litmus-rt.git - The LITMUS^RT kernel.

diff options

author	Robin Getz <robin.getz@analog.com>	2010-07-09 13:29:26 -0400
committer	Mike Frysinger <vapier@gentoo.org>	2010-10-22 03:48:55 -0400
commit	c0ab9387456d7660dead96ce1b5463741f087db1 (patch)
tree	d14c3893db3f35db1f856c59dbe68781f954b310
parent	3d7dc8836a0f08cbe6d8d499ddce05809b687f58 (diff)

Blackfin: workaround anomaly 05000481 (corruption with ITEST MMRs)

Nothing actually needs to use these MMRs (as direct cache manipulation is done with the DTEST MMRs), so simply hide the read funcs behind the anomaly define. They're generally unusable anyways when this anomaly is in effect. Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Diffstat

-rw-r--r--

arch/blackfin/include/asm/cdef_LPBlackfin.h

1 files changed, 6 insertions, 3 deletions

 #define bfin_write_ICPLB_DATA14(val)         bfin_write32(ICPLB_DATA14,val)
 #define bfin_read_ICPLB_DATA15()             bfin_read32(ICPLB_DATA15)
 #define bfin_write_ICPLB_DATA15(val)         bfin_write32(ICPLB_DATA15,val)
-#define bfin_read_ITEST_COMMAND()            bfin_read32(ITEST_COMMAND)
 #define bfin_write_ITEST_COMMAND(val)        bfin_write32(ITEST_COMMAND,val)
 #if 0
 #define ITEST_INDEX            0xFFE01304   /* Instruction Test Index Register */
 #endif
-#define bfin_read_ITEST_DATA0()              bfin_read32(ITEST_DATA0)
 #define bfin_write_ITEST_DATA0(val)          bfin_write32(ITEST_DATA0,val)
-#define bfin_read_ITEST_DATA1()              bfin_read32(ITEST_DATA1)
 #define bfin_write_ITEST_DATA1(val)          bfin_write32(ITEST_DATA1,val)
+#if ANOMALY_05000481
+#define bfin_read_ITEST_COMMAND()            bfin_read32(ITEST_COMMAND)
+#define bfin_read_ITEST_DATA0()              bfin_read32(ITEST_DATA0)
+#define bfin_read_ITEST_DATA1()              bfin_read32(ITEST_DATA1)
+#endif
 /* Event/Interrupt Registers*/
 #define bfin_read_EVT0()                     bfin_read32(EVT0)

/* * linux/kernel/signal.c * * Copyright (C) 1991, 1992 Linus Torvalds * * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson * * 2003-06-02 Jim Houston - Concurrent Computer Corp. * Changes to use preallocated sigqueue structures * to allow signals to be sent reliably. */ #include <linux/slab.h> #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/fs.h> #include <linux/tty.h> #include <linux/binfmts.h> #include <linux/security.h> #include <linux/syscalls.h> #include <linux/ptrace.h> #include <linux/signal.h> #include <linux/signalfd.h> #include <linux/ratelimit.h> #include <linux/tracehook.h> #include <linux/capability.h> #include <linux/freezer.h> #include <linux/pid_namespace.h> #include <linux/nsproxy.h> #define CREATE_TRACE_POINTS #include <trace/events/signal.h> #include <asm/param.h> #include <asm/uaccess.h> #include <asm/unistd.h> #include <asm/siginfo.h> #include "audit.h" /* audit_signal_info() */ /* * SLAB caches for signal bits. */ static struct kmem_cache *sigqueue_cachep; int print_fatal_signals __read_mostly; static void __user *sig_handler(struct task_struct *t, int sig) { return t->sighand->action[sig - 1].sa.sa_handler; } static int sig_handler_ignored(void __user *handler, int sig) { /* Is it explicitly or implicitly ignored? */ return handler == SIG_IGN || (handler == SIG_DFL && sig_kernel_ignore(sig)); } static int sig_task_ignored(struct task_struct *t, int sig, int from_ancestor_ns) { void __user *handler; handler = sig_handler(t, sig); if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && handler == SIG_DFL && !from_ancestor_ns) return 1; return sig_handler_ignored(handler, sig); } static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns) { /* * Blocked signals are never ignored, since the * signal handler may change by the time it is * unblocked. */ if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) return 0; if (!sig_task_ignored(t, sig, from_ancestor_ns)) return 0; /* * Tracers may want to know about even ignored signals. */ return !tracehook_consider_ignored_signal(t, sig); } /* * Re-calculate pending state from the set of locally pending * signals, globally pending signals, and blocked signals. */ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) { unsigned