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DRM: Replace kmalloc/memset combos with kzalloc

PATCH In review Davidlohr Bueso 3 participants 4 messages Aug 11, 2010 – Aug 12, 2010

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Davidlohr Bueso

author
#0 lore raw

PATCH 1/1 DRM: Replace kmalloc/memset combos with kzalloc

Currently most, if not all, memory allocation in drm_bufs.c is followed by initializing the memory with 0.

Replace the use of kmalloc+memset with kzalloc.

Signed-off-by Davidlohr Bueso <[email protected]>
---
 drivers/gpu/drm/drm_bufs.c |   33 +++++++++++----------------------
 1 files changed, 11 insertions(+), 22 deletions(-)
drivers/gpu/drm/drm_bufs.c +11 -22
index a5c9ce9..3e257a5 100644
@@ -328,14 +328,13 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
 		return -EINVAL;
 	}
 
-	list = kmalloc(sizeof(*list), GFP_KERNEL);
+	list = kzalloc(sizeof(*list), GFP_KERNEL);
 	if (!list) {
 		if (map->type == _DRM_REGISTERS)
 			iounmap(map->handle);
 		kfree(map);
 		return -EINVAL;
 	}
-	memset(list, 0, sizeof(*list));
 	list->map = map;
 
 	mutex_lock(&dev->struct_mutex);

@@ -678,13 +677,12 @@ int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
 		return -EINVAL;
 	}
 
-	entry->buflist = kmalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
 	if (!entry->buflist) {
 		mutex_unlock(&dev->struct_mutex);
 		atomic_dec(&dev->buf_alloc);
 		return -ENOMEM;
 	}
-	memset(entry->buflist, 0, count * sizeof(*entry->buflist));
 
 	entry->buf_size = size;
 	entry->page_order = page_order;

@@ -708,7 +706,7 @@ int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
 		buf->file_priv = NULL;
 
 		buf->dev_priv_size = dev->driver->dev_priv_size;
-		buf->dev_private = kmalloc(buf->dev_priv_size, GFP_KERNEL);
+		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
 		if (!buf->dev_private) {
 			/* Set count correctly so we free the proper amount. */
 			entry->buf_count = count;

@@ -717,7 +715,6 @@ int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
 			atomic_dec(&dev->buf_alloc);
 			return -ENOMEM;
 		}
-		memset(buf->dev_private, 0, buf->dev_priv_size);
 
 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
 

@@ -832,22 +829,20 @@ int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
 		return -EINVAL;
 	}
 
-	entry->buflist = kmalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
 	if (!entry->buflist) {
 		mutex_unlock(&dev->struct_mutex);
 		atomic_dec(&dev->buf_alloc);
 		return -ENOMEM;
 	}
-	memset(entry->buflist, 0, count * sizeof(*entry->buflist));
 
-	entry->seglist = kmalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
+	entry->seglist = kzalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
 	if (!entry->seglist) {
 		kfree(entry->buflist);
 		mutex_unlock(&dev->struct_mutex);
 		atomic_dec(&dev->buf_alloc);
 		return -ENOMEM;
 	}
-	memset(entry->seglist, 0, count * sizeof(*entry->seglist));
 
 	/* Keep the original pagelist until we know all the allocations
 	 * have succeeded

@@ -911,8 +906,8 @@ int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
 			buf->file_priv = NULL;
 
 			buf->dev_priv_size = dev->driver->dev_priv_size;
-			buf->dev_private = kmalloc(buf->dev_priv_size,
-						  GFP_KERNEL);
+			buf->dev_private = kzalloc(buf->dev_priv_size,
+						GFP_KERNEL);
 			if (!buf->dev_private) {
 				/* Set count correctly so we free the proper amount. */
 				entry->buf_count = count;

@@ -923,7 +918,6 @@ int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
 				atomic_dec(&dev->buf_alloc);
 				return -ENOMEM;
 			}
-			memset(buf->dev_private, 0, buf->dev_priv_size);
 
 			DRM_DEBUG("buffer %d @ %p\n",
 				  entry->buf_count, buf->address);

@@ -1048,14 +1042,13 @@ static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request
 		return -EINVAL;
 	}
 
-	entry->buflist = kmalloc(count * sizeof(*entry->buflist),
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
 				GFP_KERNEL);
 	if (!entry->buflist) {
 		mutex_unlock(&dev->struct_mutex);
 		atomic_dec(&dev->buf_alloc);
 		return -ENOMEM;
 	}
-	memset(entry->buflist, 0, count * sizeof(*entry->buflist));
 
 	entry->buf_size = size;
 	entry->page_order = page_order;

