LinuxLists.cc - [PATCHv4]Checks for Null value in function *get

2014-06-16 15:25:36

Subject: [PATCHv4]Checks for Null value in function *get_skub

2014-06-16 15:31:01

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

On 6/16/2014 10:25 AM, Nicholas Krause wrote:
> Signed-off-by: Nicholas Krause <[email protected]>
> ---
> drivers/infiniband/hw/cxgb4/cm.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> index f9477e2..2d56983 100644
> --- a/drivers/infiniband/hw/cxgb4/cm.c
> +++ b/drivers/infiniband/hw/cxgb4/cm.c
> @@ -340,15 +340,13 @@ static int status2errno(int status)
> */
> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
> {
> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
> skb_trim(skb, 0);
> skb_get(skb);
> skb_reset_transport_header(skb);
> } else {
> + if (skb)
> + kfree_skb (skb);
> skb = alloc_skb(len, gfp);
> }
> t4_set_arp_err_handler(skb, NULL, NULL);

Can you change the comment? This patch is now fixing a potential skb
leak. Also, kfree_sb() will ignore NULL ptrs, so we could just always
call it. But I'd add a comment like /* NULL is ignored */.

Thanks,

Steve.

2014-06-16 15:33:12

by Levente Kurusa

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

On 06/16/2014 05:30 PM, Steve Wise wrote:
> On 6/16/2014 10:25 AM, Nicholas Krause wrote:
>> Signed-off-by: Nicholas Krause <[email protected]>
>> ---
>> drivers/infiniband/hw/cxgb4/cm.c | 8 +++-----
>> 1 file changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
>> index f9477e2..2d56983 100644
>> --- a/drivers/infiniband/hw/cxgb4/cm.c
>> +++ b/drivers/infiniband/hw/cxgb4/cm.c
>> @@ -340,15 +340,13 @@ static int status2errno(int status)
>> */
>> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
>> {
>> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
>> skb_trim(skb, 0);
>> skb_get(skb);
>> skb_reset_transport_header(skb);
>> } else {
>> + if (skb)
>> + kfree_skb (skb);
>> skb = alloc_skb(len, gfp);
>> }
>> t4_set_arp_err_handler(skb, NULL, NULL);
>
> Can you change the comment? This patch is now fixing a potential skb leak.
> Also, kfree_sb() will ignore NULL ptrs, so we could just always call it.
> But I'd add a comment like /* NULL is ignored */.

AFAIK, checkpatch.pl will show you a message if it detects this:

if (x)
kfree(x);

so I guess it is not really needed.

Thanks,
Levente Kurusa.

2014-06-16 15:37:16

by Nicholas Krause

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

Signed-off-by: Nicholas Krause <[email protected]>
---
drivers/infiniband/hw/cxgb4/
cm.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index f9477e2..2d56983 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -340,15 +340,13 @@ static int status2errno(int status)
*/
static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
{
if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
skb_trim(skb, 0);
skb_get(skb);
skb_reset_transport_header(skb);
} else {
+ if (skb)
/* NULL is ignored */.
+ kfree_skb (skb);
skb = alloc_skb(len, gfp);
}
t4_set_arp_err_handler(skb, NULL, NULL);

On Mon, Jun 16, 2014 at 11:30 AM, Steve Wise
<[email protected]> wrote:
> On 6/16/2014 10:25 AM, Nicholas Krause wrote:
>>
>> Signed-off-by: Nicholas Krause <[email protected]>
>> ---
>> drivers/infiniband/hw/cxgb4/cm.c | 8 +++-----
>> 1 file changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/cxgb4/cm.c
>> b/drivers/infiniband/hw/cxgb4/cm.c
>> index f9477e2..2d56983 100644
>> --- a/drivers/infiniband/hw/cxgb4/cm.c
>> +++ b/drivers/infiniband/hw/cxgb4/cm.c
>> @@ -340,15 +340,13 @@ static int status2errno(int status)
>> */
>> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
>> {
>> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
>> skb_trim(skb, 0);
>> skb_get(skb);
>> skb_reset_transport_header(skb);
>> } else {
>> + if (skb)
>> + kfree_skb (skb);
>> skb = alloc_skb(len, gfp);
>> }
>> t4_set_arp_err_handler(skb, NULL, NULL);
>
>
> Can you change the comment? This patch is now fixing a potential skb leak.
> Also, kfree_sb() will ignore NULL ptrs, so we could just always call it.
> But I'd add a comment like /* NULL is ignored */.
>
> Thanks,
>
> Steve.

