Messages in this thread Patch in this message | | | From | Colin King <> | Subject | [PATCH] rcu: shift by 1UL rather than 1 to fix sign extension error | Date | Tue, 13 Dec 2016 10:56:46 +0000 |
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From: Colin Ian King <colin.king@canonical.com>
mask and bit are unsigned longs, so if bit is 31 we end up sign extending the 1 and mask ends up as 0xffffffff80000000. Fix this by explicitly adding integer suffix UL ensure 1 is a unsigned long rather than an signed int.
Issue found with static analysis with CoverityScan, CID 1388564
Fixes: 8965c3ce4718754db ("rcu: Use leaf_node_for_each_mask_possible_cpu() in force_qs_rnp()") Signed-off-by: Colin Ian King <colin.king@canonical.com> --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 10162ac..6ecedd8 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3051,7 +3051,7 @@ static void force_qs_rnp(struct rcu_state *rsp, leaf_node_for_each_mask_possible_cpu(rnp, rnp->qsmask, bit, cpu) if (f(per_cpu_ptr(rsp->rda, cpu), isidle, maxj)) - mask |= 1 << bit; + mask |= 1UL << bit; if (mask != 0) { /* Idle/offline CPUs, report (releases rnp->lock. */ -- 2.10.2
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