Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 23 Jun 2023 16:21:36 -0700 | Subject | Re: [GIT PULL] tracing: user_event fix for 6.4 |
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On Fri, 23 Jun 2023 at 12:29, Steven Rostedt <rostedt@goodmis.org> wrote: > > 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 data but does not "fail".
This makes no sense.
A write() returning 0 means "Disk full". It's most definitely an error, and a failure.
But zero is not a particularly _good_ failure code. At least not unless your tracing disk is full. Is it?
If tracing is disabled, and you write something to it, I would expect to get a valid and reasonable error code back. Something like EINVAL or EIO or something to show "you did something wrong".
I do not at all understand the sentence
"When user_events are disabled, its write operation should return zero"
as an "explanation" for this, and my immediate reaction is "Really? Why? That makes no sense".
Linus
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