2014-06-16 15:45:05

by Nicholas Krause

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

Can we close this bug or is it still a issue as we can'
return NULL from kfree or kfree_skb. Here is the bug
ID 44631 I would close it if we are done with the bug
otherwise I think there are no other issues with
allocating a skb,
Cheers Nick

On Mon, Jun 16, 2014 at 11:37 AM, Nick Krause <[email protected]> wrote:
> Signed-off-by: Nicholas Krause <[email protected]>
> ---
> drivers/infiniband/hw/cxgb4/
> cm.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> index f9477e2..2d56983 100644
> --- a/drivers/infiniband/hw/cxgb4/cm.c
> +++ b/drivers/infiniband/hw/cxgb4/cm.c
> @@ -340,15 +340,13 @@ static int status2errno(int status)
> */
> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
> {
> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
> skb_trim(skb, 0);
> skb_get(skb);
> skb_reset_transport_header(skb);
> } else {
> + if (skb)
> /* NULL is ignored */.
> + kfree_skb (skb);
> skb = alloc_skb(len, gfp);
> }
> t4_set_arp_err_handler(skb, NULL, NULL);
>
> On Mon, Jun 16, 2014 at 11:30 AM, Steve Wise
> <[email protected]> wrote:
>> On 6/16/2014 10:25 AM, Nicholas Krause wrote:
>>>
>>> Signed-off-by: Nicholas Krause <[email protected]>
>>> ---
>>> drivers/infiniband/hw/cxgb4/cm.c | 8 +++-----
>>> 1 file changed, 3 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/infiniband/hw/cxgb4/cm.c
>>> b/drivers/infiniband/hw/cxgb4/cm.c
>>> index f9477e2..2d56983 100644
>>> --- a/drivers/infiniband/hw/cxgb4/cm.c
>>> +++ b/drivers/infiniband/hw/cxgb4/cm.c
>>> @@ -340,15 +340,13 @@ static int status2errno(int status)
>>> */
>>> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
>>> {
>>> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
>>> skb_trim(skb, 0);
>>> skb_get(skb);
>>> skb_reset_transport_header(skb);
>>> } else {
>>> + if (skb)
>>> + kfree_skb (skb);
>>> skb = alloc_skb(len, gfp);
>>> }
>>> t4_set_arp_err_handler(skb, NULL, NULL);
>>
>>
>> Can you change the comment? This patch is now fixing a potential skb leak.
>> Also, kfree_sb() will ignore NULL ptrs, so we could just always call it.
>> But I'd add a comment like /* NULL is ignored */.
>>
>> Thanks,
>>
>> Steve.

2014-06-16 15:45:56

by Levente Kurusa

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

On 06/16/2014 05:37 PM, Nick Krause wrote:
> Signed-off-by: Nicholas Krause <[email protected]>
> ---
> drivers/infiniband/hw/cxgb4/
> cm.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
> index f9477e2..2d56983 100644
> --- a/drivers/infiniband/hw/cxgb4/cm.c
> +++ b/drivers/infiniband/hw/cxgb4/cm.c
> @@ -340,15 +340,13 @@ static int status2errno(int status)
> */
> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
> {
> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
> skb_trim(skb, 0);
> skb_get(skb);
> skb_reset_transport_header(skb);
> } else {
> + if (skb)
> /* NULL is ignored */.
> + kfree_skb (skb);
> skb = alloc_skb(len, gfp);
> }
> t4_set_arp_err_handler(skb, NULL, NULL);

This patch is severely whitespace damaged. Can you fix your MUA
or try to use git-send-email?