long ready; long i; switch (_NSIG_WORDS) { default: for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) ready |= signal->sig[i] &~ blocked->sig[i]; break; case 4: ready = signal->sig[3] &~ blocked->sig[3]; ready |= signal->sig[2] &~ blocked->sig[2]; ready |= signal->sig[1] &~ blocked->sig[1]; ready |= signal->sig[0] &~ blocked->sig[0]; break; case 2: ready = signal->sig[1] &~ blocked->sig[1]; ready |= signal->sig[0] &~ blocked->sig[0]; break; case 1: ready = signal->sig[0] &~ blocked->sig[0]; } return ready != 0; } #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) static int recalc_sigpending_tsk(struct task_struct *t) { if (t->signal->group_stop_count > 0 || PENDING(&t->pending, &t->blocked) || PENDING(&t->signal->shared_pending, &t->blocked)) { set_tsk_thread_flag(t, TIF_SIGPENDING); return 1; } /* * We must never clear the flag in another thread, or in current * when it's possible the current syscall is returning -ERESTART*. * So we don't clear it here, and only callers who know they should do. */ return 0; } /* * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. * This is superfluous when called on current, the wakeup is a harmless no-op. */ void recalc_sigpending_and_wake(struct task_struct *t) { if (recalc_sigpending_tsk(t)) signal_wake_up(t, 0); } void recalc_sigpending(void) { if (unlikely(tracehook_force_sigpending())) set_thread_flag(TIF_SIGPENDING); else if (!recalc_sigpending_tsk(current) && !freezing(current)) clear_thread_flag(TIF_SIGPENDING); } /* Given the mask, find the first available signal that should be serviced. */ #define SYNCHRONOUS_MASK \ (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ sigmask(SIGTRAP) | sigmask(SIGFPE)) int next_signal(struct sigpending *pending, sigset_t *mask) { unsigned long i, *s, *m, x; int sig = 0; s = pending->signal.sig; m = mask->sig; /* * Handle the first word specially: it contains the * synchronous signals that need to be dequeued first. */ x = *s &~ *m; if (x) { if (x & SYNCHRONOUS_MASK) x &= SYNCHRONOUS_MASK; sig = ffz(~x) + 1; return sig; } switch (_NSIG_WORDS) { default: for (i = 1; i < _NSIG_WORDS; ++i) { x = *++s &~ *++m; if (!x) continue; sig = ffz(~x) + i*_NSIG_BPW + 1; break; } break; case 2: x = s[1] &~ m[1]; if (!x) break; sig = ffz(~x) + _NSIG_BPW + 1; break; case 1: /* Nothing to do */ break; } return sig; } static inline void print_dropped_signal(int sig) { static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10); if (!print_fatal_signals) return; if (!__ratelimit(&ratelimit_state)) return; printk(KERN_INFO "%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n", current->comm, current->pid, sig); } /* * allocate a new signal queue record * - this may be called without locks if and only if t == current, otherwise an * appopriate lock must be held to stop the target task from exiting */ static struct sigqueue * __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit) { struct sigqueue *q = NULL; struct user_struct *user; /* * Protect access to @t credentials. This can go away when all * callers hold rcu read lock. */ rcu_read_lock(); user = get_uid(__task_cred(t)->user); atomic_inc(&user->sigpending); rcu_read_unlock(); if (override_rlimit || atomic_read(&user->sigpending) <= task_rlimit(t, RLIMIT_SIGPENDING)) { q = kmem_cache_alloc(sigqueue_cachep, flags); } else { print_dropped_signal(sig); } if (unlikely(q == NULL)) { atomic_dec(&user->sigpending); free_uid(user); } else { INIT_LIST_HEAD(&q->list); q->flags = 0; q->user = user; } return q; } static void __sigqueue_free(struct sigqueue *q) { if (q->flags & SIGQUEUE_PREALLOC) return; atomic_dec(&q->user->sigpending); free_uid(q->user); kmem_cache_free(sigqueue_cachep, q); } void flush_sigqueue(struct sigpending *queue) { struct sigqueue *q; sigemptyset(&queue->signal); while (!list_empty(&queue->list)) { q = list_entry(queue->list.next, struct sigqueue , list); list_del_init(&q->list); __sigqueue_free(q); } } /* * Flush all pending signals for a task. */ void __flush_signals(struct task_struct *t) { clear_tsk_thread_flag(t, TIF_SIGPENDING); flush_sigqueue(&t->pending); flush_sigqueue(&t->signal->shared_pending); } void