1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /* RxRPC individual remote procedure call handling
3   *
4   * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5   * Written by David Howells (dhowells@redhat.com)
6   */
7  
8  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9  
10  #include <linux/slab.h>
11  #include <linux/module.h>
12  #include <linux/circ_buf.h>
13  #include <linux/spinlock_types.h>
14  #include <net/sock.h>
15  #include <net/af_rxrpc.h>
16  #include "ar-internal.h"
17  
18  const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
19  	[RXRPC_CALL_UNINITIALISED]		= "Uninit  ",
20  	[RXRPC_CALL_CLIENT_AWAIT_CONN]		= "ClWtConn",
21  	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
22  	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
23  	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
24  	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
25  	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
26  	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
27  	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
28  	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
29  	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
30  	[RXRPC_CALL_COMPLETE]			= "Complete",
31  };
32  
33  const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
34  	[RXRPC_CALL_SUCCEEDED]			= "Complete",
35  	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
36  	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
37  	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
38  	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
39  };
40  
41  struct kmem_cache *rxrpc_call_jar;
42  
43  static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
44  static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
45  
rxrpc_poke_call(struct rxrpc_call * call,enum rxrpc_call_poke_trace what)46  void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
47  {
48  	struct rxrpc_local *local = call->local;
49  	bool busy;
50  
51  	if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) {
52  		spin_lock_bh(&local->lock);
53  		busy = !list_empty(&call->attend_link);
54  		trace_rxrpc_poke_call(call, busy, what);
55  		if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke))
56  			busy = true;
57  		if (!busy) {
58  			list_add_tail(&call->attend_link, &local->call_attend_q);
59  		}
60  		spin_unlock_bh(&local->lock);
61  		if (!busy)
62  			rxrpc_wake_up_io_thread(local);
63  	}
64  }
65  
rxrpc_call_timer_expired(struct timer_list * t)66  static void rxrpc_call_timer_expired(struct timer_list *t)
67  {
68  	struct rxrpc_call *call = from_timer(call, t, timer);
69  
70  	_enter("%d", call->debug_id);
71  
72  	if (!__rxrpc_call_is_complete(call)) {
73  		trace_rxrpc_timer_expired(call);
74  		rxrpc_poke_call(call, rxrpc_call_poke_timer);
75  	}
76  }
77  
78  static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
79  
80  static void rxrpc_destroy_call(struct work_struct *);
81  
82  /*
83   * find an extant server call
84   * - called in process context with IRQs enabled
85   */
rxrpc_find_call_by_user_ID(struct rxrpc_sock * rx,unsigned long user_call_ID)86  struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
87  					      unsigned long user_call_ID)
88  {
89  	struct rxrpc_call *call;
90  	struct rb_node *p;
91  
92  	_enter("%p,%lx", rx, user_call_ID);
93  
94  	read_lock(&rx->call_lock);
95  
96  	p = rx->calls.rb_node;
97  	while (p) {
98  		call = rb_entry(p, struct rxrpc_call, sock_node);
99  
100  		if (user_call_ID < call->user_call_ID)
101  			p = p->rb_left;
102  		else if (user_call_ID > call->user_call_ID)
103  			p = p->rb_right;
104  		else
105  			goto found_extant_call;
106  	}
107  
108  	read_unlock(&rx->call_lock);
109  	_leave(" = NULL");
110  	return NULL;
111  
112  found_extant_call:
113  	rxrpc_get_call(call, rxrpc_call_get_sendmsg);
114  	read_unlock(&rx->call_lock);
115  	_leave(" = %p [%d]", call, refcount_read(&call->ref));
116  	return call;
117  }
118  
119  /*
120   * allocate a new call
121   */
rxrpc_alloc_call(struct rxrpc_sock * rx,gfp_t gfp,unsigned int debug_id)122  struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
123  				    unsigned int debug_id)
124  {
125  	struct rxrpc_call *call;
126  	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
127  
128  	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
129  	if (!call)
130  		return NULL;
131  
132  	mutex_init(&call->user_mutex);
133  
134  	/* Prevent lockdep reporting a deadlock false positive between the afs
135  	 * filesystem and sys_sendmsg() via the mmap sem.
