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authorDenys Vlasenko <vda.linux@googlemail.com>2010-06-03 02:28:28 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-06-03 02:28:28 (GMT)
commit08d8b3cee1329d390f91bce419e2b4dadf484952 (patch)
tree4c8d4ed50792a9f1712dd914e7fcef62234b5f49
parent3e47cfec90fbe358692b3b960f7fa2303e465c2f (diff)
downloadbusybox-08d8b3cee1329d390f91bce419e2b4dadf484952.tar.gz
busybox-08d8b3cee1329d390f91bce419e2b4dadf484952.tar.bz2
ash: fix redirection of fd 0 in scripts are sourced from interactive ash
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--shell/ash.c35
-rw-r--r--shell/ash_test/ash-signals/signal5.right4
-rwxr-xr-xshell/ash_test/ash-signals/signal5.tests2
3 files changed, 28 insertions, 13 deletions
diff --git a/shell/ash.c b/shell/ash.c
index 08ad0f4..067feb1 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -1070,7 +1070,7 @@ ash_vmsg(const char *msg, va_list ap)
if (commandname) {
if (strcmp(arg0, commandname))
fprintf(stderr, "%s: ", commandname);
- if (!iflag || g_parsefile->fd)
+ if (!iflag || g_parsefile->fd > 0)
fprintf(stderr, "line %d: ", startlinno);
}
vfprintf(stderr, msg, ap);
@@ -5063,15 +5063,26 @@ static int is_hidden_fd(struct redirtab *rp, int fd)
if (fd == -1)
return 0;
+ /* Check open scripts' fds */
pf = g_parsefile;
while (pf) {
- if (fd == pf->fd) {
+ /* We skip fd == 0 case because of the following case:
+ * $ ash # running ash interactively
+ * $ . ./script.sh
+ * and in script.sh: "exec 9>&0".
+ * Even though top-level fd _is_ 0,
+ * it's still ok to use it: "read" builtin uses it,
+ * why should we cripple "exec" builtin?
+ */
+ if (pf->fd > 0 && fd == pf->fd) {
return 1;
}
pf = pf->prev;
}
+
if (!rp)
return 0;
+ /* Check saved fds of redirects */
fd |= COPYFD_RESTORE;
for (i = 0; i < rp->pair_count; i++) {
if (rp->two_fd[i].copy == fd) {
@@ -5084,9 +5095,7 @@ static int is_hidden_fd(struct redirtab *rp, int fd)
/*
* Process a list of redirection commands. If the REDIR_PUSH flag is set,
* old file descriptors are stashed away so that the redirection can be
- * undone by calling popredir. If the REDIR_BACKQ flag is set, then the
- * standard output, and the standard error if it becomes a duplicate of
- * stdout, is saved in memory.
+ * undone by calling popredir.
*/
/* flags passed to redirect */
#define REDIR_PUSH 01 /* save previous values of file descriptors */
@@ -5132,13 +5141,15 @@ redirect(union node *redir, int flags)
}
do {
+ int right_fd = -1;
fd = redir->nfile.fd;
if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
- int right_fd = redir->ndup.dupfd;
+ right_fd = redir->ndup.dupfd;
+ //bb_error_msg("doing %d > %d", fd, right_fd);
/* redirect from/to same file descriptor? */
if (right_fd == fd)
continue;
- /* echo >&10 and 10 is a fd opened to the sh script? */
+ /* "echo >&10" and 10 is a fd opened to a sh script? */
if (is_hidden_fd(sv, right_fd)) {
errno = EBADF; /* as if it is closed */
ash_msg_and_raise_error("%d: %m", right_fd);
@@ -5160,7 +5171,10 @@ redirect(union node *redir, int flags)
#endif
if (need_to_remember(sv, fd)) {
/* Copy old descriptor */
- i = fcntl(fd, F_DUPFD, 10);
+ /* Careful to not accidentally "save"
+ * to the same fd as right side fd in N>&M */
+ int minfd = right_fd < 10 ? 10 : right_fd + 1;
+ i = fcntl(fd, F_DUPFD, minfd);
/* You'd expect copy to be CLOEXECed. Currently these extra "saved" fds
* are closed in popredir() in the child, preventing them from leaking
* into child. (popredir() also cleans up the mess in case of failures)
@@ -12994,8 +13008,9 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
* Ensure we don't falsely claim that 0 (stdin)
* is one of stacked source fds.
* Testcase: ash -c 'exec 1>&0' must not complain. */
- if (!sflag)
- g_parsefile->fd = -1;
+ // if (!sflag) g_parsefile->fd = -1;
+ // ^^ not necessary since now we special-case fd 0
+ // in is_hidden_fd() to not be considered "hidden fd"
evalstring(minusc, 0);
}
diff --git a/shell/ash_test/ash-signals/signal5.right b/shell/ash_test/ash-signals/signal5.right
index 162f56b..7cfd411 100644
--- a/shell/ash_test/ash-signals/signal5.right
+++ b/shell/ash_test/ash-signals/signal5.right
@@ -1,5 +1,5 @@
-sleeping for 3 sec
-sleeping for 2 sec
+Sleeping
+Sleeping
Waiting
2 sec passed, sending USR1 to parent
USR1 received
diff --git a/shell/ash_test/ash-signals/signal5.tests b/shell/ash_test/ash-signals/signal5.tests
index 371120e..179bcdd 100755
--- a/shell/ash_test/ash-signals/signal5.tests
+++ b/shell/ash_test/ash-signals/signal5.tests
@@ -1,6 +1,6 @@
trap "echo USR1 received" USR1
stub() {
- echo "sleeping for $1 sec"
+ echo "Sleeping"
sleep $1
echo "$1 sec passed, sending USR1 to parent"
kill -USR1 $$