diff options
Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/shell/hush.c b/shell/hush.c index 00daf3ddd..d75b0da7e 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -1112,13 +1112,10 @@ static void restore_G_args(save_arg_t *sv, char **argv) * are to count SIGCHLDs * and to restore tty pgrp on signal-induced exit. * - * TODO compat: + * Note 2 (compat): * Standard says "When a subshell is entered, traps that are not being ignored * are set to the default actions". bash interprets it so that traps which - * are set to "" (ignore) are NOT reset to defaults. We reset them to default. - * bash example: - * # trap '' SYS; (bash -c 'kill -SYS $PPID'; echo YES) - * YES <-- subshell was not killed by SIGSYS + * are set to "" (ignore) are NOT reset to defaults. We do the same. */ enum { SPECIAL_INTERACTIVE_SIGS = 0 @@ -2605,43 +2602,51 @@ static void reset_traps_to_defaults(void) { /* This function is always called in a child shell * after fork (not vfork, NOMMU doesn't use this function). - * Child shells are not interactive. - * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling. - * Testcase: (while :; do :; done) + ^Z should background. - * Same goes for SIGTERM, SIGHUP, SIGINT. */ unsigned sig; unsigned mask; + /* Child shells are not interactive. + * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling. + * Testcase: (while :; do :; done) + ^Z should background. + * Same goes for SIGTERM, SIGHUP, SIGINT. + */ if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS)) - return; + return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */ - /* Stupid. It can be done with *single* &= op, but we can't use - * the fact that G.blocked_set is implemented as a bitmask... */ + /* Switching off SPECIAL_INTERACTIVE_SIGS. + * Stupid. It can be done with *single* &= op, but we can't use + * the fact that G.blocked_set is implemented as a bitmask + * in libc... */ mask = (SPECIAL_INTERACTIVE_SIGS >> 1); sig = 1; while (1) { - if (mask & 1) - sigdelset(&G.blocked_set, sig); + if (mask & 1) { + /* Careful. Only if no trap or trap is not "" */ + if (!G.traps || !G.traps[sig] || G.traps[sig][0]) + sigdelset(&G.blocked_set, sig); + } mask >>= 1; if (!mask) break; sig++; } - + /* Our homegrown sig mask is saner to work with :) */ G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS; + + /* Resetting all traps to default except empty ones */ mask = G.non_DFL_mask; if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) { - if (!G.traps[sig]) + if (!G.traps[sig] || !G.traps[sig][0]) continue; free(G.traps[sig]); G.traps[sig] = NULL; /* There is no signal for 0 (EXIT) */ if (sig == 0) continue; - /* There was a trap handler, we are removing it. + /* There was a trap handler, we just removed it. * But if sig still has non-DFL handling, - * we should not unblock it. */ + * we should not unblock the sig. */ if (mask & 1) continue; sigdelset(&G.blocked_set, sig); |