diff mbox series

[3/3] bpf/selftests: add test for writable bare tracepoint

Message ID 20210916135511.3787194-4-houtao1@huawei.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series add support for writable bare tracepoint | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch
bpf/vmtest-bpf-next-PR fail merge-conflict
bpf/vmtest-bpf success VM_Test
bpf/vmtest-bpf-PR success PR summary

Commit Message

Hou Tao Sept. 16, 2021, 1:55 p.m. UTC
Add a writable bare tracepoint in bpf_testmod module, and
trigger its calling when reading /sys/kernel/bpf_testmod
with a specific buffer length.

Signed-off-by: Hou Tao <houtao1@huawei.com>
---
 .../bpf/bpf_testmod/bpf_testmod-events.h      | 15 +++++++
 .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 10 +++++
 .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  5 +++
 .../selftests/bpf/prog_tests/module_attach.c  | 40 ++++++++++++++++++-
 .../selftests/bpf/progs/test_module_attach.c  | 14 +++++++
 5 files changed, 82 insertions(+), 2 deletions(-)

Comments

Yonghong Song Sept. 16, 2021, 11:46 p.m. UTC | #1
On 9/16/21 6:55 AM, Hou Tao wrote:
> Add a writable bare tracepoint in bpf_testmod module, and
> trigger its calling when reading /sys/kernel/bpf_testmod
> with a specific buffer length.

The patch cannot be applied cleanly with bpf-next tree.
Please rebase and resubmit.

> 
> Signed-off-by: Hou Tao <houtao1@huawei.com>
> ---
>   .../bpf/bpf_testmod/bpf_testmod-events.h      | 15 +++++++
>   .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 10 +++++
>   .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  5 +++
>   .../selftests/bpf/prog_tests/module_attach.c  | 40 ++++++++++++++++++-
>   .../selftests/bpf/progs/test_module_attach.c  | 14 +++++++
>   5 files changed, 82 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
> index 89c6d58e5dd6..11ee801e75e7 100644
> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
> @@ -34,6 +34,21 @@ DECLARE_TRACE(bpf_testmod_test_write_bare,
>   	TP_ARGS(task, ctx)
>   );
>   
> +#undef BPF_TESTMOD_DECLARE_TRACE
> +#ifdef DECLARE_TRACE_WRITABLE
> +#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
> +	DECLARE_TRACE_WRITABLE(call, PARAMS(proto), PARAMS(args), size)
> +#else
> +#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
> +	DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
> +#endif
> +
> +BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare,
> +	TP_PROTO(struct bpf_testmod_test_writable_ctx *ctx),
> +	TP_ARGS(ctx),
> +	sizeof(struct bpf_testmod_test_writable_ctx)
> +);
> +
>   #endif /* _BPF_TESTMOD_EVENTS_H */
>   
>   #undef TRACE_INCLUDE_PATH
> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> index 141d8da687d2..3d3fb16eaf8c 100644
> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> @@ -26,6 +26,16 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj,
>   
>   	trace_bpf_testmod_test_read(current, &ctx);
>   
> +	/* Magic number to enable writable tp */
> +	if (len == 1024) {
> +		struct bpf_testmod_test_writable_ctx writable = {
> +			.val = 1024,
> +		};
> +		trace_bpf_testmod_test_writable_bare(&writable);
> +		if (writable.ret)
> +			return snprintf(buf, len, "%d\n", writable.val);
> +	}
> +
>   	return -EIO; /* always fail */
>   }
>   EXPORT_SYMBOL(bpf_testmod_test_read);
> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
> index b3892dc40111..553d94214aa6 100644
> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
> @@ -17,4 +17,9 @@ struct bpf_testmod_test_write_ctx {
>   	size_t len;
>   };
>   
> +struct bpf_testmod_test_writable_ctx {
> +	bool ret;
> +	int val;
> +};
> +
>   #endif /* _BPF_TESTMOD_H */
> diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c
> index d85a69b7ce44..5565bcab1531 100644
> --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c
> +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c
> @@ -6,11 +6,39 @@
>   
>   static int duration;
>   
> +#define BPF_TESTMOD_PATH "/sys/kernel/bpf_testmod"
> +
> +static int trigger_module_test_writable(int *val)
> +{
> +	int fd, err;
> +	char buf[1025];

Not critical, but do you need such a big stack size?
Maybe smaller one?

