staging: zsmalloc: zsmalloc: use unsigned long instead of void *

We should use unsigned long as handle instead of void * to avoid any
confusion. Without this, users may just treat zs_malloc return value as
a pointer and try to deference it.

This patch passed compile test(zram, zcache and ramster) and zram is
tested on qemu.

changelog
  * from v2
	- remove hval pointed out by Nitin
	- based on next-20120607
  * from v1
	- change zcache's zv_create return value
	- baesd on next-20120604

Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 2734dac..d0141fb 100644 (file)
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -693,14 +693,14 @@ static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5;
 static atomic_t zv_curr_dist_counts[NCHUNKS];
 static atomic_t zv_cumul_dist_counts[NCHUNKS];
 
-static struct zv_hdr *zv_create(struct zs_pool *pool, uint32_t pool_id,
+static unsigned long zv_create(struct zs_pool *pool, uint32_t pool_id,
                                struct tmem_oid *oid, uint32_t index,
                                void *cdata, unsigned clen)
 {
        struct zv_hdr *zv;
        u32 size = clen + sizeof(struct zv_hdr);
        int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT;
-       void *handle = NULL;
+       unsigned long handle = 0;
 
        BUG_ON(!irqs_disabled());
        BUG_ON(chunks >= NCHUNKS);
@@ -721,7 +721,7 @@ out:
        return handle;
 }
 
-static void zv_free(struct zs_pool *pool, void *handle)
+static void zv_free(struct zs_pool *pool, unsigned long handle)
 {
        unsigned long flags;
        struct zv_hdr *zv;
@@ -743,7 +743,7 @@ static void zv_free(struct zs_pool *pool, void *handle)
        local_irq_restore(flags);
 }
 
-static void zv_decompress(struct page *page, void *handle)
+static void zv_decompress(struct page *page, unsigned long handle)
 {
        unsigned int clen = PAGE_SIZE;
        char *to_va;
@@ -1247,7 +1247,7 @@ static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw,
        int ret = 0;
 
        BUG_ON(is_ephemeral(pool));
-       zv_decompress((struct page *)(data), pampd);
+       zv_decompress((struct page *)(data), (unsigned long)pampd);
        return ret;
 }
 
@@ -1282,7 +1282,7 @@ static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
                atomic_dec(&zcache_curr_eph_pampd_count);
                BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0);
        } else {
-               zv_free(cli->zspool, pampd);
+               zv_free(cli->zspool, (unsigned long)pampd);
                atomic_dec(&zcache_curr_pers_pampd_count);
                BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0);
        }

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 685d612..abd69d1 100644 (file)
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -135,7 +135,7 @@ static void zram_set_disksize(struct zram *zram, size_t totalram_bytes)
 
 static void zram_free_page(struct zram *zram, size_t index)
 {
-       void *handle = zram->table[index].handle;
+       unsigned long handle = zram->table[index].handle;
 
        if (unlikely(!handle)) {
                /*
@@ -150,7 +150,7 @@ static void zram_free_page(struct zram *zram, size_t index)
        }
 
        if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
-               __free_page(handle);
+               __free_page((struct page *)handle);
                zram_clear_flag(zram, index, ZRAM_UNCOMPRESSED);
                zram_stat_dec(&zram->stats.pages_expand);
                goto out;
@@ -166,7 +166,7 @@ out:
                        zram->table[index].size);
        zram_stat_dec(&zram->stats.pages_stored);
 
-       zram->table[index].handle = NULL;
+       zram->table[index].handle = 0;
        zram->table[index].size = 0;
 }
 
@@ -189,7 +189,7 @@ static void handle_uncompressed_page(struct zram *zram, struct bio_vec *bvec,
        unsigned char *user_mem, *cmem;
 
        user_mem = kmap_atomic(page);
-       cmem = kmap_atomic(zram->table[index].handle);
+       cmem = kmap_atomic((struct page *)zram->table[index].handle);
 
        memcpy(user_mem + bvec->bv_offset, cmem + offset, bvec->bv_len);
        kunmap_atomic(cmem);
@@ -317,7 +317,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
        int ret;
        u32 store_offset;
        size_t clen;
-       void *handle;
+       unsigned long handle;
        struct zobj_header *zheader;
        struct page *page, *page_store;
        unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
@@ -399,7 +399,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
                store_offset = 0;
                zram_set_flag(zram, index, ZRAM_UNCOMPRESSED);
                zram_stat_inc(&zram->stats.pages_expand);
-               handle = page_store;
+               handle = (unsigned long)page_store;
                src = kmap_atomic(page);
                cmem = kmap_atomic(page_store);
                goto memstore;
@@ -592,12 +592,12 @@ void __zram_reset_device(struct zram *zram)
 
        /* Free all pages that are still in this zram device */
        for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) {
-               void *handle = zram->table[index].handle;
+               unsigned long handle = zram->table[index].handle;
                if (!handle)
                        continue;
 
                if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)))
-                       __free_page(handle);
+                       __free_page((struct page *)handle);
                else
                        zs_free(zram->mem_pool, handle);
        }

diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index fbe8ac9..7a7e256 100644 (file)
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -81,7 +81,7 @@ enum zram_pageflags {
 
