
 
-	for (i=1; i<=64; i++) {
+	for (i=1; i<=8*__SYSCALL_SSLEN; i++) {
 		struct sigaction sa;
-		sigaction(i, 0, &sa);
-		if (sa.sa_handler!=SIG_IGN ||
+		__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) )) {
+		     && sigismember(&attr->__def, i) ))) {
 			sa.sa_handler = SIG_DFL;
-			sigaction(i, &sa, 0);
+			__libc_sigaction(i, &sa, 0);
 		}
 	}
 
diff --git a/src/process/system.c b/src/process/system.c
index 0f1c07b5..c8f26008 100644
--- a/src/process/system.c
+++ b/src/process/system.c
@@ -3,43 +3,62 @@
 #include <signal.h>
 #include <sys/wait.h>
 #include <errno.h>
+#include "pthread_impl.h"
+#include "libc.h"
+
+static void dummy_0()
+{
+}
+weak_alias(dummy_0, __acquire_ptc);
+weak_alias(dummy_0, __release_ptc);
+
+pid_t __vfork(void);
 
 int system(const char *cmd)
 {
 	pid_t pid;
-	sigset_t old, new;
-	struct sigaction sa, oldint, oldquit;
-	int status;
+	sigset_t old;
+	struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit;
+	int status = -1, i;
 
 	if (!cmd) return 1;
 
-	sa.sa_handler = SIG_IGN;
-	sigemptyset(&sa.sa_mask);
-	sa.sa_flags = 0;
-
 	sigaction(SIGINT, &sa, &oldint);
 	sigaction(SIGQUIT, &sa, &oldquit);
-	sigaddset(&sa.sa_mask, SIGCHLD);
-	sigprocmask(SIG_BLOCK, &new, &old);
+	sigprocmask(SIG_BLOCK, SIGALL_SET, &old);
+
+	__acquire_ptc();
+	pid = __vfork();
+	__release_ptc();
 
-	pid = fork();
-	if (pid <= 0) {
+	if (pid > 0) {
+		sigset_t new = old;
+		sigaddset(&new, SIGCHLD);
+		sigprocmask(SIG_BLOCK, &new, 0);
+		while (waitpid(pid, &status, 0) && errno == EINTR);
+	}
+
+	if (pid) {
 		sigaction(SIGINT, &oldint, NULL);
 		sigaction(SIGQUIT, &oldquit, NULL);
 		sigprocmask(SIG_SETMASK, &old, NULL);
-		if (pid == 0) {
-			execl("/bin/sh", "sh", "-c", cmd, (char *)0);
-			_exit(127);
-		}
-		return -1;
+		return status;
 	}
-	while (waitpid(pid, &status, 0) == -1)
-		if (errno != EINTR) {
-			status = -1;
-			break;
+
+	/* Before we can unblock signals in the child, all signal
+	 * handlers must be eliminated -- even implementation-internal
+	 * ones. Otherwise, a signal handler could run in the child
+	 * and clobber the parent's memory (due to vfork). */
+	for (i=1; i<=8*__SYSCALL_SSLEN; i++) {
+		struct sigaction sa;
+		__libc_sigaction(i, 0, &sa);
+		if (sa.sa_handler!=SIG_IGN && sa.sa_handler!=SIG_DFL) {
+			sa.sa_handler = SIG_DFL;
+			__libc_sigaction(i, &sa, 0);
 		}
-	sigaction(SIGINT, &oldint, NULL);
-	sigaction(SIGQUIT, &oldquit, NULL);
+	}
+
 	sigprocmask(SIG_SETMASK, &old, NULL);
-	return status;
+	execl("/bin/sh", "sh", "-c", cmd, (char *)0);
+	_exit(127);
 }
diff --git a/src/stdio/popen.c b/src/stdio/popen.c
index 4f9d6e9e..0c9f24e3 100644
--- a/src/stdio/popen.c
+++ b/src/stdio/popen.c
@@ -1,18 +1,22 @@
+#include <fcntl.h>
 #include "stdio_impl.h"
+#include "pthread_impl.h"
 #include "syscall.h"
 