> +	ssize_t rd;
> +
> +	fd = open(BPF_TESTMOD_PATH, O_RDONLY);
> +	err = -errno;
> +	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
> +		return err;
> +
> +	rd = read(fd, buf, sizeof(buf) - 1);
> +	err = rd < 0 ? -errno : -EIO;
> +	if (CHECK(rd <= 0, "testmod_file_read", "failed: %d\n", err)) {

Please use ASSERT_* macros. You can take a look at other self tests.

> +		close(fd);
> +		return err;
> +	}

Put one blank line here and remove the following three blank lines.

> +	buf[rd] = '\0';
> +
> +	*val = strtol(buf, NULL, 0);
> +
> +	close(fd);
> +
> +	return 0;
> +}
> +
>   static int trigger_module_test_read(int read_sz)
>   {
>   	int fd, err;
>   
> -	fd = open("/sys/kernel/bpf_testmod", O_RDONLY);
> +	fd = open(BPF_TESTMOD_PATH, O_RDONLY);
>   	err = -errno;
>   	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
>   		return err;
> @@ -32,7 +60,7 @@ static int trigger_module_test_write(int write_sz)
>   	memset(buf, 'a', write_sz);
>   	buf[write_sz-1] = '\0';
>   
> -	fd = open("/sys/kernel/bpf_testmod", O_WRONLY);
> +	fd = open(BPF_TESTMOD_PATH, O_WRONLY);
>   	err = -errno;
>   	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) {
>   		free(buf);
> @@ -58,6 +86,7 @@ void test_module_attach(void)
>   	struct test_module_attach__bss *bss;
>   	struct bpf_link *link;
>   	int err;
> +	int writable_val;
>   
>   	skel = test_module_attach__open();
>   	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
> @@ -90,6 +119,13 @@ void test_module_attach(void)
>   	ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet");
>   	ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret");
>   
> +	bss->raw_tp_writable_bare_ret = 1;
> +	bss->raw_tp_writable_bare_val = 511;
> +	writable_val = 0;
> +	ASSERT_OK(trigger_module_test_writable(&writable_val), "trigger_writable");
> +	ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test");
> +	ASSERT_EQ(bss->raw_tp_writable_bare_val, writable_val, "writable_test");
> +
>   	test_module_attach__detach(skel);
>   
>   	/* attach fentry/fexit and make sure it get's module reference */
> diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c b/tools/testing/selftests/bpf/progs/test_module_attach.c
> index bd37ceec5587..4f5c780fcd21 100644
> --- a/tools/testing/selftests/bpf/progs/test_module_attach.c
> +++ b/tools/testing/selftests/bpf/progs/test_module_attach.c
> @@ -27,6 +27,20 @@ int BPF_PROG(handle_raw_tp_bare,
>   	return 0;
>   }
>   
> +int raw_tp_writable_bare_in_val = 0;
> +int raw_tp_writable_bare_ret = 0;
> +int raw_tp_writable_bare_val = 0;
> +
> +SEC("raw_tp_writable/bpf_testmod_test_writable_bare")
> +int BPF_PROG(handle_raw_tp_writable_bare,
> +	     struct bpf_testmod_test_writable_ctx *writable)
> +{
> +	raw_tp_writable_bare_in_val = writable->val;
> +	writable->ret = raw_tp_writable_bare_ret;
> +	writable->val = raw_tp_writable_bare_val;
> +	return 0;
> +}
> +
>   __u32 tp_btf_read_sz = 0;
>   
>   SEC("tp_btf/bpf_testmod_test_read")
>
Hou Tao Sept. 17, 2021, 2:03 p.m. UTC | #2
Hi,

