fix some more O_CLOEXEC/SOCK_CLOEXEC issues

src/ldso/dynlink.c

@@ -376,7 +376,7 @@ static int path_open(const char *name, const char *search, char *buf, size_t buf
 		z = strchr(s, ':');
 		l = z ? z-s : strlen(s);
 		snprintf(buf, buf_size, "%.*s/%s", l, s, name);
-		if ((fd = open(buf, O_RDONLY))>=0) return fd;
+		if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 		s += l;
 	}
 }
@@ -423,7 +423,7 @@ static struct dso *load_library(const char *name)
 	}
 	if (strchr(name, '/')) {
 		pathname = name;
-		fd = open(name, O_RDONLY);
+		fd = open(name, O_RDONLY|O_CLOEXEC);
 	} else {
 		/* Search for the name to see if it's already loaded */
 		for (p=head->next; p; p=p->next) {

src/misc/realpath.c

@@ -19,7 +19,7 @@ char *realpath(const char *restrict filename, char *restrict resolved)
 		return 0;
 	}
 
-	fd = open(filename, O_RDONLY|O_NONBLOCK);
+	fd = open(filename, O_RDONLY|O_NONBLOCK|O_CLOEXEC);
 	if (fd < 0) return 0;
 	snprintf(buf, sizeof buf, "/proc/self/fd/%d", fd);
 

src/network/__dns.c

@@ -91,7 +91,7 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt)
 
 	/* Get local address and open/bind a socket */
 	sa.sin.sin_family = family;
-	fd = socket(family, SOCK_DGRAM, 0);
+	fd = socket(family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
 
 	pthread_cleanup_push(cleanup, (void *)(intptr_t)fd);
 	pthread_setcancelstate(cs, 0);
@@ -100,8 +100,6 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt)
 		errcode = EAI_SYSTEM;
 		goto out;
 	}
-	/* Nonblocking to work around Linux UDP select bug */
-	fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);
 
 	pfd.fd = fd;
 	pfd.events = POLLIN;

src/stdio/__fopen_rb_ca.c

@@ -4,7 +4,7 @@ FILE *__fopen_rb_ca(const char *filename, FILE *f, unsigned char *buf, size_t le
 {
 	memset(f, 0, sizeof *f);
 
-	f->fd = syscall(SYS_open, filename, O_RDONLY|O_LARGEFILE, 0);
+	f->fd = syscall(SYS_open, filename, O_RDONLY|O_LARGEFILE|O_CLOEXEC, 0);
 	if (f->fd < 0) return 0;
 
 	f->flags = F_NOWR | F_PERM;