Merge tag 'trace-v6.4-rc7-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix user event write on buffer disabled.

  The user events write currently returns the size of what was supposed
  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, and a write is
  performed on it. Writing to the buffer that is disabled is like trying
  to write to a file opened for read only, as the buffer still can be
  read, but just not written to.

  This also includes test cases for this use case"

* tag 'trace-v6.4-rc7-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  selftests/user_events: Add test cases when event is disabled
  selftests/user_events: Enable the event before write_fault test in ftrace self-test
  tracing/user_events: Fix incorrect return value for writing operation when events are disabled

2 files changed, 10 insertions, 1 deletions

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 0536db7fef61d7..4f5e74bbdab2ca 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;
 }
diff --git a/tools/testing/selftests/user_events/ftrace_test.c b/tools/testing/selftests/user_events/ftrace_test.c
index eb6904d89f1454..5beb0aef1d8149 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")))
@@ -400,6 +404,10 @@ 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));