On 9/17/2021 7:46 AM, Yonghong Song wrote:
>
>
> On 9/16/21 6:55 AM, Hou Tao wrote:
>> Add a writable bare tracepoint in bpf_testmod module, and
>> trigger its calling when reading /sys/kernel/bpf_testmod
>> with a specific buffer length.
>
> The patch cannot be applied cleanly with bpf-next tree.
> Please rebase and resubmit.
Will do
>
>>
>> Signed-off-by: Hou Tao <houtao1@huawei.com>
>> ---
>>   .../bpf/bpf_testmod/bpf_testmod-events.h      | 15 +++++++
>>   .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 10 +++++
>>   .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  5 +++
>>   .../selftests/bpf/prog_tests/module_attach.c  | 40 ++++++++++++++++++-
>>   .../selftests/bpf/progs/test_module_attach.c  | 14 +++++++
>>   5 files changed, 82 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
>> index 89c6d58e5dd6..11ee801e75e7 100644
>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
>> @@ -34,6 +34,21 @@ DECLARE_TRACE(bpf_testmod_test_write_bare,
>>       TP_ARGS(task, ctx)
>>   );
>>   +#undef BPF_TESTMOD_DECLARE_TRACE
>> +#ifdef DECLARE_TRACE_WRITABLE
>> +#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
>> +    DECLARE_TRACE_WRITABLE(call, PARAMS(proto), PARAMS(args), size)
>> +#else
>> +#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
>> +    DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
>> +#endif
>> +
>> +BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare,
>> +    TP_PROTO(struct bpf_testmod_test_writable_ctx *ctx),
>> +    TP_ARGS(ctx),
>> +    sizeof(struct bpf_testmod_test_writable_ctx)
>> +);
>> +
>>   #endif /* _BPF_TESTMOD_EVENTS_H */
>>     #undef TRACE_INCLUDE_PATH
>> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> index 141d8da687d2..3d3fb16eaf8c 100644
>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> @@ -26,6 +26,16 @@ bpf_testmod_test_read(struct file *file, struct kobject
>> *kobj,
>>         trace_bpf_testmod_test_read(current, &ctx);
>>   +    /* Magic number to enable writable tp */
>> +    if (len == 1024) {
>> +        struct bpf_testmod_test_writable_ctx writable = {
>> +            .val = 1024,
>> +        };
>> +        trace_bpf_testmod_test_writable_bare(&writable);
>> +        if (writable.ret)
>> +            return snprintf(buf, len, "%d\n", writable.val);
>> +    }
>> +
>>       return -EIO; /* always fail */
>>   }
>>   EXPORT_SYMBOL(bpf_testmod_test_read);
>> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>> index b3892dc40111..553d94214aa6 100644
>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>> @@ -17,4 +17,9 @@ struct bpf_testmod_test_write_ctx {
>>       size_t len;
>>   };
>>   +struct bpf_testmod_test_writable_ctx {
>> +    bool ret;
>> +    int val;
>> +};
>> +
>>   #endif /* _BPF_TESTMOD_H */
>> diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c
>> b/tools/testing/selftests/bpf/prog_tests/module_attach.c
>> index d85a69b7ce44..5565bcab1531 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c
>> @@ -6,11 +6,39 @@
>>     static int duration;
>>   +#define BPF_TESTMOD_PATH "/sys/kernel/bpf_testmod"
>> +
>> +static int trigger_module_test_writable(int *val)
>> +{
>> +    int fd, err;
>> +    char buf[1025];
>
> Not critical, but do you need such a big stack size?
> Maybe smaller one?
65 is also fine.
>
>> +    ssize_t rd;
>> +
>> +    fd = open(BPF_TESTMOD_PATH, O_RDONLY);
>> +    err = -errno;
>> +    if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
>> +        return err;
>> +
>> +    rd = read(fd, buf, sizeof(buf) - 1);
>> +    err = rd < 0 ? -errno : -EIO;
>> +    if (CHECK(rd <= 0, "testmod_file_read", "failed: %d\n", err)) {
>
> Please use ASSERT_* macros. You can take a look at other self tests.
The reason using CHECK instead of ASSERT is we can output the errno
if read() fails.
>> +        close(fd);
>> +        return err;
>> +    }
>
> Put one blank line here and remove the following three blank lines.
Will do.
>
>> +    buf[rd] = '\0';
>> +
>> +    *val = strtol(buf, NULL, 0);
>> +
>> +    close(fd);
>> +
>> +    return 0;
>> +}
>> +
>>   static int trigger_module_test_read(int read_sz)
>>   {
>>       int fd, err;
>>   -    fd = open("/sys/kernel/bpf_testmod", O_RDONLY);
>> +    fd = open(BPF_TESTMOD_PATH, O_RDONLY);
>>       err = -errno;
>>       if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
>>           return err;
>> @@ -32,7 +60,7 @@ static int trigger_module_test_write(int write_sz)
>>       memset(buf, 'a', write_sz);
>>       buf[write_sz-1] = '\0';
>>   -    fd = open("/sys/kernel/bpf_testmod", O_WRONLY);
>> +    fd = open(BPF_TESTMOD_PATH, O_WRONLY);
>>       err = -errno;
>>       if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) {
>>           free(buf);
>> @@ -58,6 +86,7 @@ void test_module_attach(void)
>>       struct test_module_attach__bss *bss;
>>       struct bpf_link *link;
>>       int err;
>> +    int writable_val;
>>         skel = test_module_attach__open();
>>       if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
>> @@ -90,6 +119,13 @@ void test_module_attach(void)
>>       ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet");
>>       ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret");
>>   +    bss->raw_tp_writable_bare_ret = 1;
>> +    bss->raw_tp_writable_bare_val = 511;
>> +    writable_val = 0;
>> +    ASSERT_OK(trigger_module_test_writable(&writable_val), "trigger_writable");
>> +    ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test");
>> +    ASSERT_EQ(bss->raw_tp_writable_bare_val, writable_val, "writable_test");
>> +
>>       test_module_attach__detach(skel);
>>         /* attach fentry/fexit and make sure it get's module reference */
>> diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c
>> b/tools/testing/selftests/bpf/progs/test_module_attach.c
>> index bd37ceec5587..4f5c780fcd21 100644
>> --- a/tools/testing/selftests/bpf/progs/test_module_attach.c
>> +++ b/tools/testing/selftests/bpf/progs/test_module_attach.c
>> @@ -27,6 +27,20 @@ int BPF_PROG(handle_raw_tp_bare,
>>       return 0;
>>   }
>>   +int raw_tp_writable_bare_in_val = 0;
>> +int raw_tp_writable_bare_ret = 0;
>> +int raw_tp_writable_bare_val = 0;
>> +
>> +SEC("raw_tp_writable/bpf_testmod_test_writable_bare")
>> +int BPF_PROG(handle_raw_tp_writable_bare,
>> +         struct bpf_testmod_test_writable_ctx *writable)
>> +{
>> +    raw_tp_writable_bare_in_val = writable->val;
>> +    writable->ret = raw_tp_writable_bare_ret;
>> +    writable->val = raw_tp_writable_bare_val;
>> +    return 0;
>> +}
>> +
>>   __u32 tp_btf_read_sz = 0;
>>     SEC("tp_btf/bpf_testmod_test_read")
>>
> .
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
index 89c6d58e5dd6..11ee801e75e7 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod-events.h
@@ -34,6 +34,21 @@  DECLARE_TRACE(bpf_testmod_test_write_bare,
 	TP_ARGS(task, ctx)
 );
 
