xfrm: use separated locks to protect pointers of struct xfrm_state_afinfo

afinfo->type_map and afinfo->mode_map deserve separated locks,
they are different things.

We should just take RCU read lock to protect afinfo itself,
but not for the inner pointers.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 1522f19f273a0749d3808a7d429aa40e4efb0699..0adae918a7a24c02838d807c254e2cdb5ec3cdc9 100644 (file)
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -168,57 +168,45 @@ int __xfrm_state_delete(struct xfrm_state *x);
 int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
 void km_state_expired(struct xfrm_state *x, int hard, u32 portid);
 
-static struct xfrm_state_afinfo *xfrm_state_lock_afinfo(unsigned int family)
-{
-       struct xfrm_state_afinfo *afinfo;
-       if (unlikely(family >= NPROTO))
-               return NULL;
-       spin_lock_bh(&xfrm_state_afinfo_lock);
-       afinfo = xfrm_state_afinfo[family];
-       if (unlikely(!afinfo))
-               spin_unlock_bh(&xfrm_state_afinfo_lock);
-       return afinfo;
-}
-
-static void xfrm_state_unlock_afinfo(struct xfrm_state_afinfo *afinfo)
-{
-       spin_unlock_bh(&xfrm_state_afinfo_lock);
-}
-
+static DEFINE_SPINLOCK(xfrm_type_lock);
 int xfrm_register_type(const struct xfrm_type *type, unsigned short family)
 {
-       struct xfrm_state_afinfo *afinfo = xfrm_state_lock_afinfo(family);
+       struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
        const struct xfrm_type **typemap;
        int err = 0;
 
        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;
        typemap = afinfo->type_map;
+       spin_lock_bh(&xfrm_type_lock);
 
        if (likely(typemap[type->proto] == NULL))
                typemap[type->proto] = type;
        else
                err = -EEXIST;
-       xfrm_state_unlock_afinfo(afinfo);
+       spin_unlock_bh(&xfrm_type_lock);
+       xfrm_state_put_afinfo(afinfo);
        return err;
 }
 EXPORT_SYMBOL(xfrm_register_type);
 
 int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family)
 {
-       struct xfrm_state_afinfo *afinfo = xfrm_state_lock_afinfo(family);
+       struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family);
        const struct xfrm_type **typemap;
        int err = 0;
 
        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;
        typemap = afinfo->type_map;
+       spin_lock_bh(&xfrm_type_lock);
 
        if (unlikely(typemap[type->proto] != type))
                err = -ENOENT;
        else
                typemap[type->proto] = NULL;
-       xfrm_state_unlock_afinfo(afinfo);
+       spin_unlock_bh(&xfrm_type_lock);
+       xfrm_state_put_afinfo(afinfo);
        return err;
 }
 EXPORT_SYMBOL(xfrm_unregister_type);
@@ -255,6 +243,7 @@ static void xfrm_put_type(const struct xfrm_type *type)
        module_put(type->owner);
 }
 
+static DEFINE_SPINLOCK(xfrm_mode_lock);
 int xfrm_register_mode(struct xfrm_mode *mode, int family)
 {
        struct xfrm_state_afinfo *afinfo;
@@ -264,12 +253,13 @@ int xfrm_register_mode(struct xfrm_mode *mode, int family)
        if (unlikely(mode->encap >= XFRM_MODE_MAX))
                return -EINVAL;
 
-       afinfo = xfrm_state_lock_afinfo(family);
+       afinfo = xfrm_state_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;
 
        err = -EEXIST;
        modemap = afinfo->mode_map;
+       spin_lock_bh(&xfrm_mode_lock);
        if (modemap[mode->encap])
                goto out;
 
@@ -282,7 +272,8 @@ int xfrm_register_mode(struct xfrm_mode *mode, int family)
        err = 0;
 
 out:
-       xfrm_state_unlock_afinfo(afinfo);
+       spin_unlock_bh(&xfrm_mode_lock);
+       xfrm_state_put_afinfo(afinfo);
        return err;
 }
 EXPORT_SYMBOL(xfrm_register_mode);
@@ -296,19 +287,21 @@ int xfrm_unregister_mode(struct xfrm_mode *mode, int family)
        if (unlikely(mode->encap >= XFRM_MODE_MAX))
                return -EINVAL;
 
-       afinfo = xfrm_state_lock_afinfo(family);
+       afinfo = xfrm_state_get_afinfo(family);
        if (unlikely(afinfo == NULL))
                return -EAFNOSUPPORT;
 
        err = -ENOENT;
        modemap = afinfo->mode_map;
+       spin_lock_bh(&xfrm_mode_lock);
        if (likely(modemap[mode->encap] == mode)) {
                modemap[mode->encap] = NULL;
                module_put(mode->afinfo->owner);
                err = 0;
        }
 
-       xfrm_state_unlock_afinfo(afinfo);
+       spin_unlock_bh(&xfrm_mode_lock);
+       xfrm_state_put_afinfo(afinfo);
        return err;
 }
 EXPORT_SYMBOL(xfrm_unregister_mode);