From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- net/rds/connection.c | 1056 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1056 insertions(+) create mode 100644 net/rds/connection.c (limited to 'net/rds/connection.c') diff --git a/net/rds/connection.c b/net/rds/connection.c new file mode 100644 index 000000000..b6c4beb50 --- /dev/null +++ b/net/rds/connection.c @@ -0,0 +1,1056 @@ +/* + * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include +#include +#include +#include +#include +#include +#include + +#include "rds.h" +#include "loop.h" + +#define RDS_CONNECTION_HASH_BITS 12 +#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS) +#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1) + +/* converting this to RCU is a chore for another day.. */ +static DEFINE_SPINLOCK(rds_conn_lock); +static unsigned long rds_conn_count; +static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES]; +static struct kmem_cache *rds_conn_slab; + +static struct hlist_head *rds_conn_bucket(const struct in6_addr *laddr, + const struct in6_addr *faddr) +{ + static u32 rds6_hash_secret __read_mostly; + static u32 rds_hash_secret __read_mostly; + + __be32 lhash, fhash; + u32 hash; + + net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret)); + net_get_random_once(&rds6_hash_secret, sizeof(rds6_hash_secret)); + + lhash = laddr->s6_addr32[3]; +#if IS_ENABLED(CONFIG_IPV6) + fhash = (__force __be32)__ipv6_addr_jhash(faddr, rds6_hash_secret); +#else + fhash = faddr->s6_addr32[3]; +#endif + hash = __inet_ehashfn(lhash, 0, fhash, 0, rds_hash_secret); + + return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK]; +} + +#define rds_conn_info_set(var, test, suffix) do { \ + if (test) \ + var |= RDS_INFO_CONNECTION_FLAG_##suffix; \ +} while (0) + +/* rcu read lock must be held or the connection spinlock */ +static struct rds_connection *rds_conn_lookup(struct net *net, + struct hlist_head *head, + const struct in6_addr *laddr, + const struct in6_addr *faddr, + struct rds_transport *trans, + u8 tos, int dev_if) +{ + struct rds_connection *conn, *ret = NULL; + + hlist_for_each_entry_rcu(conn, head, c_hash_node) { + if (ipv6_addr_equal(&conn->c_faddr, faddr) && + ipv6_addr_equal(&conn->c_laddr, laddr) && + conn->c_trans == trans && + conn->c_tos == tos && + net == rds_conn_net(conn) && + conn->c_dev_if == dev_if) { + ret = conn; + break; + } + } + rdsdebug("returning conn %p for %pI6c -> %pI6c\n", ret, + laddr, faddr); + return ret; +} + +/* + * This is called by rds_conn_shutdown() once the transport has brought + * a path down. It clears partial message state so that the transport + * can start sending and receiving over this path again in the future. + * The caller owns RDS_IN_XMIT and RDS_RECV_REFILL across this call, + * which is what serializes it against the send and receive-refill + * paths. + */ +static void rds_conn_path_reset(struct rds_conn_path *cp) +{ + struct rds_connection *conn = cp->cp_conn; + + rdsdebug("connection %pI6c to %pI6c reset\n", + &conn->c_laddr, &conn->c_faddr); + + rds_stats_inc(s_conn_reset); + rds_send_path_reset(cp); + + /* Clear the bits the reset is responsible for individually: a + * blanket cp_flags = 0 is a plain store that can clobber a + * concurrent atomic read-modify-write on the same word. + * RDS_IN_XMIT and RDS_RECV_REFILL are held as locks by the + * caller, rds_conn_shutdown(), which releases them once the + * teardown is complete. + */ + clear_bit(RDS_LL_SEND_FULL, &cp->cp_flags); + clear_bit(RDS_RECONNECT_PENDING, &cp->cp_flags); + + /* Do not clear next_rx_seq here, else we cannot distinguish + * retransmitted packets from new packets, and will hand all + * of them to the application. That is not consistent with the + * reliability guarantees of RDS. */ +} + +static void __rds_conn_path_init(struct rds_connection *conn, + struct rds_conn_path *cp, bool is_outgoing) +{ + spin_lock_init(&cp->cp_lock); + cp->cp_next_tx_seq = 1; + init_waitqueue_head(&cp->cp_waitq); + INIT_LIST_HEAD(&cp->cp_send_queue); + INIT_LIST_HEAD(&cp->cp_retrans); + + cp->cp_conn = conn; + atomic_set(&cp->cp_state, RDS_CONN_DOWN); + cp->cp_send_gen = 0; + cp->cp_reconnect_jiffies = 0; + cp->cp_conn->c_proposed_version = RDS_PROTOCOL_VERSION; + INIT_DELAYED_WORK(&cp->cp_send_w, rds_send_worker); + INIT_DELAYED_WORK(&cp->cp_recv_w, rds_recv_worker); + INIT_DELAYED_WORK(&cp->cp_conn_w, rds_connect_worker); + INIT_WORK(&cp->cp_down_w, rds_shutdown_worker); + mutex_init(&cp->cp_cm_lock); + cp->cp_flags = 0; +} + +/* + * There is only every one 'conn' for a given pair of addresses in the + * system at a time. They contain messages to be retransmitted and so + * span the lifetime of the actual underlying transport connections. + * + * For now they are not garbage collected once they're created. They + * are torn down as the module is removed, if ever. + */ +static struct rds_connection *__rds_conn_create(struct net *net, + const struct in6_addr *laddr, + const struct in6_addr *faddr, + struct rds_transport *trans, + gfp_t gfp, u8 tos, + int is_outgoing, + int dev_if) +{ + struct rds_connection *conn, *parent = NULL; + struct hlist_head *head = rds_conn_bucket(laddr, faddr); + struct rds_transport *loop_trans; + struct rds_conn_path *free_cp = NULL; + unsigned long flags; + int ret, i; + int npaths = (trans->t_mp_capable ? RDS_MPATH_WORKERS : 1); + + rcu_read_lock(); + conn = rds_conn_lookup(net, head, laddr, faddr, trans, tos, dev_if); + if (conn && + conn->c_loopback && + conn->c_trans != &rds_loop_transport && + ipv6_addr_equal(laddr, faddr) && + !is_outgoing) { + /* This is a looped back IB connection, and we're + * called by the code handling the incoming connect. + * We need a second connection object into which we + * can stick the other QP. */ + parent = conn; + conn = parent->c_passive; + } + rcu_read_unlock(); + if (conn) + goto out; + + conn = kmem_cache_zalloc(rds_conn_slab, gfp); + if (!conn) { + conn = ERR_PTR(-ENOMEM); + goto out; + } + conn->c_path = kzalloc_objs(struct rds_conn_path, npaths, gfp); + if (!conn->c_path) { + kmem_cache_free(rds_conn_slab, conn); + conn = ERR_PTR(-ENOMEM); + goto out; + } + + INIT_HLIST_NODE(&conn->c_hash_node); + conn->c_laddr = *laddr; + conn->c_isv6 = !ipv6_addr_v4mapped(laddr); + conn->c_faddr = *faddr; + conn->c_dev_if = dev_if; + conn->c_tos = tos; + +#if IS_ENABLED(CONFIG_IPV6) + /* If the local address is link local, set c_bound_if to be the + * index used for this connection. Otherwise, set it to 0 as + * the socket is not bound to an interface. c_bound_if is used + * to look up a socket when a packet is received + */ + if (ipv6_addr_type(laddr) & IPV6_ADDR_LINKLOCAL) + conn->c_bound_if = dev_if; + else +#endif + conn->c_bound_if = 0; + + rds_conn_net_set(conn, net); + + ret = rds_cong_get_maps(conn); + if (ret) { + kfree(conn->c_path); + kmem_cache_free(rds_conn_slab, conn); + conn = ERR_PTR(ret); + goto out; + } + + /* + * This is where a connection becomes loopback. If *any* RDS sockets + * can bind to the destination address then we'd rather the messages + * flow through loopback rather than either transport. + */ + loop_trans = rds_trans_get_preferred(net, faddr, conn->c_dev_if); + if (loop_trans) { + rds_trans_put(loop_trans); + conn->c_loopback = 1; + if (trans->t_prefer_loopback) { + if (likely(is_outgoing)) { + /* "outgoing" connection to local address. + * Protocol says it wants the connection + * handled by the loopback transport. + * This is what TCP does. + */ + trans = &rds_loop_transport; + } else { + /* No transport currently in use + * should end up here, but if it + * does, reset/destroy the connection. + */ + kfree(conn->c_path); + kmem_cache_free(rds_conn_slab, conn); + conn = ERR_PTR(-EOPNOTSUPP); + goto out; + } + } + } + + conn->c_trans = trans; + + init_waitqueue_head(&conn->c_hs_waitq); + for (i = 0; i < npaths; i++) { + __rds_conn_path_init(conn, &conn->c_path[i], + is_outgoing); + conn->c_path[i].cp_index = i; + conn->c_path[i].cp_wq = + alloc_ordered_workqueue("krds_cp_wq#%lu/%d", 0, + rds_conn_count, i); + if (!conn->c_path[i].cp_wq) + conn->c_path[i].cp_wq = rds_wq; + } + rcu_read_lock(); + if (rds_destroy_pending(conn)) + ret = -ENETDOWN; + else + ret = trans->conn_alloc(conn, GFP_ATOMIC); + if (ret) { + rcu_read_unlock(); + free_cp = conn->c_path; + kmem_cache_free(rds_conn_slab, conn); + conn = ERR_PTR(ret); + goto out; + } + + rdsdebug("allocated conn %p for %pI6c -> %pI6c over %s %s\n", + conn, laddr, faddr, + strnlen(trans->t_name, sizeof(trans->t_name)) ? + trans->t_name : "[unknown]", is_outgoing ? "(outgoing)" : ""); + + /* + * Since we ran without holding the conn lock, someone could + * have created the same conn (either normal or passive) in the + * interim. We check while holding the lock. If we won, we complete + * init and return our conn. If we lost, we rollback and return the + * other one. + */ + spin_lock_irqsave(&rds_conn_lock, flags); + if (parent) { + /* Creating passive conn */ + if (parent->c_passive) { + trans->conn_free(conn->c_path[0].cp_transport_data); + free_cp = conn->c_path; + kmem_cache_free(rds_conn_slab, conn); + conn = parent->c_passive; + } else { + parent->c_passive = conn; + rds_cong_add_conn(conn); + rds_conn_count++; + } + } else { + /* Creating normal conn */ + struct rds_connection *found; + + found = rds_conn_lookup(net, head, laddr, faddr, trans, + tos, dev_if); + if (found) { + struct rds_conn_path *cp; + int i; + + for (i = 0; i < npaths; i++) { + cp = &conn->c_path[i]; + /* The ->conn_alloc invocation may have + * allocated resource for all paths, so all + * of them may have to be freed here. + */ + if (cp->cp_transport_data) + trans->conn_free(cp->cp_transport_data); + } + free_cp = conn->c_path; + kmem_cache_free(rds_conn_slab, conn); + conn = found; + } else { + conn->c_my_gen_num = rds_gen_num; + conn->c_peer_gen_num = 0; + hlist_add_head_rcu(&conn->c_hash_node, head); + rds_cong_add_conn(conn); + rds_conn_count++; + } + } + spin_unlock_irqrestore(&rds_conn_lock, flags); + rcu_read_unlock(); + +out: + if (free_cp) { + for (i = 0; i < npaths; i++) + if (free_cp[i].cp_wq != rds_wq) + destroy_workqueue(free_cp[i].cp_wq); + kfree(free_cp); + } + + return conn; +} + +struct rds_connection *rds_conn_create(struct net *net, + const struct in6_addr *laddr, + const struct in6_addr *faddr, + struct rds_transport *trans, u8 tos, + gfp_t gfp, int dev_if) +{ + return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 0, dev_if); +} +EXPORT_SYMBOL_GPL(rds_conn_create); + +struct rds_connection *rds_conn_create_outgoing(struct net *net, + const struct in6_addr *laddr, + const struct in6_addr *faddr, + struct rds_transport *trans, + u8 tos, gfp_t gfp, int dev_if) +{ + return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 1, dev_if); +} +EXPORT_SYMBOL_GPL(rds_conn_create_outgoing); + +void