Commit 98293e8d authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller
Browse files

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: default avatarAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9b44019

net/ipv4/fib_trie.c

+26 −27
Original line number Diff line number Diff line
@@ -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<<tn->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<<tn->bits)) {

	while (cindex < tnode_child_length(tn)) {

		struct tnode *n = tnode_get_child_rcu(tn, cindex);



		if (n) {
@@ -1874,17 +1872,18 @@ 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();

}

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