* [PATCH] drm/gma500: fix double freeing
@ 2015-09-09 12:50 ` Sudip Mukherjee
0 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-09-09 12:50 UTC (permalink / raw)
To: David Airlie, Daniel Vetter; +Cc: linux-kernel, dri-devel, Sudip Mukherjee
If backing->stolen is true then we were freeing backing by calling
psb_gtt_free_range() but we called it again after unlocking the mutex.
Lets make it NULL after freeing in psb_gtt_free_range() and check for
NULL before calling the function for the second time.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---
drivers/gpu/drm/gma500/framebuffer.c | 3 ++-
drivers/gpu/drm/gma500/gtt.c | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index 2eaf1b3..381d7af 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -474,7 +474,8 @@ out_unref:
drm_fb_helper_release_fbi(&fbdev->psb_fb_helper);
out_err1:
mutex_unlock(&dev->struct_mutex);
- psb_gtt_free_range(dev, backing);
+ if (backing)
+ psb_gtt_free_range(dev, backing);
return ret;
}
diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index ce015db..8130fa8 100644
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -385,6 +385,7 @@ void psb_gtt_free_range(struct drm_device *dev, struct gtt_range *gt)
WARN_ON(gt->in_gart && !gt->stolen);
release_resource(>->resource);
kfree(gt);
+ gt = NULL;
}
static void psb_gtt_alloc(struct drm_device *dev)
--
1.9.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH] drm/gma500: fix double freeing
@ 2015-09-09 12:50 ` Sudip Mukherjee
0 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-09-09 12:50 UTC (permalink / raw)
To: David Airlie, Daniel Vetter; +Cc: linux-kernel, dri-devel, Sudip Mukherjee
If backing->stolen is true then we were freeing backing by calling
psb_gtt_free_range() but we called it again after unlocking the mutex.
Lets make it NULL after freeing in psb_gtt_free_range() and check for
NULL before calling the function for the second time.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---
drivers/gpu/drm/gma500/framebuffer.c | 3 ++-
drivers/gpu/drm/gma500/gtt.c | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index 2eaf1b3..381d7af 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -474,7 +474,8 @@ out_unref:
drm_fb_helper_release_fbi(&fbdev->psb_fb_helper);
out_err1:
mutex_unlock(&dev->struct_mutex);
- psb_gtt_free_range(dev, backing);
+ if (backing)
+ psb_gtt_free_range(dev, backing);
return ret;
}
diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index ce015db..8130fa8 100644
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -385,6 +385,7 @@ void psb_gtt_free_range(struct drm_device *dev, struct gtt_range *gt)
WARN_ON(gt->in_gart && !gt->stolen);
release_resource(>->resource);
kfree(gt);
+ gt = NULL;
}
static void psb_gtt_alloc(struct drm_device *dev)
--
1.9.1
_______________________________________________
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dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
2015-09-09 12:50 ` Sudip Mukherjee
@ 2015-09-24 15:57 ` Sudip Mukherjee
-1 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-09-24 15:57 UTC (permalink / raw)
To: David Airlie, Daniel Vetter, Patrik Jakobsson; +Cc: linux-kernel, dri-devel
On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
> If backing->stolen is true then we were freeing backing by calling
> psb_gtt_free_range() but we called it again after unlocking the mutex.
> Lets make it NULL after freeing in psb_gtt_free_range() and check for
> NULL before calling the function for the second time.
>
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
Hi Patrik,
A gentle ping.
regards
sudip
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
@ 2015-09-24 15:57 ` Sudip Mukherjee
0 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-09-24 15:57 UTC (permalink / raw)
To: David Airlie, Daniel Vetter, Patrik Jakobsson; +Cc: linux-kernel, dri-devel
On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
> If backing->stolen is true then we were freeing backing by calling
> psb_gtt_free_range() but we called it again after unlocking the mutex.
> Lets make it NULL after freeing in psb_gtt_free_range() and check for
> NULL before calling the function for the second time.
