block uid/gid changes during posix_spawn

[musl] / src / process / posix_spawn.c

diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c
index b1a9fbd..8a6ff6d 100644 (file)
--- a/src/process/posix_spawn.c
+++ b/src/process/posix_spawn.c
@@ -5,13 +5,23 @@
 #include <fcntl.h>
 #include "syscall.h"
 #include "fdop.h"
+#include "libc.h"
 
 extern char **environ;
 
-int __posix_spawnx(pid_t *res, const char *path,
+static void dummy_0()
+{
+}
+weak_alias(dummy_0, __acquire_ptc);
+weak_alias(dummy_0, __release_ptc);
+
+pid_t __vfork(void);
+
+int __posix_spawnx(pid_t *restrict res, const char *restrict path,
        int (*exec)(const char *, char *const *),
        const posix_spawn_file_actions_t *fa,
-       const posix_spawnattr_t *attr, char **argv, char **envp)
+       const posix_spawnattr_t *restrict attr,
+       char *const argv[restrict], char *const envp[restrict])
 {
        pid_t pid;
        sigset_t oldmask;
@@ -21,7 +31,10 @@ int __posix_spawnx(pid_t *res, const char *path,
        if (!attr) attr = &dummy_attr;
 
        sigprocmask(SIG_BLOCK, (void *)(uint64_t []){-1}, &oldmask);
-       pid = __syscall(SYS_fork);
+
+       __acquire_ptc();
+       pid = __vfork();
+       __release_ptc();
 
        if (pid) {
                sigprocmask(SIG_SETMASK, &oldmask, 0);
@@ -81,16 +94,17 @@ int __posix_spawnx(pid_t *res, const char *path,
        sigprocmask(SIG_SETMASK, (attr->__flags & POSIX_SPAWN_SETSIGMASK)
                ? &attr->__mask : &oldmask, 0);
 
-       if (envp) environ = envp;
+       if (envp) environ = (char **)envp;
        exec(path, argv);
        _exit(127);
 
        return 0;
 }
 
-int posix_spawn(pid_t *res, const char *path,
+int posix_spawn(pid_t *restrict res, const char *restrict path,
        const posix_spawn_file_actions_t *fa,
-       const posix_spawnattr_t *attr, char **argv, char **envp)
+       const posix_spawnattr_t *restrict attr,
+       char *const argv[restrict], char *const envp[restrict])
 {
        return __posix_spawnx(res, path, execv, fa, attr, argv, envp);
 }