net: dccp: fix kernel crash on module load

Patch eedbbb0d98b2 "net: dccp: initialize (addr,port) ..."
added calling to inet_hashinfo2_init() from dccp_init().

However, inet_hashinfo2_init() is marked as __init(), and
thus the kernel panics when dccp is loaded as module. Removing
__init() tag from inet_hashinfo2_init() is not feasible because
it calls into __init functions in mm.

This patch adds inet_hashinfo2_init_mod() function that can
be called after the init phase is done; changes dccp_init() to
call the new function; un-marks inet_hashinfo2_init() as
exported.

Fixes: eedbbb0d98b2 ("net: dccp: initialize (addr,port) ...")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 0ce460e93dc447160c63265aec5b70c1b7ae782a..babb14136705ea5ca71aec77d5ffd13dad4c14a2 100644 (file)
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -237,6 +237,7 @@ void inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
                         unsigned long numentries, int scale,
                         unsigned long low_limit,
                         unsigned long high_limit);
+int inet_hashinfo2_init_mod(struct inet_hashinfo *h);
 
 bool inet_ehash_insert(struct sock *sk, struct sock *osk);
 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk);

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index be0b223aa862518c4a344a7b4e12f8a1db55c885..2cc5fbb1b29e98feff80a2526c818e7e47572416 100644 (file)
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1139,11 +1139,11 @@ static int __init dccp_init(void)
        rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
        if (rc)
                goto out_fail;
-       rc = -ENOBUFS;
        inet_hashinfo_init(&dccp_hashinfo);
-       inet_hashinfo2_init(&dccp_hashinfo, "dccp_listen_portaddr_hash",
-                           INET_LHTABLE_SIZE, 21,  /* one slot per 2 MB*/
-                           0, 64 * 1024);
+       rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
+       if (rc)
+               goto out_fail;
+       rc = -ENOBUFS;
        dccp_hashinfo.bind_bucket_cachep =
                kmem_cache_create("dccp_bind_bucket",
                                  sizeof(struct inet_bind_bucket), 0,

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 2445614de6a762eb5b3f64e593b44e6bdabbdb98..942265d65eb3741a6350ff685cba915538960ea5 100644 (file)
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -762,13 +762,22 @@ void inet_hashinfo_init(struct inet_hashinfo *h)
 }
 EXPORT_SYMBOL_GPL(inet_hashinfo_init);
 
+static void init_hashinfo_lhash2(struct inet_hashinfo *h)
+{
+       int i;
+
+       for (i = 0; i <= h->lhash2_mask; i++) {
+               spin_lock_init(&h->lhash2[i].lock);
+               INIT_HLIST_HEAD(&h->lhash2[i].head);
+               h->lhash2[i].count = 0;
+       }
+}
+
 void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
                                unsigned long numentries, int scale,
                                unsigned long low_limit,
                                unsigned long high_limit)
 {
-       unsigned int i;
-
        h->lhash2 = alloc_large_system_hash(name,
                                            sizeof(*h->lhash2),
                                            numentries,
@@ -778,14 +787,23 @@ void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
                                            &h->lhash2_mask,
                                            low_limit,
                                            high_limit);
+       init_hashinfo_lhash2(h);
+}
 
-       for (i = 0; i <= h->lhash2_mask; i++) {
-               spin_lock_init(&h->lhash2[i].lock);
-               INIT_HLIST_HEAD(&h->lhash2[i].head);
-               h->lhash2[i].count = 0;
-       }
+int inet_hashinfo2_init_mod(struct inet_hashinfo *h)
+{
+       h->lhash2 = kmalloc_array(INET_LHTABLE_SIZE, sizeof(*h->lhash2), GFP_KERNEL);
+       if (!h->lhash2)
+               return -ENOMEM;
+
+       h->lhash2_mask = INET_LHTABLE_SIZE - 1;
+       /* INET_LHTABLE_SIZE must be a power of 2 */
+       BUG_ON(INET_LHTABLE_SIZE & h->lhash2_mask);
+
+       init_hashinfo_lhash2(h);
+       return 0;
 }
-EXPORT_SYMBOL_GPL(inet_hashinfo2_init);
+EXPORT_SYMBOL_GPL(inet_hashinfo2_init_mod);
 
 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
 {