media: dw9807-vcm: Add regulator support to the driver

[platform/kernel/linux-rpi.git] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index c7dbb19..0bbd89f 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1324,6 +1324,34 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t,
        struct k_sigaction *action;
        int sig = info->si_signo;
 
+       /*
+        * On some archs, PREEMPT_RT has to delay sending a signal from a trap
+        * since it can not enable preemption, and the signal code's spin_locks
+        * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
+        * send the signal on exit of the trap.
+        */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+       if (in_atomic()) {
+               struct task_struct *t = current;
+
+               if (WARN_ON_ONCE(t->forced_info.si_signo))
+                       return 0;
+
+               if (is_si_special(info)) {
+                       WARN_ON_ONCE(info != SEND_SIG_PRIV);
+                       t->forced_info.si_signo = info->si_signo;
+                       t->forced_info.si_errno = 0;
+                       t->forced_info.si_code = SI_KERNEL;
+                       t->forced_info.si_pid = 0;
+                       t->forced_info.si_uid = 0;
+               } else {
+                       t->forced_info = *info;
+               }
+
+               set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+               return 0;
+       }
+#endif
        spin_lock_irqsave(&t->sighand->siglock, flags);
        action = &t->sighand->action[sig-1];
        ignored = action->sa.sa_handler == SIG_IGN;
@@ -2308,16 +2336,8 @@ static void ptrace_stop(int exit_code, int why, int clear_code, kernel_siginfo_t
                if (gstop_done && ptrace_reparented(current))
                        do_notify_parent_cldstop(current, false, why);
 
-               /*
-                * Don't want to allow preemption here, because
-                * sys_ptrace() needs this task to be inactive.
-                *
-                * XXX: implement read_unlock_no_resched().
-                */
-               preempt_disable();
                read_unlock(&tasklist_lock);
                cgroup_enter_frozen();
-               preempt_enable_no_resched();
                freezable_schedule();
                cgroup_leave_frozen(true);
        } else {