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* [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer dereference
@ 2010-05-27 12:37 Julia Lawall
  2010-05-27 16:21 ` Dmitry Torokhov
  0 siblings, 1 reply; 5+ messages in thread
From: Julia Lawall @ 2010-05-27 12:37 UTC (permalink / raw)
  To: Mattia Dongili, Matthew Garrett, platform-driver-x86,
	linux-kernel, kernel-janitors

From: Julia Lawall <julia@diku.dk>

Give different error messages if device_enum is NULL or if its type field
has the wrong value.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@

if ((E = NULL && ...) || ...)
{
  ... when != if (...) S1 else S2
      when != E = E1
* E->f
  ... when any
  return ...;
}
else S3
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
This may be too much clutter for little benefit.  Other, perhaps less
informative solutions are possible.

 drivers/platform/x86/sony-laptop.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 1387c5f..9db8d2b 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1196,8 +1196,12 @@ static void sony_nc_rfkill_setup(struct acpi_device *device)
 	}
 
 	device_enum = (union acpi_object *) buffer.pointer;
-	if (!device_enum || device_enum->type != ACPI_TYPE_BUFFER) {
-		printk(KERN_ERR "Invalid SN06 return object 0x%.2x\n",
+	if (!device_enum) {
+		pr_err("Invalid SN06 return object\n");
+		goto out_no_enum;
+	}
+	if (device_enum->type != ACPI_TYPE_BUFFER) {
+		printk(KERN_ERR "Invalid SN06 return object type 0x%.2x\n",
 				device_enum->type);
 		goto out_no_enum;
 	}

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer dereference
  2010-05-27 12:37 [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer dereference Julia Lawall
@ 2010-05-27 16:21 ` Dmitry Torokhov
  2010-05-27 16:25   ` [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer Julia Lawall
  2010-05-27 16:32   ` Julia Lawall
  0 siblings, 2 replies; 5+ messages in thread
From: Dmitry Torokhov @ 2010-05-27 16:21 UTC (permalink / raw)
  To: Julia Lawall
  Cc: Mattia Dongili, Matthew Garrett, platform-driver-x86,
	linux-kernel, kernel-janitors

On Thursday 27 May 2010 05:37:00 am Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> Give different error messages if device_enum is NULL or if its type field
> has the wrong value.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @r exists@
> expression E,E1;
> identifier f;
> statement S1,S2,S3;
> @@
> 
> if ((E = NULL && ...) || ...)
> {
>   ... when != if (...) S1 else S2
>       when != E = E1
> * E->f
>   ... when any
>   return ...;
> }
> else S3
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
> This may be too much clutter for little benefit.  Other, perhaps less
> informative solutions are possible.

Verbosity should be OK but I think that mixing pr_xxx() and naked printks
in the same patch is not very nice.

> 
>  drivers/platform/x86/sony-laptop.c |    8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/x86/sony-laptop.c
> b/drivers/platform/x86/sony-laptop.c index 1387c5f..9db8d2b 100644
> --- a/drivers/platform/x86/sony-laptop.c
> +++ b/drivers/platform/x86/sony-laptop.c
> @@ -1196,8 +1196,12 @@ static void sony_nc_rfkill_setup(struct acpi_device
> *device) }
> 
>  	device_enum = (union acpi_object *) buffer.pointer;
> -	if (!device_enum || device_enum->type != ACPI_TYPE_BUFFER) {
> -		printk(KERN_ERR "Invalid SN06 return object 0x%.2x\n",
> +	if (!device_enum) {
> +		pr_err("Invalid SN06 return object\n");
> +		goto out_no_enum;
> +	}
> +	if (device_enum->type != ACPI_TYPE_BUFFER) {
> +		printk(KERN_ERR "Invalid SN06 return object type 0x%.2x\n",
>  				device_enum->type);
>  		goto out_no_enum;
>  	}

Thanks.

-- 
Dmitry

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer
  2010-05-27 16:21 ` Dmitry Torokhov
@ 2010-05-27 16:25   ` Julia Lawall
  2010-05-27 16:32   ` Julia Lawall
  1 sibling, 0 replies; 5+ messages in thread
From: Julia Lawall @ 2010-05-27 16:25 UTC (permalink / raw)
  To: Dmitry Torokhov
  Cc: Mattia Dongili, Matthew Garrett, platform-driver-x86,
	linux-kernel, kernel-janitors

On Thu, 27 May 2010, Dmitry Torokhov wrote:

