Merge branch 'ipv4-ipv6-refcount_t'

Elena Reshetova says:

====================
v2 ipv4/ipv6 refcount conversions

Changes in v2:
 * rebase on top of net-next
 * currently by default refcount_t = atomic_t (*) and uses all
   atomic standard operations unless CONFIG_REFCOUNT_FULL is enabled.
   This is a compromise for the systems that are critical on
   performance (such as net) and cannot accept even slight delay
   on the refcounter operations.

This series, for ipv4/ipv6 network components, replaces atomic_t reference
counters with the new refcount_t type and API (see include/linux/refcount.h).
By doing this we prevent intentional or accidental
underflows or overflows that can led to use-after-free vulnerabilities.

The patches are fully independent and can be cherry-picked separately.
In order to try with refcount functionality enabled in run-time,
CONFIG_REFCOUNT_FULL must be enabled.

NOTE: automatic kernel builder for some reason doesn't like all my
network branches and regularly times out the builds on these branches.
Suggestion for "waiting a day for a good coverage" doesn't work, as
we have seen with generic network conversions. So please wait for the
full report from kernel test rebot before merging further up.
This has been compile-tested in 116 configs, but 71 timed out (including
all s390-related configs again). I am trying to see if they can fix
build coverage for me in meanwhile.

* The respective change is currently merged into -next as
  "locking/refcount: Create unchecked atomic_t implementation".
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 8 insertions, 8 deletions

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index c2044775ae7d..c4c6e1969ed0 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -375,7 +375,7 @@ static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
 	struct cipso_v4_doi *iter;
 
 	list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
-		if (iter->doi == doi && atomic_read(&iter->refcount))
+		if (iter->doi == doi && refcount_read(&iter->refcount))
 			return iter;
 	return NULL;
 }
@@ -429,7 +429,7 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def,
 		}
 	}
 
-	atomic_set(&doi_def->refcount, 1);
+	refcount_set(&doi_def->refcount, 1);
 
 	spin_lock(&cipso_v4_doi_list_lock);
 	if (cipso_v4_doi_search(doi_def->doi)) {
@@ -533,7 +533,7 @@ int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
 		ret_val = -ENOENT;
 		goto doi_remove_return;
 	}
-	if (!atomic_dec_and_test(&doi_def->refcount)) {
+	if (!refcount_dec_and_test(&doi_def->refcount)) {
 		spin_unlock(&cipso_v4_doi_list_lock);
 		ret_val = -EBUSY;
 		goto doi_remove_return;
@@ -576,7 +576,7 @@ struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
 	doi_def = cipso_v4_doi_search(doi);
 	if (!doi_def)
 		goto doi_getdef_return;
-	if (!atomic_inc_not_zero(&doi_def->refcount))
+	if (!refcount_inc_not_zero(&doi_def->refcount))
 		doi_def = NULL;
 
 doi_getdef_return:
@@ -597,7 +597,7 @@ void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
 	if (!doi_def)
 		return;
 
-	if (!atomic_dec_and_test(&doi_def->refcount))
+	if (!refcount_dec_and_test(&doi_def->refcount))
 		return;
 	spin_lock(&cipso_v4_doi_list_lock);
 	list_del_rcu(&doi_def->list);
@@ -630,7 +630,7 @@ int cipso_v4_doi_walk(u32 *skip_cnt,
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
-		if (atomic_read(&iter_doi->refcount) > 0) {
+		if (refcount_read(&iter_doi->refcount) > 0) {
 			if (doi_cnt++ < *skip_cnt)
 				continue;
 			ret_val = callback(iter_doi, cb_arg);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index ff47ea1408fe..222100103808 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1253,7 +1253,7 @@ link_it:
 	}
 
 	fi->fib_treeref++;
-	atomic_inc(&fi->fib_clntref);
+	refcount_set(&fi->fib_clntref, 1);
 	spin_lock_bh(&fib_info_lock);
 	hlist_add_head(&fi->fib_hash,
 		       &fib_info_hash[fib_info_hashfn(fi)]);
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index d56659e97a6e..64668c69dda6 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1463,7 +1463,7 @@ found:
 			}
 
 			if (!(fib_flags & FIB_LOOKUP_NOREF))
-				atomic_inc(&fi->fib_clntref);
+				refcount_inc(&fi->fib_clntref);
 
 			res->prefix = htonl(n->key);
 			res->prefixlen = KEYLENGTH - fa->fa_slen;