From 98293e8d2f51976d5f790400859a517c0f7cb598 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Wed, 31 Dec 2014 10:56:18 -0800 Subject: [PATCH] fib_trie: Use unsigned long for anything dealing with a shift by bits This change makes it so that anything that can be shifted by, or compared to a value shifted by bits is updated to be an unsigned long. This is mostly a precaution against an insanely huge address space that somehow starts coming close to the 2^32 root node size which would require something like 1.5 billion addresses. I chose unsigned long instead of unsigned long long since I do not believe it is possible to allocate a 32 bit tnode on a 32 bit system as the memory consumed would be 16GB + 28B which exceeds the addressible space for any one process. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ipv4/fib_trie.c | 53 ++++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 27 deletions(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 9d675486b38c..28a3065470bc 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -146,8 +146,8 @@ struct trie { #endif }; -static void tnode_put_child_reorg(struct tnode *tn, int i, struct tnode *n, - int wasfull); +static void tnode_put_child_reorg(struct tnode *tn, unsigned long i, + struct tnode *n, int wasfull); static struct tnode *resize(struct trie *t, struct tnode *tn); static struct tnode *inflate(struct trie *t, struct tnode *tn); static struct tnode *halve(struct trie *t, struct tnode *tn); @@ -183,25 +183,23 @@ static inline void node_set_parent(struct tnode *n, struct tnode *tp) /* This provides us with the number of children in this node, in the case of a * leaf this will return 0 meaning none of the children are accessible. */ -static inline int tnode_child_length(const struct tnode *tn) +static inline unsigned long tnode_child_length(const struct tnode *tn) { return (1ul << tn->bits) & ~(1ul); } -/* - * caller must hold RTNL - */ -static inline struct tnode *tnode_get_child(const struct tnode *tn, unsigned int i) +/* caller must hold RTNL */ +static inline struct tnode *tnode_get_child(const struct tnode *tn, + unsigned long i) { BUG_ON(i >= tnode_child_length(tn)); return rtnl_dereference(tn->child[i]); } -/* - * caller must hold RCU read lock or RTNL - */ -static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn, unsigned int i) +/* caller must hold RCU read lock or RTNL */ +static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn, + unsigned long i) { BUG_ON(i >= tnode_child_length(tn)); @@ -400,7 +398,7 @@ static inline int tnode_full(const struct tnode *tn, const struct tnode *n) return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); } -static inline void put_child(struct tnode *tn, int i, +static inline void put_child(struct tnode *tn, unsigned long i, struct tnode *n) { tnode_put_child_reorg(tn, i, n, -1); @@ -411,13 +409,13 @@ static inline void put_child(struct tnode *tn, int i, * Update the value of full_children and empty_children. */ -static void tnode_put_child_reorg(struct tnode *tn, int i, struct tnode *n, - int wasfull) +static void tnode_put_child_reorg(struct tnode *tn, unsigned long i, + struct tnode *n, int wasfull) { struct tnode *chi = rtnl_dereference(tn->child[i]); int isfull; - BUG_ON(i >= 1<bits); + BUG_ON(i >= tnode_child_length(tn)); /* update emptyChildren */ if (n == NULL && chi != NULL) @@ -607,10 +605,10 @@ no_children: static void tnode_clean_free(struct tnode *tn) { struct tnode *tofree; - int i; + unsigned long i; for (i = 0; i < tnode_child_length(tn); i++) { - tofree = rtnl_dereference(tn->child[i]); + tofree = tnode_get_child(tn, i); if (tofree) node_free(tofree); } @@ -619,10 +617,10 @@ static void tnode_clean_free(struct tnode *tn) static struct tnode *inflate(struct trie *t, struct tnode *oldtnode) { - int olen = tnode_child_length(oldtnode); + unsigned long olen = tnode_child_length(oldtnode); struct tnode *tn; + unsigned long i; t_key m; - int i; pr_debug("In inflate\n"); @@ -664,7 +662,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *oldtnode) for (i = 0; i < olen; i++) { struct tnode *inode = tnode_get_child(oldtnode, i); struct tnode *left, *right; - int size, j; + unsigned long size, j; /* An empty child */ if (inode == NULL) @@ -737,7 +735,7 @@ nomem: static struct tnode *halve(struct trie *t, struct tnode *oldtnode) { - int olen = tnode_child_length(oldtnode); + unsigned long olen = tnode_child_length(oldtnode); struct tnode *tn, *left, *right; int i; @@ -1532,9 +1530,9 @@ static int trie_flush_leaf(struct tnode *l) static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c) { do { - t_key idx = c ? idx = get_index(c->key, p) + 1 : 0; + unsigned long idx = c ? idx = get_index(c->key, p) + 1 : 0; - while (idx < 1u << p->bits) { + while (idx < tnode_child_length(p)) { c = tnode_get_child_rcu(p, idx++); if (!c) continue; @@ -1786,8 +1784,8 @@ struct fib_trie_iter { static struct tnode *fib_trie_get_next(struct fib_trie_iter *iter) { + unsigned long cindex = iter->index; struct tnode *tn = iter->tnode; - unsigned int cindex = iter->index; struct tnode *p; /* A single entry routing table */ @@ -1797,7 +1795,7 @@ static struct tnode *fib_trie_get_next(struct fib_trie_iter *iter) pr_debug("get_next iter={node=%p index=%d depth=%d}\n", iter->tnode, iter->index, iter->depth); rescan: - while (cindex < (1<bits)) { + while (cindex < tnode_child_length(tn)) { struct tnode *n = tnode_get_child_rcu(tn, cindex); if (n) { @@ -1874,15 +1872,16 @@ static void trie_collect_stats(struct trie *t, struct trie_stat *s) hlist_for_each_entry_rcu(li, &n->list, hlist) ++s->prefixes; } else { - int i; + unsigned long i; s->tnodes++; if (n->bits < MAX_STAT_DEPTH) s->nodesizes[n->bits]++; - for (i = 0; i < tnode_child_length(n); i++) + for (i = 0; i < tnode_child_length(n); i++) { if (!rcu_access_pointer(n->child[i])) s->nullpointers++; + } } } rcu_read_unlock(); -- 2.39.5