@@ -1080,7 +1073,7 @@ static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request
 		buf->file_priv = NULL;
 
 		buf->dev_priv_size = dev->driver->dev_priv_size;
-		buf->dev_private = kmalloc(buf->dev_priv_size, GFP_KERNEL);
+		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
 		if (!buf->dev_private) {
 			/* Set count correctly so we free the proper amount. */
 			entry->buf_count = count;

@@ -1090,8 +1083,6 @@ static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request
 			return -ENOMEM;
 		}
 
-		memset(buf->dev_private, 0, buf->dev_priv_size);
-
 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
 
 		offset += alignment;

@@ -1209,14 +1200,13 @@ static int drm_addbufs_fb(struct drm_device * dev, struct drm_buf_desc * request
 		return -EINVAL;
 	}
 
-	entry->buflist = kmalloc(count * sizeof(*entry->buflist),
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
 				GFP_KERNEL);
 	if (!entry->buflist) {
 		mutex_unlock(&dev->struct_mutex);
 		atomic_dec(&dev->buf_alloc);
 		return -ENOMEM;
 	}
-	memset(entry->buflist, 0, count * sizeof(*entry->buflist));
 
 	entry->buf_size = size;
 	entry->page_order = page_order;

@@ -1240,7 +1230,7 @@ static int drm_addbufs_fb(struct drm_device * dev, struct drm_buf_desc * request
 		buf->file_priv = NULL;
 
 		buf->dev_priv_size = dev->driver->dev_priv_size;
-		buf->dev_private = kmalloc(buf->dev_priv_size, GFP_KERNEL);
+		buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
 		if (!buf->dev_private) {
 			/* Set count correctly so we free the proper amount. */
 			entry->buf_count = count;

@@ -1249,7 +1239,6 @@ static int drm_addbufs_fb(struct drm_device * dev, struct drm_buf_desc * request
 			atomic_dec(&dev->buf_alloc);
 			return -ENOMEM;
 		}
-		memset(buf->dev_private, 0, buf->dev_priv_size);
 
 		DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
Signature · 1 line
1.7.0.4
#1 lore raw
Quoted 3 lines · Davidlohr Bueso

memory allocation in drm_bufs.c is followed by initializing the memory with 0.

Replace the use of kmalloc+memset with kzalloc.

Perhaps kzalloc's with a multiply could/should also be converted to kcalloc.

Review

Quoted 1 line
(quoted diff) +1 -0
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);

	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);

etc.

Quoted 4 lines
drivers/gpu/drm/drm_bufs.c +4 -0
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
+	entry->seglist = kzalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
author
#2 lore raw
Quoted 12 lines · Joe Perches
Quoted 3 lines · Davidlohr Bueso

memory allocation in drm_bufs.c is followed by initializing the memory with 0.

Replace the use of kmalloc+memset with kzalloc.

Perhaps kzalloc's with a multiply could/should also be converted to kcalloc.

Review

Quoted 1 line
(quoted diff) +1 -0
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);

	entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
Quoted 7 lines

etc.

drivers/gpu/drm/drm_bufs.c int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)

Quoted 4 lines
drivers/gpu/drm/drm_bufs.c +4 -0
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
+	entry->seglist = kzalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist),
+	entry->buflist = kzalloc(count * sizeof(*entry->buflist),

Doable, but don't see much difference. David, what do you think?

Thanks,
Davidlohr

#3 lore raw
Quoted 15 lines · Davidlohr Bueso
Quoted 14 lines · Joe Perches
Quoted 3 lines · Davidlohr Bueso

memory allocation in drm_bufs.c is followed by initializing the memory with 0.

Replace the use of kmalloc+memset with kzalloc.

Perhaps kzalloc's with a multiply could/should also be converted to kcalloc.

Quoted 1 line

+   entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);

      entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);

etc.

Quoted 7 lines
Quoted 5 lines
Quoted 4 lines

+   entry->buflist = kzalloc(count * sizeof(*entry->buflist), GFP_KERNEL);
+   entry->seglist = kzalloc(count * sizeof(*entry->seglist), GFP_KERNEL);
+   entry->buflist = kzalloc(count * sizeof(*entry->buflist),
+   entry->buflist = kzalloc(count * sizeof(*entry->buflist),

Doable, but don't see much difference. David, what do you think?

kcalloc does an integer overflow check, plus it's nice to be explicit about allocating a number of elements of a certain size in the API.

Kristian