2023-10-25 01:54:22

by Yuran Pereira

[permalink] [raw]
Subject: [PATCH bpf-next] selftests/bpf: Add malloc failure checks in bpf_iter

Since some malloc calls in bpf_iter may at times fail,
this patch adds the appropriate fail checks, and ensures that
any previously allocated resource is appropriately destroyed
before returning the function.

This is patch 2 in the sequence should be applied after d1a88d37cecc
"selftests/bpf: Convert CHECK macros to ASSERT_* macros in bpf_iter"

Patch 1:
https://lore.kernel.org/lkml/DB3PR10MB683589A5F705C6CA5BE0D325E8DFA@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM

Signed-off-by: Yuran Pereira <[email protected]>
---
tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
index 526ac4e741ee..c6cf42c64af3 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
@@ -700,7 +700,7 @@ static void test_overflow(bool test_e2big_overflow, bool ret1)
goto free_link;

buf = malloc(expected_read_len);
- if (!buf)
+ if (!ASSERT_OK_PTR(buf, "malloc"))
goto close_iter;

/* do read */
@@ -871,6 +871,10 @@ static void test_bpf_percpu_hash_map(void)

skel->rodata->num_cpus = bpf_num_possible_cpus();
val = malloc(8 * bpf_num_possible_cpus());
+ if (!ASSERT_OK_PTR(val, "malloc")) {
+ bpf_iter_bpf_percpu_hash_map__destroy(skel);
+ return;
+ }

err = bpf_iter_bpf_percpu_hash_map__load(skel);
if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_percpu_hash_map__load"))
@@ -1048,6 +1052,10 @@ static void test_bpf_percpu_array_map(void)

skel->rodata->num_cpus = bpf_num_possible_cpus();
val = malloc(8 * bpf_num_possible_cpus());
+ if (!ASSERT_OK_PTR(val, "malloc")) {
+ bpf_iter_bpf_percpu_array_map__destroy(skel);
+ return;
+ }

err = bpf_iter_bpf_percpu_array_map__load(skel);
if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_percpu_array_map__load"))
--
2.25.1


2023-10-25 02:28:45

by Kui-Feng Lee

[permalink] [raw]
Subject: Re: [PATCH bpf-next] selftests/bpf: Add malloc failure checks in bpf_iter

Thank you for the patches.

I found you have two patches in this set.
You can generate both patch at once with git format-patch.
format-patch will give each patch a number in their order.
For example, the subject of this message will be

[PATCH bpf-next 2/2] selftest/bpf: Add malloc ....

And, you put both patches in the same directory. And sent them at once
by giving the path of the directory. For example,

git send-email [email protected] path/to/the/directory/

These patches will be sent in a thread instead of two independent
messages.

On 10/24/23 18:52, Yuran Pereira wrote:
> Since some malloc calls in bpf_iter may at times fail,
> this patch adds the appropriate fail checks, and ensures that
> any previously allocated resource is appropriately destroyed
> before returning the function.
>
> This is patch 2 in the sequence should be applied after d1a88d37cecc
> "selftests/bpf: Convert CHECK macros to ASSERT_* macros in bpf_iter"
>
> Patch 1:
> https://lore.kernel.org/lkml/DB3PR10MB683589A5F705C6CA5BE0D325E8DFA@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM
>
> Signed-off-by: Yuran Pereira <[email protected]>
> ---
> tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> index 526ac4e741ee..c6cf42c64af3 100644
> --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
> @@ -700,7 +700,7 @@ static void test_overflow(bool test_e2big_overflow, bool ret1)
> goto free_link;
>
> buf = malloc(expected_read_len);
> - if (!buf)
> + if (!ASSERT_OK_PTR(buf, "malloc"))
> goto close_iter;
>
> /* do read */
> @@ -871,6 +871,10 @@ static void test_bpf_percpu_hash_map(void)
>
> skel->rodata->num_cpus = bpf_num_possible_cpus();
> val = malloc(8 * bpf_num_possible_cpus());
> + if (!ASSERT_OK_PTR(val, "malloc")) {
> + bpf_iter_bpf_percpu_hash_map__destroy(skel);
> + return;
> + }

You can just do "goto out;" here.


