Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6

[linux-2.6-omap-h63xx.git] / kernel / marker.c

diff --git a/kernel/marker.c b/kernel/marker.c
index 7d1faecd7a51bd643cc1e10f0f2048765136bf16..e9c6b2bc9400627cf183382ee55933333f0ee83b 100644 (file)
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -62,7 +62,7 @@ struct marker_entry {
        int refcount;   /* Number of times armed. 0 if disarmed. */
        struct rcu_head rcu;
        void *oldptr;
-       unsigned char rcu_pending:1;
+       int rcu_pending;
        unsigned char ptype:1;
        char name[0];   /* Contains name'\0'format'\0' */
 };
@@ -103,11 +103,11 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
        char ptype;
 
        /*
-        * preempt_disable does two things : disabling preemption to make sure
-        * the teardown of the callbacks can be done correctly when they are in
-        * modules and they insure RCU read coherency.
+        * rcu_read_lock_sched does two things : disabling preemption to make
+        * sure the teardown of the callbacks can be done correctly when they
+        * are in modules and they insure RCU read coherency.
         */
-       preempt_disable();
+       rcu_read_lock_sched();
        ptype = mdata->ptype;
        if (likely(!ptype)) {
                marker_probe_func *func;
@@ -145,7 +145,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
                        va_end(args);
                }
        }
-       preempt_enable();
+       rcu_read_unlock_sched();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb);
 
@@ -162,7 +162,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
        va_list args;   /* not initialized */
        char ptype;
 
-       preempt_disable();
+       rcu_read_lock_sched();
        ptype = mdata->ptype;
        if (likely(!ptype)) {
                marker_probe_func *func;
@@ -195,7 +195,7 @@ void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
                        multi[i].func(multi[i].probe_private, call_private,
                                mdata->format, &args);
        }
-       preempt_enable();
+       rcu_read_unlock_sched();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb_noarg);
 
@@ -560,7 +560,7 @@ static int set_marker(struct marker_entry **entry, struct marker *elem,
  * Disable a marker and its probe callback.
  * Note: only waiting an RCU period after setting elem->call to the empty
  * function insures that the original callback is not used anymore. This insured
- * by preempt_disable around the call site.
+ * by rcu_read_lock_sched around the call site.
  */
 static void disable_marker(struct marker *elem)
 {
@@ -653,11 +653,17 @@ int marker_probe_register(const char *name, const char *format,
        entry = get_marker(name);
        if (!entry) {
                entry = add_marker(name, format);
-               if (IS_ERR(entry)) {
+               if (IS_ERR(entry))
                        ret = PTR_ERR(entry);
-                       goto end;
-               }
+       } else if (format) {
+               if (!entry->format)
+                       ret = marker_set_format(&entry, format);
+               else if (strcmp(entry->format, format))
+                       ret = -EPERM;
        }
+       if (ret)
+               goto end;
+
        /*
         * If we detect that a call_rcu is pending for this marker,
         * make sure it's executed now.
@@ -674,6 +680,8 @@ int marker_probe_register(const char *name, const char *format,
        mutex_lock(&markers_mutex);
        entry = get_marker(name);
        WARN_ON(!entry);
+       if (entry->rcu_pending)
+               rcu_barrier_sched();
        entry->oldptr = old;
        entry->rcu_pending = 1;
        /* write rcu_pending before calling the RCU callback */
@@ -717,6 +725,8 @@ int marker_probe_unregister(const char *name,
        entry = get_marker(name);
        if (!entry)
                goto end;
+       if (entry->rcu_pending)
+               rcu_barrier_sched();
        entry->oldptr = old;
        entry->rcu_pending = 1;
        /* write rcu_pending before calling the RCU callback */
@@ -795,6 +805,8 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
        mutex_lock(&markers_mutex);
        entry = get_marker_from_private_data(probe, probe_private);
        WARN_ON(!entry);
+       if (entry->rcu_pending)
+               rcu_barrier_sched();
        entry->oldptr = old;
        entry->rcu_pending = 1;
        /* write rcu_pending before calling the RCU callback */