X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fsignal.c;h=83cd4336af9f1910ad611f20122f6bbc6e0ed7e4;hb=dd56fa5590eca7d8d92e4a205d91439f08375b46;hp=e38ca44916db287c6302a658ade70f2e89196350;hpb=ec9397bab20a628530ce3051167d3d0fcc2c1af7;p=linux-2.6.git diff --git a/kernel/signal.c b/kernel/signal.c index e38ca4491..83cd4336a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -20,14 +20,18 @@ #include #include #include +#include #include +#include +#include +#include +#include +#include #include #include #include #include -extern void k_getrusage(struct task_struct *, int, struct rusage *); - /* * SLAB caches for signal bits. */ @@ -152,11 +156,6 @@ static kmem_cache_t *sigqueue_cachep; (!T(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \ (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL) -#define sig_avoid_stop_race() \ - (sigtestsetmask(¤t->pending.signal, M(SIGCONT) | M(SIGKILL)) || \ - sigtestsetmask(¤t->signal->shared_pending.signal, \ - M(SIGCONT) | M(SIGKILL))) - static int sig_ignored(struct task_struct *t, int sig) { void __user * handler; @@ -216,6 +215,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) fastcall void recalc_sigpending_tsk(struct task_struct *t) { if (t->signal->group_stop_count > 0 || + (freezing(t)) || PENDING(&t->pending, &t->blocked) || PENDING(&t->signal->shared_pending, &t->blocked)) set_tsk_thread_flag(t, TIF_SIGPENDING); @@ -264,24 +264,27 @@ next_signal(struct sigpending *pending, sigset_t *mask) return sig; } -static struct sigqueue *__sigqueue_alloc(void) +static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, + int override_rlimit) { struct sigqueue *q = NULL; - if (atomic_read(¤t->user->sigpending) < - current->rlim[RLIMIT_SIGPENDING].rlim_cur) - q = kmem_cache_alloc(sigqueue_cachep, GFP_ATOMIC); - if (q) { + atomic_inc(&t->user->sigpending); + if (override_rlimit || + atomic_read(&t->user->sigpending) <= + t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) + q = kmem_cache_alloc(sigqueue_cachep, flags); + if (unlikely(q == NULL)) { + atomic_dec(&t->user->sigpending); + } else { INIT_LIST_HEAD(&q->list); q->flags = 0; - q->lock = NULL; - q->user = get_uid(current->user); - atomic_inc(&q->user->sigpending); + q->user = get_uid(t->user); } return(q); } -static inline void __sigqueue_free(struct sigqueue *q) +static void __sigqueue_free(struct sigqueue *q) { if (q->flags & SIGQUEUE_PREALLOC) return; @@ -328,13 +331,20 @@ void __exit_sighand(struct task_struct *tsk) /* Ok, we're done with the signal handlers */ tsk->sighand = NULL; if (atomic_dec_and_test(&sighand->count)) - kmem_cache_free(sighand_cachep, sighand); + sighand_free(sighand); } void exit_sighand(struct task_struct *tsk) { write_lock_irq(&tasklist_lock); - __exit_sighand(tsk); + rcu_read_lock(); + if (tsk->sighand != NULL) { + struct sighand_struct *sighand = rcu_dereference(tsk->sighand); + spin_lock(&sighand->siglock); + __exit_sighand(tsk); + spin_unlock(&sighand->siglock); + } + rcu_read_unlock(); write_unlock_irq(&tasklist_lock); } @@ -344,17 +354,20 @@ void exit_sighand(struct task_struct *tsk) void __exit_signal(struct task_struct *tsk) { struct signal_struct * sig = tsk->signal; - struct sighand_struct * sighand = tsk->sighand; + struct sighand_struct * sighand; if (!sig) BUG(); if (!atomic_read(&sig->count)) BUG(); + rcu_read_lock(); + sighand = rcu_dereference(tsk->sighand); spin_lock(&sighand->siglock); + posix_cpu_timers_exit(tsk); if (atomic_dec_and_test(&sig->count)) { - if (tsk == sig->curr_target) - sig->curr_target = next_thread(tsk); + posix_cpu_timers_exit_group(tsk); tsk->signal = NULL; + __exit_sighand(tsk); spin_unlock(&sighand->siglock); flush_sigqueue(&sig->shared_pending); } else { @@ -379,39 +392,33 @@ void __exit_signal(struct task_struct *tsk) * We won't ever get here for the group leader, since it * will have been the last reference on the signal_struct. */ - sig->utime += tsk->utime; - sig->stime += tsk->stime; + sig->utime = cputime_add(sig->utime, tsk->utime); + sig->stime = cputime_add(sig->stime, tsk->stime); sig->min_flt += tsk->min_flt; sig->maj_flt += tsk->maj_flt; sig->nvcsw += tsk->nvcsw; sig->nivcsw += tsk->nivcsw; + sig->sched_time += tsk->sched_time; + __exit_sighand(tsk); spin_unlock(&sighand->siglock); sig = NULL; /* Marker for below. */ } + rcu_read_unlock(); clear_tsk_thread_flag(tsk,TIF_SIGPENDING); flush_sigqueue(&tsk->pending); if (sig) { /* - * We are cleaning up the signal_struct here. We delayed - * calling exit_itimers until after flush_sigqueue, just in - * case our thread-local pending queue contained a queued - * timer signal that would have been cleared in - * exit_itimers. When that called sigqueue_free, it would - * attempt to re-take the tasklist_lock and deadlock. This - * can never happen if we ensure that all queues the - * timer's signal might be queued on have been flushed - * first. The shared_pending queue, and our own pending - * queue are the only queues the timer could be on, since - * there are no other threads left in the group and timer - * signals are constrained to threads inside the group. + * We are cleaning up the signal_struct here. */ - exit_itimers(sig); + exit_thread_group_keys(sig); kmem_cache_free(signal_cachep, sig); } } void exit_signal(struct task_struct *tsk) { + atomic_dec(&tsk->signal->live); + write_lock_irq(&tasklist_lock); __exit_signal(tsk); write_unlock_irq(&tasklist_lock); @@ -435,7 +442,6 @@ flush_signal_handlers(struct task_struct *t, int force_default) } } -EXPORT_SYMBOL_GPL(flush_signal_handlers); /* Notify the system that a driver wants to block all signals for this * process, and wants to be notified if any signals at all were to be @@ -471,7 +477,7 @@ unblock_all_signals(void) spin_unlock_irqrestore(¤t->sighand->siglock, flags); } -static inline int collect_signal(int sig, struct