 /* Allocated for each disk page */
 struct table {
-       void *handle;
+       unsigned long handle;
        u16 size;       /* object size (excluding header) */
        u8 count;       /* object ref count (not yet used) */
        u8 flags;

diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c
index 4496737..8e830ee 100644 (file)
--- a/drivers/staging/zsmalloc/zsmalloc-main.c
+++ b/drivers/staging/zsmalloc/zsmalloc-main.c
@@ -247,13 +247,11 @@ static void *obj_location_to_handle(struct page *page, unsigned long obj_idx)
 }
 
 /* Decode <page, obj_idx> pair from the given object handle */
-static void obj_handle_to_location(void *handle, struct page **page,
+static void obj_handle_to_location(unsigned long handle, struct page **page,
                                unsigned long *obj_idx)
 {
-       unsigned long hval = (unsigned long)handle;
-
-       *page = pfn_to_page(hval >> OBJ_INDEX_BITS);
-       *obj_idx = hval & OBJ_INDEX_MASK;
+       *page = pfn_to_page(handle >> OBJ_INDEX_BITS);
+       *obj_idx = handle & OBJ_INDEX_MASK;
 }
 
 static unsigned long obj_idx_to_offset(struct page *page,
@@ -568,12 +566,12 @@ EXPORT_SYMBOL_GPL(zs_destroy_pool);
  * @size: size of block to allocate
  *
  * On success, handle to the allocated object is returned,
- * otherwise NULL.
+ * otherwise 0.
  * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail.
  */
-void *zs_malloc(struct zs_pool *pool, size_t size)
+unsigned long zs_malloc(struct zs_pool *pool, size_t size)
 {
-       void *obj;
+       unsigned long obj;
        struct link_free *link;
        int class_idx;
        struct size_class *class;
@@ -582,7 +580,7 @@ void *zs_malloc(struct zs_pool *pool, size_t size)
        unsigned long m_objidx, m_offset;
 
        if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE))
-               return NULL;
+               return 0;
 
        class_idx = get_size_class_index(size);
        class = &pool->size_class[class_idx];
@@ -595,14 +593,14 @@ void *zs_malloc(struct zs_pool *pool, size_t size)
                spin_unlock(&class->lock);
                first_page = alloc_zspage(class, pool->flags);
                if (unlikely(!first_page))
-                       return NULL;
+                       return 0;
 
                set_zspage_mapping(first_page, class->index, ZS_EMPTY);
                spin_lock(&class->lock);
                class->pages_allocated += class->pages_per_zspage;
        }
 
-       obj = first_page->freelist;
+       obj = (unsigned long)first_page->freelist;
        obj_handle_to_location(obj, &m_page, &m_objidx);
        m_offset = obj_idx_to_offset(m_page, m_objidx, class->size);
 
@@ -621,7 +619,7 @@ void *zs_malloc(struct zs_pool *pool, size_t size)
 }
 EXPORT_SYMBOL_GPL(zs_malloc);
 
-void zs_free(struct zs_pool *pool, void *obj)
+void zs_free(struct zs_pool *pool, unsigned long obj)
 {
        struct link_free *link;
        struct page *first_page, *f_page;
@@ -648,7 +646,7 @@ void zs_free(struct zs_pool *pool, void *obj)
                                                        + f_offset);
        link->next = first_page->freelist;
        kunmap_atomic(link);
-       first_page->freelist = obj;
+       first_page->freelist = (void *)obj;
 
        first_page->inuse--;
        fullness = fix_fullness_group(pool, first_page);
@@ -672,7 +670,7 @@ EXPORT_SYMBOL_GPL(zs_free);
  * this function. When done with the object, it must be unmapped using
  * zs_unmap_object
 */
-void *zs_map_object(struct zs_pool *pool, void *handle)
+void *zs_map_object(struct zs_pool *pool, unsigned long handle)
 {
        struct page *page;
        unsigned long obj_idx, off;
@@ -712,7 +710,7 @@ void *zs_map_object(struct zs_pool *pool, void *handle)
 }
 EXPORT_SYMBOL_GPL(zs_map_object);
 
-void zs_unmap_object(struct zs_pool *pool, void *handle)
+void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
 {
        struct page *page;
        unsigned long obj_idx, off;

diff --git a/drivers/staging/zsmalloc/zsmalloc.h b/drivers/staging/zsmalloc/zsmalloc.h
index 949384e..485cbb1 100644 (file)
--- a/drivers/staging/zsmalloc/zsmalloc.h
+++ b/drivers/staging/zsmalloc/zsmalloc.h
@@ -20,11 +20,11 @@ struct zs_pool;
 struct zs_pool *zs_create_pool(const char *name, gfp_t flags);
 void zs_destroy_pool(struct zs_pool *pool);
 
-void *zs_malloc(struct zs_pool *pool, size_t size);
-void zs_free(struct zs_pool *pool, void *obj);
+unsigned long zs_malloc(struct zs_pool *pool, size_t size);
+void zs_free(struct zs_pool *pool, unsigned long obj);
 
-void *zs_map_object(struct zs_pool *pool, void *handle);
-void zs_unmap_object(struct zs_pool *pool, void *handle);
+void *zs_map_object(struct zs_pool *pool, unsigned long handle);
+void zs_unmap_object(struct zs_pool *pool, unsigned long handle);
 
 u64 zs_get_total_size_bytes(struct zs_pool *pool);