Re: [PATCH v3] drm/gma500: fix double freeing

From: Patrik Jakobsson
Date: Wed Dec 09 2015 - 07:20:36 EST


On Wed, Dec 9, 2015 at 12:53 PM, Sudip Mukherjee
<sudipm.mukherjee@xxxxxxxxx> wrote:
> On Thu, Oct 08, 2015 at 06:17:48PM +0530, Sudip Mukherjee wrote:
>> We are allocating backing using psbfb_alloc() and so
>> backing->stolen is always true. So we were freeing backing two times.
>> Moreover if we follow the execution path then we should be freeing
>> backing after we have released the helper. So remove the one which frees
>> backing before the helper is released.
>> While at it the error labels are also renamed to give a meaningful
>> name.
>>
>> Signed-off-by: Sudip Mukherjee <sudip@xxxxxxxxxxxxxxx>
>> Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>
>> ---
>
> This patch was never picked up. It will not apply now.
>
> Daniel, please let me know if you want me to resend after making
> necessary changes.

I will pick this up and pass it along to Dave. Sorry for the delay.

-Patrik

>
> regards
> sudip
>
>> drivers/gpu/drm/gma500/framebuffer.c | 13 ++++---------
>> 1 file changed, 4 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
>> index 2eaf1b3..52e2bf3 100644
>> --- a/drivers/gpu/drm/gma500/framebuffer.c
>> +++ b/drivers/gpu/drm/gma500/framebuffer.c
>> @@ -411,7 +411,7 @@ static int psbfb_create(struct psb_fbdev *fbdev,
>> info = drm_fb_helper_alloc_fbi(&fbdev->psb_fb_helper);
>> if (IS_ERR(info)) {
>> ret = PTR_ERR(info);
>> - goto out_err1;
>> + goto err_unlock;
>> }
>> info->par = fbdev;
>>
>> @@ -419,7 +419,7 @@ static int psbfb_create(struct psb_fbdev *fbdev,
>>
>> ret = psb_framebuffer_init(dev, psbfb, &mode_cmd, backing);
>> if (ret)
>> - goto out_unref;
>> + goto err_release;
>>
>> fb = &psbfb->base;
>> psbfb->fbdev = info;
>> @@ -465,14 +465,9 @@ static int psbfb_create(struct psb_fbdev *fbdev,
>>
>> mutex_unlock(&dev->struct_mutex);
>> return 0;
>> -out_unref:
>> - if (backing->stolen)
>> - psb_gtt_free_range(dev, backing);
>> - else
>> - drm_gem_object_unreference(&backing->gem);
>> -
>> +err_release:
>> drm_fb_helper_release_fbi(&fbdev->psb_fb_helper);
>> -out_err1:
>> +err_unlock:
>> mutex_unlock(&dev->struct_mutex);
>> psb_gtt_free_range(dev, backing);
>> return ret;
>> --
>> 1.9.1
>>
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