Use xfrm_state_afinfo_get_rcu() everywhere, this also moves rcu read (un)lock responsibility to the callers.
This avoids the conditional locking scheme we currently have. Signed-off-by: Florian Westphal <[email protected]> --- include/net/xfrm.h | 1 - net/xfrm/xfrm_output.c | 3 +- net/xfrm/xfrm_state.c | 97 +++++++++++++++++++++++++++++++------------------- 3 files changed, 62 insertions(+), 39 deletions(-) diff --git a/include/net/xfrm.h b/include/net/xfrm.h index c52197cf51dc..d81e153bfeee 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -342,7 +342,6 @@ struct xfrm_state_afinfo { int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo); int xfrm_state_unregister_afinfo(struct xfrm_state_afinfo *afinfo); -struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family); struct xfrm_state_afinfo *xfrm_state_afinfo_get_rcu(unsigned int family); struct xfrm_input_afinfo { diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c index 8ba29fe58352..351efd207d88 100644 --- a/net/xfrm/xfrm_output.c +++ b/net/xfrm/xfrm_output.c @@ -245,7 +245,8 @@ void xfrm_local_error(struct sk_buff *skb, int mtu) else return; - afinfo = xfrm_state_get_afinfo(proto); + rcu_read_lock(); + afinfo = xfrm_state_afinfo_get_rcu(proto); if (afinfo) afinfo->local_error(skb, mtu); rcu_read_unlock(); diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 0245df063bd7..1a7f0c0ec3bd 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -178,12 +178,17 @@ void km_state_expired(struct xfrm_state *x, int hard, u32 portid); 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_get_afinfo(family); + struct xfrm_state_afinfo *afinfo; const struct xfrm_type **typemap; int err = 0; - if (unlikely(afinfo == NULL)) + rcu_read_lock(); + + afinfo = xfrm_state_afinfo_get_rcu(family); + if (!afinfo) { + rcu_read_unlock(); return -EAFNOSUPPORT; + } typemap = afinfo->type_map; spin_lock_bh(&xfrm_type_lock); @@ -199,12 +204,17 @@ EXPORT_SYMBOL(xfrm_register_type); int xfrm_unregister_type(const struct xfrm_type *type, unsigned short family) { - struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family); + struct xfrm_state_afinfo *afinfo; const struct xfrm_type **typemap; int err = 0; - if (unlikely(afinfo == NULL)) + rcu_read_lock(); + + afinfo = xfrm_state_afinfo_get_rcu(family); + if (!afinfo) { + rcu_read_unlock(); return -EAFNOSUPPORT; + } typemap = afinfo->type_map; spin_lock_bh(&xfrm_type_lock); @@ -226,9 +236,13 @@ static const struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family) int modload_attempted = 0; retry: - afinfo = xfrm_state_get_afinfo(family); - if (unlikely(afinfo == NULL)) + rcu_read_lock(); + afinfo = xfrm_state_afinfo_get_rcu(family); + if (unlikely(!afinfo)) { + rcu_read_unlock(); return NULL; + } + typemap = afinfo->type_map; type = READ_ONCE(typemap[proto]); @@ -261,9 +275,12 @@ int xfrm_register_mode(struct xfrm_mode *mode, int family) if (unlikely(mode->encap >= XFRM_MODE_MAX)) return -EINVAL; - afinfo = xfrm_state_get_afinfo(family); - if (unlikely(afinfo == NULL)) + rcu_read_lock(); + afinfo = xfrm_state_afinfo_get_rcu(family); + if (!afinfo) { + rcu_read_unlock(); return -EAFNOSUPPORT; + } err = -EEXIST; modemap = afinfo->mode_map; @@ -295,9 +312,12 @@ int xfrm_unregister_mode(struct xfrm_mode *mode, int family) if (unlikely(mode->encap >= XFRM_MODE_MAX)) return -EINVAL; - afinfo = xfrm_state_get_afinfo(family); - if (unlikely(afinfo == NULL)) + rcu_read_lock(); + afinfo = xfrm_state_afinfo_get_rcu(family); + if (!afinfo) { + rcu_read_unlock(); return -EAFNOSUPPORT; + } err = -ENOENT; modemap = afinfo->mode_map; @@ -322,17 +342,21 @@ static struct xfrm_mode *xfrm_get_mode(unsigned int encap, int family) if (unlikely(encap >= XFRM_MODE_MAX)) return NULL; - retry: - afinfo = xfrm_state_get_afinfo(family); - if (unlikely(afinfo == NULL)) + rcu_read_lock(); + + afinfo = xfrm_state_afinfo_get_rcu(family); + if (unlikely(!afinfo)) { + rcu_read_unlock(); return NULL; + } mode = READ_ONCE(afinfo->mode_map[encap]); if (unlikely(mode && !try_module_get(mode->owner))) mode = NULL; rcu_read_unlock(); + if (!mode && !modload_attempted) { request_module("xfrm-mode-%d-%d", family, encap); modload_attempted = 1; @@ -1463,15 +1487,21 @@ int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n, unsigned short family, struct net *net) { - int err = 0; - struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family); + struct xfrm_state_afinfo *afinfo; + int err = -EAFNOSUPPORT; + + rcu_read_lock(); + + afinfo = xfrm_state_afinfo_get_rcu(family); if (!afinfo) - return -EAFNOSUPPORT; + goto error; + err = 0; spin_lock_bh(&net->xfrm.xfrm_state_lock); /*FIXME*/ if (afinfo->tmpl_sort) err = afinfo->tmpl_sort(dst, src, n); spin_unlock_bh(&net->xfrm.xfrm_state_lock); +error: rcu_read_unlock(); return err; } @@ -1481,17 +1511,20 @@ int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n, unsigned short family) { - int err = 0; - struct xfrm_state_afinfo *afinfo = xfrm_state_get_afinfo(family); + struct xfrm_state_afinfo *afinfo; struct net *net = xs_net(*src); + int err = -EAFNOSUPPORT; + afinfo = xfrm_state_afinfo_get_rcu(family); if (!afinfo) - return -EAFNOSUPPORT; + goto error; + err = 0; spin_lock_bh(&net->xfrm.xfrm_state_lock); if (afinfo->state_sort) err = afinfo->state_sort(dst, src, n); spin_unlock_bh(&net->xfrm.xfrm_state_lock); +error: rcu_read_unlock(); return err; } @@ -1972,18 +2005,6 @@ struct xfrm_state_afinfo *xfrm_state_afinfo_get_rcu(unsigned int family) return rcu_dereference(xfrm_state_afinfo[family]); } -struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned int family) -{ - struct xfrm_state_afinfo *afinfo; - if (unlikely(family >= NPROTO)) - return NULL; - rcu_read_lock(); - afinfo = rcu_dereference(xfrm_state_afinfo[family]); - if (unlikely(!afinfo)) - rcu_read_unlock(); - return afinfo; -} - /* Temporarily located here until net/xfrm/xfrm_tunnel.c is created */ void xfrm_state_delete_tunnel(struct xfrm_state *x) { @@ -2018,14 +2039,16 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay) struct xfrm_state_afinfo *afinfo; struct xfrm_mode *inner_mode; int family = x->props.family; - int err; + int err = 0; - err = -EAFNOSUPPORT; - afinfo = xfrm_state_get_afinfo(family); - if (!afinfo) - goto error; + rcu_read_lock(); + + afinfo = xfrm_state_afinfo_get_rcu(family); + if (!afinfo) { + rcu_read_unlock(); + return -EAFNOSUPPORT; + } - err = 0; if (afinfo->init_flags) err = afinfo->init_flags(x); -- 2.7.3
