Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1593406 > unrolled thread

[PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t Elena Reshetova <elena.reshetova@intel.com> - 2017-03-06 15:30 +0100
    Re: [PATCH 11/29] drivers, media: convert cx88_core.refcount from  atomic_t to refcount_t Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2017-03-06 17:40 +0100
      RE: [PATCH 11/29] drivers, media: convert cx88_core.refcount from  atomic_t to refcount_t "Reshetova, Elena" <elena.reshetova@intel.com> - 2017-03-07 09:00 +0100
        Re: [PATCH 11/29] drivers, media: convert cx88_core.refcount from  atomic_t to refcount_t Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2017-03-07 12:00 +0100
    Re: [PATCH 11/29] drivers, media: convert cx88_core.refcount from  atomic_t to refcount_t Sakari Ailus <sakari.ailus@iki.fi> - 2017-03-07 09:30 +0100

#1593406 — [PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
 drivers/media/pci/cx88/cx88-cards.c | 2 +-
 drivers/media/pci/cx88/cx88-core.c  | 4 ++--
 drivers/media/pci/cx88/cx88.h       | 3 ++-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/media/pci/cx88/cx88-cards.c b/drivers/media/pci/cx88/cx88-cards.c
index cdfbde2..7fc5f5f 100644
--- a/drivers/media/pci/cx88/cx88-cards.c
+++ b/drivers/media/pci/cx88/cx88-cards.c
@@ -3670,7 +3670,7 @@ struct cx88_core *cx88_core_create(struct pci_dev *pci, int nr)
 	if (!core)
 		return NULL;
 
-	atomic_inc(&core->refcount);
+	refcount_set(&core->refcount, 1);
 	core->pci_bus  = pci->bus->number;
 	core->pci_slot = PCI_SLOT(pci->devfn);
 	core->pci_irqmask = PCI_INT_RISC_RD_BERRINT | PCI_INT_RISC_WR_BERRINT |
diff --git a/drivers/media/pci/cx88/cx88-core.c b/drivers/media/pci/cx88/cx88-core.c
index 973a9cd4..8bfa5b7 100644
--- a/drivers/media/pci/cx88/cx88-core.c
+++ b/drivers/media/pci/cx88/cx88-core.c
@@ -1052,7 +1052,7 @@ struct cx88_core *cx88_core_get(struct pci_dev *pci)
 			mutex_unlock(&devlist);
 			return NULL;
 		}
-		atomic_inc(&core->refcount);
+		refcount_inc(&core->refcount);
 		mutex_unlock(&devlist);
 		return core;
 	}
@@ -1073,7 +1073,7 @@ void cx88_core_put(struct cx88_core *core, struct pci_dev *pci)
 	release_mem_region(pci_resource_start(pci, 0),
 			   pci_resource_len(pci, 0));
 
-	if (!atomic_dec_and_test(&core->refcount))
+	if (!refcount_dec_and_test(&core->refcount))
 		return;
 
 	mutex_lock(&devlist);
diff --git a/drivers/media/pci/cx88/cx88.h b/drivers/media/pci/cx88/cx88.h
index 115414c..16c1313 100644
--- a/drivers/media/pci/cx88/cx88.h
+++ b/drivers/media/pci/cx88/cx88.h
@@ -24,6 +24,7 @@
 #include <linux/i2c-algo-bit.h>
 #include <linux/videodev2.h>
 #include <linux/kdev_t.h>
+#include <linux/refcount.h>
 
 #include <media/v4l2-device.h>
 #include <media/v4l2-fh.h>
@@ -339,7 +340,7 @@ struct cx8802_dev;
 
 struct cx88_core {
 	struct list_head           devlist;
-	atomic_t                   refcount;
+	refcount_t                   refcount;
 
 	/* board name */
 	int                        nr;
-- 
2.7.4

[toc] | [next] | [standalone]

#1593518 — Re: [PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t

Hello.

