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>
This commit is contained in:
Denys Vlasenko
2022-01-17 03:02:40 +01:00
parent a277506a64
commit 12566e7f9b
9 changed files with 122 additions and 41 deletions

View File

@ -2161,12 +2161,30 @@ static int lineedit_read_key(char *read_key_buffer, int timeout)
* insist on full MB_CUR_MAX buffer to declare input like
* "\xff\n",pause,"ls\n" invalid and thus won't lose "ls".
*
* If LI_INTERRUPTIBLE, return -1 if got EINTR in poll()
* inside read_key, or if bb_got_signal != 0 (IOW: if signal
* arrived before poll() is reached).
*
* Note: read_key sets errno to 0 on success.
*/
IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 1;)
ic = read_key(STDIN_FILENO, read_key_buffer, timeout);
IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 0;)
do {
if ((state->flags & LI_INTERRUPTIBLE) && bb_got_signal) {
errno = EINTR;
return -1;
}
//FIXME: still races here with signals, but small window to poll() inside read_key
IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 1;)
ic = read_key(STDIN_FILENO, read_key_buffer, timeout);
IF_FEATURE_EDITING_WINCH(S.ok_to_redraw = 0;)
} while (!(state->flags & LI_INTERRUPTIBLE) && errno == EINTR);
if (errno) {
/* LI_INTERRUPTIBLE can bail out with EINTR here,
* but nothing really guarantees that bb_got_signal
* is nonzero. Follow the least surprise principle:
*/
if (errno == EINTR && bb_got_signal == 0)
bb_got_signal = 255; /* something nonzero */
#if ENABLE_UNICODE_SUPPORT
if (errno == EAGAIN && unicode_idx != 0)
goto pushback;