-static inline void nc_close(int fd)
+static void dummy_0()
 {
-	__syscall(SYS_close, fd);
 }
-#define close(x) nc_close(x)
+weak_alias(dummy_0, __acquire_ptc);
+weak_alias(dummy_0, __release_ptc);
+
+pid_t __vfork(void);
 
 FILE *popen(const char *cmd, const char *mode)
 {
-	int p[2];
-	int op;
+	int p[2], op, i;
 	pid_t pid;
 	FILE *f;
+	sigset_t old;
 	const char *modes = "rw", *mi = strchr(modes, *mode);
 
 	if (mi) {
@@ -22,29 +26,45 @@ FILE *popen(const char *cmd, const char *mode)
 		return 0;
 	}
 	
-	if (pipe(p)) return NULL;
+	if (pipe2(p, O_CLOEXEC)) return NULL;
 	f = fdopen(p[op], mode);
 	if (!f) {
-		close(p[0]);
-		close(p[1]);
+		__syscall(SYS_close, p[0]);
+		__syscall(SYS_close, p[1]);
 		return NULL;
 	}
+
+	sigprocmask(SIG_BLOCK, SIGALL_SET, &old);
 	
-	pid = fork();
-	switch (pid) {
-	case -1:
-		fclose(f);
-		close(p[0]);
-		close(p[1]);
-		return NULL;
-	case 0:
-		if (dup2(p[1-op], 1-op) < 0) _exit(127);
-		if (p[0] != 1-op) close(p[0]);
-		if (p[1] != 1-op) close(p[1]);
-		execl("/bin/sh", "sh", "-c", cmd, (char *)0);
-		_exit(127);
+	__acquire_ptc();
+	pid = __vfork();
+	__release_ptc();
+
+	if (pid) {
+		__syscall(SYS_close, p[1-op]);
+		sigprocmask(SIG_BLOCK, SIGALL_SET, &old);
+		if (pid < 0) {
+			fclose(f);
+			return 0;
+		}
+		f->pipe_pid = pid;
+		return f;
+	}
+
+	/* See notes in system.c for why this is needed. */
+	for (i=1; i<=8*__SYSCALL_SSLEN; i++) {
+		struct sigaction sa;
+		__libc_sigaction(i, 0, &sa);
+		if (sa.sa_handler!=SIG_IGN && sa.sa_handler!=SIG_DFL) {
+			sa.sa_handler = SIG_DFL;
+			__libc_sigaction(i, &sa, 0);
+		}
 	}
-	close(p[1-op]);
-	f->pipe_pid = pid;
-	return f;
+	if (dup2(p[1-op], 1-op) < 0) _exit(127);
+	fcntl(1-op, F_SETFD, 0);
+	if (p[0] != 1-op) __syscall(SYS_close, p[0]);
+	if (p[1] != 1-op) __syscall(SYS_close, p[1]);
+	sigprocmask(SIG_SETMASK, &old, 0);
+	execl("/bin/sh", "sh", "-c", cmd, (char *)0);
+	_exit(127);
 }
diff --git a/src/unistd/pipe2.c b/src/unistd/pipe2.c
index 83282bb9..04e0c128 100644
--- a/src/unistd/pipe2.c
+++ b/src/unistd/pipe2.c
@@ -1,8 +1,22 @@
-#define _GNU_SOURCE
 #include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
 #include "syscall.h"
 
-int pipe2(int fd[2], int flg)
+int pipe2(int fd[2], int flag)
 {
-	return syscall(SYS_pipe2, fd, flg);
+	if (!flag) return syscall(SYS_pipe, fd);
+	int ret = __syscall(SYS_pipe2, fd, flag);
+	if (ret != -ENOSYS) return __syscall_ret(ret);
+	ret = syscall(SYS_pipe, fd);
+	if (ret) return __syscall_ret(ret);
+	if (flag & O_CLOEXEC) {
+		fcntl(fd[0], F_SETFD, FD_CLOEXEC);
+		fcntl(fd[1], F_SETFD, FD_CLOEXEC);
+	}
+	if (flag & O_NONBLOCK) {
+		fcntl(fd[0], F_SETFL, fcntl(fd[0], F_GETFL) | O_NONBLOCK);
+		fcntl(fd[1], F_SETFL, fcntl(fd[1], F_GETFL) | O_NONBLOCK);
+	}
+	return 0;
 }