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fib_hash: fix rcu sparse and logical errors

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While fixing CONFIG_SPARSE_RCU_POINTER errors, I had to fix accesses to
fz->fz_hash for real.

-	&fz->fz_hash[fn_hash(f->fn_key, fz)]
+	rcu_dereference(fz->fz_hash) + fn_hash(f->fn_key, fz)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-10-26 03:24:16 +00:00 committed by David S. Miller
parent ebb9fed2de
commit ded85aa86b
1 changed files with 20 additions and 16 deletions
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36
net/ipv4/fib_hash.c
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@ -120,11 +120,12 @@ static inline void fn_rebuild_zone(struct fn_zone *fz,
struct fib_node *f; struct fib_node *f;
hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) { hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
struct hlist_head __rcu *new_head; struct hlist_head *new_head;
hlist_del_rcu(&f->fn_hash); hlist_del_rcu(&f->fn_hash);
new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)]; new_head = rcu_dereference_protected(fz->fz_hash, 1) +
fn_hash(f->fn_key, fz);
hlist_add_head_rcu(&f->fn_hash, new_head); hlist_add_head_rcu(&f->fn_hash, new_head);
} }
} }
@ -179,8 +180,8 @@ static void fn_rehash_zone(struct fn_zone *fz)
memcpy(&nfz, fz, sizeof(nfz)); memcpy(&nfz, fz, sizeof(nfz));
write_seqlock_bh(&fz->fz_lock); write_seqlock_bh(&fz->fz_lock);
old_ht = fz->fz_hash; old_ht = rcu_dereference_protected(fz->fz_hash, 1);
nfz.fz_hash = ht; RCU_INIT_POINTER(nfz.fz_hash, ht);
nfz.fz_hashmask = new_hashmask; nfz.fz_hashmask = new_hashmask;
nfz.fz_divisor = new_divisor; nfz.fz_divisor = new_divisor;
fn_rebuild_zone(&nfz, old_ht, old_divisor); fn_rebuild_zone(&nfz, old_ht, old_divisor);
@ -236,7 +237,7 @@ fn_new_zone(struct fn_hash *table, int z)
seqlock_init(&fz->fz_lock); seqlock_init(&fz->fz_lock);
fz->fz_divisor = z ? EMBEDDED_HASH_SIZE : 1; fz->fz_divisor = z ? EMBEDDED_HASH_SIZE : 1;
fz->fz_hashmask = fz->fz_divisor - 1; fz->fz_hashmask = fz->fz_divisor - 1;
fz->fz_hash = fz->fz_embedded_hash; RCU_INIT_POINTER(fz->fz_hash, fz->fz_embedded_hash);
fz->fz_order = z; fz->fz_order = z;
fz->fz_revorder = 32 - z; fz->fz_revorder = 32 - z;
fz->fz_mask = inet_make_mask(z); fz->fz_mask = inet_make_mask(z);
@ -272,7 +273,7 @@ int fib_table_lookup(struct fib_table *tb,
for (fz = rcu_dereference(t->fn_zone_list); for (fz = rcu_dereference(t->fn_zone_list);
fz != NULL; fz != NULL;
fz = rcu_dereference(fz->fz_next)) { fz = rcu_dereference(fz->fz_next)) {
struct hlist_head __rcu *head; struct hlist_head *head;
struct hlist_node *node; struct hlist_node *node;
struct fib_node *f; struct fib_node *f;
__be32 k; __be32 k;
@ -282,7 +283,7 @@ int fib_table_lookup(struct fib_table *tb,
seq = read_seqbegin(&fz->fz_lock); seq = read_seqbegin(&fz->fz_lock);
k = fz_key(flp->fl4_dst, fz); k = fz_key(flp->fl4_dst, fz);
head = &fz->fz_hash[fn_hash(k, fz)]; head = rcu_dereference(fz->fz_hash) + fn_hash(k, fz);
hlist_for_each_entry_rcu(f, node, head, fn_hash) { hlist_for_each_entry_rcu(f, node, head, fn_hash) {
if (f->fn_key != k) if (f->fn_key != k)
continue; continue;
@ -311,6 +312,7 @@ void fib_table_select_default(struct fib_table *tb,
struct fib_info *last_resort; struct fib_info *last_resort;
struct fn_hash *t = (struct fn_hash *)tb->tb_data; struct fn_hash *t = (struct fn_hash *)tb->tb_data;
