Commit f38b24c9 authored by Firo Yang's avatar Firo Yang Committed by David S. Miller
Browse files

fib_trie: coding style: Use pointer after check 



As Alexander Duyck pointed out that:
struct tnode {
        ...
        struct key_vector kv[1];
}
The kv[1] member of struct tnode is an arry that refernced by
a null pointer will not crash the system, like this:
struct tnode *p = NULL;
struct key_vector *kv = p->kv;
As such p->kv doesn't actually dereference anything, it is simply a
means for getting the offset to the array from the pointer p.

This patch make the code more regular to avoid making people feel
odd when they look at the code.

Signed-off-by: default avatarFiro Yang <firogm@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cbab1510

net/ipv4/fib_trie.c

+13 −8
Original line number Diff line number Diff line
@@ -325,13 +325,15 @@ static inline void empty_child_dec(struct key_vector *n) 


static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)

{

	struct tnode *kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);

	struct key_vector *l = kv->kv;

	struct key_vector *l;

	struct tnode *kv;



	kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);

	if (!kv)

		return NULL;



	/* initialize key vector */

	l = kv->kv;

	l->key = key;

	l->pos = 0;

	l->bits = 0;
@@ -346,24 +348,26 @@ static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 


static struct key_vector *tnode_new(t_key key, int pos, int bits)

{

	struct tnode *tnode = tnode_alloc(bits);

	unsigned int shift = pos + bits;

	struct key_vector *tn = tnode->kv;

	struct key_vector *tn;

	struct tnode *tnode;



	/* verify bits and pos their msb bits clear and values are valid */

	BUG_ON(!bits || (shift > KEYLENGTH));



	pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),

		 sizeof(struct key_vector *) << bits);



	tnode = tnode_alloc(bits);

	if (!tnode)

		return NULL;



	pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),

		 sizeof(struct key_vector *) << bits);



	if (bits == KEYLENGTH)

		tnode->full_children = 1;

	else

		tnode->empty_children = 1ul << bits;



	tn = tnode->kv;

	tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;

	tn->pos = pos;

	tn->bits = bits;
@@ -2054,11 +2058,12 @@ static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 
static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,

					     struct trie *t)

{

	struct key_vector *n, *pn = t->kv;

	struct key_vector *n, *pn;



	if (!t)

		return NULL;



	pn = t->kv;

	n = rcu_dereference(pn->tnode[0]);

	if (!n)

		return NULL;

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