From 7c40ddd9500907925041131374cb43eb87ef5494 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 2 Aug 2017 16:37:39 +0200 Subject: NOFORK fixes "rm -i FILE" and "yes" can now be interrupted by ^C in hush. This also now works: $ usleep 19999999 ^C $ echo $? 130 function old new delta run_pipe 1668 1711 +43 pseudo_exec_argv 312 321 +9 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/0 up/down: 52/0) Total: 52 bytes Signed-off-by: Denys Vlasenko --- shell/hush.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) (limited to 'shell') diff --git a/shell/hush.c b/shell/hush.c index 9f946d82f..cfefb7324 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -7363,6 +7363,8 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save, */ close_saved_fds_and_FILE_fds(); //FIXME: should also close saved redir fds + /* Without this, "rm -i FILE" can't be ^C'ed: */ + switch_off_special_sigs(G.special_sig_mask); debug_printf_exec("running applet '%s'\n", argv[0]); run_applet_no_and_exit(a, argv[0], argv); } @@ -8045,6 +8047,24 @@ static NOINLINE int run_pipe(struct pipe *pi) add_vars(old_vars); /* clean_up_and_ret0: */ restore_redirects(squirrel); + /* + * Try "usleep 99999999" + ^C + "echo $?" + * with FEATURE_SH_NOFORK=y. + */ + if (!funcp) { + /* It was builtin or nofork. + * if this would be a real fork/execed program, + * it should have died if a fatal sig was received. + * But OTOH, there was no separate process, + * the sig was sent to _shell_, not to non-existing + * child. + * Let's just handle ^C only, this one is obvious: + * we aren't ok with exitcode 0 when ^C was pressed + * during builtin/nofork. + */ + if (sigismember(&G.pending_set, SIGINT)) + rcode = 128 + SIGINT; + } clean_up_and_ret1: free(argv_expanded); IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) @@ -8060,6 +8080,14 @@ static NOINLINE int run_pipe(struct pipe *pi) if (rcode == 0) { debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]); + /* + * Note: signals (^C) can't interrupt here. + * We remember them and they will be acted upon + * after applet returns. + * This makes applets which can run for a long time + * and/or wait for user input ineligible for NOFORK: + * for example, "yes" or "rm" (rm -i waits for input). + */ rcode = run_nofork_applet(n, argv_expanded); } goto clean_up_and_ret; @@ -8491,7 +8519,7 @@ static int run_list(struct pipe *pi) G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid; G.last_bg_pid_exitcode = 0; debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n"); -/* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */ +/* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */ rcode = EXIT_SUCCESS; goto check_traps; } else { @@ -10178,6 +10206,7 @@ static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid /* So, did we get a signal? */ sig = check_and_run_traps(); if (sig /*&& sig != SIGCHLD - always true */) { + /* Do this for any (non-ignored) signal, not only for ^C */ ret = 128 + sig; break; } -- cgit v1.2.3