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>

diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index a326f27..0b479a6 100644 (file)
--- 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. */