+#undef BPF_TESTMOD_DECLARE_TRACE
+#ifdef DECLARE_TRACE_WRITABLE
+#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
+	DECLARE_TRACE_WRITABLE(call, PARAMS(proto), PARAMS(args), size)
+#else
+#define BPF_TESTMOD_DECLARE_TRACE(call, proto, args, size) \
+	DECLARE_TRACE(call, PARAMS(proto), PARAMS(args))
+#endif
+
+BPF_TESTMOD_DECLARE_TRACE(bpf_testmod_test_writable_bare,
+	TP_PROTO(struct bpf_testmod_test_writable_ctx *ctx),
+	TP_ARGS(ctx),
+	sizeof(struct bpf_testmod_test_writable_ctx)
+);
+
 #endif /* _BPF_TESTMOD_EVENTS_H */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 141d8da687d2..3d3fb16eaf8c 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -26,6 +26,16 @@  bpf_testmod_test_read(struct file *file, struct kobject *kobj,
 
 	trace_bpf_testmod_test_read(current, &ctx);
 
+	/* Magic number to enable writable tp */
+	if (len == 1024) {
+		struct bpf_testmod_test_writable_ctx writable = {
+			.val = 1024,
+		};
+		trace_bpf_testmod_test_writable_bare(&writable);
+		if (writable.ret)
+			return snprintf(buf, len, "%d\n", writable.val);
+	}
+
 	return -EIO; /* always fail */
 }
 EXPORT_SYMBOL(bpf_testmod_test_read);
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
index b3892dc40111..553d94214aa6 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
@@ -17,4 +17,9 @@  struct bpf_testmod_test_write_ctx {
 	size_t len;
 };
 
