The advantage of kcalloc is, that will prevent integer overflows which could result from the multiplication of number of elements and size and it is also a bit nicer to read.
The semantic patch that makes this change is available in https://lkml.org/lkml/2011/11/25/107 Signed-off-by: Thomas Meyer <thomas at m3y3r.de> --- diff -u -p a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c 2011-11-13 11:07:24.343455126 +0100 +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c 2011-11-28 19:50:07.413502824 +0100 @@ -140,7 +140,7 @@ int vmw_present_ioctl(struct drm_device goto out_clips; } - clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL); + clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL); if (clips == NULL) { DRM_ERROR("Failed to allocate clip rect list.\n"); ret = -ENOMEM; @@ -232,7 +232,7 @@ int vmw_present_readback_ioctl(struct dr goto out_clips; } - clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL); + clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL); if (clips == NULL) { DRM_ERROR("Failed to allocate clip rect list.\n"); ret = -ENOMEM;
