On Thu, Nov 08, 2018 at 07:48:16AM +0100, Thomas Gleixner wrote:
Florian,
On Wed, 7 Nov 2018, Florian Fainelli wrote:
On 11/1/18 1:02 PM, Florian Fainelli wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> [ Upstream commit 78c9c4dfbf8c04883941445a195276bb4bb92c76 ]
>
> 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: Team OWL337 <icytxw@xxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Acked-by: John Stultz <john.stultz@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
> Link: https://lkml.kernel.org/r/20180626132705.018623573@xxxxxxxxxxxxx
> [florian: Make patch apply to v4.9.135]
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> Thomas, can you review for correctness? Thanks!
Thomas, John, does that look like a reasonable backport for 4.9?
Looks correct.
Queued for 4.9, thanks all.
--
Thanks,
Sasha
