* [PATCH] backlight: check null deference of name when device is registered
@ 2013-01-04 8:29 Jingoo Han
2013-01-08 0:01 ` Andrew Morton
0 siblings, 1 reply; 6+ messages in thread
From: Jingoo Han @ 2013-01-04 8:29 UTC (permalink / raw)
To: 'Andrew Morton', 'LKML'
Cc: linux-fbdev, 'Richard Purdie', 'Devendra Naga',
'Jingoo Han'
NULL deference of name is checked when device is registered.
If the name is null, it will cause a kernel oops in dev_set_name().
Acked-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
---
drivers/video/backlight/backlight.c | 5 +++++
drivers/video/backlight/lcd.c | 5 +++++
2 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 345f666..f2db904 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name,
struct backlight_device *new_bd;
int rc;
+ if (name = NULL) {
+ pr_err("backlight name is null\n");
+ return ERR_PTR(-EINVAL);
+ }
+
pr_debug("backlight_device_register: name=%s\n", name);
new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 34fb6bd..3d0ac0c 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -207,6 +207,11 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
struct lcd_device *new_ld;
int rc;
+ if (name = NULL) {
+ pr_err("lcd name is null\n");
+ return ERR_PTR(-EINVAL);
+ }
+
pr_debug("lcd_device_register: name=%s\n", name);
new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
--
1.7.2.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] backlight: check null deference of name when device is registered
2013-01-04 8:29 [PATCH] backlight: check null deference of name when device is registered Jingoo Han
@ 2013-01-08 0:01 ` Andrew Morton
2013-01-08 1:25 ` Jingoo Han
0 siblings, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2013-01-08 0:01 UTC (permalink / raw)
To: Jingoo Han
Cc: 'LKML', linux-fbdev, 'Richard Purdie',
'Devendra Naga'
On Fri, 04 Jan 2013 17:29:11 +0900
Jingoo Han <jg1.han@samsung.com> wrote:
> NULL deference of name is checked when device is registered.
> If the name is null, it will cause a kernel oops in dev_set_name().
>
> ...
>
> --- a/drivers/video/backlight/backlight.c
> +++ b/drivers/video/backlight/backlight.c
> @@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name,
> struct backlight_device *new_bd;
> int rc;
>
> + if (name = NULL) {
> + pr_err("backlight name is null\n");
> + return ERR_PTR(-EINVAL);
> + }
> +
> pr_debug("backlight_device_register: name=%s\n", name);
I don't understand this.
Is there some driver which is calling these functions with name=NULL?
If so, which one(s)?
If "no" then why don't we declare that "passing name=NULL is a bug" and
leave the code as-is?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] backlight: check null deference of name when device is registered
2013-01-08 0:01 ` Andrew Morton
@ 2013-01-08 1:25 ` Jingoo Han
2013-01-08 1:35 ` Andrew Morton
0 siblings, 1 reply; 6+ messages in thread
From: Jingoo Han @ 2013-01-08 1:25 UTC (permalink / raw)
To: 'Andrew Morton'
Cc: 'LKML', linux-fbdev, 'Richard Purdie',
'Devendra Naga', 'Jingoo Han'
On Tuesday, January 08, 2013 9:02 AM, Andrew Morton wrote
> On Fri, 04 Jan 2013 17:29:11 +0900
> Jingoo Han <jg1.han@samsung.com> wrote:
>
> > NULL deference of name is checked when device is registered.
> > If the name is null, it will cause a kernel oops in dev_set_name().
> >
> > ...
> >
> > --- a/drivers/video/backlight/backlight.c
> > +++ b/drivers/video/backlight/backlight.c
> > @@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name,
> > struct backlight_device *new_bd;
> > int rc;
> >
> > + if (name = NULL) {
> > + pr_err("backlight name is null\n");
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > pr_debug("backlight_device_register: name=%s\n", name);
>
> I don't understand this.
>
> Is there some driver which is calling these functions with name=NULL?
> If so, which one(s)?
No, there is no one.
>
> If "no" then why don't we declare that "passing name=NULL is a bug" and
> leave the code as-is?
Do you mean following?
+ if (name = NULL)
+ pr_err("passing name=NULL is a bug");
+
pr_debug("backlight_device_register: name=%s\n", name);
Best regards,
Jingoo Han
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] backlight: check null deference of name when device is registered
2013-01-08 1:25 ` Jingoo Han
@ 2013-01-08 1:35 ` Andrew Morton
2013-01-08 1:39 ` Jingoo Han
2013-01-08 4:28 ` devendra.aaru
0 siblings, 2 replies; 6+ messages in thread
From: Andrew Morton @ 2013-01-08 1:35 UTC (permalink / raw)
To: Jingoo Han
Cc: 'LKML', linux-fbdev, 'Richard Purdie',
'Devendra Naga'
On Tue, 08 Jan 2013 10:25:35 +0900 Jingoo Han <jg1.han@samsung.com> wrote:
> On Tuesday, January 08, 2013 9:02 AM, Andrew Morton wrote
> > On Fri, 04 Jan 2013 17:29:11 +0900
> > Jingoo Han <jg1.han@samsung.com> wrote:
> >
> > > NULL deference of name is checked when device is registered.
> > > If the name is null, it will cause a kernel oops in dev_set_name().
> > >
> > > ...
> > >
> > > --- a/drivers/video/backlight/backlight.c
> > > +++ b/drivers/video/backlight/backlight.c
> > > @@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name,
> > > struct backlight_device *new_bd;
> > > int rc;
> > >
> > > + if (name = NULL) {
> > > + pr_err("backlight name is null\n");
> > > + return ERR_PTR(-EINVAL);
> > > + }
> > > +
> > > pr_debug("backlight_device_register: name=%s\n", name);
> >
> > I don't understand this.
