Commit 53c03520 authored Jul 17, 2013 by Baruch Siach Committed by John Stultz Jul 22, 2013

sched_clock: Fix integer overflow



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.

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>
Signed-off-by: John Stultz <john.stultz@linaro.org>

parent b0ec636c

kernel/time/sched_clock.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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. */