+struct bpf_testmod_test_writable_ctx {
+	bool ret;
+	int val;
+};
+
 #endif /* _BPF_TESTMOD_H */
diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c
index d85a69b7ce44..5565bcab1531 100644
--- a/tools/testing/selftests/bpf/prog_tests/module_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c
@@ -6,11 +6,39 @@ 
 
 static int duration;
 
+#define BPF_TESTMOD_PATH "/sys/kernel/bpf_testmod"
+
+static int trigger_module_test_writable(int *val)
+{
+	int fd, err;
+	char buf[1025];
+	ssize_t rd;
+
+	fd = open(BPF_TESTMOD_PATH, O_RDONLY);
+	err = -errno;
+	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
+		return err;
+
+	rd = read(fd, buf, sizeof(buf) - 1);
+	err = rd < 0 ? -errno : -EIO;
+	if (CHECK(rd <= 0, "testmod_file_read", "failed: %d\n", err)) {
+		close(fd);
+		return err;
+	}
+	buf[rd] = '\0';
+
+	*val = strtol(buf, NULL, 0);
+
+	close(fd);
+
+	return 0;
+}
+
 static int trigger_module_test_read(int read_sz)
 {
 	int fd, err;
 
-	fd = open("/sys/kernel/bpf_testmod", O_RDONLY);
+	fd = open(BPF_TESTMOD_PATH, O_RDONLY);
 	err = -errno;
 	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err))
 		return err;
@@ -32,7 +60,7 @@  static int trigger_module_test_write(int write_sz)
 	memset(buf, 'a', write_sz);
 	buf[write_sz-1] = '\0';
 
-	fd = open("/sys/kernel/bpf_testmod", O_WRONLY);
+	fd = open(BPF_TESTMOD_PATH, O_WRONLY);
 	err = -errno;
 	if (CHECK(fd < 0, "testmod_file_open", "failed: %d\n", err)) {
 		free(buf);
@@ -58,6 +86,7 @@  void test_module_attach(void)
 	struct test_module_attach__bss *bss;
 	struct bpf_link *link;
 	int err;
+	int writable_val;
 
 	skel = test_module_attach__open();
 	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
@@ -90,6 +119,13 @@  void test_module_attach(void)
 	ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet");
 	ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret");
 
+	bss->raw_tp_writable_bare_ret = 1;
+	bss->raw_tp_writable_bare_val = 511;
+	writable_val = 0;
+	ASSERT_OK(trigger_module_test_writable(&writable_val), "trigger_writable");
+	ASSERT_EQ(bss->raw_tp_writable_bare_in_val, 1024, "writable_test");
+	ASSERT_EQ(bss->raw_tp_writable_bare_val, writable_val, "writable_test");
+
 	test_module_attach__detach(skel);
 
 	/* attach fentry/fexit and make sure it get's module reference */
diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c b/tools/testing/selftests/bpf/progs/test_module_attach.c
index bd37ceec5587..4f5c780fcd21 100644
--- a/tools/testing/selftests/bpf/progs/test_module_attach.c
+++ b/tools/testing/selftests/bpf/progs/test_module_attach.c
@@ -27,6 +27,20 @@  int BPF_PROG(handle_raw_tp_bare,
 	return 0;
 }
 
+int raw_tp_writable_bare_in_val = 0;
+int raw_tp_writable_bare_ret = 0;
+int raw_tp_writable_bare_val = 0;
+
+SEC("raw_tp_writable/bpf_testmod_test_writable_bare")
+int BPF_PROG(handle_raw_tp_writable_bare,
+	     struct bpf_testmod_test_writable_ctx *writable)
+{
+	raw_tp_writable_bare_in_val = writable->val;
+	writable->ret = raw_tp_writable_bare_ret;
+	writable->val = raw_tp_writable_bare_val;
+	return 0;
+}
+
 __u32 tp_btf_read_sz = 0;
 
 SEC("tp_btf/bpf_testmod_test_read")