flush_signals(struct task_struct *t) { unsigned long flags; spin_lock_irqsave(&t->sighand->siglock, flags); __flush_signals(t); spin_unlock_irqrestore(&t->sighand->siglock, flags); } static void __flush_itimer_signals(struct sigpending *pending) { sigset_t signal, retain; struct sigqueue *q, *n; signal = pending->signal; sigemptyset(&retain); list_for_each_entry_safe(q, n, &pending->list, list) { int sig = q->info.si_signo; if (likely(q->info.si_code != SI_TIMER)) { sigaddset(&retain, sig); } else { sigdelset(&signal, sig); list_del_init(&q->list); __sigqueue_free(q); } } sigorsets(&pending->signal, &signal, &retain); } void flush_itimer_signals(void) { struct task_struct *tsk = current; unsigned long flags; spin_lock_irqsave(&tsk->sighand->siglock, flags); __flush_itimer_signals(&tsk->pending); __flush_itimer_signals(&tsk->signal->shared_pending); spin_unlock_irqrestore(&tsk->sighand->siglock, flags); } void ignore_signals(struct task_struct *t) { int i; for (i = 0; i < _NSIG; ++i) t->sighand->action[i].sa.sa_handler = SIG_IGN; flush_signals(t); } /* * Flush all handlers for a task. */ void flush_signal_handlers(struct task_struct *t, int force_default) { int i; struct k_sigaction *ka = &t->sighand->action[0]; for (i = _NSIG ; i != 0 ; i--) { if (force_default || ka->sa.sa_handler != SIG_IGN) ka->sa.sa_handler = SIG_DFL; ka->sa.sa_flags = 0; sigemptyset(&ka->sa.sa_mask); ka++; } } int unhandled_signal(struct task_struct *tsk, int sig) { void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; if (is_global_init(tsk)) return 1; if (handler != SIG_IGN && handler != SIG_DFL) return 0; return !tracehook_consider_fatal_signal(tsk, sig); } /* 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 * sent/acted upon. If the notifier routine returns non-zero, then the * signal will be acted upon after all. If the notifier routine returns 0, * then then signal will be blocked. Only one block per process is * allowed. priv is a pointer to private data that the notifier routine * can use to determine if the signal should be blocked or not. */ void block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) { unsigned long flags; spin_lock_irqsave(&current->sighand->siglock, flags); current->notifier_mask = mask; current->notifier_data = priv; current->notifier = notifier; spin_unlock_irqrestore(&current->sighand->siglock, flags); } /* Notify the system that blocking has ended. */ void unblock_all_signals(void) { unsigned long flags; spin_lock_irqsave(&current->sighand->siglock, flags); current->notifier = NULL; current->notifier_data = NULL; recalc_sigpending(); spin_unlock_irqrestore(&current->sighand->siglock, flags); } static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) { struct sigqueue *q, *first = NULL; /* * Collect the siginfo appropriate to this signal. Check if * there is another siginfo for the same signal. */ list_for_each_entry(q, &list->list, list) { if (q->info.si_signo == sig) { if (first) goto still_pending; first = q; } } sigdelset(&list->signal, sig); if (first) { still_pending: list_del_init(&first->list); copy_siginfo(info, &first->info); __sigqueue_free(first); } else { /* Ok, it wasn't in the queue. This must be a fast-pathed signal or we must have been out of queue space. So zero out the info. */ info->si_signo = sig; info->si_errno = 0; info->si_code = SI_USER; info->si_pid = 0; info->si_uid = 0; } } static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, siginfo_t *info) { int sig = next_signal(pending, mask); if (sig) { if (current->notifier) { if (sigismember(current->notifier_mask, sig)) { if (!