Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 25 Apr 2023 13:56:15 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 2/3] tracing/user_events: Ensure bit is cleared on unregister |
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On Tue, 25 Apr 2023 10:06:54 -0700 Beau Belgrave <beaub@linux.microsoft.com> wrote:
> That's a good point, user_event_mm_fault() is a wrapper around > fixup_user_fault(). We retry if it works, so I guess if the user could > somehow cause a fail on the write and succeed to page in repeatedly, it > could keep the loop going for that time period. I cannot think of a way > to achieve this forever, but that doesn't mean it couldn't happen. > > I can certainly add an upper bound of retries (maybe 3 or so?) if you > think it would be possible for this to occur. I think we need retries of > some amount to handle spurious faults.
Even 10 is fine. With a comment saying, "This really shouldn't loop more than a couple of times, but we want to make sure some mischievous user doesn't take advantage of this looping".
-- Steve
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