>
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
Hi Patrik,
A gentle ping.
regards
sudip
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
2015-09-24 15:57 ` Sudip Mukherjee
@ 2015-09-29 13:20 ` Patrik Jakobsson
-1 siblings, 0 replies; 13+ messages in thread
From: Patrik Jakobsson @ 2015-09-29 13:20 UTC (permalink / raw)
To: Sudip Mukherjee; +Cc: David Airlie, Daniel Vetter, linux-kernel, dri-devel
On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
>> If backing->stolen is true then we were freeing backing by calling
>> psb_gtt_free_range() but we called it again after unlocking the mutex.
>> Lets make it NULL after freeing in psb_gtt_free_range() and check for
>> NULL before calling the function for the second time.
>>
>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>> ---
> Hi Patrik,
> A gentle ping.
>
> regards
> sudip
Hi, sorry for the late reply.
Why are we freeing the range twice in the first case?
-Patrik
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
@ 2015-09-29 13:20 ` Patrik Jakobsson
0 siblings, 0 replies; 13+ messages in thread
From: Patrik Jakobsson @ 2015-09-29 13:20 UTC (permalink / raw)
To: Sudip Mukherjee; +Cc: Daniel Vetter, linux-kernel, dri-devel
On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
>> If backing->stolen is true then we were freeing backing by calling
>> psb_gtt_free_range() but we called it again after unlocking the mutex.
>> Lets make it NULL after freeing in psb_gtt_free_range() and check for
>> NULL before calling the function for the second time.
>>
>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>> ---
> Hi Patrik,
> A gentle ping.
>
> regards
> sudip
Hi, sorry for the late reply.
Why are we freeing the range twice in the first case?
-Patrik
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
2015-09-29 13:20 ` Patrik Jakobsson
@ 2015-09-30 6:12 ` Sudip Mukherjee
-1 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-09-30 6:12 UTC (permalink / raw)
To: Patrik Jakobsson; +Cc: David Airlie, Daniel Vetter, linux-kernel, dri-devel
On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
> <sudipm.mukherjee@gmail.com> wrote:
> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
> >> If backing->stolen is true then we were freeing backing by calling
> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
> >> NULL before calling the function for the second time.
> >>
> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >> ---
> > Hi Patrik,
> > A gentle ping.
> >
> > regards
> > sudip
>
> Hi, sorry for the late reply.
>
> Why are we freeing the range twice in the first case?
I think,
if backing->stolen is true then backing is released using
psb_gtt_free_range() but if backing->stolen is false then the gem object
is freed but the backing is not yet freed. To free that backing
psb_gtt_free_range() has been called second time. My patch tried to fix
the possibility of backing->stolen being true and backing being freed 2
times.
regards
sudip
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
@ 2015-09-30 6:12 ` Sudip Mukherjee
0 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-09-30 6:12 UTC (permalink / raw)
To: Patrik Jakobsson; +Cc: Daniel Vetter, linux-kernel, dri-devel
On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
> <sudipm.mukherjee@gmail.com> wrote:
> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
> >> If backing->stolen is true then we were freeing backing by calling
> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
> >> NULL before calling the function for the second time.
> >>
> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >> ---
> > Hi Patrik,
> > A gentle ping.
> >
> > regards
> > sudip
>
> Hi, sorry for the late reply.
>
> Why are we freeing the range twice in the first case?
I think,
if backing->stolen is true then backing is released using
psb_gtt_free_range() but if backing->stolen is false then the gem object
is freed but the backing is not yet freed. To free that backing
psb_gtt_free_range() has been called second time. My patch tried to fix
the possibility of backing->stolen being true and backing being freed 2
times.
regards
sudip
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
2015-09-30 6:12 ` Sudip Mukherjee
@ 2015-10-01 17:07 ` Patrik Jakobsson
-1 siblings, 0 replies; 13+ messages in thread
From: Patrik Jakobsson @ 2015-10-01 17:07 UTC (permalink / raw)
To: Sudip Mukherjee; +Cc: David Airlie, Daniel Vetter, linux-kernel, dri-devel
On Wed, Sep 30, 2015 at 8:12 AM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
>> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
>> <sudipm.mukherjee@gmail.com> wrote:
>> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
>> >> If backing->stolen is true then we were freeing backing by calling
>> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
>> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
>> >> NULL before calling the function for the second time.
