hush: restore redirected stdin
function old new delta
restore_redirects 52 95 +43
save_fd_on_redirect 243 253 +10
hfopen 90 99 +9
fgetc_interactive 259 261 +2
builtin_type 117 115 -2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 64/-2) Total: 62 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/hush.c b/shell/hush.c
index 96a9358..25e5fb9 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -573,7 +573,6 @@
char *cur;
char *end;
struct HFILE *next_hfile;
- int is_stdin;
int fd;
char buf[1024];
} HFILE;
@@ -973,6 +972,7 @@
unsigned execute_lineno;
#endif
HFILE *HFILE_list;
+ HFILE *HFILE_stdin;
/* Which signals have non-DFL handler (even with no traps set)?
* Set at the start to:
* (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
@@ -1603,7 +1603,8 @@
}
fp = xmalloc(sizeof(*fp));
- fp->is_stdin = (name == NULL);
+ if (name == NULL)
+ G.HFILE_stdin = fp;
fp->fd = fd;
fp->cur = fp->end = fp->buf;
fp->next_hfile = G.HFILE_list;
@@ -2666,7 +2667,7 @@
{
int ch;
/* If it's interactive stdin, get new line. */
- if (G_interactive_fd && i->file->is_stdin) {
+ if (G_interactive_fd && i->file == G.HFILE_stdin) {
/* Returns first char (or EOF), the rest is in i->p[] */
ch = get_user_input(i);
G.promptmode = 1; /* PS2 */
@@ -7605,7 +7606,9 @@
avoid_fd = 9;
#if ENABLE_HUSH_INTERACTIVE
- if (fd == G_interactive_fd) {
+ if (fd != 0 /* don't trigger for G_interactive_fd == 0 (that's "not interactive" flag) */
+ && fd == G_interactive_fd
+ ) {
/* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
G_interactive_fd = xdup_CLOEXEC_and_close(G_interactive_fd, avoid_fd);
debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G_interactive_fd);
@@ -7619,7 +7622,7 @@
/* No need to move script fds.
* For NOMMU case, it's actively wrong: we'd change ->fd
* fields in memory for the parent, but parent's fds
- * aren't be moved, it would use wrong fd!
+ * aren't moved, it would use wrong fd!
* Reproducer: "cmd 3>FILE" in script.
* If we would call move_HFILEs_on_redirect(), child would:
* fcntl64(3, F_DUPFD_CLOEXEC, 10) = 10
@@ -7683,6 +7686,20 @@
}
free(sq);
}
+ if (G.HFILE_stdin
+ && G.HFILE_stdin->fd != STDIN_FILENO
+ ) {
+ /* Testcase: interactive "read r <FILE; echo $r; read r; echo $r".
+ * Redirect moves ->fd to e.g. 10,
+ * and it is not restored above (we do not restore script fds
+ * after redirects, we just use new, "moved" fds).
+ * However for stdin, get_user_input() -> read_line_input(),
+ * and read builtin, depend on fd == STDIN_FILENO.
+ */
+ debug_printf_redir("restoring %d to stdin\n", G.HFILE_stdin->fd);
+ xmove_fd(G.HFILE_stdin->fd, STDIN_FILENO);
+ G.HFILE_stdin->fd = STDIN_FILENO;
+ }
/* If moved, G_interactive_fd stays on new fd, not restoring it */
}
@@ -10214,8 +10231,6 @@
G_saved_tty_pgrp = 0;
}
}
-// TODO: track & disallow any attempts of user
-// to (inadvertently) close/redirect G_interactive_fd
}
debug_printf("interactive_fd:%d\n", G_interactive_fd);
if (G_interactive_fd) {