2021-03-22 10:02:32

by Jiapeng Chong

Subject: [PATCH] ndtest: Remove redundant NULL check

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 <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
---
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

2021-03-22 20:24:01

by Ira Weiny

Subject: Re: [PATCH] ndtest: Remove redundant NULL check

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 <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>
> ---
> 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
>

2021-03-23 02:35:01

by Santosh Sivaraj

Subject: Re: [PATCH] ndtest: Remove redundant NULL check

Hi Ira,

Ira Weiny <[email protected]> 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 <[email protected]>
>> Signed-off-by: Jiapeng Chong <[email protected]>
>> ---
>> 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
>>

2022-11-13 11:37:13

by Kang Minchul

Subject: Re: [PATCH] ndtest: Remove redundant NULL check

2022년 11월 13일 (일) 오후 8:26, Kang Minchul <[email protected]>님이 작성:
>
> This addresses cocci warning as follows:
> WARNING: NULL check before some freeing functions is not needed.
>
> Signed-off-by: Kang Minchul <[email protected]>
> ---
> 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