diff options
| author | Denys Vlasenko <vda.linux@googlemail.com> | 2022-01-17 03:02:40 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2022-01-17 11:46:23 +0100 |
| commit | 12566e7f9b5e5c5d445bc4d36991d134b431dc6c (patch) | |
| tree | 2571356a77f7d421da368e9b31dad182e83b2408 /shell/ash.c | |
| parent | a277506a64404e6c4472ff89c944c4f353db1c33 (diff) | |
| download | busybox-12566e7f9b5e5c5d445bc4d36991d134b431dc6c.tar.gz | |
ash,hush: fix handling of SIGINT while waiting for interactive input
function old new delta
lineedit_read_key 160 237 +77
__pgetc 522 589 +67
fgetc_interactive 244 309 +65
safe_read_key - 39 +39
read_key 588 607 +19
record_pending_signo 23 32 +9
signal_handler 75 81 +6
.rodata 104312 104309 -3
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 6/1 up/down: 282/-3) Total: 279 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell/ash.c')
| -rw-r--r-- | shell/ash.c | 39 |
1 files changed, 30 insertions, 9 deletions
diff --git a/shell/ash.c b/shell/ash.c index 086773dd7..55df54bd0 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -3679,7 +3679,9 @@ signal_handler(int signo) if (!trap[SIGCHLD]) return; } - +#if ENABLE_FEATURE_EDITING + bb_got_signal = signo; /* for read_line_input: "we got a signal" */ +#endif gotsig[signo - 1] = 1; pending_sig = signo; @@ -10784,33 +10786,52 @@ preadfd(void) # endif reinit_unicode_for_ash(); again: -//BUG: not in INT_OFF/INT_ON section - SIGINT et al would longjmp out of read_line_input()! -//This would cause a memory leak in interactive shell -//(repeated internal allocations in read_line_input): -// (while kill -INT $$; do :; done) & + /* For shell, LI_INTERRUPTIBLE is set: + * read_line_input will abort on either + * getting EINTR in poll(), or if it sees bb_got_signal != 0 + * (IOW: if signal arrives before poll() is reached). + * Interactive testcases: + * (while kill -INT $$; do sleep 1; done) & + * #^^^ prints ^C, prints prompt, repeats + * trap 'echo I' int; (while kill -INT $$; do sleep 1; done) & + * #^^^ prints ^C, prints "I", prints prompt, repeats + * trap 'echo T' term; (while kill $$; do sleep 1; done) & + * #^^^ prints "T", prints prompt, repeats + * #(bash 5.0.17 exits after first "T", looks like a bug) + */ + bb_got_signal = 0; + INT_OFF; /* no longjmp'ing out of read_line_input please */ nr = read_line_input(line_input_state, cmdedit_prompt, buf, IBUFSIZ); + if (bb_got_signal == SIGINT) + write(STDOUT_FILENO, "^C\n", 3); + INT_ON; /* here non-blocked SIGINT will longjmp */ if (nr == 0) { /* ^C pressed, "convert" to SIGINT */ - write(STDOUT_FILENO, "^C", 2); - raise(SIGINT); + write(STDOUT_FILENO, "^C\n", 3); + raise(SIGINT); /* here non-blocked SIGINT will longjmp */ /* raise(SIGINT) did not work! (e.g. if SIGINT * is SIG_IGNed on startup, it stays SIG_IGNed) */ if (trap[SIGINT]) { + empty_line_input: buf[0] = '\n'; buf[1] = '\0'; return 1; } exitstatus = 128 + SIGINT; /* bash behavior on ^C + ignored SIGINT: */ - write(STDOUT_FILENO, "\n", 1); goto again; } if (nr < 0) { if (errno == 0) { - /* Ctrl+D pressed */ + /* ^D pressed */ nr = 0; } + else if (errno == EINTR) { /* got signal? */ + if (bb_got_signal != SIGINT) + write(STDOUT_FILENO, "\n", 1); + goto empty_line_input; + } # if ENABLE_ASH_IDLE_TIMEOUT else if (errno == EAGAIN && timeout > 0) { puts("\007timed out waiting for input: auto-logout"); |