[PARISC] futex: special case cmpxchg NULL in kernel space

[sfrench/cifs-2.6.git] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index 84917fe507f77b8ff949af7f958e11ac2ed423b7..6af1210092c39a45db3552ecc9199728f8938410 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1623,7 +1623,6 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
        /* Let the debugger run.  */
        __set_current_state(TASK_TRACED);
        spin_unlock_irq(&current->sighand->siglock);
-       try_to_freeze();
        read_lock(&tasklist_lock);
        if (!unlikely(killed) && may_ptrace_stop()) {
                do_notify_parent_cldstop(current, CLD_TRAPPED);
@@ -1640,6 +1639,13 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
                read_unlock(&tasklist_lock);
        }
 
+       /*
+        * While in TASK_TRACED, we were considered "frozen enough".
+        * Now that we woke up, it's crucial if we're supposed to be
+        * frozen that we freeze now before running anything substantial.
+        */
+       try_to_freeze();
+
        /*
         * We are back.  Now reacquire the siglock before touching
         * last_siginfo, so that we are sure to have synchronized with
@@ -1757,9 +1763,15 @@ int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
        sigset_t *mask = &current->blocked;
        int signr = 0;
 
+relock:
+       /*
+        * We'll jump back here after any time we were stopped in TASK_STOPPED.
+        * While in TASK_STOPPED, we were considered "frozen enough".
+        * Now that we woke up, it's crucial if we're supposed to be
+        * frozen that we freeze now before running anything substantial.
+        */
        try_to_freeze();
 
-relock:
        spin_lock_irq(&current->sighand->siglock);
        for (;;) {
                struct k_sigaction *ka;