>> >>
>> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>> >> ---
>> > Hi Patrik,
>> > A gentle ping.
>> >
>> > regards
>> > sudip
>>
>> Hi, sorry for the late reply.
>>
>> Why are we freeing the range twice in the first case?
> I think,
> if backing->stolen is true then backing is released using
> psb_gtt_free_range() but if backing->stolen is false then the gem object
> is freed but the backing is not yet freed. To free that backing
> psb_gtt_free_range() has been called second time. My patch tried to fix
> the possibility of backing->stolen being true and backing being freed 2
> times.
>
> regards
> sudip
There are some special handling of the stolen framebuffer that I don't
remember entirely but the basic concept is that we free the backing
when we drop the last reference on a gem object. That will trigger a
psb_gtt_free_range(). So in this case it looks to me that the extra
free is not needed at all. That's my quick reasoning, feel free to
prove me wrong :)
Thanks
Patrik
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
@ 2015-10-01 17:07 ` Patrik Jakobsson
0 siblings, 0 replies; 13+ messages in thread
From: Patrik Jakobsson @ 2015-10-01 17:07 UTC (permalink / raw)
To: Sudip Mukherjee; +Cc: Daniel Vetter, linux-kernel, dri-devel
On Wed, Sep 30, 2015 at 8:12 AM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
>> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
>> <sudipm.mukherjee@gmail.com> wrote:
>> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
>> >> If backing->stolen is true then we were freeing backing by calling
>> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
>> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
>> >> NULL before calling the function for the second time.
>> >>
>> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>> >> ---
>> > Hi Patrik,
>> > A gentle ping.
>> >
>> > regards
>> > sudip
>>
>> Hi, sorry for the late reply.
>>
>> Why are we freeing the range twice in the first case?
> I think,
> if backing->stolen is true then backing is released using
> psb_gtt_free_range() but if backing->stolen is false then the gem object
> is freed but the backing is not yet freed. To free that backing
> psb_gtt_free_range() has been called second time. My patch tried to fix
> the possibility of backing->stolen being true and backing being freed 2
> times.
>
> regards
> sudip
There are some special handling of the stolen framebuffer that I don't
remember entirely but the basic concept is that we free the backing
when we drop the last reference on a gem object. That will trigger a
psb_gtt_free_range(). So in this case it looks to me that the extra
free is not needed at all. That's my quick reasoning, feel free to
prove me wrong :)
Thanks
Patrik
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
2015-10-01 17:07 ` Patrik Jakobsson
@ 2015-10-02 15:56 ` Sudip Mukherjee
-1 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-10-02 15:56 UTC (permalink / raw)
To: Patrik Jakobsson; +Cc: David Airlie, Daniel Vetter, linux-kernel, dri-devel
On Thu, Oct 01, 2015 at 07:07:33PM +0200, Patrik Jakobsson wrote:
> On Wed, Sep 30, 2015 at 8:12 AM, Sudip Mukherjee
> <sudipm.mukherjee@gmail.com> wrote:
> > On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
> >> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
> >> <sudipm.mukherjee@gmail.com> wrote:
> >> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
> >> >> If backing->stolen is true then we were freeing backing by calling
> >> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
> >> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
> >> >> NULL before calling the function for the second time.
> >> >>
> >> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >> >> ---
> >> > Hi Patrik,
> >> > A gentle ping.
> >> >
> >> > regards
> >> > sudip
> >>
> >> Hi, sorry for the late reply.
