diff options
| -rw-r--r-- | src/process/posix_spawn.c | 28 | ||||
| -rw-r--r-- | src/signal/sigaction.c | 16 | ||||
| -rw-r--r-- | src/signal/sigismember.c | 5 |
3 files changed, 37 insertions, 12 deletions
diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c index c6886526..eb98f9f6 100644 --- a/src/process/posix_spawn.c +++ b/src/process/posix_spawn.c @@ -20,29 +20,43 @@ struct args { char *const *argv, *const *envp; }; +void __get_handler_set(sigset_t *); + static int child(void *args_vp) { int i, ret; - struct sigaction sa; + struct sigaction sa = {0}; struct args *args = args_vp; int p = args->p[1]; const posix_spawn_file_actions_t *fa = args->fa; const posix_spawnattr_t *restrict attr = args->attr; + sigset_t hset; close(args->p[0]); /* All signal dispositions must be either SIG_DFL or SIG_IGN * before signals are unblocked. Otherwise a signal handler * from the parent might get run in the child while sharing - * memory, with unpredictable and dangerous results. */ + * memory, with unpredictable and dangerous results. To + * reduce overhead, sigaction has tracked for us which signals + * potentially have a signal handler. */ + __get_handler_set(&hset); for (i=1; i<_NSIG; i++) { - __libc_sigaction(i, 0, &sa); - if (sa.sa_handler!=SIG_DFL && (sa.sa_handler!=SIG_IGN || - ((attr->__flags & POSIX_SPAWN_SETSIGDEF) - && sigismember(&attr->__def, i) ))) { + if ((attr->__flags & POSIX_SPAWN_SETSIGDEF) + && sigismember(&attr->__def, i)) { sa.sa_handler = SIG_DFL; - __libc_sigaction(i, &sa, 0); + } else if (sigismember(&hset, i)) { + if (i-32<3U) { + sa.sa_handler = SIG_IGN; + } else { + __libc_sigaction(i, 0, &sa); + if (sa.sa_handler==SIG_IGN) continue; + sa.sa_handler = SIG_DFL; + } + } else { + continue; } + __libc_sigaction(i, &sa, 0); } if (attr->__flags & POSIX_SPAWN_SETPGROUP) diff --git a/src/signal/sigaction.c b/src/signal/sigaction.c index 1f09bb96..5499bd18 100644 --- a/src/signal/sigaction.c +++ b/src/signal/sigaction.c @@ -12,12 +12,26 @@ void __restore(), __restore_rt(); static pthread_t dummy(void) { return 0; } weak_alias(dummy, __pthread_self_def); +static unsigned long handler_set[_NSIG/(8*sizeof(long))]; + +void __get_handler_set(sigset_t *set) +{ + memcpy(set, handler_set, sizeof handler_set); +} + int __libc_sigaction(int sig, const struct sigaction *restrict sa, struct sigaction *restrict old) { struct k_sigaction ksa, ksa_old; + if (sig >= (unsigned)_NSIG) { + errno = EINVAL; + return -1; + } if (sa) { - if ((uintptr_t)sa->sa_handler > 1UL) + if ((uintptr_t)sa->sa_handler > 1UL) { + a_or_l(handler_set+(sig-1)/(8*sizeof(long)), + 1UL<<(sig-1)%(8*sizeof(long))); __pthread_self_def(); + } ksa.handler = sa->sa_handler; ksa.flags = sa->sa_flags | SA_RESTORER; ksa.restorer = (sa->sa_flags & SA_SIGINFO) ? __restore_rt : __restore; diff --git a/src/signal/sigismember.c b/src/signal/sigismember.c index e887b95f..1a22108b 100644 --- a/src/signal/sigismember.c +++ b/src/signal/sigismember.c @@ -4,9 +4,6 @@ int sigismember(const sigset_t *set, int sig) { unsigned s = sig-1; - if (s >= 8*sizeof(sigset_t) || sig-32U<3) { - errno = EINVAL; - return -1; - } + if (s >= 8*sizeof(sigset_t)) return 0; return !!(set->__bits[s/8/sizeof *set->__bits] & 1UL<<(s&8*sizeof *set->__bits-1)); } |