rds_conn_shutdown(struct rds_conn_path *cp) +{ + struct rds_connection *conn = cp->cp_conn; + + /* shut it down unless it's down already */ + if (!rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_DOWN)) { + /* + * Quiesce the connection mgmt handlers before we start tearing + * things down. We don't hold the mutex for the entire + * duration of the shutdown operation, else we may be + * deadlocking with the CM handler. Instead, the CM event + * handler is supposed to check for state DISCONNECTING + */ + mutex_lock(&cp->cp_cm_lock); + if (!rds_conn_path_transition(cp, RDS_CONN_UP, + RDS_CONN_DISCONNECTING) && + !rds_conn_path_transition(cp, RDS_CONN_ERROR, + RDS_CONN_DISCONNECTING) && + !rds_conn_path_transition(cp, RDS_CONN_RESETTING, + RDS_CONN_DISCONNECTING)) { + rds_conn_path_error(cp, + "shutdown called in state %d\n", + atomic_read(&cp->cp_state)); + mutex_unlock(&cp->cp_cm_lock); + return; + } + mutex_unlock(&cp->cp_cm_lock); + + /* Quiesce the transmit and receive-refill paths by + * acquiring their bit locks, not merely waiting for + * them to be released: with a plain wait, either path + * can re-take its lock the instant after we sample it + * clear and then run concurrently with the transport + * shutdown and the path reset below. Holding both + * locks across the teardown makes that structurally + * impossible. + */ + wait_event(cp->cp_waitq, + !test_and_set_bit_lock(RDS_IN_XMIT, &cp->cp_flags)); + wait_event(cp->cp_waitq, + !test_and_set_bit(RDS_RECV_REFILL, &cp->cp_flags)); + + conn->c_trans->conn_path_shutdown(cp); + rds_conn_path_reset(cp); + + /* Release the two locks and wake any waiter (e.g. + * rds_tcp_reset_callbacks()) that blocked on them while + * we held them. The unlock orders the transport's ring + * re-initialization and the path reset above before + * either bit is seen clear. rds_conn_path_reset() leaves + * both bits alone: ownership ends here, not inside the + * reset. + */ + clear_bit_unlock(RDS_IN_XMIT, &cp->cp_flags); + clear_bit_unlock(RDS_RECV_REFILL, &cp->cp_flags); + wake_up_all(&cp->cp_waitq); + + if (!rds_conn_path_transition(cp, RDS_CONN_DISCONNECTING, + RDS_CONN_DOWN)) { + /* The path was dropped again while we tore it + * down: by a socket state-change callback in + * irq context on receipt of a FIN, or by an + * accept that claimed the path just before a + * drop put it back to RDS_CONN_ERROR and then + * installed a fresh socket on it. Unless a + * pending destroy suppressed it, the drop also + * queued another shutdown pass, and that pass + * must run, because it is what tears down + * whatever attached to the path after the + * transport shutdown above sampled its state. + * Consuming the RDS_CONN_ERROR here would turn + * that pass into a no-op: leave the state + * alone, and let the pass finish the job. + * + * Quiesce the reconnect timer before bailing + * out, though. When a pending destroy did + * suppress the queue, no later pass runs, and + * rds_conn_path_destroy() is about to flush + * cp_down_w and free the path: it must not + * find cp_conn_w still armed. A successor + * pass, when there is one, re-arms the + * reconnect from its own tail. + */ + cancel_delayed_work_sync(&cp->cp_conn_w); + clear_bit(RDS_RECONNECT_PENDING, &cp->cp_flags); + + if (rds_conn_path_state(cp) == RDS_CONN_ERROR) + return; + /* No current cp_state writer leaves a + * DISCONNECTING path in any state but + * RDS_CONN_ERROR; report loudly if one ever + * does. + */ + rds_conn_path_error(cp, "%s: failed to transition " + "to state DOWN, current state " + "is %d\n", __func__, + atomic_read(&cp->cp_state)); + return; + } + } + + /* Then reconnect if it's still live. + * The passive side of an IB loopback connection is never added + * to the conn hash, so we never trigger a reconnect on this + * conn - the reconnect is always triggered by the active peer. */ + cancel_delayed_work_sync(&cp->cp_conn_w); + + clear_bit(RDS_RECONNECT_PENDING, &cp->cp_flags); + rcu_read_lock(); + if (!hlist_unhashed(&conn->c_hash_node)) { + rcu_read_unlock(); + if (conn->c_trans->t_mp_capable && + cp->cp_index == 0) + rds_send_ping(conn, 0); + rds_queue_reconnect(cp); + } else { + rcu_read_unlock(); + } + + /* we do not hold the socket lock here but it is safe because + * fan-out is disabled when calling conn_slots_available() + */ + if (conn->c_trans->conn_slots_available) + conn->c_trans->conn_slots_available(conn, false); +} + +/* destroy a single rds_conn_path. rds_conn_destroy() iterates over + * all paths using rds_conn_path_destroy() + */ +static void rds_conn_path_destroy(struct rds_conn_path *cp) +{ + struct rds_message *rm, *rtmp; + + if (!cp->cp_transport_data) + return; + + /* make sure lingering queued work won't try to ref the conn */ + cancel_delayed_work_sync(&cp->cp_send_w); + cancel_delayed_work_sync(&cp->cp_recv_w); + + rds_conn_path_drop(cp, true); + flush_work(&cp->cp_down_w); + + /* tear down queued messages */ + list_for_each_entry_safe(rm, rtmp, + &cp->cp_send_queue, + m_conn_item) { + list_del_init(&rm->m_conn_item); + BUG_ON(!list_empty(&rm->m_sock_item)); + rds_message_put(rm); + } + if (cp->cp_xmit_rm) + rds_message_put(cp->cp_xmit_rm); + + WARN_ON(delayed_work_pending(&cp->cp_send_w)); + WARN_ON(delayed_work_pending(&cp->cp_recv_w)); + WARN_ON(delayed_work_pending(&cp->cp_conn_w)); + WARN_ON(work_pending(&cp->cp_down_w)); + + if (cp->cp_wq != rds_wq) { + destroy_workqueue(cp->cp_wq); + cp->cp_wq = NULL; + } + + cp->cp_conn->c_trans->conn_free(cp->cp_transport_data); +} + +/* + * Stop and free a connection. + * + * This can only be used in very limited circumstances. It assumes that once + * the conn has been shutdown that no one else is referencing the connection. + * We can only ensure this in the rmmod path in the current code. + */ +void rds_conn_destroy(struct rds_connection *conn) +{ + unsigned long flags; + int i; + struct rds_conn_path *cp; + int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1); + + rdsdebug("freeing conn %p for %pI4 -> " + "%pI4\n", conn, &conn->c_laddr, + &conn->c_faddr); + + /* Ensure conn will not be scheduled for reconnect */ + spin_lock_irq(&rds_conn_lock); + hlist_del_init_rcu(&conn->c_hash_node); + spin_unlock_irq(&rds_conn_lock); + synchronize_rcu(); + + /* shut the connection down */ + for (i = 0; i < npaths; i++) { + cp = &conn->c_path[i]; + rds_conn_path_destroy(cp); + BUG_ON(!list_empty(&cp->cp_retrans)); + } + + /* + * The congestion maps aren't freed up here. They're + * freed by rds_cong_exit() after all the connections + * have been freed. + */ + rds_cong_remove_conn(conn); + + kfree(conn->c_path); + kmem_cache_free(rds_conn_slab, conn); + + spin_lock_irqsave(&rds_conn_lock, flags); + rds_conn_count--; + spin_unlock_irqrestore(&rds_conn_lock, flags); +} +EXPORT_SYMBOL_GPL(rds_conn_destroy); + +static void __rds_inc_msg_cp(struct rds_incoming *inc, + struct rds_info_iterator *iter, + void *saddr, void *daddr, int flip, bool isv6) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (isv6) + rds6_inc_info_copy(inc, iter, saddr, daddr, flip); + else +#endif + rds_inc_info_copy(inc, iter, *(__be32 *)saddr, + *(__be32 *)daddr, flip); +} + +static void