136  	 */
137  	if (rx->sk.sk_kern_sock)
138  		lockdep_set_class(&call->user_mutex,
139  				  &rxrpc_call_user_mutex_lock_class_key);
140  
141  	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
142  	INIT_WORK(&call->destroyer, rxrpc_destroy_call);
143  	INIT_LIST_HEAD(&call->link);
144  	INIT_LIST_HEAD(&call->wait_link);
145  	INIT_LIST_HEAD(&call->accept_link);
146  	INIT_LIST_HEAD(&call->recvmsg_link);
147  	INIT_LIST_HEAD(&call->sock_link);
148  	INIT_LIST_HEAD(&call->attend_link);
149  	INIT_LIST_HEAD(&call->tx_sendmsg);
150  	INIT_LIST_HEAD(&call->tx_buffer);
151  	skb_queue_head_init(&call->recvmsg_queue);
152  	skb_queue_head_init(&call->rx_oos_queue);
153  	init_waitqueue_head(&call->waitq);
154  	spin_lock_init(&call->notify_lock);
155  	spin_lock_init(&call->tx_lock);
156  	refcount_set(&call->ref, 1);
157  	call->debug_id		= debug_id;
158  	call->tx_total_len	= -1;
159  	call->next_rx_timo	= 20 * HZ;
160  	call->next_req_timo	= 1 * HZ;
161  	call->ackr_window	= 1;
162  	call->ackr_wtop		= 1;
163  	call->delay_ack_at	= KTIME_MAX;
164  	call->ack_lost_at	= KTIME_MAX;
165  	call->resend_at		= KTIME_MAX;
166  	call->ping_at		= KTIME_MAX;
167  	call->keepalive_at	= KTIME_MAX;
168  	call->expect_rx_by	= KTIME_MAX;
169  	call->expect_req_by	= KTIME_MAX;
170  	call->expect_term_by	= KTIME_MAX;
171  
172  	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
173  
174  	call->rx_winsize = rxrpc_rx_window_size;
175  	call->tx_winsize = 16;
176  
177  	call->cong_cwnd = RXRPC_MIN_CWND;
178  	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
179  
180  	call->rxnet = rxnet;
181  	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
182  	atomic_inc(&rxnet->nr_calls);
183  	return call;
184  }
185  
186  /*
187   * Allocate a new client call.
188   */
rxrpc_alloc_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)189  static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
190  						  struct rxrpc_conn_parameters *cp,
191  						  struct rxrpc_call_params *p,
192  						  gfp_t gfp,
193  						  unsigned int debug_id)
194  {
195  	struct rxrpc_call *call;
196  	ktime_t now;
197  	int ret;
198  
199  	_enter("");
200  
201  	call = rxrpc_alloc_call(rx, gfp, debug_id);
202  	if (!call)
203  		return ERR_PTR(-ENOMEM);
204  	now = ktime_get_real();
205  	call->acks_latest_ts	= now;
206  	call->cong_tstamp	= now;
207  	call->dest_srx		= cp->peer->srx;
208  	call->dest_srx.srx_service = cp->service_id;
209  	call->interruptibility	= p->interruptibility;
210  	call->tx_total_len	= p->tx_total_len;
211  	call->key		= key_get(cp->key);
212  	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
213  	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
214  	call->security_level	= cp->security_level;
215  	if (p->kernel)
216  		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
217  	if (cp->upgrade)
218  		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
219  	if (cp->exclusive)
220  		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
221  
222  	if (p->timeouts.normal)
223  		call->next_rx_timo = min(p->timeouts.normal, 1);
224  	if (p->timeouts.idle)
225  		call->next_req_timo = min(p->timeouts.idle, 1);
226  	if (p->timeouts.hard)
227  		call->hard_timo = p->timeouts.hard;
228  
229  	ret = rxrpc_init_client_call_security(call);
230  	if (ret < 0) {
231  		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
232  		rxrpc_put_call(call, rxrpc_call_put_discard_error);
233  		return ERR_PTR(ret);
234  	}
235  
236  	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
237  
238  	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
239  			 p->user_call_ID, rxrpc_call_new_client);
240  
241  	_leave(" = %p", call);
242  	return call;
243  }
244  
245  /*
246   * Initiate the call ack/resend/expiry timer.
