Messages in this thread | | | From | John Stultz <> | Date | Thu, 28 Jun 2018 21:24:42 -0700 | Subject | Re: [patch 2/2] posix-timers: Sanitize overrun handling |
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On Tue, Jun 26, 2018 at 6:21 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > The posix timer overrun handling is broken because the forwarding functions > can return a huge number of overruns which does not fit in an int. As a > consequence timer_getoverrun(2) and siginfo::si_overrun can turn into > random number generators. > > The k_clock::timer_forward() callbacks return a 64 bit value now. Make > k_itimer::ti_overrun[_last] 64bit as well, so the kernel internal > accounting is correct. 3Remove the temporary (int) casts. > > Add a helper function which clamps the overrun value returned to user space > via timer_getoverrun(2) or siginfo::si_overrun limited to a positive value > between 0 and INT_MAX. INT_MAX is an indicator for user space that the > overrun value has been clamped. > > Reported-by: air icy <icytxw@gmail.com> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Looks ok, and doesn't trip any regressions in testing so far.
Acked-by: John Stultz <john.stultz@linaro.org>
thanks -john
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