(current->notifier)(current->notifier_data)) { clear_thread_flag(TIF_SIGPENDING); return 0; } } } collect_signal(sig, pending, info); } return sig; } /* * Dequeue a signal and return the element to the caller, which is * expected to free it. * * All callers have to hold the siglock. */ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) { int signr; /* We only dequeue private signals from ourselves, we don't let * signalfd steal them */ signr = __dequeue_signal(&tsk->pending, mask, info); if (!signr) { signr = __dequeue_signal(&tsk->signal->shared_pending, mask, info); /* * itimer signal ? * * itimers are process shared and we restart periodic * itimers in the signal delivery path to prevent DoS * attacks in the high resolution timer case. This is * compliant with the old way of self restarting * itimers, as the SIGALRM is a legacy signal and only * queued once. Changing the restart behaviour to * restart the timer in the signal dequeue path is * reducing the timer noise on heavy loaded !highres * systems too. */ if (unlikely(signr == SIGALRM)) { struct hrtimer *tmr = &tsk->signal->real_timer; if (!hrtimer_is_queued(tmr) && tsk->signal->it_real_incr.tv64 != 0) { hrtimer_forward(tmr, tmr->base->get_time(), tsk->signal->it_real_incr); hrtimer_restart(tmr); } } } recalc_sigpending(); if (!signr) return 0; if (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. */ tsk->signal->flags |= SIGNAL_STOP_DEQUEUED; } if ((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; } /* * Tell a process that it has a new active signal.. * * NOTE! we rely on the previous spin_lock to * lock interrupts for us! We can only be called with * "siglock" held, and the local interrupt must * have been disabled when that got acquired! * * No need to set need_resched since signal event passing * goes through ->blocked */ void signal_wake_up(struct task_struct *t, int resume) { unsigned int mask; set_tsk_thread_flag(t, TIF_SIGPENDING); /* * For SIGKILL, we want to wake it up in the stopped/traced/killable * 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 using wake_up_state, we ensure the process will wake up and * handle its death signal. */ mask = TASK_INTERRUPTIBLE; if (resume) mask |= TASK_WAKEKILL; 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. * * All callers must be holding the siglock. */ static int rm_from_queue(unsigned long mask, struct sigpending *s) { struct sigqueue *q, *n; if (!sigtestsetmask(&s->signal, mask)) return 0; sigdelsetmask(&s->signal, mask); list_for_each_entry_safe(q, n, &s->list, list) { if (q->info.si_signo < SIGRTMIN && (mask & sigmask(q->info.si_signo))) { list_del_init(&q->list); __sigqueue_free(q); } } return 1; } static inline int is_si_special(const struct siginfo *info) { return info <= SEND_SIG_FORCED; } static inline bool si_fromuser(const struct siginfo *info) { return info == SEND_SIG_NOINFO || (!is_si_special(info) && SI_FROMUSER(info)); } /* * Bad permissions for sending the signal * - the caller must hold the RCU read lock */ static int check_kill_permission(int sig, struct siginfo *info, struct task_struct *t) { const struct cred *cred, *tcred; struct pid *sid; int error; if (!valid_signal(sig)) return -EINVAL; if (!si_fromuser(info)) return 0; error = audit_signal_info(sig, t); /* Let audit system see the signal */ if (error) return error; cred = current_cred(); tcred = __task_cred(t); if (!same_thread_group(current, t) && (cred->euid ^ tcred->suid) && (cred->euid ^ tcred->uid) && (cred->uid ^ tcred->suid) && (cred->uid ^ tcred->uid) && !capable(CAP_KILL)) { switch (sig) { case SIGCONT: sid = task_session(t); /* * We don't return the error if sid == NULL. The * task was unhashed, the caller must notice this. */ if (!sid || sid == task_session(current)) break; default: return -EPERM; } } return security_task_kill(t, info, sig, 0); } /* * Handle magic process-wide effects of stop/continue signals. Unlike * the signal actions, these happen immediately at signal-generation * time regardless of blocking, ignoring, or handling. This does the * actual continuing for SIGCONT, but not the actual stopping for stop * signals. The process stop is done as a signal action for SIG_DFL. * * Returns true if the signal should be actually delivered, otherwise * it should be dropped. */ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) { struct signal_struct *signal = p->signal; struct task_struct *t; if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { /* * The process is in the middle of dying, nothing to do. */ } else if (sig_kernel_stop(sig)) { /* * This is a stop signal. Remove SIGCONT from all queues. */ rm_from_queue(sigmask(SIGCONT), &signal->shared_pending); t = p; do { rm_from_queue(sigmask(SIGCONT), &t->pending); } while_each_thread(p, t); } else if (sig == SIGCONT) { unsigned int why; /* * Remove all stop signals from all queues, * and wake all threads. */ rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); t = p; do { unsigned int state; rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); /* * If there is a handler for SIGCONT, we must make * sure that no thread returns to user mode before * we post the signal, in case it was the only * thread eligible to run the signal handler--then * it must not do anything between resuming and * running the handler. With the TIF_SIGPENDING * flag set, the thread will pause and acquire the * siglock that we hold now and until we've queued * the pending signal. * * Wake up the stopped thread _after_ setting * TIF_SIGPENDING */ state = __TASK_STOPPED; if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) { set_tsk_thread_flag(t, TIF_SIGPENDING); state |= TASK_INTERRUPTIBLE; } wake_up_state(t, state); } while_each_thread(p, t); /* * Notify the parent with CLD_CONTINUED if we were stopped. * * If we were in the middle of a group stop, we pretend it * was already finished, and then continued. Since SIGCHLD * doesn't queue we report only CLD_STOPPED, as if the next * CLD_CONTINUED was dropped. */ why = 0; if (signal->flags & SIGNAL_STOP_STOPPED) why |= SIGNAL_CLD_CONTINUED; else if (signal->group_stop_count) why |= SIGNAL_CLD_STOPPED; if (why) { /* * The first thread which returns from do_signal_stop() * will take ->siglock, notice SIGNAL_CLD_MASK, and * notify its parent. See get_signal_to_deliver(). */ signal->flags = why | SIGNAL_STOP_CONTINUED; signal->group_stop_count = 0; signal->group_exit_code = 0; } 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. */ signal->flags &= ~SIGNAL_STOP_DEQUEUED; } } return !sig_ignored(p, sig, from_ancestor_ns); } /* * Test if P wants to take SIG. After we've checked all threads with this, * it's equivalent to finding no threads not blocking SIG. Any threads not * blocking SIG were ruled out because they are not running and already * have pending signals. Such threads will dequeue from the shared queue * as soon as they're available, so putting the signal on the shared queue * will be equivalent to sending it to one such thread. */ 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 (task_is_stopped_or_traced(p)) return 0; return task_curr(p) || !signal_pending(p); } static void complete_signal(int sig, struct task_struct *p, int group) { struct signal_struct *signal = p->signal; struct task_struct *t; /* * 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)) t = p; else if (!group || thread_group_empty(p)) /* * There is just one thread and it does not need to be woken. * It will dequeue unblocked signals before it runs again. */ return; else { /* * Otherwise try to find a suitable thread. */ t = signal->curr_target; while (!wants_signal(sig, t)) { t = next_thread(t); if (t == signal->curr_target) /* * No thread needs to be woken. * Any eligible threads will see * the signal in the queue soon. */ return; } signal->curr_target = t; } /* * Found a killable thread. If the signal will be fatal, * then start taking the whole group down immediately. */ if (sig_fatal(p, sig) && !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && !sigismember(&t->real_blocked, sig) && (sig == SIGKILL || !tracehook_consider_fatal_signal(t, sig))) { /* * This signal will be fatal to the whole group. */ if (!sig_kernel_coredump(sig)) { /* * Start a group exit and wake everybody up. * This way we don't have other threads * running and doing things after a slower * thread has the fatal signal pending. */ signal->flags = SIGNAL_GROUP_EXIT; signal->group_exit_code = sig; signal->group_stop_count = 0; t = p; do { sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); } while_each_thread(p, t); return; } } /* * The signal is already in the shared-pending queue. * Tell the chosen thread to wake up and dequeue it. */ signal_wake_up(t, sig == SIGKILL); return; } static inline int legacy_queue(struct sigpending *signals, int