[PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Hao Ge]

From: Hao Ge <gehao@kylinos.cn>

Smatch reported the following warning:
    ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
    warn: variable dereferenced before check 'buf' (see line 454)

It seems correct,so let's modify it based on it's suggestion.

Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
check in get_xlated_program()") fixed an issue in the test_verifier.c
once,but it was reverted this time.

Let's solve this issue with the minimal changes possible.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
---
 tools/testing/selftests/bpf/testing_helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index d5379a0e6da8..34dfea295c8e 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -451,7 +451,7 @@ int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt)
 
 	*cnt = xlated_prog_len / buf_element_size;
 	*buf = calloc(*cnt, buf_element_size);
-	if (!buf) {
+	if (!*buf) {
 		perror("can't allocate xlated program buffer");
 		return -ENOMEM;
 	}
-- 
2.25.1

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Hao Ge]

Hi

I apologize for the confusion.

  I mistakenly thought that my previous email 
(https://lore.kernel.org/all/20240820023447.29002-1-hao.ge@linux.dev/)

didn't send due to network issues on my computer, so I resent it.

However, it seems that was not the case.

Please kindly disregard this patch as it is identical to the previous one.

I sincerely apologize for wasting everyone's time

On 8/20/24 10:36, Hao Ge wrote:
> From: Hao Ge <gehao@kylinos.cn>
>
> Smatch reported the following warning:
>      ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
>      warn: variable dereferenced before check 'buf' (see line 454)
>
> It seems correct,so let's modify it based on it's suggestion.
>
> Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
> check in get_xlated_program()") fixed an issue in the test_verifier.c
> once,but it was reverted this time.
>
> Let's solve this issue with the minimal changes possible.
>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
> Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
> Signed-off-by: Hao Ge <gehao@kylinos.cn>
> ---
>   tools/testing/selftests/bpf/testing_helpers.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
> index d5379a0e6da8..34dfea295c8e 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.c
> +++ b/tools/testing/selftests/bpf/testing_helpers.c
> @@ -451,7 +451,7 @@ int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt)
>   
>   	*cnt = xlated_prog_len / buf_element_size;
>   	*buf = calloc(*cnt, buf_element_size);
> -	if (!buf) {
> +	if (!*buf) {
>   		perror("can't allocate xlated program buffer");
>   		return -ENOMEM;
>   	}
Thanks

Best regards

Hao

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Tue, 20 Aug 2024 10:36:22 +0800 you wrote:
> From: Hao Ge <gehao@kylinos.cn>
> 
> Smatch reported the following warning:
>     ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
>     warn: variable dereferenced before check 'buf' (see line 454)
> 
> It seems correct,so let's modify it based on it's suggestion.
> 
> [...]

Here is the summary with links:
  - selftests/bpf: Fix incorrect parameters in NULL pointer checking
    https://git.kernel.org/bpf/bpf-next/c/c264487e5410

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

[PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Hao Ge]

From: Hao Ge <gehao@kylinos.cn>

Smatch reported the following warning:
    ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
    warn: variable dereferenced before check 'buf' (see line 454)

It seems correct,so let's modify it based on it's suggestion.

Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
check in get_xlated_program()") fixed an issue in the test_verifier.c
once,but it was reverted this time.

Let's solve this issue with the minimal changes possible.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
---
 tools/testing/selftests/bpf/testing_helpers.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index d5379a0e6da8..34dfea295c8e 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -451,7 +451,7 @@ int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt)
 
 	*cnt = xlated_prog_len / buf_element_size;
 	*buf = calloc(*cnt, buf_element_size);
-	if (!buf) {
+	if (!*buf) {
 		perror("can't allocate xlated program buffer");
 		return -ENOMEM;
 	}
-- 
2.25.1

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Yonghong Song]

On 8/19/24 7:34 PM, Hao Ge wrote:
> From: Hao Ge <gehao@kylinos.cn>
>
> Smatch reported the following warning:
>      ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
>      warn: variable dereferenced before check 'buf' (see line 454)
>
> It seems correct,so let's modify it based on it's suggestion.
>
> Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
> check in get_xlated_program()") fixed an issue in the test_verifier.c
> once,but it was reverted this time.
>
> Let's solve this issue with the minimal changes possible.
>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
> Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
> Signed-off-by: Hao Ge <gehao@kylinos.cn>

In the future, please change subject '[PATCH] ...' to '[PATCH bpf-next] ...'
so CI can properly test it.

