[PATCH] ndtest: Remove redundant NULL check

[PATCH] ndtest: Remove redundant NULL check

[Jiapeng Chong]

Fix the following coccicheck warnings:

./tools/testing/nvdimm/test/ndtest.c:491:2-7: WARNING: NULL check before
some freeing functions is not needed.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
---
 tools/testing/nvdimm/test/ndtest.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c
index 6862915..98b4a43 100644
--- a/tools/testing/nvdimm/test/ndtest.c
+++ b/tools/testing/nvdimm/test/ndtest.c
@@ -487,8 +487,7 @@ static void *ndtest_alloc_resource(struct ndtest_priv *p, size_t size,
 buf_err:
 	if (__dma && size >= DIMM_SIZE)
 		gen_pool_free(ndtest_pool, __dma, size);
-	if (buf)
-		vfree(buf);
+	vfree(buf);
 	kfree(res);
 
 	return NULL;
-- 
1.8.3.1
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Re: [PATCH] ndtest: Remove redundant NULL check

[Ira Weiny]

On Mon, Mar 22, 2021 at 06:00:40PM +0800, Jiapeng Chong wrote:
> Fix the following coccicheck warnings:
> 
> ./tools/testing/nvdimm/test/ndtest.c:491:2-7: WARNING: NULL check before
> some freeing functions is not needed.

I don't think there is anything wrong with this patch specifically but why is
buf not checked for null after the vmalloc?

It seems to me that if size >= DIMM_SIZE and the vmalloc fails the gen pool
allocation is going to be leaked.

Ira

> 
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
> ---
>  tools/testing/nvdimm/test/ndtest.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c
> index 6862915..98b4a43 100644
> --- a/tools/testing/nvdimm/test/ndtest.c
> +++ b/tools/testing/nvdimm/test/ndtest.c
> @@ -487,8 +487,7 @@ static void *ndtest_alloc_resource(struct ndtest_priv *p, size_t size,
>  buf_err:
>  	if (__dma && size >= DIMM_SIZE)
>  		gen_pool_free(ndtest_pool, __dma, size);
> -	if (buf)
> -		vfree(buf);
> +	vfree(buf);
>  	kfree(res);
>  
>  	return NULL;
> -- 
> 1.8.3.1
> 
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Re: [PATCH] ndtest: Remove redundant NULL check

[Santosh Sivaraj]

Hi Ira,

Ira Weiny <ira.weiny@intel.com> writes:

> On Mon, Mar 22, 2021 at 06:00:40PM +0800, Jiapeng Chong wrote:
>> Fix the following coccicheck warnings:
>> 
>> ./tools/testing/nvdimm/test/ndtest.c:491:2-7: WARNING: NULL check before
>> some freeing functions is not needed.
>
> I don't think there is anything wrong with this patch specifically but why is
> buf not checked for null after the vmalloc?
>
> It seems to me that if size >= DIMM_SIZE and the vmalloc fails the gen pool
> allocation is going to be leaked.
>

If vmalloc fails, gen_pool_free will get called through ndtest_release_resource,
registered with devm_action. But we will still need to check for vmalloc fail.

I will fix that when I send my inject-error support for the driver.

Thanks,
Santosh

> Ira
>
>> 
>> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
>> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
>> ---
>>  tools/testing/nvdimm/test/ndtest.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>> 
>> diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c
>> index 6862915..98b4a43 100644
>> --- a/tools/testing/nvdimm/test/ndtest.c
>> +++ b/tools/testing/nvdimm/test/ndtest.c
>> @@ -487,8 +487,7 @@ static void *ndtest_alloc_resource(struct ndtest_priv *p, size_t size,
>>  buf_err:
>>  	if (__dma && size >= DIMM_SIZE)
>>  		gen_pool_free(ndtest_pool, __dma, size);
>> -	if (buf)
>> -		vfree(buf);
>> +	vfree(buf);
>>  	kfree(res);
>>  
>>  	return NULL;
>> -- 
>> 1.8.3.1
>> 
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Re: [PATCH] ndtest: Remove redundant NULL check

[Kang Minchul]

2022년 11월 13일 (일) 오후 8:26, Kang Minchul <tegongkang@gmail.com>님이 작성:
>
> This addresses cocci warning as follows:
> WARNING: NULL check before some freeing functions is not needed.
>
> Signed-off-by: Kang Minchul <tegongkang@gmail.com>
> ---
>  tools/testing/nvdimm/test/ndtest.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c
> index 01ceb98c15a0..de4bc34bc47b 100644
> --- a/tools/testing/nvdimm/test/ndtest.c
> +++ b/tools/testing/nvdimm/test/ndtest.c
> @@ -370,8 +370,7 @@ static void *ndtest_alloc_resource(struct ndtest_priv *p, size_t size,
>  buf_err:
>         if (__dma && size >= DIMM_SIZE)
>                 gen_pool_free(ndtest_pool, __dma, size);
> -       if (buf)
> -               vfree(buf);
> +       vfree(buf);
>         kfree(res);
>
>         return NULL;
> --
> 2.34.1
>

I just found an earlier discussion about the same patch as mine.
Please ignore this patch.

Thanks.

Kang Minchul

[PATCH] ndtest: Remove redundant NULL check

[Kang Minchul]

This addresses cocci warning as follows:
WARNING: NULL check before some freeing functions is not needed.

Signed-off-by: Kang Minchul <tegongkang@gmail.com>
---
 tools/testing/nvdimm/test/ndtest.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c
index 01ceb98c15a0..de4bc34bc47b 100644
--- a/tools/testing/nvdimm/test/ndtest.c
+++ b/tools/testing/nvdimm/test/ndtest.c
@@ -370,8 +370,7 @@ static void *ndtest_alloc_resource(struct ndtest_priv *p, size_t size,
 buf_err:
 	if (__dma && size >= DIMM_SIZE)
 		gen_pool_free(ndtest_pool, __dma, size);
-	if (buf)
-		vfree(buf);
+	vfree(buf);
 	kfree(res);
 
 	return NULL;
-- 
2.34.1