> >
> > Is there some driver which is calling these functions with name=NULL?
> > If so, which one(s)?
>
> No, there is no one.
>
> >
> > If "no" then why don't we declare that "passing name=NULL is a bug" and
> > leave the code as-is?
>
> Do you mean following?
>
> + if (name = NULL)
> + pr_err("passing name=NULL is a bug");
> +
> pr_debug("backlight_device_register: name=%s\n", name);
Nope; I'm suggesting we leave the code alone. If someone passes in
NULL they will get a nice oops and their bug will then get fixed.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] backlight: check null deference of name when device is registered
2013-01-08 1:35 ` Andrew Morton
@ 2013-01-08 1:39 ` Jingoo Han
2013-01-08 4:28 ` devendra.aaru
1 sibling, 0 replies; 6+ messages in thread
From: Jingoo Han @ 2013-01-08 1:39 UTC (permalink / raw)
To: 'Andrew Morton'
Cc: 'LKML', linux-fbdev, 'Richard Purdie',
'Devendra Naga', 'Jingoo Han'
On Tuesday, January 08, 2013 10:36 AM, Andrew Morton wrote
> On Tue, 08 Jan 2013 10:25:35 +0900 Jingoo Han <jg1.han@samsung.com> wrote:
>
> > On Tuesday, January 08, 2013 9:02 AM, Andrew Morton wrote
> > > On Fri, 04 Jan 2013 17:29:11 +0900
> > > Jingoo Han <jg1.han@samsung.com> wrote:
> > >
> > > > NULL deference of name is checked when device is registered.
> > > > If the name is null, it will cause a kernel oops in dev_set_name().
> > > >
> > > > ...
> > > >
> > > > --- a/drivers/video/backlight/backlight.c
> > > > +++ b/drivers/video/backlight/backlight.c
> > > > @@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name,
> > > > struct backlight_device *new_bd;
> > > > int rc;
> > > >
> > > > + if (name = NULL) {
> > > > + pr_err("backlight name is null\n");
> > > > + return ERR_PTR(-EINVAL);
> > > > + }
> > > > +
> > > > pr_debug("backlight_device_register: name=%s\n", name);
> > >
> > > I don't understand this.
> > >
> > > Is there some driver which is calling these functions with name=NULL?
> > > If so, which one(s)?
> >
> > No, there is no one.
> >
> > >
> > > If "no" then why don't we declare that "passing name=NULL is a bug" and
> > > leave the code as-is?
> >
> > Do you mean following?
> >
> > + if (name = NULL)
> > + pr_err("passing name=NULL is a bug");
> > +
> > pr_debug("backlight_device_register: name=%s\n", name);
>
> Nope; I'm suggesting we leave the code alone. If someone passes in
> NULL they will get a nice oops and their bug will then get fixed.
I see. I agree with you.
Please, abandon this patch.
Best regards,
Jingoo Han
>
> --
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] backlight: check null deference of name when device is registered
2013-01-08 1:35 ` Andrew Morton
2013-01-08 1:39 ` Jingoo Han
@ 2013-01-08 4:28 ` devendra.aaru
1 sibling, 0 replies; 6+ messages in thread
From: devendra.aaru @ 2013-01-08 4:28 UTC (permalink / raw)
To: Andrew Morton; +Cc: Jingoo Han, LKML, linux-fbdev, Richard Purdie
On Mon, Jan 7, 2013 at 8:35 PM, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Tue, 08 Jan 2013 10:25:35 +0900 Jingoo Han <jg1.han@samsung.com> wrote:
>
>> On Tuesday, January 08, 2013 9:02 AM, Andrew Morton wrote
>> > On Fri, 04 Jan 2013 17:29:11 +0900
>> > Jingoo Han <jg1.han@samsung.com> wrote:
>> >
>> > > NULL deference of name is checked when device is registered.
>> > > If the name is null, it will cause a kernel oops in dev_set_name().
>> > >
>> > > ...
>> > >
>> > > --- a/drivers/video/backlight/backlight.c
>> > > +++ b/drivers/video/backlight/backlight.c
>> > > @@ -292,6 +292,11 @@ struct backlight_device *backlight_device_register(const char *name,
>> > > struct backlight_device *new_bd;
>> > > int rc;
>> > >
>> > > + if (name = NULL) {
>> > > + pr_err("backlight name is null\n");
>> > > + return ERR_PTR(-EINVAL);
>> > > + }
>> > > +
>> > > pr_debug("backlight_device_register: name=%s\n", name);
>> >
>> > I don't understand this.
>> >
>> > Is there some driver which is calling these functions with name=NULL?
>> > If so, which one(s)?
>>
>> No, there is no one.
>>
>> >
>> > If "no" then why don't we declare that "passing name=NULL is a bug" and
>> > leave the code as-is?
>>
>> Do you mean following?
>>
>> + if (name = NULL)
>> + pr_err("passing name=NULL is a bug");
>> +
>> pr_debug("backlight_device_register: name=%s\n", name);
>
> Nope; I'm suggesting we leave the code alone. If someone passes in
> NULL they will get a nice oops and their bug will then get fixed.
>
We still fail the probe in the patch Jingoo Han sent,
anyways if i catch your point correctly is this the lines you wanted?
+ /**
+ * BUG if the name of the backlight device
+ * is a NULL
+ */
+ BUG_ON(!name);
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-01-08 4:28 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2013-01-04 8:29 [PATCH] backlight: check null deference of name when device is registered Jingoo Han
2013-01-08 0:01 ` Andrew Morton
2013-01-08 1:25 ` Jingoo Han
2013-01-08 1:35 ` Andrew Morton
2013-01-08 1:39 ` Jingoo Han
2013-01-08 4:28 ` devendra.aaru
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