sigpending *list, siginfo_t *info) +static int collect_signal(int sig, struct sigpending *list, siginfo_t *info) { struct sigqueue *q, *first = NULL; int still_pending = 0; @@ -551,10 +557,34 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) if (!signr) signr = __dequeue_signal(&tsk->signal->shared_pending, mask, info); + if (signr && unlikely(sig_kernel_stop(signr))) { + /* + * Set a marker that we have dequeued a stop signal. Our + * caller might release the siglock and then the pending + * stop signal it is about to process is no longer in the + * pending bitmasks, but must still be cleared by a SIGCONT + * (and overruled by a SIGKILL). So those cases clear this + * shared flag after we've set it. Note that this flag may + * remain set after the signal we return is ignored or + * handled. That doesn't matter because its only purpose + * is to alert stop-signal processing code when another + * processor has come along and cleared the flag. + */ + if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) + tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; + } if ( signr && ((info->si_code & __SI_MASK) == __SI_TIMER) && info->si_sys_private){ + /* + * Release the siglock to ensure proper locking order + * of timer locks outside of siglocks. Note, we leave + * irqs disabled here, since the posix-timers code is + * about to disable them again anyway. + */ + spin_unlock(&tsk->sighand->siglock); do_schedule_next_timer(info); + spin_lock(&tsk->sighand->siglock); } return signr; } @@ -577,19 +607,46 @@ void signal_wake_up(struct task_struct *t, int resume) set_tsk_thread_flag(t, TIF_SIGPENDING); /* - * If resume is set, we want to wake it up in the TASK_STOPPED case. - * We don't check for TASK_STOPPED because there is a race with it + * For SIGKILL, we want to wake it up in the stopped/traced case. + * We don't check t->state here because there is a race with it * executing another processor and just now entering stopped state. - * By calling wake_up_process any time resume is set, we ensure - * the process will wake up and handle its stop or death signal. + * By using wake_up_state, we ensure the process will wake up and + * handle its death signal. */ mask = TASK_INTERRUPTIBLE; if (resume) - mask |= TASK_STOPPED; + mask |= TASK_STOPPED | TASK_TRACED; if (!wake_up_state(t, mask)) kick_process(t); } +/* + * Remove signals in mask from the pending set and queue. + * Returns 1 if any signals were found. + * + * All callers must be holding the siglock. + * + * This version takes a sigset mask and looks at all signals, + * not just those in the first mask word. + */ +static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) +{ + struct sigqueue *q, *n; + sigset_t m; + + sigandsets(&m, mask, &s->signal); + if (sigisemptyset(&m)) + return 0; + + signandsets(&s->signal, &s->signal, mask); + list_for_each_entry_safe(q, n, &s->list, list) { + if (sigismember(mask, q->info.si_signo)) { + list_del_init(&q->list); + __sigqueue_free(q); + } + } + return 1; +} /* * Remove signals in mask from the pending set and queue. * Returns 1 if any signals were found. @@ -620,20 +677,18 @@ static int rm_from_queue(unsigned long mask, struct sigpending *s) static int check_kill_permission(int sig, struct siginfo *info, struct task_struct *t) { - int error = -EINVAL; int user; + int error = -EINVAL; - if (sig < 0 || sig > _NSIG) + if (!valid_signal(sig)) return error; - user = (!info || - (info != SEND_SIG_PRIV && - info != SEND_SIG_FORCED && - SI_FROMUSER(info))); + user = ((info == SEND_SIG_NOINFO) || + (!is_si_special(info) && SI_FROMUSER(info))); error = -EPERM; - if (user && (sig != SIGCONT || - current->signal->session != t->signal->session) + if (user && ((sig != SIGCONT) || + (current->signal->session != t->signal->session)) && (current->euid ^ t->suid) && (current->euid ^ t->uid) && (current->uid ^ t->suid) && (current->uid ^ t->uid) && !capable(CAP_KILL)) @@ -643,12 +698,15 @@ static int check_kill_permission(int sig, struct siginfo *info, if (user && !vx_check(vx_task_xid(t), VX_ADMIN|VX_IDENT)) return error; - return security_task_kill(t, info, sig); + error = security_task_kill(t, info, sig); + if (!error) + audit_signal_info(sig, t); /* Let audit system see the signal */ + return error; } /* forward decl */ static void do_notify_parent_cldstop(struct task_struct *tsk, - struct task_struct *parent, + int to_self, int why); /* @@ -662,6 +720,12 @@ static void handle_stop_signal(int sig, struct task_struct *p) { struct task_struct *t; + if (p->signal->flags & SIGNAL_GROUP_EXIT) + /* + * The process is in the middle of dying already. + */ + return; + if (sig_kernel_stop(sig)) { /* * This is a stop signal. Remove SIGCONT from all queues. @@ -691,16 +755,9 @@ static void handle_stop_signal(int sig, struct task_struct *p) * the SIGCHLD was pending on entry to this kill. */ p->signal->group_stop_count = 0; - p->signal->stop_state = 1; + p->signal->flags = SIGNAL_STOP_CONTINUED; spin_unlock(&p->sighand->siglock); - if (p->ptrace & PT_PTRACED) - do_notify_parent_cldstop(p, p->parent, - CLD_STOPPED); - else - do_notify_parent_cldstop( - p->group_leader, - p->group_leader->real_parent, - CLD_STOPPED); + do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_STOPPED); spin_lock(&p->sighand->siglock); } rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending); @@ -733,24 +790,30 @@ static void handle_stop_signal(int sig, struct task_struct *p) t = next_thread(t); } while (t != p); - if (p->signal->stop_state > 0) { + if (p->signal->flags & SIGNAL_STOP_STOPPED) { /* * We were in fact stopped, and are now continued. * Notify the parent with CLD_CONTINUED. */ - p->signal->stop_state = -1; + p->signal->flags = SIGNAL_STOP_CONTINUED; p->signal->group_exit_code = 0; spin_unlock(&p->sighand->siglock); - if (p->ptrace & PT_PTRACED) - do_notify_parent_cldstop(p, p->parent, - CLD_CONTINUED); - else - do_notify_parent_cldstop( - p->group_leader, - p->group_leader->real_parent, - CLD_CONTINUED); + do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_CONTINUED); spin_lock(&p->sighand->siglock); + } else { + /* + * We are not stopped, but there could be a stop + * signal in the middle of being processed after + * being removed from the queue. Clear that too. + */ + p->signal->flags = 0; } + } else if (sig == SIGKILL) { + /* + * Make sure that any pending stop signal already dequeued + * is undone by the wakeup for SIGKILL. + */ + p->signal->flags = 0; } } @@ -764,7 +827,7 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, * fast-pathed signals for kernel-internal things like SIGSTOP * or SIGKILL. */ - if ((unsigned long)info == 2) + if (info == SEND_SIG_FORCED) goto out_set; /* Real-time signals must be queued if sent by sigqueue, or @@ -775,24 +838,20 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, make sure at least one signal gets delivered and don't pass on the info struct. */ - if (atomic_read(&t->user->sigpending) < - t->rlim[RLIMIT_SIGPENDING].rlim_cur) - q = kmem_cache_alloc(sigqueue_cachep, GFP_ATOMIC); - + q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN && + (is_si_special(info) || + info->si_code >= 0))); if (q) { - q->flags = 0; - q->user = get_uid(t->user); - atomic_inc(&q->user->sigpending); list_add_tail(&q->list, &signals->list); switch ((unsigned long) info) { - case 0: + case (unsigned long) SEND_SIG_NOINFO: q->info.si_signo = sig; q->info.si_errno = 0; q->info.si_code = SI_USER; q->info.si_pid = current->pid; q->info.si_uid = current->uid; break; - case 1: + case (unsigned long) SEND_SIG_PRIV: q->info.si_signo = sig; q->info.si_errno = 0; q->info.si_code = SI_KERNEL; @@ -803,20 +862,13 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, copy_siginfo(&q->info, info); break; } - } else { - if (sig >= SIGRTMIN && info && (unsigned long)info != 1 - && info->si_code != SI_USER) + } else if (!is_si_special(info)) { + if (sig >= SIGRTMIN && info->si_code != SI_USER) /* * Queue overflow, abort. We may abort if the signal was rt * and sent by user using something other than kill(). */ return -EAGAIN; - if (((unsigned long)info > 1) && (info->si_code == SI_TIMER)) - /* - * Set up a return to indicate that we dropped - * the signal. - */ - ret = info->si_sys_private; } out_set: @@ -835,16 +887,7 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) if (!irqs_disabled()) BUG(); -#ifdef CONFIG_SMP - if (!spin_is_locked(&t->sighand->siglock)) - BUG(); -#endif - - if (((unsigned long)info > 2) && (info->si_code == SI_TIMER)) - /* - * Set up a return to indicate that we dropped the signal. - */ - ret = info->si_sys_private; + assert_spin_locked(&t->sighand->siglock); /* Short-circuit ignored signals. */ if (sig_ignored(t, sig)) @@ -875,11 +918,13 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t) int ret; spin_lock_irqsave(&t->sighand->siglock, flags); - if (sigismember(&t->blocked, sig) || t->sighand->action[sig-1].sa.sa_handler == SIG_IGN) { + if (t->sighand->action[sig-1].sa.sa_handler == SIG_IGN) { t->sighand->action[sig-1].sa.sa_handler = SIG_DFL; + } + if (sigismember(&t->blocked, sig)) { sigdelset(&t->blocked, sig); - recalc_sigpending_tsk(t); } + recalc_sigpending_tsk(t); ret = specific_send_sig_info(sig, info, t); spin_unlock_irqrestore(&t->sighand->siglock, flags); @@ -889,15 +934,7 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t) void force_sig_specific(int sig, struct task_struct *t) { - unsigned long int flags; - - spin_lock_irqsave(&t->sighand->siglock, flags); - if (t->sighand->action[sig-1].sa.sa_handler == SIG_IGN) - t->sighand->action[sig-1].sa.sa_handler = SIG_DFL; - sigdelset(&t->blocked, sig); - recalc_sigpending_tsk(t); - specific_send_sig_info(sig, (void *)2, t); - spin_unlock_irqrestore(&t->sighand->siglock, flags); + force_sig_info(sig, SEND_SIG_FORCED, t); } /* @@ -908,34 +945,31 @@ force_sig_specific(int sig, struct task_struct *t) * as soon as they're available, so putting the signal on the shared queue * will be equivalent to sending it to one such thread. */ -#define wants_signal(sig, p, mask) \ - (!sigismember(&(p)->blocked, sig) \ - && !((p)->state & mask) \ - && !((p)->flags & PF_EXITING) \ - && (task_curr(p) || !signal_pending(p))) - +static inline int wants_signal(int sig, struct task_struct *p) +{ + if (sigismember(&p->blocked, sig)) + return 0; + if (p->flags & PF_EXITING) + return 0; + if (sig == SIGKILL) + return 1; + if (p->state & (TASK_STOPPED | TASK_TRACED)) + return 0; + return task_curr(p) || !signal_pending(p); +} static void __group_complete_signal(int sig, struct task_struct *p) { - unsigned int mask; struct task_struct *t; - /* - * Don't bother zombies and stopped tasks (but - * SIGKILL will punch through stopped state) - */ - mask = EXIT_DEAD | EXIT_ZOMBIE | TASK_TRACED; - if (sig != SIGKILL) - mask |= TASK_STOPPED; - /* * Now find a thread we can wake up to take the signal off the queue. * * If the main thread wants the signal, it gets first crack. * Probably the least surprising to the average bear. */ - if (wants_signal(sig, p, mask)) + if (wants_signal(sig, p)) t = p; else if (thread_group_empty(p)) /* @@ -951,9 +985,8 @@ __group_complete_signal(int sig, struct task_struct *p) if (t == NULL) /* restart balancing at this thread */ t = p->signal->curr_target = p; - BUG_ON(t->tgid != p->tgid); - while (!wants_signal(sig, t, mask)) { + while (!wants_signal(sig, t)) { t = next_thread(t); if (t == p->signal->curr_target) /* @@ -970,7 +1003,7 @@ __group_complete_signal(int sig, struct task_struct *p) * Found a killable thread. If the signal will be fatal, * then start taking the whole group down immediately. */ - if (sig_fatal(p, sig) && !p->signal->group_exit && + if (sig_fatal(p, sig) && !