]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/marker.c
vmemmap: warn about page_structs with remote distance
[linux-2.6-omap-h63xx.git] / kernel / marker.c
index b5a9fe1d50d5ce1c480ca7ca1777e55e6deb485e..e9c6b2bc9400627cf183382ee55933333f0ee83b 100644 (file)
@@ -55,14 +55,14 @@ static DEFINE_MUTEX(markers_mutex);
 struct marker_entry {
        struct hlist_node hlist;
        char *format;
-       void (*call)(const struct marker *mdata,        /* Probe wrapper */
-               void *call_private, const char *fmt, ...);
+                       /* Probe wrapper */
+       void (*call)(const struct marker *mdata, void *call_private, ...);
        struct marker_probe_closure single;
        struct marker_probe_closure *multi;
        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' */
 };
@@ -91,25 +91,23 @@ EXPORT_SYMBOL_GPL(__mark_empty_function);
  * marker_probe_cb Callback that prepares the variable argument list for probes.
  * @mdata: pointer of type struct marker
  * @call_private: caller site private data
- * @fmt: format string
  * @...:  Variable argument list.
  *
  * Since we do not use "typical" pointer based RCU in the 1 argument case, we
  * need to put a full smp_rmb() in this branch. This is why we do not use
  * rcu_dereference() for the pointer read.
  */
-void marker_probe_cb(const struct marker *mdata, void *call_private,
-       const char *fmt, ...)
+void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
 {
        va_list args;
        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;
@@ -120,12 +118,18 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
                /* Must read the ptr before private data. They are not data
                 * dependant, so we put an explicit smp_rmb() here. */
                smp_rmb();
-               va_start(args, fmt);
-               func(mdata->single.probe_private, call_private, fmt, &args);
+               va_start(args, call_private);
+               func(mdata->single.probe_private, call_private, mdata->format,
+                       &args);
                va_end(args);
        } else {
                struct marker_probe_closure *multi;
                int i;
+               /*
+                * Read mdata->ptype before mdata->multi.
+                */
+               smp_rmb();
+               multi = mdata->multi;
                /*
                 * multi points to an array, therefore accessing the array
                 * depends on reading multi. However, even in this case,
@@ -134,15 +138,14 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
                 * in the fast path, so put the explicit barrier here.
                 */
                smp_read_barrier_depends();
-               multi = mdata->multi;
                for (i = 0; multi[i].func; i++) {
-                       va_start(args, fmt);
-                       multi[i].func(multi[i].probe_private, call_private, fmt,
-                               &args);
+                       va_start(args, call_private);
+                       multi[i].func(multi[i].probe_private, call_private,
+                               mdata->format, &args);
                        va_end(args);
                }
        }
-       preempt_enable();
+       rcu_read_unlock_sched();
 }
 EXPORT_SYMBOL_GPL(marker_probe_cb);
 
@@ -150,18 +153,16 @@ EXPORT_SYMBOL_GPL(marker_probe_cb);
  * marker_probe_cb Callback that does not prepare the variable argument list.
  * @mdata: pointer of type struct marker
  * @call_private: caller site private data
- * @fmt: format string
  * @...:  Variable argument list.
  *
  * Should be connected to markers "MARK_NOARGS".
  */
-void marker_probe_cb_noarg(const struct marker *mdata,
-       void *call_private, const char *fmt, ...)
+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;
@@ -172,10 +173,16 @@ void marker_probe_cb_noarg(const struct marker *mdata,
                /* Must read the ptr before private data. They are not data
                 * dependant, so we put an explicit smp_rmb() here. */
                smp_rmb();
-               func(mdata->single.probe_private, call_private, fmt, &args);
+               func(mdata->single.probe_private, call_private, mdata->format,
+                       &args);
        } else {
                struct marker_probe_closure *multi;
                int i;
+               /*
+                * Read mdata->ptype before mdata->multi.
+                */
+               smp_rmb();
+               multi = mdata->multi;
                /*
                 * multi points to an array, therefore accessing the array
                 * depends on reading multi. However, even in this case,
@@ -184,12 +191,11 @@ void marker_probe_cb_noarg(const struct marker *mdata,
                 * in the fast path, so put the explicit barrier here.
                 */
                smp_read_barrier_depends();
-               multi = mdata->multi;
                for (i = 0; multi[i].func; i++)
-                       multi[i].func(multi[i].probe_private, call_private, fmt,
-                               &args);
+                       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);
 
@@ -443,7 +449,7 @@ static int remove_marker(const char *name)
        hlist_del(&e->hlist);
        /* Make sure the call_rcu has been executed */
        if (e->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        kfree(e);
        return 0;
 }
@@ -478,7 +484,7 @@ static int marker_set_format(struct marker_entry **entry, const char *format)
        hlist_del(&(*entry)->hlist);
        /* Make sure the call_rcu has been executed */
        if ((*entry)->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        kfree(*entry);
        *entry = e;
        trace_mark(core_marker_format, "name %s format %s",
@@ -554,7 +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)
 {
@@ -647,17 +653,23 @@ 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.
         */
        if (entry->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        old = marker_entry_add_probe(entry, probe, probe_private);
        if (IS_ERR(old)) {
                ret = PTR_ERR(old);
@@ -668,14 +680,13 @@ 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 */
        smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-       synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-       call_rcu(&entry->rcu, free_old_closure);
+       call_rcu_sched(&entry->rcu, free_old_closure);
 end:
        mutex_unlock(&markers_mutex);
        return ret;
@@ -706,7 +717,7 @@ int marker_probe_unregister(const char *name,
        if (!entry)
                goto end;
        if (entry->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        old = marker_entry_remove_probe(entry, probe, probe_private);
        mutex_unlock(&markers_mutex);
        marker_update_probes();         /* may update entry */
@@ -714,14 +725,13 @@ 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 */
        smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-       synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-       call_rcu(&entry->rcu, free_old_closure);
+       call_rcu_sched(&entry->rcu, free_old_closure);
        remove_marker(name);    /* Ignore busy error message */
        ret = 0;
 end:
@@ -788,21 +798,20 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
                goto end;
        }
        if (entry->rcu_pending)
-               rcu_barrier();
+               rcu_barrier_sched();
        old = marker_entry_remove_probe(entry, NULL, probe_private);
        mutex_unlock(&markers_mutex);
        marker_update_probes();         /* may update entry */
        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 */
        smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-       synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-       call_rcu(&entry->rcu, free_old_closure);
+       call_rcu_sched(&entry->rcu, free_old_closure);
        remove_marker(entry->name);     /* Ignore busy error message */
 end:
        mutex_unlock(&markers_mutex);