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-rw-r--r--shell/hush.c62
1 files changed, 43 insertions, 19 deletions
diff --git a/shell/hush.c b/shell/hush.c
index eabe83ac6..8bdbd4b8d 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1477,19 +1477,50 @@ static sighandler_t install_sighandler(int sig, sighandler_t handler)
return old_sa.sa_handler;
}
+static void hush_exit(int exitcode) NORETURN;
+static void fflush_and__exit(void) NORETURN;
+static void restore_ttypgrp_and__exit(void) NORETURN;
+
+static void restore_ttypgrp_and__exit(void)
+{
+ /* xfunc has failed! die die die */
+ /* no EXIT traps, this is an escape hatch! */
+ G.exiting = 1;
+ hush_exit(xfunc_error_retval);
+}
+
+/* Needed only on some libc:
+ * It was observed that on exit(), fgetc'ed buffered data
+ * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
+ * With the net effect that even after fork(), not vfork(),
+ * exit() in NOEXECed applet in "sh SCRIPT":
+ * noexec_applet_here
+ * echo END_OF_SCRIPT
+ * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
+ * This makes "echo END_OF_SCRIPT" executed twice.
+ * Similar problems can be seen with die_if_script() -> xfunc_die()
+ * and in `cmd` handling.
+ * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
+ */
+static void fflush_and__exit(void)
+{
+ fflush_all();
+ _exit(xfunc_error_retval);
+}
+
#if ENABLE_HUSH_JOB
-static void xfunc_has_died(void);
/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
-# define disable_restore_tty_pgrp_on_exit() (die_func = NULL)
+# define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
/* After [v]fork, in parent: restore tty pgrp on xfunc death */
-# define enable_restore_tty_pgrp_on_exit() (die_func = xfunc_has_died)
+# define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
/* Restores tty foreground process group, and exits.
* May be called as signal handler for fatal signal
* (will resend signal to itself, producing correct exit state)
* or called directly with -EXITCODE.
- * We also call it if xfunc is exiting. */
+ * We also call it if xfunc is exiting.
+ */
static void sigexit(int sig) NORETURN;
static void sigexit(int sig)
{
@@ -1544,7 +1575,6 @@ static sighandler_t pick_sighandler(unsigned sig)
}
/* Restores tty foreground process group, and exits. */
-static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
@@ -1580,23 +1610,14 @@ static void hush_exit(int exitcode)
}
#endif
-#if ENABLE_HUSH_JOB
fflush_all();
+#if ENABLE_HUSH_JOB
sigexit(- (exitcode & 0xff));
#else
- exit(exitcode);
+ _exit(exitcode);
#endif
}
-static void xfunc_has_died(void) NORETURN;
-static void xfunc_has_died(void)
-{
- /* xfunc has failed! die die die */
- /* no EXIT traps, this is an escape hatch! */
- G.exiting = 1;
- hush_exit(xfunc_error_retval);
-}
-
//TODO: return a mask of ALL handled sigs?
static int check_and_run_traps(void)
@@ -5913,7 +5934,8 @@ static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
) {
static const char *const argv[] = { NULL, NULL };
builtin_trap((char**)argv);
- exit(0); /* not _exit() - we need to fflush */
+ fflush_all(); /* important */
+ _exit(0);
}
# if BB_MMU
reset_traps_to_defaults();
@@ -6466,7 +6488,8 @@ static void dump_cmd_in_x_mode(char **argv)
* Never returns.
* Don't exit() here. If you don't exec, use _exit instead.
* The at_exit handlers apparently confuse the calling process,
- * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
+ * in particular stdin handling. Not sure why? -- because of vfork! (vda)
+ */
static void pseudo_exec_argv(nommu_save_t *nommu_save,
char **argv, int assignment_cnt,
char **argv_expanded) NORETURN;
@@ -7787,6 +7810,7 @@ int hush_main(int argc, char **argv)
INIT_G();
if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
G.last_exitcode = EXIT_SUCCESS;
+
#if ENABLE_HUSH_FAST
G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
#endif
@@ -7876,7 +7900,7 @@ int hush_main(int argc, char **argv)
/* Initialize some more globals to non-zero values */
cmdedit_update_prompt();
- die_func = xfunc_has_died;
+ die_func = restore_ttypgrp_and__exit;
/* Shell is non-interactive at first. We need to call
* install_special_sighandlers() if we are going to execute "sh <script>",