[PATCH] thermal: thermal_core: policy store via sysfs is broken

[PATCH] thermal: thermal_core: policy store via sysfs is broken

[Shawn Guo]

When function __find_governor() gets called from policy_store(), the
argument 'buf' has a '\n' character at the end.  This causes strnicmp()
mismatches all the time.  Consequently, policy_store() will always
return -EINVAL, and hence the policy store via sysfs will always fail
even when users store a correct policy name.

Fix the problem by using strncasecmp() for policy name matching in
__find_governor().

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
 drivers/thermal/thermal_core.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index d755440..6ba869f 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -57,9 +57,10 @@ static struct thermal_governor *__find_governor(const char *name)
 {
 	struct thermal_governor *pos;
 
-	list_for_each_entry(pos, &thermal_governor_list, governor_list)
-		if (!strnicmp(name, pos->name, THERMAL_NAME_LENGTH))
+	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
+		if (!strncasecmp(name, pos->name, strlen(pos->name)))
 			return pos;
+	}
 
 	return NULL;
 }
-- 
1.7.9.5

[PATCH] thermal: thermal_core: policy store via sysfs is broken

[Shawn Guo]

When function __find_governor() gets called from policy_store(), the
argument 'buf' has a '\n' character at the end.  This causes strnicmp()
mismatches all the time.  Consequently, policy_store() will always
return -EINVAL, and hence the policy store via sysfs will always fail
even when users store a correct policy name.

Fix the problem by using strncasecmp() for policy name matching in
__find_governor().

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
 drivers/thermal/thermal_core.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index d755440..6ba869f 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -57,9 +57,10 @@ static struct thermal_governor *__find_governor(const char *name)
 {
 	struct thermal_governor *pos;
 
-	list_for_each_entry(pos, &thermal_governor_list, governor_list)
-		if (!strnicmp(name, pos->name, THERMAL_NAME_LENGTH))
+	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
+		if (!strncasecmp(name, pos->name, strlen(pos->name)))
 			return pos;
+	}
 
 	return NULL;
 }
-- 
1.7.9.5

Re: [PATCH] thermal: thermal_core: policy store via sysfs is broken

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 1624 bytes --]

Shawn,

On 03-06-2013 09:59, Shawn Guo wrote:
> When function __find_governor() gets called from policy_store(), the
> argument 'buf' has a '\n' character at the end.  This causes strnicmp()
> mismatches all the time.  Consequently, policy_store() will always
> return -EINVAL, and hence the policy store via sysfs will always fail
> even when users store a correct policy name.
> 
> Fix the problem by using strncasecmp() for policy name matching in
> __find_governor().
> 
Thanks for your patch, but Andy has fixed this issue already here:

http://git.kernel.org/cgit/linux/kernel/git/rzhang/linux.git/commit/?h=next&id=42a5bf507d7f7ecbf606eb392dd9d2e4d009c36b

Patch is present in thermal/next.


> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> ---
>  drivers/thermal/thermal_core.c |    5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index d755440..6ba869f 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -57,9 +57,10 @@ static struct thermal_governor *__find_governor(const char *name)
>  {
>  	struct thermal_governor *pos;
>  
> -	list_for_each_entry(pos, &thermal_governor_list, governor_list)
> -		if (!strnicmp(name, pos->name, THERMAL_NAME_LENGTH))
> +	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
> +		if (!strncasecmp(name, pos->name, strlen(pos->name)))
>  			return pos;
> +	}
>  
>  	return NULL;
>  }
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 295 bytes --]

[PATCH] thermal: thermal_core: policy store via sysfs is broken

[Eduardo Valentin]

Shawn,

On 03-06-2013 09:59, Shawn Guo wrote:
> When function __find_governor() gets called from policy_store(), the
> argument 'buf' has a '\n' character at the end.  This causes strnicmp()
> mismatches all the time.  Consequently, policy_store() will always
> return -EINVAL, and hence the policy store via sysfs will always fail
> even when users store a correct policy name.
> 
> Fix the problem by using strncasecmp() for policy name matching in
> __find_governor().
> 
Thanks for your patch, but Andy has fixed this issue already here:

http://git.kernel.org/cgit/linux/kernel/git/rzhang/linux.git/commit/?h=next&id=42a5bf507d7f7ecbf606eb392dd9d2e4d009c36b

Patch is present in thermal/next.


> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> ---
>  drivers/thermal/thermal_core.c |    5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index d755440..6ba869f 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -57,9 +57,10 @@ static struct thermal_governor *__find_governor(const char *name)
>  {
>  	struct thermal_governor *pos;
>  
> -	list_for_each_entry(pos, &thermal_governor_list, governor_list)
> -		if (!strnicmp(name, pos->name, THERMAL_NAME_LENGTH))
> +	list_for_each_entry(pos, &thermal_governor_list, governor_list) {
> +		if (!strncasecmp(name, pos->name, strlen(pos->name)))
>  			return pos;
> +	}
>  
>  	return NULL;
>  }
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 295 bytes
Desc: OpenPGP digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20130603/85efb595/attachment.sig>