struct fn_zone *fz = t->fn_zones[0]; struct fn_zone *fz = t->fn_zones[0];
struct hlist_head *head;
if (fz == NULL) if (fz == NULL)
return; return;
@ -320,7 +322,8 @@ void fib_table_select_default(struct fib_table *tb,
order = -1; order = -1;
rcu_read_lock(); rcu_read_lock();
hlist_for_each_entry_rcu(f, node, &fz->fz_hash[0], fn_hash) { head = rcu_dereference(fz->fz_hash);
hlist_for_each_entry_rcu(f, node, head, fn_hash) {
struct fib_alias *fa; struct fib_alias *fa;
list_for_each_entry_rcu(fa, &f->fn_alias, fa_list) { list_for_each_entry_rcu(fa, &f->fn_alias, fa_list) {
@ -374,7 +377,7 @@ out:
/* Insert node F to FZ. */ /* Insert node F to FZ. */
static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f) static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
{ {
struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)]; struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(f->fn_key, fz);
hlist_add_head_rcu(&f->fn_hash, head); hlist_add_head_rcu(&f->fn_hash, head);
} }
@ -382,7 +385,7 @@ static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
/* Return the node in FZ matching KEY. */ /* Return the node in FZ matching KEY. */
static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key) static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
{ {
struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)]; struct hlist_head *head = rtnl_dereference(fz->fz_hash) + fn_hash(key, fz);
struct hlist_node *node; struct hlist_node *node;
struct fib_node *f; struct fib_node *f;
@ -662,7 +665,7 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
static int fn_flush_list(struct fn_zone *fz, int idx) static int fn_flush_list(struct fn_zone *fz, int idx)
{ {
struct hlist_head *head = &fz->fz_hash[idx]; struct hlist_head *head = rtnl_dereference(fz->fz_hash) + idx;
struct hlist_node *node, *n; struct hlist_node *node, *n;
struct fib_node *f; struct fib_node *f;
int found = 0; int found = 0;
@ -761,14 +764,15 @@ fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
struct fn_zone *fz) struct fn_zone *fz)
{ {
int h, s_h; int h, s_h;
struct hlist_head *head = rcu_dereference(fz->fz_hash);
if (fz->fz_hash == NULL) if (head == NULL)
return skb->len; return skb->len;
s_h = cb->args[3]; s_h = cb->args[3];
for (h = s_h; h < fz->fz_divisor; h++) { for (h = s_h; h < fz->fz_divisor; h++) {
if (hlist_empty(&fz->fz_hash[h])) if (hlist_empty(head + h))
continue; continue;
if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) { if (fn_hash_dump_bucket(skb, cb, tb, fz, head + h) < 0) {
cb->args[3] = h; cb->args[3] = h;
return -1; return -1;
} }
@ -872,7 +876,7 @@ static struct fib_alias *fib_get_first(struct seq_file *seq)
if (!iter->zone->fz_nent) if (!iter->zone->fz_nent)
continue; continue;
iter->hash_head = iter->zone->fz_hash; iter->hash_head = rcu_dereference(iter->zone->fz_hash);
maxslot = iter->zone->fz_divisor; maxslot = iter->zone->fz_divisor;
for (iter->bucket = 0; iter->bucket < maxslot; for (iter->bucket = 0; iter->bucket < maxslot;
@ -957,7 +961,7 @@ static struct fib_alias *fib_get_next(struct seq_file *seq)
goto out; goto out;
iter->bucket = 0; iter->bucket = 0;
iter->hash_head = iter->zone->fz_hash; iter->hash_head = rcu_dereference(iter->zone->fz_hash);
hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
list_for_each_entry(fa, &fn->fn_alias, fa_list) { list_for_each_entry(fa, &fn->fn_alias, fa_list) {