>
> err = bpf_iter_bpf_percpu_hash_map__load(skel);
> if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_percpu_hash_map__load"))
> @@ -1048,6 +1052,10 @@ static void test_bpf_percpu_array_map(void)
>
> skel->rodata->num_cpus = bpf_num_possible_cpus();
> val = malloc(8 * bpf_num_possible_cpus());
> + if (!ASSERT_OK_PTR(val, "malloc")) {
> + bpf_iter_bpf_percpu_array_map__destroy(skel);
> + return;
> + }

Same here, even it will call free(val), free(val) will do nothing when
val is NULL.

>
> err = bpf_iter_bpf_percpu_array_map__load(skel);
> if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_percpu_array_map__load"))

2023-10-25 04:18:29

by Yonghong Song

[permalink] [raw]
Subject: Re: [PATCH bpf-next] selftests/bpf: Add malloc failure checks in bpf_iter


On 10/24/23 7:28 PM, Kui-Feng Lee wrote:
> Thank you for the patches.
>
> I found you have two patches in this set.
> You can generate both patch at once with git format-patch.
> format-patch will give each patch a number in their order.
> For example, the subject of this message will be
>
>   [PATCH bpf-next 2/2] selftest/bpf: Add malloc ....
>
> And, you put both patches in the same directory.  And sent them at once
> by giving the path of the directory. For example,
>
>   git send-email [email protected] path/to/the/directory/
>
> These patches will be sent in a thread instead of two independent
> messages.


Yuran, second to Kui-Feng's suggestion which is also my original
suggestion although I forgot to explicitly mention that two
patches should be in the same patch set.
I found one issue with the CHECK->ASSERT patch, so please
respin with patch v2 with two patches as the same set.


>
> On 10/24/23 18:52, Yuran Pereira wrote:
>> Since some malloc calls in bpf_iter may at times fail,
>> this patch adds the appropriate fail checks, and ensures that
>> any previously allocated resource is appropriately destroyed
>> before returning the function.
>>
>> This is patch 2 in the sequence should be applied after d1a88d37cecc
>> "selftests/bpf: Convert CHECK macros to ASSERT_* macros in bpf_iter"
>>
>> Patch 1:
>> https://lore.kernel.org/lkml/DB3PR10MB683589A5F705C6CA5BE0D325E8DFA@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM
>>
>>
>> Signed-off-by: Yuran Pereira <[email protected]>
>> ---
>>   tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 10 +++++++++-
>>   1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
>> b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
>> index 526ac4e741ee..c6cf42c64af3 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
>> @@ -700,7 +700,7 @@ static void test_overflow(bool
>> test_e2big_overflow, bool ret1)
>>           goto free_link;
>>         buf = malloc(expected_read_len);
>> -    if (!buf)
>> +    if (!ASSERT_OK_PTR(buf, "malloc"))
>>           goto close_iter;
>>         /* do read */
>> @@ -871,6 +871,10 @@ static void test_bpf_percpu_hash_map(void)
>>         skel->rodata->num_cpus = bpf_num_possible_cpus();
>>       val = malloc(8 * bpf_num_possible_cpus());
>> +    if (!ASSERT_OK_PTR(val, "malloc")) {
>> +        bpf_iter_bpf_percpu_hash_map__destroy(skel);
>> +        return;
>> +    }
>
> You can just do "goto out;" here.
>
>
>>         err = bpf_iter_bpf_percpu_hash_map__load(skel);
>>       if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_percpu_hash_map__load"))
>> @@ -1048,6 +1052,10 @@ static void test_bpf_percpu_array_map(void)
>>         skel->rodata->num_cpus = bpf_num_possible_cpus();
>>       val = malloc(8 * bpf_num_possible_cpus());
>> +    if (!ASSERT_OK_PTR(val, "malloc")) {
>> +        bpf_iter_bpf_percpu_array_map__destroy(skel);
>> +        return;
>> +    }
>
> Same here, even it will call free(val), free(val) will do nothing when
> val is NULL.
>
>>         err = bpf_iter_bpf_percpu_array_map__load(skel);
>>       if (!ASSERT_OK_PTR(skel, "bpf_iter_bpf_percpu_array_map__load"))