On 03/06/2017 05:20 PM, Elena Reshetova wrote:

> refcount_t type and corresponding API should be
> used instead of atomic_t when the variable is used as
> a reference counter. This allows to avoid accidental
> refcounter overflows that might lead to use-after-free
> situations.
>
> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: David Windsor <dwindsor@gmail.com>
[...]
> diff --git a/drivers/media/pci/cx88/cx88.h b/drivers/media/pci/cx88/cx88.h
> index 115414c..16c1313 100644
> --- a/drivers/media/pci/cx88/cx88.h
> +++ b/drivers/media/pci/cx88/cx88.h
> @@ -24,6 +24,7 @@
>  #include <linux/i2c-algo-bit.h>
>  #include <linux/videodev2.h>
>  #include <linux/kdev_t.h>
> +#include <linux/refcount.h>
>
>  #include <media/v4l2-device.h>
>  #include <media/v4l2-fh.h>
> @@ -339,7 +340,7 @@ struct cx8802_dev;
>
>  struct cx88_core {
>  	struct list_head           devlist;
> -	atomic_t                   refcount;
> +	refcount_t                   refcount;

    Could you please keep the name aligned with above and below?

>
>  	/* board name */
>  	int                        nr;
>

MBR, Sergei

[toc] | [prev] | [next] | [standalone]

#1593953 — RE: [PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t

> Hello.
> 
> On 03/06/2017 05:20 PM, Elena Reshetova wrote:
> 
> > refcount_t type and corresponding API should be
> > used instead of atomic_t when the variable is used as
> > a reference counter. This allows to avoid accidental
> > refcounter overflows that might lead to use-after-free
> > situations.
> >
> > Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
> > Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > Signed-off-by: David Windsor <dwindsor@gmail.com>
> [...]
> > diff --git a/drivers/media/pci/cx88/cx88.h b/drivers/media/pci/cx88/cx88.h
> > index 115414c..16c1313 100644
> > --- a/drivers/media/pci/cx88/cx88.h
> > +++ b/drivers/media/pci/cx88/cx88.h
> > @@ -24,6 +24,7 @@
> >  #include <linux/i2c-algo-bit.h>
> >  #include <linux/videodev2.h>
> >  #include <linux/kdev_t.h>
> > +#include <linux/refcount.h>
> >
> >  #include <media/v4l2-device.h>
> >  #include <media/v4l2-fh.h>
> > @@ -339,7 +340,7 @@ struct cx8802_dev;
> >
> >  struct cx88_core {
> >  	struct list_head           devlist;
> > -	atomic_t                   refcount;
> > +	refcount_t                   refcount;
> 
>     Could you please keep the name aligned with above and below?

You mean "not aligned" to devlist, but with a shift like it was before? 
Sure, will fix. Is the patch ok otherwise?

Best Regards,
Elena.

> 
> >
> >  	/* board name */
> >  	int                        nr;
> >
> 
> MBR, Sergei

[toc] | [prev] | [next] | [standalone]

#1594114 — Re: [PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t

On 3/7/2017 10:52 AM, Reshetova, Elena wrote:

>>> refcount_t type and corresponding API should be
>>> used instead of atomic_t when the variable is used as
>>> a reference counter. This allows to avoid accidental
>>> refcounter overflows that might lead to use-after-free
>>> situations.
>>>
>>> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
>>> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>> Signed-off-by: David Windsor <dwindsor@gmail.com>
>> [...]
>>> diff --git a/drivers/media/pci/cx88/cx88.h b/drivers/media/pci/cx88/cx88.h
>>> index 115414c..16c1313 100644
>>> --- a/drivers/media/pci/cx88/cx88.h
>>> +++ b/drivers/media/pci/cx88/cx88.h
[...]
>>> @@ -339,7 +340,7 @@ struct cx8802_dev;
>>>
>>>  struct cx88_core {
>>>  	struct list_head           devlist;
>>> -	atomic_t                   refcount;
>>> +	refcount_t                   refcount;
>>
>>     Could you please keep the name aligned with above and below?
>
> You mean "not aligned" to devlist, but with a shift like it was before?

    I mean aligned, like it was before. :-)

> Sure, will fix. Is the patch ok otherwise?

    I haven't noticed anything else...

> Best Regards,
> Elena.
[...]

MBR, Sergei

[toc] | [prev] | [next] | [standalone]

#1593979 — Re: [PATCH 11/29] drivers, media: convert cx88_core.refcount from atomic_t to refcount_t

On Mon, Mar 06, 2017 at 04:20:58PM +0200, Elena Reshetova wrote:
> refcount_t type and corresponding API should be
> used instead of atomic_t when the variable is used as
> a reference counter. This allows to avoid accidental
> refcounter overflows that might lead to use-after-free
> situations.
> 
> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: David Windsor <dwindsor@gmail.com>

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web