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-rw-r--r--kernel/signal.c108
1 files changed, 52 insertions, 56 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index ded28b91fa5..a4077e90f19 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -33,6 +33,8 @@
#include <linux/uprobes.h>
#include <linux/compat.h>
#include <linux/cn_proc.h>
+#include <linux/compiler.h>
+
#define CREATE_TRACE_POINTS
#include <trace/events/signal.h>
@@ -275,6 +277,7 @@ void task_clear_jobctl_trapping(struct task_struct *task)
{
if (unlikely(task->jobctl & JOBCTL_TRAPPING)) {
task->jobctl &= ~JOBCTL_TRAPPING;
+ smp_mb(); /* advised by wake_up_bit() */
wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT);
}
}
@@ -703,11 +706,8 @@ void signal_wake_up_state(struct task_struct *t, unsigned int state)
* 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)
+static int flush_sigqueue_mask(sigset_t *mask, struct sigpending *s)
{
struct sigqueue *q, *n;
sigset_t m;
@@ -725,29 +725,6 @@ static int rm_from_queue_full(sigset_t *mask, struct sigpending *s)
}
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)
{
@@ -859,6 +836,7 @@ static bool prepare_signal(int sig, struct task_struct *p, bool force)
{
struct signal_struct *signal = p->signal;
struct task_struct *t;
+ sigset_t flush;
if (signal->flags & (SIGNAL_GROUP_EXIT | SIGNAL_GROUP_COREDUMP)) {
if (signal->flags & SIGNAL_GROUP_COREDUMP)
@@ -870,26 +848,25 @@ static bool prepare_signal(int sig, struct task_struct *p, bool force)
/*
* 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);
+ siginitset(&flush, sigmask(SIGCONT));
+ flush_sigqueue_mask(&flush, &signal->shared_pending);
+ for_each_thread(p, t)
+ flush_sigqueue_mask(&flush, &t->pending);
} else if (sig == SIGCONT) {
unsigned int why;
/*
* Remove all stop signals from all queues, wake all threads.
*/
- rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending);
- t = p;
- do {
+ siginitset(&flush, SIG_KERNEL_STOP_MASK);
+ flush_sigqueue_mask(&flush, &signal->shared_pending);
+ for_each_thread(p, t) {
+ flush_sigqueue_mask(&flush, &t->pending);
task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING);
- rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
if (likely(!(t->ptrace & PT_SEIZED)))
wake_up_state(t, __TASK_STOPPED);
else
ptrace_trap_notify(t);
- } while_each_thread(p, t);
+ }
/*
* Notify the parent with CLD_CONTINUED if we were stopped.
@@ -2047,8 +2024,8 @@ static bool do_signal_stop(int signr)
if (task_set_jobctl_pending(current, signr | gstop))
sig->group_stop_count++;
- for (t = next_thread(current); t != current;
- t = next_thread(t)) {
+ t = current;
+ while_each_thread(current, t) {
/*
* Setting state to TASK_STOPPED for a group
* stop is always done with the siglock held,
@@ -2382,7 +2359,7 @@ relock:
* @regs: user register state
* @stepping: nonzero if debugger single-step or block-step in use
*
- * This function should be called when a signal has succesfully been
+ * This function should be called when a signal has successfully been
* delivered. It updates the blocked signals accordingly (@ka->sa.sa_mask
* is always blocked, and the signal itself is blocked unless %SA_NODEFER
* is set in @ka->sa.sa_flags. Tracing is notified.
@@ -2723,7 +2700,7 @@ COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset,
#ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
-int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from)
+int copy_siginfo_to_user(siginfo_t __user *to, const siginfo_t *from)
{
int err;
@@ -2852,7 +2829,7 @@ int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
spin_lock_irq(&tsk->sighand->siglock);
__set_task_blocked(tsk, &tsk->real_blocked);
- siginitset(&tsk->real_blocked, 0);
+ sigemptyset(&tsk->real_blocked);
sig = dequeue_signal(tsk, &mask, info);
}
spin_unlock_irq(&tsk->sighand->siglock);
@@ -3089,18 +3066,39 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo,
}
#endif
+/*
+ * For kthreads only, must not be used if cloned with CLONE_SIGHAND
+ */
+void kernel_sigaction(int sig, __sighandler_t action)
+{
+ spin_lock_irq(&current->sighand->siglock);
+ current->sighand->action[sig - 1].sa.sa_handler = action;
+ if (action == SIG_IGN) {
+ sigset_t mask;
+
+ sigemptyset(&mask);
+ sigaddset(&mask, sig);
+
+ flush_sigqueue_mask(&mask, &current->signal->shared_pending);
+ flush_sigqueue_mask(&mask, &current->pending);
+ recalc_sigpending();
+ }
+ spin_unlock_irq(&current->sighand->siglock);
+}
+EXPORT_SYMBOL(kernel_sigaction);
+
int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
{
- struct task_struct *t = current;
+ struct task_struct *p = current, *t;
struct k_sigaction *k;
sigset_t mask;
if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig)))
return -EINVAL;
- k = &t->sighand->action[sig-1];
+ k = &p->sighand->action[sig-1];
- spin_lock_irq(&current->sighand->siglock);
+ spin_lock_irq(&p->sighand->siglock);
if (oact)
*oact = *k;
@@ -3119,22 +3117,20 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
* (for example, SIGCHLD), shall cause the pending signal to
* be discarded, whether or not it is blocked"
*/
- if (sig_handler_ignored(sig_handler(t, sig), sig)) {
+ if (sig_handler_ignored(sig_handler(p, sig), sig)) {
sigemptyset(&mask);
sigaddset(&mask, sig);
- rm_from_queue_full(&mask, &t->signal->shared_pending);
- do {
- rm_from_queue_full(&mask, &t->pending);
- t = next_thread(t);
- } while (t != current);
+ flush_sigqueue_mask(&mask, &p->signal->shared_pending);
+ for_each_thread(p, t)
+ flush_sigqueue_mask(&mask, &t->pending);
}
}
- spin_unlock_irq(&current->sighand->siglock);
+ spin_unlock_irq(&p->sighand->siglock);
return 0;
}
-static int
+static int
do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp)
{
stack_t oss;
@@ -3495,7 +3491,7 @@ COMPAT_SYSCALL_DEFINE3(sigaction, int, sig,
}
#endif
-#ifdef __ARCH_WANT_SYS_SGETMASK
+#ifdef CONFIG_SGETMASK_SYSCALL
/*
* For backwards compatibility. Functionality superseded by sigprocmask.
@@ -3516,7 +3512,7 @@ SYSCALL_DEFINE1(ssetmask, int, newmask)
return old;
}
-#endif /* __ARCH_WANT_SGETMASK */
+#endif /* CONFIG_SGETMASK_SYSCALL */
#ifdef __ARCH_WANT_SYS_SIGNAL
/*
@@ -3619,7 +3615,7 @@ SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask)
}
#endif
-__attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma)
+__weak const char *arch_vma_name(struct vm_area_struct *vma)
{
return NULL;
}
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