[2/5] drm/i915: Use kcalloc more

Message ID	1379585916-6521-2-git-send-email-daniel.vetter@ffwll.ch (mailing list archive)
State	New, archived
Headers	show Return-Path: <intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org> From: Daniel Vetter <daniel.vetter@ffwll.ch> To: Intel Graphics Development <intel-gfx@lists.freedesktop.org> Date: Thu, 19 Sep 2013 12:18:33 +0200 Message-Id: <1379585916-6521-2-git-send-email-daniel.vetter@ffwll.ch> In-Reply-To: <1379585916-6521-1-git-send-email-daniel.vetter@ffwll.ch> References: <1379585916-6521-1-git-send-email-daniel.vetter@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Subject: [Intel-gfx] [PATCH 2/5] drm/i915: Use kcalloc more Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+patchwork-intel-gfx=patchwork.kernel.org@lists.freedesktop.org

Daniel Vetter Sept. 19, 2013, 10:18 a.m. UTC

No buffer overflows here, but better safe than sorry.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c | 5 +++--
 drivers/gpu/drm/i915/i915_gem_gtt.c        | 8 ++++----
 drivers/gpu/drm/i915/i915_gem_tiling.c     | 6 +++---
 drivers/gpu/drm/i915/i915_gpu_error.c      | 4 ++--
 drivers/gpu/drm/i915/intel_display.c       | 2 +-
 5 files changed, 13 insertions(+), 12 deletions(-)

Jani Nikula Sept. 19, 2013, 10:38 a.m. UTC | #1

On Thu, 19 Sep 2013, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> No buffer overflows here, but better safe than sorry.
>
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/gpu/drm/i915/i915_gem_execbuffer.c | 5 +++--
>  drivers/gpu/drm/i915/i915_gem_gtt.c        | 8 ++++----
>  drivers/gpu/drm/i915/i915_gem_tiling.c     | 6 +++---
>  drivers/gpu/drm/i915/i915_gpu_error.c      | 4 ++--
>  drivers/gpu/drm/i915/intel_display.c       | 2 +-
>  5 files changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index ee93357..a733118 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -1047,7 +1047,8 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
>  			return -EINVAL;
>  		}
>  
> -		cliprects = kmalloc(args->num_cliprects * sizeof(*cliprects),
> +		cliprects = kcalloc(args->num_cliprects,
> +				    sizeof(*cliprects),
>  				    GFP_KERNEL);
>  		if (cliprects == NULL) {
>  			ret = -ENOMEM;
> @@ -1302,7 +1303,7 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data,
>  		return -EINVAL;
>  	}
>  
> -	exec2_list = kmalloc(sizeof(*exec2_list)*args->buffer_count,
> +	exec2_list = kcalloc(args->buffer_count, sizeof(*exec2_list),
>  			     GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
>  	if (exec2_list == NULL)
>  		exec2_list = drm_malloc_ab(sizeof(*exec2_list),
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 212f6d8..dafbdb7 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -336,8 +336,8 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
>  	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
>  	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
>  	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
> -	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
> -				  GFP_KERNEL);
> +	ppgtt->pt_pages = kcalloc(ppgtt->num_pd_entries, sizeof(struct page *),
> +				  GFP_KERNEL | __GFP_ZERO);

kcalloc implies __GFP_ZERO, specifying it is redundant. Ditto
below. This also means this patch does a bunch of zeroing that's
strictly not necessary.

>  	if (!ppgtt->pt_pages)
>  		return -ENOMEM;
>  
> @@ -347,8 +347,8 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
>  			goto err_pt_alloc;
>  	}
>  
> -	ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t) *ppgtt->num_pd_entries,
> -				     GFP_KERNEL);
> +	ppgtt->pt_dma_addr = kcalloc(ppgtt->num_pd_entries, sizeof(dma_addr_t),
> +				     GFP_KERNEL | __GFP_ZERO);
>  	if (!ppgtt->pt_dma_addr)
>  		goto err_pt_alloc;
>  
> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
> index 032e9ef..ac9ebe9 100644
> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
> @@ -393,7 +393,7 @@ i915_gem_set_tiling(struct drm_device *dev, void *data,
>  	/* Try to preallocate memory required to save swizzling on put-pages */
>  	if (i915_gem_object_needs_bit17_swizzle(obj)) {
>  		if (obj->bit_17 == NULL) {
> -			obj->bit_17 = kmalloc(BITS_TO_LONGS(obj->base.size >> PAGE_SHIFT) *
> +			obj->bit_17 = kcalloc(BITS_TO_LONGS(obj->base.size >> PAGE_SHIFT),
>  					      sizeof(long), GFP_KERNEL);
>  		}
>  	} else {
> @@ -504,8 +504,8 @@ i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj)
>  	int i;
>  
>  	if (obj->bit_17 == NULL) {
> -		obj->bit_17 = kmalloc(BITS_TO_LONGS(page_count) *
> -					   sizeof(long), GFP_KERNEL);
> +		obj->bit_17 = kcalloc(BITS_TO_LONGS(page_count),
> +				      sizeof(long), GFP_KERNEL);
>  		if (obj->bit_17 == NULL) {
>  			DRM_ERROR("Failed to allocate memory for bit 17 "
>  				  "record\n");
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index c38d575..763283e 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -791,7 +791,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
>  
>  		error->ring[i].num_requests = count;
>  		error->ring[i].requests =
> -			kmalloc(count*sizeof(struct drm_i915_error_request),
> +			kcalloc(count, sizeof(error->ring[i].requests),

Crash boom bang.