(p->signal->flags & SIGNAL_GROUP_EXIT) && !sigismember(&t->real_blocked, sig) && (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) { /* @@ -983,7 +1016,7 @@ __group_complete_signal(int sig, struct task_struct *p) * running and doing things after a slower * thread has the fatal signal pending. */ - p->signal->group_exit = 1; + p->signal->flags = SIGNAL_GROUP_EXIT; p->signal->group_exit_code = sig; p->signal->group_stop_count = 0; t = p; @@ -1027,23 +1060,14 @@ __group_complete_signal(int sig, struct task_struct *p) return; } -static int +int __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { int ret = 0; -#ifdef CONFIG_SMP - if (!spin_is_locked(&p->sighand->siglock)) - BUG(); -#endif + assert_spin_locked(&p->sighand->siglock); handle_stop_signal(sig, p); - if (((unsigned long)info > 2) && (info->si_code == SI_TIMER)) - /* - * Set up a return to indicate that we dropped the signal. - */ - ret = info->si_sys_private; - /* Short-circuit ignored signals. */ if (sig_ignored(p, sig)) return ret; @@ -1072,6 +1096,7 @@ void zap_other_threads(struct task_struct *p) { struct task_struct *t; + p->signal->flags = SIGNAL_GROUP_EXIT; p->signal->group_stop_count = 0; if (thread_group_empty(p)) @@ -1081,7 +1106,7 @@ void zap_other_threads(struct task_struct *p) /* * Don't bother with already dead threads */ - if (t->exit_state & (EXIT_ZOMBIE|EXIT_DEAD)) + if (t->exit_state) continue; /* @@ -1095,25 +1120,36 @@ void zap_other_threads(struct task_struct *p) if (t != p->group_leader) t->exit_signal = -1; + /* SIGKILL will be handled before any pending SIGSTOP */ sigaddset(&t->pending.signal, SIGKILL); - rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); signal_wake_up(t, 1); } } /* - * Must be called with the tasklist_lock held for reading! + * Must be called under rcu_read_lock() or with tasklist_lock read-held. */ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { unsigned long flags; + struct sighand_struct *sp; int ret; +retry: ret = check_kill_permission(sig, info, p); - if (!ret && sig && p->sighand) { - spin_lock_irqsave(&p->sighand->siglock, flags); + if (!ret && sig && (sp = rcu_dereference(p->sighand))) { + spin_lock_irqsave(&sp->siglock, flags); + if (p->sighand != sp) { + spin_unlock_irqrestore(&sp->siglock, flags); + goto retry; + } + if ((atomic_read(&sp->count) == 0) || + (atomic_read(&p->usage) == 0)) { + spin_unlock_irqrestore(&sp->siglock, flags); + return -ESRCH; + } ret = __group_send_sig_info(sig, info, p); - spin_unlock_irqrestore(&p->sighand->siglock, flags); + spin_unlock_irqrestore(&sp->siglock, flags); } return ret; @@ -1126,7 +1162,7 @@ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) int __kill_pg_info(int sig, struct siginfo *info, pid_t pgrp) { - struct task_struct *p; + struct task_struct *p = NULL; int retval, success; if (pgrp <= 0) @@ -1158,45 +1194,57 @@ int kill_proc_info(int sig, struct siginfo *info, pid_t pid) { int error; + int acquired_tasklist_lock = 0; struct task_struct *p; - read_lock(&tasklist_lock); + rcu_read_lock(); + if (unlikely(sig_kernel_stop(sig) || sig == SIGCONT)) { + read_lock(&tasklist_lock); + acquired_tasklist_lock = 1; + } p = find_task_by_pid(pid); error = -ESRCH; - if (p) + if (p && vx_check(vx_task_xid(p), VX_IDENT)) error = group_send_sig_info(sig, info, p); - read_unlock(&tasklist_lock); + if (unlikely(acquired_tasklist_lock)) + read_unlock(&tasklist_lock); + rcu_read_unlock(); return error; } -int print_fatal_signals = 0; - -static void print_fatal_signal(struct pt_regs *regs, int signr) +/* like kill_proc_info(), but doesn't use uid/euid of "current" */ +int kill_proc_info_as_uid(int sig, struct siginfo *info, pid_t pid, + uid_t uid, uid_t euid) { - int i; - unsigned char insn; - printk("%s/%d: potentially unexpected fatal signal %d.\n", - current->comm, current->pid, signr); - -#ifdef __i386__ - printk("code at %08lx: ", regs->eip); - for (i = 0; i < 16; i++) { - __get_user(insn, (unsigned char *)(regs->eip + i)); - printk("%02x ", insn); - } -#endif - printk("\n"); - show_regs(regs); -} + int ret = -EINVAL; + struct task_struct *p; -static int __init setup_print_fatal_signals(char *str) -{ - get_option (&str, &print_fatal_signals); + if (!valid_signal(sig)) + return ret; - return 1; + read_lock(&tasklist_lock); + p = find_task_by_pid(pid); + if (!p) { + ret = -ESRCH; + goto out_unlock; + } + if ((info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info))) + && (euid != p->suid) && (euid != p->uid) + && (uid != p->suid) && (uid != p->uid)) { + ret = -EPERM; + goto out_unlock; + } + if (sig && p->sighand) { + unsigned long flags; + spin_lock_irqsave(&p->sighand->siglock, flags); + ret = __group_send_sig_info(sig, info, p); + spin_unlock_irqrestore(&p->sighand->siglock, flags); + } +out_unlock: + read_unlock(&tasklist_lock); + return ret; } - -__setup("print-fatal-signals=", setup_print_fatal_signals); +EXPORT_SYMBOL_GPL(kill_proc_info_as_uid); /* * kill_something_info() interprets pid in interesting ways just like kill(2). @@ -1215,7 +1263,8 @@ static int kill_something_info(int sig, struct siginfo *info, int pid) read_lock(&tasklist_lock); for_each_process(p) { - if (p->pid > 1 && p->tgid != current->tgid) { + if (vx_check(vx_task_xid(p), VX_ADMIN|VX_IDENT)&& + p->pid > 1 && p->tgid != current->tgid) { int err = group_send_sig_info(sig, info, p); ++count; if (err != -EPERM) @@ -1249,7 +1298,7 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p) * Make sure legacy kernel users don't send in bad values * (normal paths check this in check_kill_permission). */ - if (sig < 0 || sig > _NSIG) + if (!valid_signal(sig)) return -EINVAL; /* @@ -1266,10 +1315,13 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p) return ret; } +#define __si_special(priv) \ + ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) + int