rds_conn_message_info_cmn(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens, + int want_send, bool isv6) +{ + struct net *net = sock_net(sock->sk); + struct hlist_head *head; + struct list_head *list; + struct rds_connection *conn; + struct rds_message *rm; + unsigned int total = 0; + unsigned long flags; + size_t i; + int j; + + if (isv6) + len /= sizeof(struct rds6_info_message); + else + len /= sizeof(struct rds_info_message); + + rcu_read_lock(); + + for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); + i++, head++) { + hlist_for_each_entry_rcu(conn, head, c_hash_node) { + struct rds_conn_path *cp; + int npaths; + + /* Only show connections in the caller's netns. */ + if (!net_eq(rds_conn_net(conn), net)) + continue; + if (!isv6 && conn->c_isv6) + continue; + + npaths = (conn->c_trans->t_mp_capable ? + RDS_MPATH_WORKERS : 1); + + for (j = 0; j < npaths; j++) { + cp = &conn->c_path[j]; + if (want_send) + list = &cp->cp_send_queue; + else + list = &cp->cp_retrans; + + spin_lock_irqsave(&cp->cp_lock, flags); + + /* XXX too lazy to maintain counts.. */ + list_for_each_entry(rm, list, m_conn_item) { + total++; + if (total <= len) + __rds_inc_msg_cp(&rm->m_inc, + iter, + &conn->c_laddr, + &conn->c_faddr, + 0, isv6); + } + + spin_unlock_irqrestore(&cp->cp_lock, flags); + } + } + } + rcu_read_unlock(); + + lens->nr = total; + if (isv6) + lens->each = sizeof(struct rds6_info_message); + else + lens->each = sizeof(struct rds_info_message); +} + +static void rds_conn_message_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens, + int want_send) +{ + rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void rds6_conn_message_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens, + int want_send) +{ + rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true); +} +#endif + +static void rds_conn_message_info_send(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + rds_conn_message_info(sock, len, iter, lens, 1); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void rds6_conn_message_info_send(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + rds6_conn_message_info(sock, len, iter, lens, 1); +} +#endif + +static void rds_conn_message_info_retrans(struct socket *sock, + unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + rds_conn_message_info(sock, len, iter, lens, 0); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void rds6_conn_message_info_retrans(struct socket *sock, + unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + rds6_conn_message_info(sock, len, iter, lens, 0); +} +#endif + +void rds_for_each_conn_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens, + int (*visitor)(struct rds_connection *, void *), + u64 *buffer, + size_t item_len) +{ + struct net *net = sock_net(sock->sk); + struct hlist_head *head; + struct rds_connection *conn; + size_t i; + + rcu_read_lock(); + + lens->nr = 0; + lens->each = item_len; + + for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); + i++, head++) { + hlist_for_each_entry_rcu(conn, head, c_hash_node) { + /* Only show connections in the caller's netns. */ + if (!net_eq(rds_conn_net(conn), net)) + continue; + + /* Zero the per-item buffer before handing it to the + * visitor so any field the visitor does not write - + * including implicit alignment padding - cannot leak + * stack contents to user space via rds_info_copy(). + */ + memset(buffer, 0, item_len); + + /* XXX no c_lock usage.. */ + if (!visitor(conn, buffer)) + continue; + + /* We copy as much as we can fit in the buffer, + * but we count all items so that the caller + * can resize the buffer. */ + if (len >= item_len) { + rds_info_copy(iter, buffer, item_len); + len -= item_len; + } + lens->nr++; + } + } + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(rds_for_each_conn_info); + +static void rds_walk_conn_path_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens, + int (*visitor)(struct rds_conn_path *, void *), + u64 *buffer, + size_t item_len) +{ + struct net *net = sock_net(sock->sk); + struct hlist_head *head; + struct rds_connection *conn; + size_t i; + + rcu_read_lock(); + + lens->nr = 0; + lens->each = item_len; + + for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash); + i++, head++) { + hlist_for_each_entry_rcu(conn, head, c_hash_node) { + struct rds_conn_path *cp; + + /* Only show connections in the caller's netns. */ + if (!net_eq(rds_conn_net(conn), net)) + continue; + + /* XXX We only copy the information from the first + * path for now. The problem is that if there are + * more than one underlying paths, we cannot report + * information of all of them using the existing + * API. For example, there is only one next_tx_seq, + * which path's next_tx_seq should we report? It is + * a bug in the design of MPRDS. + */ + cp = conn->c_path; + + /* Zero the per-item buffer for the same reason as + * rds_for_each_conn_info(): any byte the visitor + * does not write (including alignment padding) must + * not leak stack contents via rds_info_copy(). + */ + memset(buffer, 0, item_len); + + /* XXX no cp_lock usage.. */ + if (!visitor(cp, buffer)) + continue; + + /* We copy as much as we can fit in the buffer, + * but we count all items so that the caller + * can resize the buffer. + */ + if (len >= item_len) { + rds_info_copy(iter, buffer, item_len); + len -= item_len; + } + lens->nr++; + } + } + rcu_read_unlock(); +} + +static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer) +{ + struct rds_info_connection *cinfo = buffer; + struct rds_connection *conn = cp->cp_conn; + + if (conn->c_isv6) + return 0; + + cinfo->next_tx_seq = cp->cp_next_tx_seq; + cinfo->next_rx_seq = cp->cp_next_rx_seq; + cinfo->laddr = conn->c_laddr.s6_addr32[3]; + cinfo->faddr = conn->c_faddr.s6_addr32[3]; + cinfo->tos = conn->c_tos; + strscpy_pad(cinfo->transport, conn->c_trans->t_name); + cinfo->flags = 0; + + rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags), + SENDING); + /* XXX Future: return the state rather than these funky bits */ + rds_conn_info_set(cinfo->flags, + atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING, + CONNECTING); + rds_conn_info_set(cinfo->flags, + atomic_read(&cp->cp_state) == RDS_CONN_UP, + CONNECTED); + return 1; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer) +{ + struct rds6_info_connection *cinfo6 = buffer; + struct rds_connection *conn = cp->cp_conn; + + cinfo6->next_tx_seq = cp->cp_next_tx_seq; + cinfo6->next_rx_seq = cp->cp_next_rx_seq; + cinfo6->laddr = conn->c_laddr; + cinfo6->faddr = conn->c_faddr; + strscpy_pad(cinfo6->transport, conn->c_trans->t_name); + cinfo6->flags = 0; + + rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags), + SENDING); + /* XXX Future: return the state rather than these funky bits */ + rds_conn_info_set(cinfo6->flags, + atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING, + CONNECTING); + rds_conn_info_set(cinfo6->flags, + atomic_read(&cp->cp_state) == RDS_CONN_UP, + CONNECTED); + /* Just return 1 as there is no error case. This is a helper function + * for rds_walk_conn_path_info() and it wants a return value. + */ + return 1; +} +#endif + +static void rds_conn_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + u64 buffer[(sizeof(struct rds_info_connection) + 