> On Thursday 27 May 2010 05:37:00 am Julia Lawall wrote:
> > From: Julia Lawall <julia@diku.dk>
> > 
> > Give different error messages if device_enum is NULL or if its type field
> > has the wrong value.
> > 
> > A simplified version of the semantic match that finds this problem is as
> > follows: (http://coccinelle.lip6.fr/)
> > 
> > // <smpl>
> > @r exists@
> > expression E,E1;
> > identifier f;
> > statement S1,S2,S3;
> > @@
> > 
> > if ((E = NULL && ...) || ...)
> > {
> >   ... when != if (...) S1 else S2
> >       when != E = E1
> > * E->f
> >   ... when any
> >   return ...;
> > }
> > else S3
> > // </smpl>
> > 
> > Signed-off-by: Julia Lawall <julia@diku.dk>
> > 
> > ---
> > This may be too much clutter for little benefit.  Other, perhaps less
> > informative solutions are possible.
> 
> Verbosity should be OK but I think that mixing pr_xxx() and naked printks
> in the same patch is not very nice.

Oops, sorry about that.  I will change it.

julia


> >  drivers/platform/x86/sony-laptop.c |    8 ++++++--
> >  1 file changed, 6 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/platform/x86/sony-laptop.c
> > b/drivers/platform/x86/sony-laptop.c index 1387c5f..9db8d2b 100644
> > --- a/drivers/platform/x86/sony-laptop.c
> > +++ b/drivers/platform/x86/sony-laptop.c
> > @@ -1196,8 +1196,12 @@ static void sony_nc_rfkill_setup(struct acpi_device
> > *device) }
> > 
> >  	device_enum = (union acpi_object *) buffer.pointer;
> > -	if (!device_enum || device_enum->type != ACPI_TYPE_BUFFER) {
> > -		printk(KERN_ERR "Invalid SN06 return object 0x%.2x\n",
> > +	if (!device_enum) {
> > +		pr_err("Invalid SN06 return object\n");
> > +		goto out_no_enum;
> > +	}
> > +	if (device_enum->type != ACPI_TYPE_BUFFER) {
> > +		printk(KERN_ERR "Invalid SN06 return object type 0x%.2x\n",
> >  				device_enum->type);
> >  		goto out_no_enum;
> >  	}
> 
> Thanks.
> 
> -- 
> Dmitry
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer
  2010-05-27 16:21 ` Dmitry Torokhov
  2010-05-27 16:25   ` [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer Julia Lawall
@ 2010-05-27 16:32   ` Julia Lawall
  2010-05-28 17:25     ` Matthew Garrett
  1 sibling, 1 reply; 5+ messages in thread
From: Julia Lawall @ 2010-05-27 16:32 UTC (permalink / raw)
  To: Dmitry Torokhov
  Cc: Mattia Dongili, Matthew Garrett, platform-driver-x86,
	linux-kernel, kernel-janitors

From: Julia Lawall <julia@diku.dk>

Give different error messages if device_enum is NULL or if its type field
has the wrong value.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@

if ((E = NULL && ...) || ...)
{
  ... when != if (...) S1 else S2
      when != E = E1
* E->f
  ... when any
  return ...;
}
else S3
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 drivers/platform/x86/sony-laptop.c  |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 1387c5f..a47fd4e 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1196,9 +1196,13 @@ static void sony_nc_rfkill_setup(struct acpi_device *device)
 	}
 
 	device_enum = (union acpi_object *) buffer.pointer;
-	if (!device_enum || device_enum->type != ACPI_TYPE_BUFFER) {
-		printk(KERN_ERR "Invalid SN06 return object 0x%.2x\n",
-				device_enum->type);
+	if (!device_enum) {
+		pr_err("Invalid SN06 return object\n");
+		goto out_no_enum;
+	}
+	if (device_enum->type != ACPI_TYPE_BUFFER) {
+		pr_err("Invalid SN06 return object type 0x%.2x\n",
+		       device_enum->type);
 		goto out_no_enum;
 	}
 

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer
  2010-05-27 16:32   ` Julia Lawall
@ 2010-05-28 17:25     ` Matthew Garrett
  0 siblings, 0 replies; 5+ messages in thread
From: Matthew Garrett @ 2010-05-28 17:25 UTC (permalink / raw)
  To: Julia Lawall
  Cc: Dmitry Torokhov, Mattia Dongili, platform-driver-x86,
	linux-kernel, kernel-janitors

Applied this version, thanks.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2010-05-28 17:25 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-05-27 12:37 [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer dereference Julia Lawall
2010-05-27 16:21 ` Dmitry Torokhov
2010-05-27 16:25   ` [PATCH 9/11] drivers/platform/x86: Eliminate a NULL pointer Julia Lawall
2010-05-27 16:32   ` Julia Lawall
2010-05-28 17:25     ` Matthew Garrett

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