Commit ae6a2330 authored by Erick Archer's avatar Erick Archer Committed by Alex Deucher
Browse files

drm/radeon/radeon_display: Decrease the size of allocated memory 

This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1] [2].

In this case, the memory allocated to store RADEONFB_CONN_LIMIT pointers
to "drm_connector" structures can be avoided. This is because this
memory area is never accessed.

Also, in the kzalloc function, it is preferred to use sizeof(*pointer)
instead of sizeof(type) due to the type of the variable can change and
one needs not change the former (unlike the latter).

At the same time take advantage to remove the "#if 0" block, the code
where the removed memory area was accessed, and the RADEONFB_CONN_LIMIT
constant due to now is never used.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1]
Link: https://github.com/KSPP/linux/issues/160

 [2]
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarErick Archer <erick.archer@outlook.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 08f7c681

drivers/gpu/drm/radeon/radeon.h

+0 −1
Original line number Diff line number Diff line
@@ -132,7 +132,6 @@ extern int radeon_cik_support; 
/* RADEON_IB_POOL_SIZE must be a power of 2 */

#define RADEON_IB_POOL_SIZE			16

#define RADEON_DEBUGFS_MAX_COMPONENTS		32

#define RADEONFB_CONN_LIMIT			4

#define RADEON_BIOS_NUM_SCRATCH			8



/* internal ring indices */

drivers/gpu/drm/radeon/radeon_display.c

+1 −7
Original line number Diff line number Diff line
@@ -683,7 +683,7 @@ static void radeon_crtc_init(struct drm_device *dev, int index) 
	struct radeon_device *rdev = dev->dev_private;

	struct radeon_crtc *radeon_crtc;



	radeon_crtc = kzalloc(sizeof(struct radeon_crtc) + (RADEONFB_CONN_LIMIT * sizeof(struct drm_connector *)), GFP_KERNEL);

	radeon_crtc = kzalloc(sizeof(*radeon_crtc), GFP_KERNEL);

	if (radeon_crtc == NULL)

		return;
@@ -709,12 +709,6 @@ static void radeon_crtc_init(struct drm_device *dev, int index) 
	dev->mode_config.cursor_width = radeon_crtc->max_cursor_width;

	dev->mode_config.cursor_height = radeon_crtc->max_cursor_height;



#if 0

	radeon_crtc->mode_set.crtc = &radeon_crtc->base;

	radeon_crtc->mode_set.connectors = (struct drm_connector **)(radeon_crtc + 1);

	radeon_crtc->mode_set.num_connectors = 0;

#endif



	if (rdev->is_atom_bios && (ASIC_IS_AVIVO(rdev) || radeon_r4xx_atom))

		radeon_atombios_init_crtc(dev, radeon_crtc);

	else