kasan: avoid overflowing quarantine size on low memory systems

[cascardo/linux.git] / mm / zsmalloc.c

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 72e0b29..b0bc023 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -20,6 +20,7 @@
  *     page->freelist(index): links together all component pages of a zspage
  *             For the huge page, this is always 0, so we use this field
  *             to store handle.
+ *     page->units: first object offset in a subpage of zspage
  *
  * Usage of struct page flags:
  *     PG_private: identifies the first component page
@@ -137,9 +138,6 @@
  */
 #define ZS_SIZE_CLASS_DELTA    (PAGE_SIZE >> CLASS_BITS)
 
-/*
- * We do not maintain any list for completely empty or full pages
- */
 enum fullness_group {
        ZS_EMPTY,
        ZS_ALMOST_EMPTY,
@@ -467,11 +465,6 @@ static struct zpool_driver zs_zpool_driver = {
 MODULE_ALIAS("zpool-zsmalloc");
 #endif /* CONFIG_ZPOOL */
 
-static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage)
-{
-       return pages_per_zspage * PAGE_SIZE / size;
-}
-
 /* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
 static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
 
@@ -944,8 +937,8 @@ static void unpin_tag(unsigned long handle)
 static void reset_page(struct page *page)
 {
        __ClearPageMovable(page);
-       clear_bit(PG_private, &page->flags);
-       clear_bit(PG_private_2, &page->flags);
+       ClearPagePrivate(page);
+       ClearPagePrivate2(page);
        set_page_private(page, 0);
        page_mapcount_reset(page);
        ClearPageHugeObject(page);
@@ -1348,7 +1341,7 @@ static void zs_unregister_cpu_notifier(void)
        cpu_notifier_register_done();
 }
 
-static void init_zs_size_classes(void)
+static void __init init_zs_size_classes(void)
 {
        int nr;
 
@@ -1359,16 +1352,14 @@ static void init_zs_size_classes(void)
        zs_size_classes = nr;
 }
 
-static bool can_merge(struct size_class *prev, int size, int pages_per_zspage)
+static bool can_merge(struct size_class *prev, int pages_per_zspage,
+                                       int objs_per_zspage)
 {
-       if (prev->pages_per_zspage != pages_per_zspage)
-               return false;
-
-       if (prev->objs_per_zspage
-               != get_maxobj_per_zspage(size, pages_per_zspage))
-               return false;
+       if (prev->pages_per_zspage == pages_per_zspage &&
+               prev->objs_per_zspage == objs_per_zspage)
+               return true;
 
-       return true;
+       return false;
 }
 
 static bool zspage_full(struct size_class *class, struct zspage *zspage)
@@ -1539,6 +1530,7 @@ static unsigned long obj_malloc(struct size_class *class,
  * zs_malloc - Allocate block of given size from pool.
  * @pool: pool to allocate from
  * @size: size of block to allocate
+ * @gfp: gfp flags when allocating object
  *
  * On success, handle to the allocated object is returned,
  * otherwise 0.
@@ -2182,8 +2174,7 @@ static int zs_register_migration(struct zs_pool *pool)
 static void zs_unregister_migration(struct zs_pool *pool)
 {
        flush_work(&pool->free_work);
-       if (pool->inode)
-               iput(pool->inode);
+       iput(pool->inode);
 }
 
 /*
@@ -2398,7 +2389,7 @@ static int zs_register_shrinker(struct zs_pool *pool)
 
 /**
  * zs_create_pool - Creates an allocation pool to work from.
- * @flags: allocation flags used to allocate pool metadata
+ * @name: pool name to be created
  *
  * This function must be called before anything when using
  * the zsmalloc allocator.
@@ -2438,6 +2429,7 @@ struct zs_pool *zs_create_pool(const char *name)
        for (i = zs_size_classes - 1; i >= 0; i--) {
                int size;
                int pages_per_zspage;
+               int objs_per_zspage;
                struct size_class *class;
                int fullness = 0;
 
@@ -2445,6 +2437,7 @@ struct zs_pool *zs_create_pool(const char *name)
                if (size > ZS_MAX_ALLOC_SIZE)
                        size = ZS_MAX_ALLOC_SIZE;
                pages_per_zspage = get_pages_per_zspage(size);
+               objs_per_zspage = pages_per_zspage * PAGE_SIZE / size;
 
                /*
                 * size_class is used for normal zsmalloc operation such
@@ -2456,7 +2449,7 @@ struct zs_pool *zs_create_pool(const char *name)
                 * previous size_class if possible.
                 */
                if (prev_class) {
-                       if (can_merge(prev_class, size, pages_per_zspage)) {
+                       if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) {
                                pool->size_class[i] = prev_class;
                                continue;
                        }
@@ -2469,8 +2462,7 @@ struct zs_pool *zs_create_pool(const char *name)
                class->size = size;
                class->index = i;
                class->pages_per_zspage = pages_per_zspage;
-               class->objs_per_zspage = get_maxobj_per_zspage(class->size,
-                                                       class->pages_per_zspage);
+               class->objs_per_zspage = objs_per_zspage;
                spin_lock_init(&class->lock);
                pool->size_class[i] = class;
                for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS;