On Thu, Jun 08, 2023 at 09:15:52AM +0800, sunliming wrote: > The writing operation return the count of writes whether events are > enabled or disabled. This is incorrect when events are disabled. Fix > this by just return -EFAULT when events are disabled. > > Signed-off-by: sunliming <sunliming@xxxxxxxxxx> > --- > 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..970bac0503fd 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 -EFAULT; > I'm not sure this is a good idea. Imagine this scenario: A user process writes out a user_event and it hits a fault that gets returned as errno (EFAULT). The user process is likely to either forget it and say, not worth retrying, or it will retry (potentially in a loop). If the process does retry and it's now disabled, it might try many times. I think that -ENOENT is a better error to use here. That way a user process will know it got disabled mid-write vs a fault that might want to be re-attempted. Thanks, -Beau > return ret; > } > -- > 2.25.1
