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authorDenys Vlasenko2017-07-24 12:42:17 +0200
committerDenys Vlasenko2017-07-24 12:42:17 +0200
commit621fc50e83f7446a060f0b9689dc8dc59ee0743a (patch)
tree7b40c2368fe3f7387ab44a1f0758d850cbd29929 /shell/hush.c
parentb72f1ef17b97802d33f0ac522f64bea0f65442c5 (diff)
downloadbusybox-621fc50e83f7446a060f0b9689dc8dc59ee0743a.zip
busybox-621fc50e83f7446a060f0b9689dc8dc59ee0743a.tar.gz
hush: fix a case when redirect to a closed fd #1 is not restoring (closing) it
function old new delta setup_redirects 200 245 +45 append_squirrel - 41 +41 save_fds_on_redirect 256 221 -35 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/1 up/down: 86/-35) Total: 51 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell/hush.c')
-rw-r--r--shell/hush.c34
1 files changed, 27 insertions, 7 deletions
diff --git a/shell/hush.c b/shell/hush.c
index 309ed21..20b0923 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -6643,8 +6643,18 @@ struct squirrel {
/* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
};
+static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
+{
+ sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
+ sq[i].orig_fd = orig;
+ sq[i].moved_to = moved;
+ sq[i+1].orig_fd = -1; /* end marker */
+ return sq;
+}
+
static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
{
+ int moved_to;
int i = 0;
if (sq) while (sq[i].orig_fd >= 0) {
@@ -6664,15 +6674,12 @@ static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
i++;
}
- sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
- sq[i].orig_fd = fd;
/* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
- sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
- debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
- if (sq[i].moved_to < 0 && errno != EBADF)
+ moved_to = fcntl_F_DUPFD(fd, avoid_fd);
+ debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
+ if (moved_to < 0 && errno != EBADF)
xfunc_die();
- sq[i+1].orig_fd = -1; /* end marker */
- return sq;
+ return append_squirrel(sq, i, fd, moved_to);
}
/* fd: redirect wants this fd to be used (e.g. 3>file).
@@ -6778,6 +6785,19 @@ static int setup_redirects(struct command *prog, struct squirrel **sqp)
*/
return 1;
}
+ if (openfd == redir->rd_fd && sqp) {
+ /* open() gave us precisely the fd we wanted.
+ * This means that this fd was not busy
+ * (not opened to anywhere).
+ * Remember to close it on restore:
+ */
+ struct squirrel *sq = *sqp;
+ int i = 0;
+ if (sq) while (sq[i].orig_fd >= 0)
+ i++;
+ *sqp = append_squirrel(sq, i, openfd, -1); /* -1 = "it was closed" */
+ debug_printf_redir("redir to previously closed fd %d\n", openfd);
+ }
} else {
/* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
openfd = redir->rd_dup;