Messages in this thread | | | Date | Mon, 12 Aug 2013 06:03:29 +0300 | From | Baruch Siach <> | Subject | Re: [Linux-Xtensa] Re: [PATCH] time: sched_clock: fix integer overflow |
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Hi Thomas, John,
On Mon, Jul 29, 2013 at 08:59:39AM +0300, Baruch Siach wrote: > On Wed, Jul 17, 2013 at 12:46:53PM +0300, Baruch Siach wrote: > > The expression '(1 << 32)' happens to evaluate as 0 on ARM, but it evaluates as > > 1 on xtensa and x86_64. This zeros sched_clock_mask, and breaks sched_clock(). > > Set the type of 1 to 'unsigned long long' to get the value we need. > > Ping? -rc3 is out, and this bug (which currently breaks xtensa) is not fixed > yet. Please consider applying.
Sorry to bother again, but -rc5 is here and xtensa sched_clock is still broken.
baruch
> > Reported-by: Max Filippov <jcmvbkbc@gmail.com> > > Tested-by: Max Filippov <jcmvbkbc@gmail.com> > > Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> > > Signed-off-by: Baruch Siach <baruch@tkos.co.il> > > --- > > kernel/time/sched_clock.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c > > index a326f27..0b479a6 100644 > > --- a/kernel/time/sched_clock.c > > +++ b/kernel/time/sched_clock.c > > @@ -121,7 +121,7 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) > > BUG_ON(bits > 32); > > WARN_ON(!irqs_disabled()); > > read_sched_clock = read; > > - sched_clock_mask = (1 << bits) - 1; > > + sched_clock_mask = (1ULL << bits) - 1; > > cd.rate = rate; > > > > /* calculate the mult/shift to convert counter ticks to ns. */ > > --
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