1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
Work around FD_ISSET() accessing an invalid address
and preventing modules such as caca.so to load sucessfully:
# gdb /usr/local/sbin/vlock-main
(gdb) set args caca
(gdb) set environment VLOCK_TIMEOUT=2
(gdb) set follow-fork-mode child
(gdb) run
Thread 2.1 received signal SIGBUS, Bus error.
Object-specific hardware error.
[Switching to LWP 100235 of process 83087]
0x00000000002075b0 in close_fds (except_fds=0x7fffffffe668) at src/process.c:125
125 if (!FD_ISSET(fd, except_fds))
(gdb) p fd
$1 = 52416
--- src/process.c.orig 2011-09-18 15:22:35 UTC
+++ src/process.c
@@ -105,27 +105,6 @@ void ensure_death(pid_t pid)
(void) waitpid(pid, &status, 0);
}
-/* Close all possibly open file descriptors except the ones specified in the
- * given set. */
-static void close_fds(fd_set *except_fds)
-{
- struct rlimit r;
- int maxfd;
-
- /* Get the maximum number of file descriptors. */
- if (getrlimit(RLIMIT_NOFILE, &r) == 0)
- maxfd = r.rlim_cur;
- else
- /* Hopefully safe default. */
- maxfd = 1024;
-
- /* Close all possibly open file descriptors except STDIN_FILENO,
- * STDOUT_FILENO and STDERR_FILENO. */
- for (int fd = 0; fd < maxfd; fd++)
- if (!FD_ISSET(fd, except_fds))
- (void) close(fd);
-}
-
static int open_devnull(void)
{
static int devnull_fd = -1;
@@ -175,8 +154,6 @@ bool create_child(struct child_process *child)
if (child->pid == 0) {
/* Child. */
- fd_set except_fds;
-
if (child->stdin_fd == REDIRECT_PIPE)
(void) dup2(stdin_pipe[0], STDIN_FILENO);
else if (child->stdin_fd == REDIRECT_DEV_NULL)
@@ -198,13 +175,7 @@ bool create_child(struct child_process *child)
else if (child->stderr_fd != NO_REDIRECT)
(void) dup2(child->stderr_fd, STDERR_FILENO);
- FD_ZERO(&except_fds);
- FD_SET(STDIN_FILENO, &except_fds);
- FD_SET(STDOUT_FILENO, &except_fds);
- FD_SET(STDERR_FILENO, &except_fds);
- FD_SET(status_pipe[1], &except_fds);
-
- (void) close_fds(&except_fds);
+ (void) closefrom(status_pipe[1] + 1);
(void) setgid(getgid());
(void) setuid(getuid());
|