247   */
rxrpc_start_call_timer(struct rxrpc_call * call)248  void rxrpc_start_call_timer(struct rxrpc_call *call)
249  {
250  	if (call->hard_timo) {
251  		ktime_t delay = ms_to_ktime(call->hard_timo * 1000);
252  
253  		call->expect_term_by = ktime_add(ktime_get_real(), delay);
254  		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
255  	}
256  	call->timer.expires = jiffies;
257  }
258  
259  /*
260   * Wait for a call slot to become available.
261   */
rxrpc_get_call_slot(struct rxrpc_call_params * p,gfp_t gfp)262  static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
263  {
264  	struct semaphore *limiter = &rxrpc_call_limiter;
265  
266  	if (p->kernel)
267  		limiter = &rxrpc_kernel_call_limiter;
268  	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
269  		down(limiter);
270  		return limiter;
271  	}
272  	return down_interruptible(limiter) < 0 ? NULL : limiter;
273  }
274  
275  /*
276   * Release a call slot.
277   */
rxrpc_put_call_slot(struct rxrpc_call * call)278  static void rxrpc_put_call_slot(struct rxrpc_call *call)
279  {
280  	struct semaphore *limiter = &rxrpc_call_limiter;
281  
282  	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
283  		limiter = &rxrpc_kernel_call_limiter;
284  	up(limiter);
285  }
286  
287  /*
288   * Start the process of connecting a call.  We obtain a peer and a connection
289   * bundle, but the actual association of a call with a connection is offloaded
290   * to the I/O thread to simplify locking.
291   */
rxrpc_connect_call(struct rxrpc_call * call,gfp_t gfp)292  static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
293  {
294  	struct rxrpc_local *local = call->local;
295  	int ret = -ENOMEM;
296  
297  	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
298  
299  	ret = rxrpc_look_up_bundle(call, gfp);
300  	if (ret < 0)
301  		goto error;
302  
303  	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
304  	rxrpc_get_call(call, rxrpc_call_get_io_thread);
305  	spin_lock(&local->client_call_lock);
306  	list_add_tail(&call->wait_link, &local->new_client_calls);
307  	spin_unlock(&local->client_call_lock);
308  	rxrpc_wake_up_io_thread(local);
309  	return 0;
310  
311  error:
312  	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
313  	return ret;
314  }
315  
316  /*
317   * Set up a call for the given parameters.
318   * - Called with the socket lock held, which it must release.
319   * - If it returns a call, the call's lock will need releasing by the caller.
320   */
rxrpc_new_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)321  struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
322  					 struct rxrpc_conn_parameters *cp,
323  					 struct rxrpc_call_params *p,
324  					 gfp_t gfp,
325  					 unsigned int debug_id)
326  	__releases(&rx->sk.sk_lock.slock)
327  	__acquires(&call->user_mutex)
328  {
329  	struct rxrpc_call *call, *xcall;
330  	struct rxrpc_net *rxnet;
331  	struct semaphore *limiter;
332  	struct rb_node *parent, **pp;
333  	int ret;
334  
335  	_enter("%p,%lx", rx, p->user_call_ID);
336  
337  	if (WARN_ON_ONCE(!cp->peer)) {
338  		release_sock(&rx->sk);
339  		return ERR_PTR(-EIO);
340  	}
341  
342  	limiter = rxrpc_get_call_slot(p, gfp);
343  	if (!limiter) {
344  		release_sock(&rx->sk);
345  		return ERR_PTR(-ERESTARTSYS);
346  	}
347  
348  	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
349  	if (IS_ERR(call)) {
350  		release_sock(&rx->sk);
351  		up(limiter);
352  		_leave(" = %ld", PTR_ERR(call));
353  		return call;
354  	}
355  
356  	/* We need to protect a partially set up call against the user as we
357  	 * will be acting outside the socket lock.