> >>
> >> Why are we freeing the range twice in the first case?
> > I think,
> > if backing->stolen is true then backing is released using
> > psb_gtt_free_range() but if backing->stolen is false then the gem object
> > is freed but the backing is not yet freed. To free that backing
> > psb_gtt_free_range() has been called second time. My patch tried to fix
> > the possibility of backing->stolen being true and backing being freed 2
> > times.
> >
> > regards
> > sudip
>
> There are some special handling of the stolen framebuffer that I don't
> remember entirely but the basic concept is that we free the backing
> when we drop the last reference on a gem object. That will trigger a
> psb_gtt_free_range(). So in this case it looks to me that the extra
> free is not needed at all. That's my quick reasoning, feel free to
> prove me wrong :)
In this case we are allocating backing using psbfb_alloc() and so
backing->stolen is always true. So we can remove the backing->stolen
condition. And if drm_fb_helper_alloc_fbi() fails then we
are jumping to out_err1. So the fitst free will not be needed.
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index 2eaf1b3..932f07b 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -466,11 +466,6 @@ 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);
-
drm_fb_helper_release_fbi(&fbdev->psb_fb_helper);
out_err1:
mutex_unlock(&dev->struct_mutex);
If it is ok, I can submit the v2.
regards
sudip
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
@ 2015-10-02 15:56 ` Sudip Mukherjee
0 siblings, 0 replies; 13+ messages in thread
From: Sudip Mukherjee @ 2015-10-02 15:56 UTC (permalink / raw)
To: Patrik Jakobsson; +Cc: Daniel Vetter, linux-kernel, dri-devel
On Thu, Oct 01, 2015 at 07:07:33PM +0200, Patrik Jakobsson wrote:
> On Wed, Sep 30, 2015 at 8:12 AM, Sudip Mukherjee
> <sudipm.mukherjee@gmail.com> wrote:
> > On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
> >> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
> >> <sudipm.mukherjee@gmail.com> wrote:
> >> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
> >> >> If backing->stolen is true then we were freeing backing by calling
> >> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
> >> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
> >> >> NULL before calling the function for the second time.
> >> >>
> >> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >> >> ---
> >> > Hi Patrik,
> >> > A gentle ping.
> >> >
> >> > regards
> >> > sudip
> >>
> >> Hi, sorry for the late reply.
> >>
> >> Why are we freeing the range twice in the first case?
> > I think,
> > if backing->stolen is true then backing is released using
> > psb_gtt_free_range() but if backing->stolen is false then the gem object
> > is freed but the backing is not yet freed. To free that backing
> > psb_gtt_free_range() has been called second time. My patch tried to fix
> > the possibility of backing->stolen being true and backing being freed 2
> > times.
> >
> > regards
> > sudip
>
> There are some special handling of the stolen framebuffer that I don't
> remember entirely but the basic concept is that we free the backing
> when we drop the last reference on a gem object. That will trigger a
> psb_gtt_free_range(). So in this case it looks to me that the extra
> free is not needed at all. That's my quick reasoning, feel free to
> prove me wrong :)
In this case we are allocating backing using psbfb_alloc() and so
backing->stolen is always true. So we can remove the backing->stolen
condition. And if drm_fb_helper_alloc_fbi() fails then we
are jumping to out_err1. So the fitst free will not be needed.
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index 2eaf1b3..932f07b 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -466,11 +466,6 @@ 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);
-
drm_fb_helper_release_fbi(&fbdev->psb_fb_helper);
out_err1:
mutex_unlock(&dev->struct_mutex);
If it is ok, I can submit the v2.
regards
sudip
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH] drm/gma500: fix double freeing
2015-10-02 15:56 ` Sudip Mukherjee
(?)
