From 36a15d7dee063b6b8ce0480482969e4ba49460a4 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 28 Jan 2016 00:17:47 +1100 Subject: [PATCH] idtree: Fix undefined behaviour (left shift of signed value) ~0 will be signed and negative on any 2s complement system, and left shifting a negative value has undefined behaviour in C. Signed-off-by: David Gibson --- ccan/idtree/idtree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ccan/idtree/idtree.c b/ccan/idtree/idtree.c index 5bd88822..6e75450e 100644 --- a/ccan/idtree/idtree.c +++ b/ccan/idtree/idtree.c @@ -278,7 +278,7 @@ void *idtree_lookup(const struct idtree *idp, int id) * present. If so, tain't one of ours! */ if (n + IDTREE_BITS < 31 && - (id & ~(~0 << MAX_ID_SHIFT)) >> (n + IDTREE_BITS)) + (id & ~(~0U << MAX_ID_SHIFT)) >> (n + IDTREE_BITS)) return NULL; /* Mask off upper bits we don't use for the search. */ -- 2.39.2