[GIT,PULL,v3] tracing: tracing: user_event fix for 6.4
Commit Message
Linus,
tracing: Fix user event write on buffer disabled
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, 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
Please pull the latest trace-v6.4-rc7-v3 tree, which can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace-v6.4-rc7-v3
Tag SHA1: e50c9719e4ccc09a792544dee295b09f16877544
Head SHA1: d34a271accf8fad00e05aad2cecb9fb53a840a94
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(-)
---------------------------
Comments
The pull request you sent on Wed, 28 Jun 2023 11:06:04 -0400:
> git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git trace-v6.4-rc7-v3
has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/3ad7b12c72ae6ba34d452e88a60c37c9fb368fbb
Thank you!
@@ -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;
}
@@ -324,6 +324,10 @@ TEST_F(user, write_events) {
io[0].iov_base = ®.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, ®));
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));