Acked-by: Yonghong Song <yonghong.song@linux.dev>

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Dan Carpenter]

On Wed, Aug 21, 2024 at 02:03:17PM -0700, Yonghong Song wrote:
> 
> On 8/19/24 7:34 PM, Hao Ge wrote:
> > From: Hao Ge <gehao@kylinos.cn>
> > 
> > Smatch reported the following warning:
> >      ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
> >      warn: variable dereferenced before check 'buf' (see line 454)
> > 
> > It seems correct,so let's modify it based on it's suggestion.
> > 
> > Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
> > check in get_xlated_program()") fixed an issue in the test_verifier.c
> > once,but it was reverted this time.
> > 
> > Let's solve this issue with the minimal changes possible.
> > 
> > Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> > Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
> > Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
> > Signed-off-by: Hao Ge <gehao@kylinos.cn>
> 
> In the future, please change subject '[PATCH] ...' to '[PATCH bpf-next] ...'
> so CI can properly test it.

It feels like there should be a technical solution to this.  The CI system is
something on AWS and it's too expensive to just check every patch that's sent to
the bpf list?  My understanding is that there are only two bpf trees.

	if [ "$FIXES_HASH" == "" ] ; then
		TREE=next
	elif git merge-base --is-ancestor $FIXES_HASH origin/master ; then
		TREE=linus
	else
		TREE=next
	fi

These days the zero day bot people are checking around a thousand git trees.
They pull emails off the various lists and apply them to the right places.  It's
a doable thing.

regards,
dan carpenter

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Alexei Starovoitov]

On Wed, Aug 21, 2024 at 2:50 PM Dan Carpenter <dan.carpenter@linaro.org> wrote:
>
> On Wed, Aug 21, 2024 at 02:03:17PM -0700, Yonghong Song wrote:
> >
> > On 8/19/24 7:34 PM, Hao Ge wrote:
> > > From: Hao Ge <gehao@kylinos.cn>
> > >
> > > Smatch reported the following warning:
> > >      ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
> > >      warn: variable dereferenced before check 'buf' (see line 454)
> > >
> > > It seems correct,so let's modify it based on it's suggestion.
> > >
> > > Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
> > > check in get_xlated_program()") fixed an issue in the test_verifier.c
> > > once,but it was reverted this time.
> > >
> > > Let's solve this issue with the minimal changes possible.
> > >
> > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> > > Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
> > > Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
> > > Signed-off-by: Hao Ge <gehao@kylinos.cn>
> >
> > In the future, please change subject '[PATCH] ...' to '[PATCH bpf-next] ...'
> > so CI can properly test it.
>
> It feels like there should be a technical solution to this.  The CI system is
> something on AWS and it's too expensive to just check every patch that's sent to
> the bpf list?  My understanding is that there are only two bpf trees.
>
>         if [ "$FIXES_HASH" == "" ] ; then
>                 TREE=next
>         elif git merge-base --is-ancestor $FIXES_HASH origin/master ; then
>                 TREE=linus
>         else
>                 TREE=next
>         fi
>
> These days the zero day bot people are checking around a thousand git trees.
> They pull emails off the various lists and apply them to the right places.  It's
> a doable thing.

Dan,

Various people pointed out that you need to use the proper subject in
the patches.
You clearly knew that rule and yet you ignored it,
and worse still you keep coming up with these excuses.
Don't be surprised that people who are supposed to review your patches
will take a long time to reply or "forget" about them as you "forget"
about patch submission rules.

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Dan Carpenter]

On Wed, Aug 21, 2024 at 03:07:27PM -0700, Alexei Starovoitov wrote:
> On Wed, Aug 21, 2024 at 2:50 PM Dan Carpenter <dan.carpenter@linaro.org> wrote:
> >
> > On Wed, Aug 21, 2024 at 02:03:17PM -0700, Yonghong Song wrote:
> > >
> > > On 8/19/24 7:34 PM, Hao Ge wrote:
> > > > From: Hao Ge <gehao@kylinos.cn>
> > > >
> > > > Smatch reported the following warning:
> > > >      ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
> > > >      warn: variable dereferenced before check 'buf' (see line 454)
> > > >
> > > > It seems correct,so let's modify it based on it's suggestion.
> > > >
> > > > Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
> > > > check in get_xlated_program()") fixed an issue in the test_verifier.c
> > > > once,but it was reverted this time.
> > > >
> > > > Let's solve this issue with the minimal changes possible.
> > > >
> > > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> > > > Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
> > > > Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
> > > > Signed-off-by: Hao Ge <gehao@kylinos.cn>
> > >
> > > In the future, please change subject '[PATCH] ...' to '[PATCH bpf-next] ...'
> > > so CI can properly test it.
> >
> > It feels like there should be a technical solution to this.  The CI system is
> > something on AWS and it's too expensive to just check every patch that's sent to
> > the bpf list?  My understanding is that there are only two bpf trees.
> >
> >         if [ "$FIXES_HASH" == "" ] ; then
> >                 TREE=next
> >         elif git merge-base --is-ancestor $FIXES_HASH origin/master ; then
> >                 TREE=linus
> >         else
> >                 TREE=next
> >         fi
> >
> > These days the zero day bot people are checking around a thousand git trees.
> > They pull emails off the various lists and apply them to the right places.  It's
> > a doable thing.
> 
> Dan,
> 
> Various people pointed out that you need to use the proper subject in
> the patches.
> You clearly knew that rule and yet you ignored it,
> and worse still you keep coming up with these excuses.
> Don't be surprised that people who are supposed to review your patches
> will take a long time to reply or "forget" about them as you "forget"
> about patch submission rules.