358  	 */
359  	mutex_lock(&call->user_mutex);
360  
361  	/* Publish the call, even though it is incompletely set up as yet */
362  	write_lock(&rx->call_lock);
363  
364  	pp = &rx->calls.rb_node;
365  	parent = NULL;
366  	while (*pp) {
367  		parent = *pp;
368  		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
369  
370  		if (p->user_call_ID < xcall->user_call_ID)
371  			pp = &(*pp)->rb_left;
372  		else if (p->user_call_ID > xcall->user_call_ID)
373  			pp = &(*pp)->rb_right;
374  		else
375  			goto error_dup_user_ID;
376  	}
377  
378  	rcu_assign_pointer(call->socket, rx);
379  	call->user_call_ID = p->user_call_ID;
380  	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
381  	rxrpc_get_call(call, rxrpc_call_get_userid);
382  	rb_link_node(&call->sock_node, parent, pp);
383  	rb_insert_color(&call->sock_node, &rx->calls);
384  	list_add(&call->sock_link, &rx->sock_calls);
385  
386  	write_unlock(&rx->call_lock);
387  
388  	rxnet = call->rxnet;
389  	spin_lock(&rxnet->call_lock);
390  	list_add_tail_rcu(&call->link, &rxnet->calls);
391  	spin_unlock(&rxnet->call_lock);
392  
393  	/* From this point on, the call is protected by its own lock. */
394  	release_sock(&rx->sk);
395  
396  	/* Set up or get a connection record and set the protocol parameters,
397  	 * including channel number and call ID.
398  	 */
399  	ret = rxrpc_connect_call(call, gfp);
400  	if (ret < 0)
401  		goto error_attached_to_socket;
402  
403  	_leave(" = %p [new]", call);
404  	return call;
405  
406  	/* We unexpectedly found the user ID in the list after taking
407  	 * the call_lock.  This shouldn't happen unless the user races
408  	 * with itself and tries to add the same user ID twice at the
409  	 * same time in different threads.
410  	 */
411  error_dup_user_ID:
412  	write_unlock(&rx->call_lock);
413  	release_sock(&rx->sk);
414  	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
415  	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
416  			 rxrpc_call_see_userid_exists);
417  	mutex_unlock(&call->user_mutex);
418  	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
419  	_leave(" = -EEXIST");
420  	return ERR_PTR(-EEXIST);
421  
422  	/* We got an error, but the call is attached to the socket and is in
423  	 * need of release.  However, we might now race with recvmsg() when it
424  	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
425  	 * leave the error to recvmsg() to deal with.
426  	 */
427  error_attached_to_socket:
428  	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
429  			 rxrpc_call_see_connect_failed);
430  	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
431  	_leave(" = c=%08x [err]", call->debug_id);
432  	return call;
433  }
434  
435  /*
436   * Set up an incoming call.  call->conn points to the connection.
437   * This is called in BH context and isn't allowed to fail.
438   */
rxrpc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb)439  void rxrpc_incoming_call(struct rxrpc_sock *rx,
440  			 struct rxrpc_call *call,
441  			 struct sk_buff *skb)
442  {
443  	struct rxrpc_connection *conn = call->conn;
444  	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
445  	u32 chan;
446  
447  	_enter(",%d", call->conn->debug_id);
448  
449  	rcu_assign_pointer(call->socket, rx);
450  	call->call_id		= sp->hdr.callNumber;
451  	call->dest_srx.srx_service = sp->hdr.serviceId;
452  	call->cid		= sp->hdr.cid;
453  	call->cong_tstamp	= skb->tstamp;
454  
455  	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
456  	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
457  
458  	spin_lock(&conn->state_lock);
459  
460  	switch (conn->state) {
461  	case RXRPC_CONN_SERVICE_UNSECURED:
462  	case RXRPC_CONN_SERVICE_CHALLENGING:
463  		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
464  		break;
465  	case RXRPC_CONN_SERVICE:
466  		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
467  		break;
468  
469  	case RXRPC_CONN_ABORTED:
470  		rxrpc_set_call_completion(call, conn->completion,
471  					  conn->abort_code, conn->error);
472  		break;
473  	default:
474  		BUG();
475  	}
476  
477  	rxrpc_get_call(call, rxrpc_call_get_io_thread);
478  
479  	/* Set the channel for this call.  We don't get channel_lock as we're
480  	 * only defending against the data_ready handler (which we're called
481  	 * from) and the RESPONSE packet parser (which is only really
482  	 * interested in call_counter and can cope with a disagreement with the
483  	 * call pointer).
