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@linutronix.de
[ 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@gmail.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: John Stultz john.stultz@linaro.org Cc: Peter Zijlstra peterz@infradead.org Cc: Michael Kerrisk mtk.manpages@gmail.com Link: https://lkml.kernel.org/r/20180626132705.018623573@linutronix.de [florian: Make patch apply to v4.9.135] Signed-off-by: Florian Fainelli f.fainelli@gmail.com
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