You're emailing the wrong person.  This isn't my patch.  I don't send BPF
patches.

regards,
dan carpenter

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Hao Ge]

Hi Dan and Alexei


I apologize for any inconvenience my mistake may have caused to both of you.


On 8/22/24 06:31, Dan Carpenter wrote:
> On Wed, Aug 21, 2024 at 03:07:27PM -0700, Alexei Starovoitov wrote:
>> On Wed, Aug 21, 2024 at 2:50 PM Dan Carpenter <dan.carpenter@linaro.org> wrote:
>>> On Wed, Aug 21, 2024 at 02:03:17PM -0700, Yonghong Song wrote:
>>>> On 8/19/24 7:34 PM, Hao Ge wrote:
>>>>> From: Hao Ge <gehao@kylinos.cn>
>>>>>
>>>>> Smatch reported the following warning:
>>>>>       ./tools/testing/selftests/bpf/testing_helpers.c:455 get_xlated_program()
>>>>>       warn: variable dereferenced before check 'buf' (see line 454)
>>>>>
>>>>> It seems correct,so let's modify it based on it's suggestion.
>>>>>
>>>>> Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
>>>>> check in get_xlated_program()") fixed an issue in the test_verifier.c
>>>>> once,but it was reverted this time.
>>>>>
>>>>> Let's solve this issue with the minimal changes possible.
>>>>>
>>>>> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
>>>>> Closes: https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
>>>>> Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() helper")
>>>>> Signed-off-by: Hao Ge <gehao@kylinos.cn>
>>>> In the future, please change subject '[PATCH] ...' to '[PATCH bpf-next] ...'
>>>> so CI can properly test it.
>>> It feels like there should be a technical solution to this.  The CI system is
>>> something on AWS and it's too expensive to just check every patch that's sent to
>>> the bpf list?  My understanding is that there are only two bpf trees.
>>>
>>>          if [ "$FIXES_HASH" == "" ] ; then
>>>                  TREE=next
>>>          elif git merge-base --is-ancestor $FIXES_HASH origin/master ; then
>>>                  TREE=linus
>>>          else
>>>                  TREE=next
>>>          fi
>>>
>>> These days the zero day bot people are checking around a thousand git trees.
>>> They pull emails off the various lists and apply them to the right places.  It's
>>> a doable thing.
>> Dan,
>>
>> Various people pointed out that you need to use the proper subject in
>> the patches.
>> You clearly knew that rule and yet you ignored it,
>> and worse still you keep coming up with these excuses.
>> Don't be surprised that people who are supposed to review your patches
>> will take a long time to reply or "forget" about them as you "forget"
>> about patch submission rules.


Perhaps it was referring to me? Regardless, I will reflect on myself and 
make improvements.


> You're emailing the wrong person.  This isn't my patch.  I don't send BPF
> patches.
>
> regards,
> dan carpenter

Re: [PATCH] selftests/bpf: Fix incorrect parameters in NULL pointer checking

[Hao Ge]

Hi Yonghong


Thank you very much for taking the time to review my patch.


On 8/22/24 05:03, Yonghong Song wrote:
>
> On 8/19/24 7:34 PM, Hao Ge wrote:
>> From: Hao Ge <gehao@kylinos.cn>
>>
>> Smatch reported the following warning:
>>      ./tools/testing/selftests/bpf/testing_helpers.c:455 
>> get_xlated_program()
>>      warn: variable dereferenced before check 'buf' (see line 454)
>>
>> It seems correct,so let's modify it based on it's suggestion.
>>
>> Actually,commit b23ed4d74c4d ("selftests/bpf: Fix invalid pointer
>> check in get_xlated_program()") fixed an issue in the test_verifier.c
>> once,but it was reverted this time.
>>
>> Let's solve this issue with the minimal changes possible.
>>
>> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
>> Closes: 
>> https://lore.kernel.org/all/1eb3732f-605a-479d-ba64-cd14250cbf91@stanley.mountain/
>> Fixes: b4b7a4099b8c ("selftests/bpf: Factor out get_xlated_program() 
>> helper")
>> Signed-off-by: Hao Ge <gehao@kylinos.cn>
>
> In the future, please change subject '[PATCH] ...' to '[PATCH 
> bpf-next] ...'
> so CI can properly test it.
>

OK, I understand. I will follow this rule in the future.


> Acked-by: Yonghong Song <yonghong.song@linux.dev>
>