[PATCH v4 0/3] tracing/user_events: Fix incorrect return value for writes when events are disabled and add its tests

[PATCH v4 0/3] tracing/user_events: Fix incorrect return value for writes when events are disabled and add its tests

[sunliming]

Now the writing operation return the count of writes regardless of whether
events are enabled or disabled. Fix this by just return -EBADF when events
are disabled.

v3 -> v4:
- Change the return value from zero to -EBADF

v2 -> v3:
- Change the return value from -ENOENT to zero

v1 -> v2:
- Change the return value from -EFAULT to -ENOENT

sunliming (3):
  tracing/user_events: Fix incorrect return value for writing operation
    when events are disabled
  selftests/user_events: Enable the event before write_fault test in
    ftrace self-test
  selftests/user_events: Add test cases when event is disabled

 kernel/trace/trace_events_user.c                  | 3 ++-
 tools/testing/selftests/user_events/ftrace_test.c | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

-- 
2.25.1

[PATCH v4 1/3] tracing/user_events: Fix incorrect return value for writing operation when events are disabled

[sunliming]

The writing operation return the count of writes regardless of whether events
are enabled or disabled. Switch it to return -EBADF to indicates that the event
is disabled.

Signed-off-by: sunliming <sunliming@kylinos.cn>
---
 kernel/trace/trace_events_user.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 1ac5ba5685ed..146bb2e9758f 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1957,7 +1957,8 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i)
 
 		if (unlikely(faulted))
 			return -EFAULT;
-	}
+	} else
+		return -EBADF;
 
 	return ret;
 }
-- 
2.25.1

[PATCH v4 2/3] selftests/user_events: Enable the event before write_fault test in ftrace self-test

[sunliming]

The user_event has not be enabled in write_fault test in ftrace
self-test, Just enable it.

Signed-off-by: sunliming <sunliming@kylinos.cn>
---
 tools/testing/selftests/user_events/ftrace_test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/user_events/ftrace_test.c b/tools/testing/selftests/user_events/ftrace_test.c
index abfb49558a26..d33bd31425db 100644
--- a/tools/testing/selftests/user_events/ftrace_test.c
+++ b/tools/testing/selftests/user_events/ftrace_test.c
@@ -373,6 +373,10 @@ TEST_F(user, write_fault) {
 	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
 	ASSERT_EQ(0, reg.write_index);
 
+	/* Enable event */
+	self->enable_fd = open(enable_file, O_RDWR);
+	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
+
 	/* Write should work normally */
 	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 2));
 
-- 
2.25.1

[PATCH v4 3/3] selftests/user_events: Add test cases when event is disabled

[sunliming]

When user_events are disabled, it's write operation should return -EBADF.
Add this test cases.

Signed-off-by: sunliming <sunliming@kylinos.cn>
---
 tools/testing/selftests/user_events/ftrace_test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/user_events/ftrace_test.c b/tools/testing/selftests/user_events/ftrace_test.c
index d33bd31425db..c9dc99bcafec 100644
--- a/tools/testing/selftests/user_events/ftrace_test.c
+++ b/tools/testing/selftests/user_events/ftrace_test.c
@@ -297,6 +297,10 @@ TEST_F(user, write_events) {
 	io[0].iov_base = &reg.write_index;
 	io[0].iov_len = sizeof(reg.write_index);
 
+	/* Write should return -EBADF when event is not enabled */
+	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
+	ASSERT_EQ(EBADF, errno);
+
 	/* Enable event */
 	self->enable_fd = open(enable_file, O_RDWR);
 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
-- 
2.25.1

Re: [PATCH v4 0/3] tracing/user_events: Fix incorrect return value for writes when events are disabled and add its tests

[Beau Belgrave]

On Mon, Jun 26, 2023 at 07:13:41PM +0800, sunliming wrote:
> Now the writing operation return the count of writes regardless of whether
> events are enabled or disabled. Fix this by just return -EBADF when events
> are disabled.
> 
> v3 -> v4:
> - Change the return value from zero to -EBADF
> 

Applied these locally, ran a few tests. This looks good to me.

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>

Thanks,
-Beau

> v2 -> v3:
> - Change the return value from -ENOENT to zero
> 
> v1 -> v2:
> - Change the return value from -EFAULT to -ENOENT
> 
> sunliming (3):
>   tracing/user_events: Fix incorrect return value for writing operation
>     when events are disabled
>   selftests/user_events: Enable the event before write_fault test in
>     ftrace self-test
>   selftests/user_events: Add test cases when event is disabled
> 
>  kernel/trace/trace_events_user.c                  | 3 ++-
>  tools/testing/selftests/user_events/ftrace_test.c | 8 ++++++++
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> -- 
> 2.25.1