send_sig(int sig, struct task_struct *p, int priv) { - return send_sig_info(sig, (void*)(long)(priv != 0), p); + return send_sig_info(sig, __si_special(priv), p); } /* @@ -1289,7 +1341,7 @@ send_group_sig_info(int sig, struct siginfo *info, struct task_struct *p) void force_sig(int sig, struct task_struct *p) { - force_sig_info(sig, (void*)1L, p); + force_sig_info(sig, SEND_SIG_PRIV, p); } /* @@ -1314,13 +1366,13 @@ force_sigsegv(int sig, struct task_struct *p) int kill_pg(pid_t pgrp, int sig, int priv) { - return kill_pg_info(sig, (void *)(long)(priv != 0), pgrp); + return kill_pg_info(sig, __si_special(priv), pgrp); } int kill_proc(pid_t pid, int sig, int priv) { - return kill_proc_info(sig, (void *)(long)(priv != 0), pid); + return kill_proc_info(sig, __si_special(priv), pid); } /* @@ -1337,7 +1389,7 @@ struct sigqueue *sigqueue_alloc(void) { struct sigqueue *q; - if ((q = __sigqueue_alloc())) + if ((q = __sigqueue_alloc(current, GFP_KERNEL, 0))) q->flags |= SIGQUEUE_PREALLOC; return(q); } @@ -1351,11 +1403,12 @@ void sigqueue_free(struct sigqueue *q) * pending queue. */ if (unlikely(!list_empty(&q->list))) { - read_lock(&tasklist_lock); - spin_lock_irqsave(q->lock, flags); + spinlock_t *lock = ¤t->sighand->siglock; + read_lock(&tasklist_lock); + spin_lock_irqsave(lock, flags); if (!list_empty(&q->list)) list_del_init(&q->list); - spin_unlock_irqrestore(q->lock, flags); + spin_unlock_irqrestore(lock, flags); read_unlock(&tasklist_lock); } q->flags &= ~SIGQUEUE_PREALLOC; @@ -1367,17 +1420,55 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) { unsigned long flags; int ret = 0; + struct sighand_struct *sh; + + BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); /* - * We need the tasklist lock even for the specific - * thread case (when we don't need to follow the group - * lists) in order to avoid races with "p->sighand" - * going away or changing from under us. + * The rcu based delayed sighand destroy makes it possible to + * run this without tasklist lock held. The task struct itself + * cannot go away as create_timer did get_task_struct(). + * + * We return -1, when the task is marked exiting, so + * posix_timer_event can redirect it to the group leader */ - BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); - read_lock(&tasklist_lock); - spin_lock_irqsave(&p->sighand->siglock, flags); - + rcu_read_lock(); + + if (unlikely(p->flags & PF_EXITING)) { + ret = -1; + goto out_err; + } + +retry: + sh = rcu_dereference(p->sighand); + + spin_lock_irqsave(&sh->siglock, flags); + if (p->sighand != sh) { + /* We raced with exec() in a multithreaded process... */ + spin_unlock_irqrestore(&sh->siglock, flags); + goto retry; + } + + /* + * We do the check here again to handle the following scenario: + * + * CPU 0 CPU 1 + * send_sigqueue + * check PF_EXITING + * interrupt exit code running + * __exit_signal + * lock sighand->siglock + * unlock sighand->siglock + * lock sh->siglock + * add(tsk->pending) flush_sigqueue(tsk->pending) + * + */ + + if (unlikely(p->flags & PF_EXITING)) { + ret = -1; + goto out; + } + if (unlikely(!list_empty(&q->list))) { /* * If an SI_TIMER entry is already queue just increment @@ -1387,23 +1478,24 @@ send_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) BUG(); q->info.si_overrun++; goto out; - } + } /* Short-circuit ignored signals. */ if (sig_ignored(p, sig)) { ret = 1; goto out; } - q->lock = &p->sighand->siglock; list_add_tail(&q->list, &p->pending.list); sigaddset(&p->pending.signal, sig); if (!sigismember(&p->blocked, sig)) signal_wake_up(p, sig == SIGKILL); out: - spin_unlock_irqrestore(&p->sighand->siglock, flags); - read_unlock(&tasklist_lock); - return(ret); + spin_unlock_irqrestore(&sh->siglock, flags); +out_err: + rcu_read_unlock(); + + return ret; } int @@ -1413,7 +1505,9 @@ send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) int ret = 0; BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); + read_lock(&tasklist_lock); + /* Since it_lock is held, p->sighand cannot be NULL. */ spin_lock_irqsave(&p->sighand->siglock, flags); handle_stop_signal(sig, p); @@ -1440,7 +1534,6 @@ send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) * We always use the shared queue for process-wide signals, * to avoid several races. */ - q->lock = &p->sighand->siglock; list_add_tail(&q->list, &p->signal->shared_pending.list); sigaddset(&p->signal->shared_pending.signal, sig); @@ -1448,32 +1541,16 @@ send_group_sigqueue(int sig, struct sigqueue *q, struct task_struct *p) out: spin_unlock_irqrestore(&p->sighand->siglock, flags); read_unlock(&tasklist_lock); - return(ret); + return ret; } /* - * Joy. Or not. Pthread wants us to wake up every thread - * in our parent group. + * Wake up any threads in the parent blocked in wait* syscalls. */ -static void __wake_up_parent(struct task_struct *p, +static inline void __wake_up_parent(struct task_struct *p, struct task_struct *parent) { - struct task_struct *tsk = parent; - - /* - * Fortunately this is not necessary for thread groups: - */ - if (p->tgid == tsk->tgid) { - wake_up_interruptible_sync(&tsk->wait_chldexit); - return; - } - - do { - wake_up_interruptible_sync(&tsk->wait_chldexit); - tsk = next_thread(tsk); - if (tsk->signal != parent->signal) - BUG(); - } while (tsk != parent); + wake_up_interruptible_sync(&parent->signal->wait_chldexit); } /* @@ -1487,8 +1564,7 @@ void do_notify_parent(struct task_struct *tsk, int sig) unsigned long flags; struct sighand_struct *psig; - if (sig == -1) - BUG(); + BUG_ON(sig == -1); /* do_notify_parent_cldstop should have been called instead. */ BUG_ON(tsk->state & (TASK_STOPPED|TASK_TRACED)); @@ -1502,8 +1578,10 @@ void do_notify_parent(struct task_struct *tsk, int sig) info.si_uid = tsk->uid; /* FIXME: find out whether or not this is supposed to be c*time. */ - info.si_utime = tsk->utime + tsk->signal->utime; - info.si_stime = tsk->stime + tsk->signal->stime; + info.si_utime = cputime_to_jiffies(cputime_add(tsk->utime, + tsk->signal->utime)); + info.si_stime = cputime_to_jiffies(cputime_add(tsk->stime, + tsk->signal->stime)); info.si_status = tsk->exit_code & 0x7f; if (tsk->exit_code & 0x80) @@ -1517,7 +1595,7 @@ void do_notify_parent(struct task_struct *tsk, int sig) psig = tsk->parent->sighand; spin_lock_irqsave(&psig->siglock, flags); - if (sig == SIGCHLD && + if (!tsk->ptrace && sig == SIGCHLD && (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { /* @@ -1539,28 +1617,34 @@ void do_notify_parent(struct task_struct *tsk, int sig) if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) sig = 0; } - if (sig > 0 && sig <= _NSIG) + if (valid_signal(sig) && sig > 0) __group_send_sig_info(sig, &info, tsk->parent); __wake_up_parent(tsk, tsk->parent); spin_unlock_irqrestore(&psig->siglock, flags); } -static void -do_notify_parent_cldstop(struct task_struct *tsk, struct task_struct *parent, - int why) +static void do_notify_parent_cldstop(struct task_struct *tsk, int to_self, int why) { struct siginfo info; unsigned long flags; + struct task_struct *parent; struct sighand_struct *sighand; + if (to_self) + parent = tsk->parent; + else { + tsk = tsk->group_leader; + parent = tsk->real_parent; + } + info.si_signo = SIGCHLD; info.si_errno = 0; info.si_pid = tsk->pid; info.si_uid = tsk->uid; /* FIXME: find out whether or not this is supposed to be c*time. */ - info.si_utime = tsk->utime; - info.si_stime = tsk->stime; + info.si_utime = cputime_to_jiffies(tsk->utime); + info.si_stime = cputime_to_jiffies(tsk->stime); info.si_code = why; switch (why) { @@ -1596,11 +1680,12 @@ do_notify_parent_cldstop(struct task_struct *tsk, struct task_struct *parent, * We always set current->last_siginfo while stopped here. * That makes it a way to test a stopped process for * being ptrace-stopped vs being job-control-stopped. + * + * If we actually decide not to stop at all because the tracer is gone, + * we leave nostop_code in current->exit_code. */ -static void ptrace_stop(int exit_code, siginfo_t *info) +static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info) { - BUG_ON(!(current->ptrace & PT_PTRACED)); - /* * If there is a group stop in progress, * we must participate in the bookkeeping. @@ -1614,10 +1699,25 @@ static void ptrace_stop(int exit_code, siginfo_t *info) /* Let the debugger run. */ set_current_state(TASK_TRACED); spin_unlock_irq(¤t->sighand->siglock); + try_to_freeze(); read_lock(&tasklist_lock); - do_notify_parent_cldstop(current, current->parent, CLD_TRAPPED); - read_unlock(&tasklist_lock); - schedule(); + if (likely(current->ptrace & PT_PTRACED) && + likely(current->parent != current->real_parent || + !(current->ptrace & PT_ATTACHED)) && + (likely(current->parent->signal != current->signal) || + !unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) { + do_notify_parent_cldstop(current, 1, CLD_TRAPPED); + read_unlock(&tasklist_lock); + schedule(); + } else { + /* + * By the time we got the lock, our tracer went away. + * Don't stop here. + */ + read_unlock(&tasklist_lock); + set_current_state(TASK_RUNNING); + current->exit_code = nostop_code; + } /* * We are back. Now reacquire the siglock before touching @@ -1648,34 +1748,32 @@ void ptrace_notify(int exit_code) /* Let the debugger run. */ spin_lock_irq(¤t->sighand->siglock); - ptrace_stop(exit_code, &info); + ptrace_stop(exit_code, 0, &info); spin_unlock_irq(¤t->sighand->siglock); } -#ifndef HAVE_ARCH_GET_SIGNAL_TO_DELIVER - static void finish_stop(int stop_count) { + int to_self; + /* * If there are no other threads in the group, or if there is * a group stop in progress and we are the last to stop, * report to the parent. When ptraced, every thread reports itself. */ - if (stop_count < 0 || (current->ptrace & PT_PTRACED)) { - read_lock(&tasklist_lock); - do_notify_parent_cldstop(current, current->parent, - CLD_STOPPED); - read_unlock(&tasklist_lock); - } - else if (stop_count == 0) { - read_lock(&tasklist_lock); - do_notify_parent_cldstop(current->group_leader, - current->group_leader->real_parent, - CLD_STOPPED); - read_unlock(&tasklist_lock); - } + if (stop_count < 0 || (current->ptrace & PT_PTRACED)) + to_self = 1; + else if (stop_count == 0) + to_self = 0; + else + goto out; + read_lock(&tasklist_lock); + do_notify_parent_cldstop(current, to_self, CLD_STOPPED); + read_unlock(&tasklist_lock); + +out: schedule(); /* * Now we don't run again until continued. @@ -1686,15 +1784,18 @@ finish_stop(int stop_count) /* * This performs the stopping for SIGSTOP and other stop signals. * We have to stop all threads in the thread group. + * Returns nonzero if we've actually stopped and released the siglock. + * Returns zero if we didn't stop and still hold the siglock. */ -static void +static int do_signal_stop(int signr) { struct signal_struct *sig = current->signal; struct sighand_struct *sighand = current->sighand; int stop_count = -1; - /* spin_lock_irq(&sighand->siglock) is now done in caller */ + if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED)) + return 0; if (sig->group_stop_count > 0) { /* @@ -1706,7 +1807,7 @@ do_signal_stop(int signr) current->exit_code = signr; set_current_state(TASK_STOPPED); if (stop_count == 0) - sig->stop_state = 1; + sig->flags = SIGNAL_STOP_STOPPED; spin_unlock_irq(&sighand->siglock); } else if (thread_group_empty(current)) { @@ -1715,7 +1816,7 @@ do_signal_stop(int signr) */ current->exit_code = current->signal->group_exit_code = signr; set_current_state(TASK_STOPPED); - sig->stop_state = 1; + sig->flags = SIGNAL_STOP_STOPPED; spin_unlock_irq(&sighand->siglock); } else { @@ -1736,25 +1837,17 @@ do_signal_stop(int signr) read_lock(&tasklist_lock); spin_lock_irq(&sighand->siglock); - if (unlikely(sig->group_exit)) { - /* - * There is a group exit in progress now. - * We'll just ignore the stop and process the - * associated fatal signal. - */ - spin_unlock_irq(&sighand->siglock); - read_unlock(&tasklist_lock); - return; - } - - if (unlikely(sig_avoid_stop_race())) { + if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED)) { /* - * Either a SIGCONT or a SIGKILL signal was - * posted in the siglock-not-held window. + * Another stop or continue happened while we + * didn't have the lock. We can just swallow this + * signal now. If we raced with a SIGCONT, that + * should have just cleared it now. If we raced + * with another processor delivering a stop signal, + * then the SIGCONT that wakes us up should clear it. */ - spin_unlock_irq(&sighand->siglock); read_unlock(&tasklist_lock); - return; + return 0; } if (sig->group_stop_count == 0) { @@ -1767,7 +1860,8 @@ do_signal_stop(int signr) * stop is always done with the siglock held, * so this check has no races. */ - if (t->state < TASK_STOPPED) { + if (!t->exit_state && + !(t->state & (TASK_STOPPED|TASK_TRACED))) { stop_count++; signal_wake_up(t, 0); } @@ -1782,13 +1876,14 @@ do_signal_stop(int signr) current->exit_code = signr; set_current_state(TASK_STOPPED); if (stop_count == 0) - sig->stop_state = 1; + sig->flags = SIGNAL_STOP_STOPPED; spin_unlock_irq(&sighand->siglock); read_unlock(&tasklist_lock); } finish_stop(stop_count); + return 1; } /* @@ -1797,7 +1892,7 @@ do_signal_stop(int signr) * We return zero if we still hold the siglock and should look * for another signal without checking group_stop_count again. */ -static inline int handle_group_stop(void) +static int handle_group_stop(void) { int stop_count; @@ -1810,7 +1905,7 @@ static inline int handle_group_stop(void) return 0; } - if (current->signal->group_exit) + if (current->signal->flags & SIGNAL_GROUP_EXIT) /* * Group stop is so another thread can do a core dump, * or else we are racing against a death signal. @@ -1824,7 +1919,7 @@ static inline int handle_group_stop(void) */ stop_count = --current->signal->group_stop_count; if (stop_count == 0) - current->signal->stop_state = 1; + current->signal->flags = SIGNAL_STOP_STOPPED; current->exit_code = current->signal->group_exit_code; set_current_state(TASK_STOPPED); spin_unlock_irq(¤t->sighand->siglock); @@ -1852,16 +1947,11 @@ relock: if (!signr) break; /* will return 0 */ - if ((signr == SIGSEGV) && print_fatal_signals) { - spin_unlock_irq(¤t->sighand->siglock); - print_fatal_signal(regs, signr); - spin_lock_irq(¤t->sighand->siglock); - } if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) { ptrace_signal_deliver(regs, cookie); /* Let the debugger run. */ - ptrace_stop(signr, info); + ptrace_stop(signr, signr, info); /* We're back. Did the debugger cancel the sig? */ signr = current->exit_code; @@ -1912,6 +2002,11 @@ relock: if (current->pid == 1) continue; + /* virtual init is protected against user signals */ + if ((info->si_code == SI_USER) && + vx_current_initpid(current->pid)) + continue; + if (sig_kernel_stop(signr)) { /* * The default action is to stop all threads in @@ -1923,28 +2018,27 @@ relock: * This allows an intervening SIGCONT to be posted. * We need to check for that and bail out if necessary. */ - if (signr == SIGSTOP) { - do_signal_stop(signr); /* releases siglock */ - goto relock; - } - spin_unlock_irq(¤t->sighand->siglock); + if (signr != SIGSTOP) { + spin_unlock_irq(¤t->sighand->siglock); - /* signals can be posted during this window */ + /* signals can be posted during this window */ - if (is_orphaned_pgrp(process_group(current))) - goto relock; + if (is_orphaned_pgrp(process_group(current))) + goto relock; - spin_lock_irq(¤t->sighand->siglock); - if (unlikely(sig_avoid_stop_race())) { - /* - * Either a SIGCONT or a SIGKILL signal was - * posted in the siglock-not-held window. - */ - continue; + spin_lock_irq(¤t->sighand->siglock); } - do_signal_stop(signr); /* releases siglock */ - goto relock; + if (likely(do_signal_stop(signr))) { + /* It released the siglock. */ + goto relock; + } + + /* + * We didn't actually stop, due to a race + * with SIGCONT or something like that. + */ + continue; } spin_unlock_irq(¤t->sighand->siglock); @@ -1953,24 +2047,16 @@ relock: * Anything else is fatal, maybe with a core dump. */ current->flags |= PF_SIGNALED; - if (print_fatal_signals) - print_fatal_signal(regs, signr); - if (sig_kernel_coredump(signr) && - do_coredump((long)signr, signr, regs)) { + if (sig_kernel_coredump(signr)) { /* - * That killed all other threads in the group and - * synchronized with their demise, so there can't - * be any more left to kill now. The group_exit - * flags are set by do_coredump. Note that - * thread_group_empty won't always be true yet, - * because those threads were blocked in __exit_mm - * and we just let them go to finish dying. + * If it was able to dump core, this kills all + * other threads in the group and synchronizes with + * their demise. If we lost the race with another + * thread getting here, it set group_exit_code + * first and our do_group_exit call below will use + * that value and ignore the one we pass it. */ - const int code = signr | 0x80; - BUG_ON(!current->signal->group_exit); - BUG_ON(current->signal->group_exit_code != code); - do_exit(code); - /* NOTREACHED */ + do_coredump((long)signr, signr, regs); } /* @@ -1983,8 +2069,6 @@ relock: return signr; } -#endif - EXPORT_SYMBOL(recalc_sigpending); EXPORT_SYMBOL_GPL(dequeue_signal); EXPORT_SYMBOL(flush_signals); @@ -1998,6 +2082,7 @@ EXPORT_SYMBOL(sigprocmask); EXPORT_SYMBOL(block_all_signals); EXPORT_SYMBOL(unblock_all_signals); + /* * System call entry points. */ @@ -2236,9 +2321,9 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese, recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - current->state = TASK_INTERRUPTIBLE; - timeout = schedule_timeout(timeout); + timeout = schedule_timeout_interruptible(timeout); + try_to_freeze(); spin_lock_irq(¤t->sighand->siglock); sig = dequeue_signal(current, &these, &info); current->blocked = current->real_blocked; @@ -2277,26 +2362,13 @@ sys_kill(int pid, int sig) return kill_something_info(sig, &info, pid); } -/** - * sys_tgkill - send signal to one specific thread - * @tgid: the thread group ID of the thread - * @pid: the PID of the thread - * @sig: signal to be sent - * - * This syscall also checks the tgid and returns -ESRCH even if the PID - * exists but it's not belonging to the target process anymore. This - * method solves the problem of threads exiting and PIDs getting reused. - */ -asmlinkage long sys_tgkill(int tgid, int pid, int sig) +static int do_tkill(int tgid, int pid, int sig) { - struct siginfo info; int error; + struct siginfo info; struct task_struct *p; - /* This is only valid for single tasks */ - if (pid <= 0 || tgid <= 0) - return -EINVAL; - + error = -ESRCH; info.si_signo = sig; info.si_errno = 0; info.si_code = SI_TKILL; @@ -2305,8 +2377,7 @@ asmlinkage long sys_tgkill(int tgid, int pid, int sig) read_lock(&tasklist_lock); p = find_task_by_pid(pid); - error = -ESRCH; - if (p && (p->tgid == tgid)) { + if (p && (tgid <= 0 || p->tgid == tgid)) { error = check_kill_permission(sig, &info, p); /* * The null signal is a permissions and process existence @@ -2320,47 +2391,40 @@ asmlinkage long sys_tgkill(int tgid, int pid, int sig) } } read_unlock(&tasklist_lock); + return error; } +/** + * sys_tgkill - send signal to one specific thread + * @tgid: the thread group ID of the thread + * @pid: the PID of the thread + * @sig: signal to be sent + * + * This syscall also checks the tgid and returns -ESRCH even if the PID + * exists but it's not belonging to the target process anymore. This + * method solves the problem of threads exiting and PIDs getting reused. + */ +asmlinkage long sys_tgkill(int tgid, int pid, int sig) +{ + /* This is only valid for single tasks */ + if (pid <= 0 || tgid <= 0) + return -EINVAL; + + return do_tkill(tgid, pid, sig); +} + /* * Send a signal to only one task, even if it's a CLONE_THREAD task. */ asmlinkage long sys_tkill(int pid, int sig) { - struct siginfo info; - int error; - struct task_struct *p; - /* This is only valid for single tasks */ if (pid <= 0) return -EINVAL; - info.si_signo = sig; - info.si_errno = 0; - info.si_code = SI_TKILL; - info.si_pid = current->tgid; - info.si_uid = current->uid; - - read_lock(&tasklist_lock); - p = find_task_by_pid(pid); - error = -ESRCH; - if (p) { - error = check_kill_permission(sig, &info, p); - /* - * The null signal is a permissions and process existence - * probe. No signal is actually delivered. - */ - if (!error && sig && p->sighand) { - spin_lock_irq(&p->sighand->siglock); - handle_stop_signal(sig, p); - error = specific_send_sig_info(sig, &info, p); - spin_unlock_irq(&p->sighand->siglock); - } - } - read_unlock(&tasklist_lock); - return error; + return do_tkill(0, pid, sig); } asmlinkage long @@ -2382,11 +2446,12 @@ sys_rt_sigqueueinfo(int pid, int sig, siginfo_t __user *uinfo) } int -do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact) +do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) { struct k_sigaction *k; + sigset_t mask; - if (sig < 1 || sig > _NSIG || (act && sig_kernel_only(sig))) + if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) return -EINVAL; k = ¤t->sighand->action[sig-1]; @@ -2405,6 +2470,8 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact) *oact = *k; if (act) { + sigdelsetmask(&act->sa.sa_mask, + sigmask(SIGKILL) | sigmask(SIGSTOP)); /* * POSIX 3.3.1.3: * "Setting a signal action to SIG_IGN for a signal that is @@ -2430,11 +2497,11 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact) read_lock(&tasklist_lock); spin_lock_irq(&t->sighand->siglock); *k = *act; - sigdelsetmask(&k->sa.sa_mask, - sigmask(SIGKILL) | sigmask(SIGSTOP)); - rm_from_queue(sigmask(sig), &t->signal->shared_pending); + sigemptyset(&mask); + sigaddset(&mask, sig); + rm_from_queue_full(&mask, &t->signal->shared_pending); do { - rm_from_queue(sigmask(sig), &t->pending); + rm_from_queue_full(&mask, &t->pending); recalc_sigpending_tsk(t); t = next_thread(t); } while (t != current); @@ -2444,8 +2511,6 @@ do_sigaction(int sig, const struct k_sigaction *act, struct k_sigaction *oact) } *k = *act; - sigdelsetmask(&k->sa.sa_mask, - sigmask(SIGKILL) | sigmask(SIGSTOP)); } spin_unlock_irq(¤t->sighand->siglock); @@ -2470,7 +2535,7 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s int ss_flags; error = -EFAULT; - if (verify_area(VERIFY_READ, uss, sizeof(*uss)) + if (!access_ok(VERIFY_READ, uss, sizeof(*uss)) || __get_user(ss_sp, &uss->ss_sp) || __get_user(ss_flags, &uss->ss_flags) || __get_user(ss_size, &uss->ss_size)) @@ -2651,6 +2716,7 @@ sys_signal(int sig, __sighandler_t handler) new_sa.sa.sa_handler = handler; new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; + sigemptyset(&new_sa.sa.sa_mask); ret = do_sigaction(sig, &new_sa, &old_sa); @@ -2670,6 +2736,32 @@ sys_pause(void) #endif +#ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND +asmlinkage long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize) +{ + sigset_t newset; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&newset, unewset, sizeof(newset))) + return -EFAULT; + sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); + + spin_lock_irq(¤t->sighand->siglock); + current->saved_sigmask = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + current->state = TASK_INTERRUPTIBLE; + schedule(); + set_thread_flag(TIF_RESTORE_SIGMASK); + return -ERESTARTNOHAND; +} +#endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ + void __init signals_init(void) { sigqueue_cachep =