sig) { return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); } static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, int group, int from_ancestor_ns) { struct sigpending *pending; struct sigqueue *q; int override_rlimit; trace_signal_generate(sig, info, t); assert_spin_locked(&t->sighand->siglock); if (!prepare_signal(sig, t, from_ancestor_ns)) return 0; pending = group ? &t->signal->shared_pending : &t->pending; /* * Short-circuit ignored signals and support queuing * exactly one non-rt signal, so that we can get more * detailed information about the cause of the signal. */ if (legacy_queue(pending, sig)) return 0; /* * fast-pathed signals for kernel-internal things like SIGSTOP * or SIGKILL. */ if (info == SEND_SIG_FORCED) goto out_set; /* Real-time signals must be queued if sent by sigqueue, or some other real-time mechanism. It is implementation defined whether kill() does so. We attempt to do so, on the principle of least surprise, but since kill is not allowed to fail with EAGAIN when low on memory we just make sure at least one signal gets delivered and don't pass on the info struct. */ if (sig < SIGRTMIN) override_rlimit = (is_si_special(info) || info->si_code >= 0); else override_rlimit = 0; q = __sigqueue_alloc(sig, t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE, override_rlimit); if (q) { list_add_tail(&q->list, &pending->list); switch ((unsigned long) info) { 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 = task_tgid_nr_ns(current, task_active_pid_ns(t)); q->info.si_uid = current_uid(); break; case (unsigned long) SEND_SIG_PRIV: q->info.si_signo = sig; q->info.si_errno = 0; q->info.si_code = SI_KERNEL; q->info.si_pid = 0; q->info.si_uid = 0; break; default: copy_siginfo(&q->info, info); if (from_ancestor_ns) q->info.si_pid = 0; break; } } 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(). */ trace_signal_overflow_fail(sig, group, info); return -EAGAIN; } else { /* * This is a silent loss of information. We still * send the signal, but the *info bits are lost. */ trace_signal_lose_info(sig, group, info); } } out_set: signalfd_notify(t, sig); sigaddset(&pending->signal, sig); complete_signal(sig, t, group); return 0; } static int send_signal(int sig, struct siginfo *info, struct task_struct *t, int group) { int from_ancestor_ns = 0; #ifdef CONFIG_PID_NS from_ancestor_ns = si_fromuser(info) && !task_pid_nr_ns(current, task_active_pid_ns(t)); #endif return __send_signal(sig, info, t, group, from_ancestor_ns); } static void print_fatal_signal(struct pt_regs *regs, int signr) { printk("%s/%d: potentially unexpected fatal signal %d.\n", current->comm, task_pid_nr(current), signr); #if defined(__i386__) && !defined(__arch_um__) printk("code at %08lx: ", regs->ip); { int i; for (i = 0; i < 16; i++) { unsigned char insn; if (get_user(insn, (unsigned char *)(regs->ip + i))) break; printk("%02x ", insn); } } #endif printk("\n"); preempt_disable(); show_regs(regs); preempt_enable(); } static int __init setup_print_fatal_signals(char *str) { get_option (&str, &print_fatal_signals); return 1; } __setup("print-fatal-signals=", setup_print_fatal_signals); int __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { return send_signal(sig, info, p, 1); } static int specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) { return send_signal(sig, info, t, 0); } int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, bool group) { unsigned long flags; int ret = -ESRCH; if (lock_task_sighand(p, &flags)) { ret = send_signal(sig, info, p, group); unlock_task_sighand(p, &flags); } return ret; } /* * Force a signal that the process can't ignore: if necessary * we unblock the signal and change any SIG_IGN to SIG_DFL. * * Note: If we unblock the signal, we always reset it to SIG_DFL, * since we do not want to have a signal handler that was blocked * be invoked when user space had explicitly blocked it. * * We don't want to have recursive SIGSEGV's etc, for example, * that is why we also clear SIGNAL_UNKILLABLE. */ int force_sig_info(int sig, struct siginfo *info, struct task_struct *t) { unsigned long int flags; int ret, blocked, ignored; struct k_sigaction *action; spin_lock_irqsave(&t->sighand->siglock, flags); action = &t->sighand->action[sig-1]; ignored = action->sa.sa_handler == SIG_IGN; blocked = sigismember(&t->blocked, sig); if (blocked || ignored) { action->sa.sa_handler = SIG_DFL; if (blocked) { sigdelset(&t->blocked, sig); recalc_sigpending_and_wake(t); } } if (action->sa.sa_handler == SIG_DFL) t->signal->flags &= ~SIGNAL_UNKILLABLE; ret = specific_send_sig_info(sig, info, t); spin_unlock_irqrestore(&t->sighand->siglock, flags); return ret; } /* * Nuke all other threads in the group. */ int zap_other_threads(struct task_struct *p) { struct task_struct *t = p; int count = 0; p->signal->group_stop_count = 0; while_each_thread(p, t) { count++; /* Don't bother with already dead threads */ if (t->exit_state) continue; sigaddset(&t->pending.signal, SIGKILL); signal_wake_up(t, 1); } return count; } struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, unsigned long *flags) { struct sighand_struct *sighand; rcu_read_lock(); for (;;) { sighand = rcu_dereference(tsk->sighand); if (unlikely(sighand == NULL)) break; spin_lock_irqsave(&sighand->siglock, *flags); if (likely(sighand == tsk->sighand)) break; spin_unlock_irqrestore(&sighand->siglock, *flags); } rcu_read_unlock(); return sighand; } /* * send signal info to all the members of a group */ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { int ret; rcu_read_lock(); ret = check_kill_permission(sig, info, p); rcu_read_unlock(); if (!ret && sig) ret = do_send_sig_info(sig, info, p, true); return ret; } /* * __kill_pgrp_info() sends a signal to a process group: this is what the tty * control characters do (^C, ^Z etc) * - the caller must hold at least a readlock on tasklist_lock */ int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) { struct task_struct *p = NULL; int retval, success; success = 0; retval = -ESRCH; do_each_pid_task(pgrp, PIDTYPE_PGID, p) { int err = group_send_sig_info(sig, info, p); success |= !err; retval = err; } while_each_pid_task(pgrp, PIDTYPE_PGID, p); return success ? 0 : retval; } int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) { int error = -ESRCH; struct task_struct *p; rcu_read_lock(); retry: p = pid_task(pid, PIDTYPE_PID); if (p) { error = group_send_sig_info(sig, info, p); if (unlikely(error == -ESRCH)) /* * The task was unhashed in between, try again. * If it is dead, pid_task() will return NULL, * if we race with de_thread() it will find the * new leader. */ goto retry; } rcu_read_unlock(); return error; } int kill_proc_info(int sig, struct siginfo *info, pid_t pid) { int error; rcu_read_lock(); error = kill_pid_info(sig, info, find_vpid(pid)); rcu_read_unlock(); return error; } /* like kill_pid_info(), but doesn't use uid/euid of "current" */ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, uid_t uid, uid_t euid, u32 secid) { int ret = -EINVAL; struct task_struct *p; const struct cred *pcred; unsigned long flags; if (!valid_signal(sig)) return ret; rcu_read_lock(); p = pid_task(pid, PIDTYPE_PID); if (!p) { ret = -ESRCH; goto out_unlock; } pcred = __task_cred(p); if (si_fromuser(info) && euid != pcred->suid && euid != pcred->uid && uid != pcred->suid && uid != pcred->uid) { ret = -EPERM; goto out_unlock; } ret = security_task_kill(p, info, sig, secid); if (ret) goto out_unlock; if (sig) { if (lock_task_sighand(p, &flags)) { ret = __send_signal(sig, info, p, 1, 0); unlock_task_sighand(p, &flags); } else ret = -ESRCH; } out_unlock: rcu_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); /* * kill_something_info() interprets pid in interesting ways just like kill(2). * * POSIX specifies that kill(-1,sig) is unspecified, but what we have * is probably wrong. Should make it like BSD or SYSV. */ static int kill_something_info(int sig, struct siginfo *info, pid_t pid) { int ret; if (pid > 0) { rcu_read_lock(); ret = kill_pid_info(sig, info, find_vpid(pid)); rcu_read_unlock(); return ret; } read_lock(&tasklist_lock); if (pid != -1) { ret = __kill_pgrp_info(sig, info, pid ? find_vpid(-pid) : task_pgrp(current)); } else { int retval = 0, count = 0; struct task_struct * p; for_each_process(p) { if (task_pid_vnr(p) > 1 &&


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