7) / 8]; + + rds_walk_conn_path_info(sock, len, iter, lens, + rds_conn_info_visitor, + buffer, + sizeof(struct rds_info_connection)); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void rds6_conn_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + u64 buffer[(sizeof(struct rds6_info_connection) + 7) / 8]; + + rds_walk_conn_path_info(sock, len, iter, lens, + rds6_conn_info_visitor, + buffer, + sizeof(struct rds6_info_connection)); +} +#endif + +int rds_conn_init(void) +{ + int ret; + + ret = rds_loop_net_init(); /* register pernet callback */ + if (ret) + return ret; + + rds_conn_slab = KMEM_CACHE(rds_connection, 0); + if (!rds_conn_slab) { + rds_loop_net_exit(); + return -ENOMEM; + } + + rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info); + rds_info_register_func(RDS_INFO_SEND_MESSAGES, + rds_conn_message_info_send); + rds_info_register_func(RDS_INFO_RETRANS_MESSAGES, + rds_conn_message_info_retrans); +#if IS_ENABLED(CONFIG_IPV6) + rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info); + rds_info_register_func(RDS6_INFO_SEND_MESSAGES, + rds6_conn_message_info_send); + rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES, + rds6_conn_message_info_retrans); +#endif + return 0; +} + +void rds_conn_exit(void) +{ + rds_loop_net_exit(); /* unregister pernet callback */ + rds_loop_exit(); + + WARN_ON(!hlist_empty(rds_conn_hash)); + + kmem_cache_destroy(rds_conn_slab); + + rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info); + rds_info_deregister_func(RDS_INFO_SEND_MESSAGES, + rds_conn_message_info_send); + rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES, + rds_conn_message_info_retrans); +#if IS_ENABLED(CONFIG_IPV6) + rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info); + rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES, + rds6_conn_message_info_send); + rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES, + rds6_conn_message_info_retrans); +#endif +} + +/* + * Force a disconnect + */ +void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy) +{ + atomic_set(&cp->cp_state, RDS_CONN_ERROR); + + rcu_read_lock(); + if (!destroy && rds_destroy_pending(cp->cp_conn)) { + rcu_read_unlock(); + return; + } + queue_work(cp->cp_wq, &cp->cp_down_w); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(rds_conn_path_drop); + +void rds_conn_drop(struct rds_connection *conn) +{ + WARN_ON(conn->c_trans->t_mp_capable); + rds_conn_path_drop(&conn->c_path[0], false); +} +EXPORT_SYMBOL_GPL(rds_conn_drop); + +/* + * If the connection is down, trigger a connect. We may have scheduled a + * delayed reconnect however - in this case we should not interfere. + */ +void rds_conn_path_connect_if_down(struct rds_conn_path *cp) +{ + rcu_read_lock(); + if (rds_destroy_pending(cp->cp_conn)) { + rcu_read_unlock(); + return; + } + if (rds_conn_path_state(cp) == RDS_CONN_DOWN && + !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags)) + queue_delayed_work(cp->cp_wq, &cp->cp_conn_w, 0); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down); + +/* Check connectivity of all paths + */ +void rds_check_all_paths(struct rds_connection *conn) +{ + int i = 0; + + do { + rds_conn_path_connect_if_down(&conn->c_path[i]); + } while (++i < conn->c_npaths); +} + +void rds_conn_connect_if_down(struct rds_connection *conn) +{ + WARN_ON(conn->c_trans->t_mp_capable); + rds_conn_path_connect_if_down(&conn->c_path[0]); +} +EXPORT_SYMBOL_GPL(rds_conn_connect_if_down); + +void +__rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + vprintk(fmt, ap); + va_end(ap); + + rds_conn_path_drop(cp, false); +} -- cgit v1.3.1