BR,
Jani.

>  				GFP_ATOMIC);
>  		if (error->ring[i].requests == NULL) {
>  			error->ring[i].num_requests = 0;
> @@ -833,7 +833,7 @@ static void i915_gem_capture_vm(struct drm_i915_private *dev_priv,
>  	error->pinned_bo_count[ndx] = i - error->active_bo_count[ndx];
>  
>  	if (i) {
> -		active_bo = kmalloc(sizeof(*active_bo)*i, GFP_ATOMIC);
> +		active_bo = kcalloc(i, sizeof(*active_bo), GFP_ATOMIC);
>  		if (active_bo)
>  			pinned_bo = active_bo + error->active_bo_count[ndx];
>  	}
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index fe8db37..6b8a107 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9031,7 +9031,7 @@ static int __intel_set_mode(struct drm_crtc *crtc,
>  	unsigned disable_pipes, prepare_pipes, modeset_pipes;
>  	int ret = 0;
>  
> -	saved_mode = kmalloc(2 * sizeof(*saved_mode), GFP_KERNEL);
> +	saved_mode = kcalloc(2, sizeof(*saved_mode), GFP_KERNEL);
>  	if (!saved_mode)
>  		return -ENOMEM;
>  	saved_hwmode = saved_mode + 1;
> -- 
> 1.8.4.rc3
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Chris Wilson Sept. 19, 2013, 10:46 a.m. UTC | #2

On Thu, Sep 19, 2013 at 12:18:33PM +0200, Daniel Vetter wrote:
> No buffer overflows here, but better safe than sorry.

You are also introducing needless memsets.
-Chris

Chris Wilson Sept. 19, 2013, 10:50 a.m. UTC | #3

On Thu, Sep 19, 2013 at 01:38:18PM +0300, Jani Nikula wrote:
> On Thu, 19 Sep 2013, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> > diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> > index c38d575..763283e 100644
> > --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> > +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> > @@ -791,7 +791,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
> >  
> >  		error->ring[i].num_requests = count;
> >  		error->ring[i].requests =
> > -			kmalloc(count*sizeof(struct drm_i915_error_request),
> > +			kcalloc(count, sizeof(error->ring[i].requests),
> 
> Crash boom bang.

Not quite. This is evaluated at compile time by parsing the type rather
than by pointer dereference.
-Chris

Jani Nikula Sept. 19, 2013, 11 a.m. UTC | #4

On Thu, 19 Sep 2013, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> On Thu, Sep 19, 2013 at 01:38:18PM +0300, Jani Nikula wrote:
>> On Thu, 19 Sep 2013, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>> > diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
>> > index c38d575..763283e 100644
>> > --- a/drivers/gpu/drm/i915/i915_gpu_error.c
>> > +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
>> > @@ -791,7 +791,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
>> >  
>> >  		error->ring[i].num_requests = count;
>> >  		error->ring[i].requests =
>> > -			kmalloc(count*sizeof(struct drm_i915_error_request),
>> > +			kcalloc(count, sizeof(error->ring[i].requests),
>> 
>> Crash boom bang.
>
> Not quite. This is evaluated at compile time by parsing the type rather
> than by pointer dereference.

Sizeof changes from sizeof(struct drm_i915_error_request) to
sizeof(struct drm_i915_error_request *). It'll break something. Maybe
not as spectacularly as I was implying.

Jani.

Chris Wilson Sept. 19, 2013, 11:12 a.m. UTC | #5

On Thu, Sep 19, 2013 at 02:00:30PM +0300, Jani Nikula wrote:
> On Thu, 19 Sep 2013, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > On Thu, Sep 19, 2013 at 01:38:18PM +0300, Jani Nikula wrote:
> >> On Thu, 19 Sep 2013, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> >> > diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> >> > index c38d575..763283e 100644
> >> > --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> >> > +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> >> > @@ -791,7 +791,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
> >> >  
> >> >  		error->ring[i].num_requests = count;
> >> >  		error->ring[i].requests =
> >> > -			kmalloc(count*sizeof(struct drm_i915_error_request),
> >> > +			kcalloc(count, sizeof(error->ring[i].requests),
> >> 
> >> Crash boom bang.
> >
> > Not quite. This is evaluated at compile time by parsing the type rather
> > than by pointer dereference.
> 
> Sizeof changes from sizeof(struct drm_i915_error_request) to
> sizeof(struct drm_i915_error_request *). It'll break something. Maybe
> not as spectacularly as I was implying.

Apologies, I automatically go into CLANG is a not a valid C compiler
mode...

sizeof(*error->ring[i].requests)
-Chris

Daniel Vetter Sept. 19, 2013, 11:53 a.m. UTC | #6

On Thu, Sep 19, 2013 at 11:46:55AM +0100, Chris Wilson wrote:
> On Thu, Sep 19, 2013 at 12:18:33PM +0200, Daniel Vetter wrote:
> > No buffer overflows here, but better safe than sorry.
> 
> You are also introducing needless memsets.

Meh, somehow I've thought kcalloc won't zero. I'll drop the redundant
GFP_ZEROs that Jani spotted and switch kcalloc to kmalloc_array in the
place we care about speed and want to avoid the memset.
-Daniel

[2/5] drm/i915: Use kcalloc more

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