perf probe: Fix memory leak when synthesizing SDT probes

[linux-2.6-microblaze.git] / lib / sbitmap.c

diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 267aa77..d693d92 100644 (file)
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -12,33 +12,24 @@
 /*
  * See if we have deferred clears that we can batch move
  */
-static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index)
+static inline bool sbitmap_deferred_clear(struct sbitmap_word *map)
 {
-       unsigned long mask, val;
-       bool ret = false;
-       unsigned long flags;
+       unsigned long mask;
 
-       spin_lock_irqsave(&sb->map[index].swap_lock, flags);
-
-       if (!sb->map[index].cleared)
-               goto out_unlock;
+       if (!READ_ONCE(map->cleared))
+               return false;
 
        /*
         * First get a stable cleared mask, setting the old mask to 0.
         */
-       mask = xchg(&sb->map[index].cleared, 0);
+       mask = xchg(&map->cleared, 0);
 
        /*
         * Now clear the masked bits in our free word
         */
-       do {
-               val = sb->map[index].word;
-       } while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val);
-
-       ret = true;
-out_unlock:
-       spin_unlock_irqrestore(&sb->map[index].swap_lock, flags);
-       return ret;
+       atomic_long_andnot(mask, (atomic_long_t *)&map->word);
+       BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word));
+       return true;
 }
 
 int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
@@ -80,7 +71,6 @@ int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
        for (i = 0; i < sb->map_nr; i++) {
                sb->map[i].depth = min(depth, bits_per_word);
                depth -= sb->map[i].depth;
-               spin_lock_init(&sb->map[i].swap_lock);
        }
        return 0;
 }
@@ -92,7 +82,7 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth)
        unsigned int i;
 
        for (i = 0; i < sb->map_nr; i++)
-               sbitmap_deferred_clear(sb, i);
+               sbitmap_deferred_clear(&sb->map[i]);
 
        sb->depth = depth;
        sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
@@ -107,9 +97,11 @@ EXPORT_SYMBOL_GPL(sbitmap_resize);
 static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
                              unsigned int hint, bool wrap)
 {
-       unsigned int orig_hint = hint;
        int nr;
 
+       /* don't wrap if starting from 0 */
+       wrap = wrap && hint;
+
        while (1) {
                nr = find_next_zero_bit(word, depth, hint);
                if (unlikely(nr >= depth)) {
@@ -118,8 +110,8 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
                         * offset to 0 in a failure case, so start from 0 to
                         * exhaust the map.
                         */
-                       if (orig_hint && hint && wrap) {
-                               hint = orig_hint = 0;
+                       if (hint && wrap) {
+                               hint = 0;
                                continue;
                        }
                        return -1;
@@ -139,15 +131,15 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
 static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
                                     unsigned int alloc_hint, bool round_robin)
 {
+       struct sbitmap_word *map = &sb->map[index];
        int nr;
 
        do {
-               nr = __sbitmap_get_word(&sb->map[index].word,
-                                       sb->map[index].depth, alloc_hint,
+               nr = __sbitmap_get_word(&map->word, map->depth, alloc_hint,
                                        !round_robin);
                if (nr != -1)
                        break;
-               if (!sbitmap_deferred_clear(sb, index))
+               if (!sbitmap_deferred_clear(map))
                        break;
        } while (1);
 
@@ -207,7 +199,7 @@ again:
                        break;
                }
 
-               if (sbitmap_deferred_clear(sb, index))
+               if (sbitmap_deferred_clear(&sb->map[index]))
                        goto again;
 
                /* Jump to next index. */