Merge tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner...
[sfrench/cifs-2.6.git] / kernel / signal.c
index 268bed80244fe0c04d49214d5c3b3b867b451acd..b7953934aa994e7993254aa6b04438815ed37f1f 100644 (file)
@@ -690,6 +690,48 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, kernel_siginfo_t *in
 }
 EXPORT_SYMBOL_GPL(dequeue_signal);
 
+static int dequeue_synchronous_signal(kernel_siginfo_t *info)
+{
+       struct task_struct *tsk = current;
+       struct sigpending *pending = &tsk->pending;
+       struct sigqueue *q, *sync = NULL;
+
+       /*
+        * Might a synchronous signal be in the queue?
+        */
+       if (!((pending->signal.sig[0] & ~tsk->blocked.sig[0]) & SYNCHRONOUS_MASK))
+               return 0;
+
+       /*
+        * Return the first synchronous signal in the queue.
+        */
+       list_for_each_entry(q, &pending->list, list) {
+               /* Synchronous signals have a postive si_code */
+               if ((q->info.si_code > SI_USER) &&
+                   (sigmask(q->info.si_signo) & SYNCHRONOUS_MASK)) {
+                       sync = q;
+                       goto next;
+               }
+       }
+       return 0;
+next:
+       /*
+        * Check if there is another siginfo for the same signal.
+        */
+       list_for_each_entry_continue(q, &pending->list, list) {
+               if (q->info.si_signo == sync->info.si_signo)
+                       goto still_pending;
+       }
+
+       sigdelset(&pending->signal, sync->info.si_signo);
+       recalc_sigpending();
+still_pending:
+       list_del_init(&sync->list);
+       copy_siginfo(info, &sync->info);
+       __sigqueue_free(sync);
+       return info->si_signo;
+}
+
 /*
  * Tell a process that it has a new active signal..
  *
@@ -1059,10 +1101,9 @@ static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struc
 
        result = TRACE_SIGNAL_DELIVERED;
        /*
-        * Skip useless siginfo allocation for SIGKILL SIGSTOP,
-        * and kernel threads.
+        * Skip useless siginfo allocation for SIGKILL and kernel threads.
         */
-       if (sig_kernel_only(sig) || (t->flags & PF_KTHREAD))
+       if ((sig == SIGKILL) || (t->flags & PF_KTHREAD))
                goto out_set;
 
        /*
@@ -2396,6 +2437,14 @@ relock:
                goto relock;
        }
 
+       /* Has this task already been marked for death? */
+       if (signal_group_exit(signal)) {
+               ksig->info.si_signo = signr = SIGKILL;
+               sigdelset(&current->pending.signal, SIGKILL);
+               recalc_sigpending();
+               goto fatal;
+       }
+
        for (;;) {
                struct k_sigaction *ka;
 
@@ -2409,7 +2458,15 @@ relock:
                        goto relock;
                }
 
-               signr = dequeue_signal(current, &current->blocked, &ksig->info);
+               /*
+                * Signals generated by the execution of an instruction
+                * need to be delivered before any other pending signals
+                * so that the instruction pointer in the signal stack
+                * frame points to the faulting instruction.
+                */
+               signr = dequeue_synchronous_signal(&ksig->info);
+               if (!signr)
+                       signr = dequeue_signal(current, &current->blocked, &ksig->info);
 
                if (!signr)
                        break; /* will return 0 */
@@ -2491,6 +2548,7 @@ relock:
                        continue;
                }
 
+       fatal:
                spin_unlock_irq(&sighand->siglock);
 
                /*
@@ -3399,7 +3457,7 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time64, compat_sigset_t __user *, uthese,
 }
 
 #ifdef CONFIG_COMPAT_32BIT_TIME
-COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
+COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time32, compat_sigset_t __user *, uthese,
                struct compat_siginfo __user *, uinfo,
                struct old_timespec32 __user *, uts, compat_size_t, sigsetsize)
 {