The changelog as well is of low quality. Maybe something like this:

infiniband: cxgb4: fix memory skb memory leak

... would be better.

Also, this fails the build, due to the extra dot character after
the comment. :-(

Thanks,
Levente Kurusa.

2014-06-16 16:32:19

by Nicholas Krause

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

Hey Guys ,
It states tot run cleanfile or cleanpatch script but it doesn't work
how do I run these scripts.
Thanks Nick

On Mon, Jun 16, 2014 at 11:45 AM, Levente Kurusa <[email protected]> wrote:
> On 06/16/2014 05:37 PM, Nick Krause wrote:
>>
>> Signed-off-by: Nicholas Krause <[email protected]>
>> ---
>> drivers/infiniband/hw/cxgb4/
>> cm.c | 8 +++-----
>> 1 file changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/cxgb4/cm.c
>> b/drivers/infiniband/hw/cxgb4/cm.c
>> index f9477e2..2d56983 100644
>> --- a/drivers/infiniband/hw/cxgb4/cm.c
>> +++ b/drivers/infiniband/hw/cxgb4/cm.c
>> @@ -340,15 +340,13 @@ static int status2errno(int status)
>> */
>> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
>> {
>> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
>> skb_trim(skb, 0);
>> skb_get(skb);
>> skb_reset_transport_header(skb);
>> } else {
>> + if (skb)
>> /* NULL is ignored */.
>> + kfree_skb (skb);
>> skb = alloc_skb(len, gfp);
>> }
>> t4_set_arp_err_handler(skb, NULL, NULL);
>
>
> This patch is severely whitespace damaged. Can you fix your MUA
> or try to use git-send-email?
>
> The changelog as well is of low quality. Maybe something like this:
>
> infiniband: cxgb4: fix memory skb memory leak
>
> ... would be better.
>
> Also, this fails the build, due to the extra dot character after
> the comment. :-(
>
> Thanks,
> Levente Kurusa.

2014-06-16 16:37:56

by Steve Wise

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

On 6/16/2014 10:45 AM, Levente Kurusa wrote:
> On 06/16/2014 05:37 PM, Nick Krause wrote:
>> Signed-off-by: Nicholas Krause <[email protected]>
>> ---
>> drivers/infiniband/hw/cxgb4/
>> cm.c | 8 +++-----
>> 1 file changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/cxgb4/cm.c
>> b/drivers/infiniband/hw/cxgb4/cm.c
>> index f9477e2..2d56983 100644
>> --- a/drivers/infiniband/hw/cxgb4/cm.c
>> +++ b/drivers/infiniband/hw/cxgb4/cm.c
>> @@ -340,15 +340,13 @@ static int status2errno(int status)
>> */
>> static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t
>> gfp)
>> {
>> if (skb && !skb_is_nonlinear(skb) && !skb_cloned(skb)) {
>> skb_trim(skb, 0);
>> skb_get(skb);
>> skb_reset_transport_header(skb);
>> } else {
>> + if (skb)
>> /* NULL is ignored */.
>> + kfree_skb (skb);
>> skb = alloc_skb(len, gfp);
>> }
>> t4_set_arp_err_handler(skb, NULL, NULL);
>
> This patch is severely whitespace damaged. Can you fix your MUA
> or try to use git-send-email?
>
> The changelog as well is of low quality. Maybe something like this:
>
> infiniband: cxgb4: fix memory skb memory leak
>
> ... would be better.
>
> Also, this fails the build, due to the extra dot character after
> the comment. :-(
>

Agreed. Start over with this patch, do what we asked, and make sure it
passes checkpatch...

> Thanks,
> Levente Kurusa.

2014-06-16 17:18:50

by Steve Wise

[permalink] [raw]

Subject: Re: [PATCHv4]Checks for Null value in function *get_skub

On 6/16/2014 10:45 AM, Nick Krause wrote:
> Can we close this bug or is it still a issue as we can'
> return NULL from kfree or kfree_skb. Here is the bug
> ID 44631 I would close it if we are done with the bug
> otherwise I think there are no other issues with
> allocating a skb,
>

In what database is this bug ID 44631?