Commit-ID: 98a01e779f3c66b0b11cd7e64d531c0e41c95762 Gitweb: http://git.kernel.org/tip/98a01e779f3c66b0b11cd7e64d531c0e41c95762 Author: Jiri Bohac <jbohac@xxxxxxx> AuthorDate: Fri, 18 Apr 2014 17:23:11 +0200 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Wed, 30 Apr 2014 13:46:17 +0200 timer: Prevent overflow in apply_slack On architectures with sizeof(int) < sizeof (long), the computation of mask inside apply_slack() can be undefined if the computed bit is > 32. E.g. with: expires = 0xffffe6f5 and slack = 25, we get: expires_limit = 0x20000000e bit = 33 mask = (1 << 33) - 1 /* undefined */ On x86, mask becomes 1 and and the slack is not applied properly. On s390, mask is -1, expires is set to 0 and the timer fires immediately. Use 1UL << bit to solve that issue. Suggested-by: Deborah Townsend <dstownse@xxxxxxxxxx> Signed-off-by: Jiri Bohac <jbohac@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20140418152310.GA13654@xxxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- kernel/timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/timer.c b/kernel/timer.c index 87bd529..3bb01a3 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -838,7 +838,7 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) bit = find_last_bit(&mask, BITS_PER_LONG); - mask = (1 << bit) - 1; + mask = (1UL << bit) - 1; expires_limit = expires_limit & ~(mask); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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