[for-linus][PATCH 0/3] tracing: Final updates for 6.4+

[for-linus][PATCH 0/3] tracing: Final updates for 6.4+

[Steven Rostedt]

The user events write currently returns the size of what was suppose to be
written when tracing is disabled and nothing was written. Instead, behave like
trace_marker and return -EBADF, as that is what is returned if a file is opened
for read only,

Before user events become an ABI, fix the return value of the write
operation when tracing is disabled. It should not return an error, but
simply report it wrote zero bytes. Just like any other write operation
that doesn't write but does not "fail".

This also includes test cases for this use case.

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/urgent

Head SHA1: e155047e53d25f09d055c08ae9d6c269520e90d8


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(-)

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

[Steven Rostedt]

From: sunliming <sunliming@kylinos.cn>

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.

Link: https://lkml.kernel.org/r/20230626111344.19136-2-sunliming@kylinos.cn

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 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 8df0550415e7..09f7d9167b8e 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -2096,7 +2096,8 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i)
 
 		if (unlikely(faulted))
 			return -EFAULT;
-	}
+	} else
+		return -EBADF;
 
 	return ret;
 }
-- 
2.39.2

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

[Steven Rostedt]

From: sunliming <sunliming@kylinos.cn>

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

Link: https://lkml.kernel.org/r/20230626111344.19136-3-sunliming@kylinos.cn

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 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 eb6904d89f14..88898749e5b7 100644
--- a/tools/testing/selftests/user_events/ftrace_test.c
+++ b/tools/testing/selftests/user_events/ftrace_test.c
@@ -400,6 +400,10 @@ 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));
 
-- 
2.39.2

[for-linus][PATCH 3/3] selftests/user_events: Add test cases when event is disabled

[Steven Rostedt]

From: sunliming <sunliming@kylinos.cn>

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

Link: https://lkml.kernel.org/r/20230626111344.19136-4-sunliming@kylinos.cn

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 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 88898749e5b7..5beb0aef1d81 100644
--- a/tools/testing/selftests/user_events/ftrace_test.c
+++ b/tools/testing/selftests/user_events/ftrace_test.c
@@ -324,6 +324,10 @@ 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")))
-- 
2.39.2

Re: [for-linus][PATCH 0/3] tracing: Final updates for 6.4+

[Steven Rostedt]

On Wed, 28 Jun 2023 08:54:48 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> The user events write currently returns the size of what was suppose to be
> written when tracing is disabled and nothing was written. Instead, behave like
> trace_marker and return -EBADF, as that is what is returned if a file is opened
> for read only,

I accidentally sent this before it was ready to go (I was editing the
change log from the previous one) I didn't finish the above paragraph,
and was suppose to delete the below one.

That's because I was about to rush to a talk at EOSS, and hit save and
exit forgetting that sends the emails out! (I'm using quilt)

I'll finish it properly for when I do the proper pull request.

-- Steve


> 
> Before user events become an ABI, fix the return value of the write
> operation when tracing is disabled. It should not return an error, but
> simply report it wrote zero bytes. Just like any other write operation
> that doesn't write but does not "fail".
> 
> This also includes test cases for this use case.
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
> trace/urgent
> 
> Head SHA1: e155047e53d25f09d055c08ae9d6c269520e90d8
> 
> 
> 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(-)