@ 2015-10-05 23:54 ` Patrik Jakobsson
-1 siblings, 0 replies; 13+ messages in thread
From: Patrik Jakobsson @ 2015-10-05 23:54 UTC (permalink / raw)
To: Sudip Mukherjee; +Cc: David Airlie, Daniel Vetter, linux-kernel, dri-devel
On Fri, Oct 2, 2015 at 5:56 PM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> On Thu, Oct 01, 2015 at 07:07:33PM +0200, Patrik Jakobsson wrote:
>> On Wed, Sep 30, 2015 at 8:12 AM, Sudip Mukherjee
>> <sudipm.mukherjee@gmail.com> wrote:
>> > On Tue, Sep 29, 2015 at 03:20:35PM +0200, Patrik Jakobsson wrote:
>> >> On Thu, Sep 24, 2015 at 5:57 PM, Sudip Mukherjee
>> >> <sudipm.mukherjee@gmail.com> wrote:
>> >> > On Wed, Sep 09, 2015 at 06:20:40PM +0530, Sudip Mukherjee wrote:
>> >> >> If backing->stolen is true then we were freeing backing by calling
>> >> >> psb_gtt_free_range() but we called it again after unlocking the mutex.
>> >> >> Lets make it NULL after freeing in psb_gtt_free_range() and check for
>> >> >> NULL before calling the function for the second time.
>> >> >>
>> >> >> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>> >> >> ---
>> >> > Hi Patrik,
>> >> > A gentle ping.
>> >> >
>> >> > regards
>> >> > sudip
>> >>
>> >> Hi, sorry for the late reply.
>> >>
>> >> Why are we freeing the range twice in the first case?
>> > I think,
>> > if backing->stolen is true then backing is released using
>> > psb_gtt_free_range() but if backing->stolen is false then the gem object
>> > is freed but the backing is not yet freed. To free that backing
>> > psb_gtt_free_range() has been called second time. My patch tried to fix
>> > the possibility of backing->stolen being true and backing being freed 2
>> > times.
>> >
>> > regards
>> > sudip
>>
>> There are some special handling of the stolen framebuffer that I don't
>> remember entirely but the basic concept is that we free the backing
>> when we drop the last reference on a gem object. That will trigger a
>> psb_gtt_free_range(). So in this case it looks to me that the extra
>> free is not needed at all. That's my quick reasoning, feel free to
>> prove me wrong :)
>
> In this case we are allocating backing using psbfb_alloc() and so
> backing->stolen is always true. So we can remove the backing->stolen
> condition. And if drm_fb_helper_alloc_fbi() fails then we
> are jumping to out_err1. So the fitst free will not be needed.
Sounds good, could you also rename the labels to what they're doing
now. I'm thinking out_release and out_unlock or something you feel is
suitable.
Thanks
Patrik
> diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
> index 2eaf1b3..932f07b 100644
> --- a/drivers/gpu/drm/gma500/framebuffer.c
> +++ b/drivers/gpu/drm/gma500/framebuffer.c
> @@ -466,11 +466,6 @@ 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);
> -
> drm_fb_helper_release_fbi(&fbdev->psb_fb_helper);
> out_err1:
> mutex_unlock(&dev->struct_mutex);
>
>
> If it is ok, I can submit the v2.
>
> regards
> sudip
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2015-10-05 23:54 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-09-09 12:50 [PATCH] drm/gma500: fix double freeing Sudip Mukherjee
2015-09-09 12:50 ` Sudip Mukherjee
2015-09-24 15:57 ` Sudip Mukherjee
2015-09-24 15:57 ` Sudip Mukherjee
2015-09-29 13:20 ` Patrik Jakobsson
2015-09-29 13:20 ` Patrik Jakobsson
2015-09-30 6:12 ` Sudip Mukherjee
2015-09-30 6:12 ` Sudip Mukherjee
2015-10-01 17:07 ` Patrik Jakobsson
2015-10-01 17:07 ` Patrik Jakobsson
2015-10-02 15:56 ` Sudip Mukherjee
2015-10-02 15:56 ` Sudip Mukherjee
2015-10-05 23:54 ` Patrik Jakobsson
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