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

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

[Steven Rostedt]

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: 131966049074b8025a8cba0e99d3745311fcef5b


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 | 7 +++++++
 2 files changed, 9 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 0 to indicates that the event
is disabled.

Link: https://lore.kernel.org/linux-trace-kernel/20230621060827.151564-2-sunliming@kylinos.cn

Signed-off-by: sunliming <sunliming@kylinos.cn>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
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..902cae005df4 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 0;
 
 	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 been enabled in write_fault test in ftrace
self-test, Just enable it.

Link: https://lkml.kernel.org/r/20230621063438.154271-1-sunliming@kylinos.cn

Signed-off-by: sunliming <sunliming@kylinos.cn>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
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, its write operation should return zero.
Add this test cases.

Link: https://lkml.kernel.org/r/20230621063502.154378-1-sunliming@kylinos.cn

Signed-off-by: sunliming <sunliming@kylinos.cn>
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 tools/testing/selftests/user_events/ftrace_test.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/user_events/ftrace_test.c b/tools/testing/selftests/user_events/ftrace_test.c
index 88898749e5b7..f42a20520175 100644
--- a/tools/testing/selftests/user_events/ftrace_test.c
+++ b/tools/testing/selftests/user_events/ftrace_test.c
@@ -324,6 +324,9 @@ TEST_F(user, write_events) {
 	io[0].iov_base = &reg.write_index;
 	io[0].iov_len = sizeof(reg.write_index);
 
+	/* Write should return zero when event is not enabled */
+	ASSERT_EQ(0, writev(self->data_fd, (const struct iovec *)io, 3));
+
 	/* Enable event */
 	self->enable_fd = open(enable_file, O_RDWR);
 	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
-- 
2.39.2