484  	 */
485  	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
486  	conn->channels[chan].call_counter = call->call_id;
487  	conn->channels[chan].call_id = call->call_id;
488  	conn->channels[chan].call = call;
489  	spin_unlock(&conn->state_lock);
490  
491  	spin_lock(&conn->peer->lock);
492  	hlist_add_head(&call->error_link, &conn->peer->error_targets);
493  	spin_unlock(&conn->peer->lock);
494  
495  	rxrpc_start_call_timer(call);
496  	_leave("");
497  }
498  
499  /*
500   * Note the re-emergence of a call.
501   */
rxrpc_see_call(struct rxrpc_call * call,enum rxrpc_call_trace why)502  void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
503  {
504  	if (call) {
505  		int r = refcount_read(&call->ref);
506  
507  		trace_rxrpc_call(call->debug_id, r, 0, why);
508  	}
509  }
510  
rxrpc_try_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)511  struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
512  				      enum rxrpc_call_trace why)
513  {
514  	int r;
515  
516  	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
517  		return NULL;
518  	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
519  	return call;
520  }
521  
522  /*
523   * Note the addition of a ref on a call.
524   */
rxrpc_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)525  void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
526  {
527  	int r;
528  
529  	__refcount_inc(&call->ref, &r);
530  	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
531  }
532  
533  /*
534   * Clean up the Rx skb ring.
535   */
rxrpc_cleanup_ring(struct rxrpc_call * call)536  static void rxrpc_cleanup_ring(struct rxrpc_call *call)
537  {
538  	rxrpc_purge_queue(&call->recvmsg_queue);
539  	rxrpc_purge_queue(&call->rx_oos_queue);
540  }
541  
542  /*
543   * Detach a call from its owning socket.
544   */
rxrpc_release_call(struct rxrpc_sock * rx,struct rxrpc_call * call)545  void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
546  {
547  	struct rxrpc_connection *conn = call->conn;
548  	bool put = false, putu = false;
549  
550  	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
551  
552  	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
553  			 call->flags, rxrpc_call_see_release);
554  
555  	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
556  		BUG();
557  
558  	rxrpc_put_call_slot(call);
559  
560  	/* Make sure we don't get any more notifications */
561  	spin_lock(&rx->recvmsg_lock);
562  
563  	if (!list_empty(&call->recvmsg_link)) {
564  		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
565  		       call, call->events, call->flags);
566  		list_del(&call->recvmsg_link);
567  		put = true;
568  	}
569  
570  	/* list_empty() must return false in rxrpc_notify_socket() */
571  	call->recvmsg_link.next = NULL;
572  	call->recvmsg_link.prev = NULL;
573  
574  	spin_unlock(&rx->recvmsg_lock);
575  	if (put)
576  		rxrpc_put_call(call, rxrpc_call_put_unnotify);
577  
578  	write_lock(&rx->call_lock);
579  
580  	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
581  		rb_erase(&call->sock_node, &rx->calls);
582  		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
583  		putu = true;
584  	}
585  
586  	list_del(&call->sock_link);
587  	write_unlock(&rx->call_lock);
588  
589  	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
590  
591  	if (putu)
592  		rxrpc_put_call(call, rxrpc_call_put_userid);
593  
594  	_leave("");
595  }
596  
597  /*
598   * release all the calls associated with a socket
599   */
rxrpc_release_calls_on_socket(struct rxrpc_sock * rx)600  void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
601  {
602  	struct rxrpc_call *call;
603  
604  	_enter("%p", rx);
605  
606  	while (!list_empty(&rx->to_be_accepted)) {
607  		call = list_entry(rx->to_be_accepted.next,
608  				  struct rxrpc_call, accept_link);
609  		list_del(&call->accept_link);
610  		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
611  				    rxrpc_abort_call_sock_release_tba);
612  		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
613  	}
614  
615  	while (!list_empty(&rx->sock_calls)) {
616  		call = list_entry(rx->sock_calls.next,
617  				  struct rxrpc_call, sock_link);
618  		rxrpc_get_call(call, rxrpc_call_get_release_sock);
619  		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
620  				    rxrpc_abort_call_sock_release);
621  		rxrpc_release_call(rx, call);
622  		rxrpc_put_call(call, rxrpc_call_put_release_sock);
623  	}
624  
625  	_leave("");
626  }
627  
628  /*
629   * release a call
630   */
rxrpc_put_call(struct rxrpc_call * call,enum rxrpc_call_trace why)631  void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
632  {
633  	struct rxrpc_net *rxnet = call->rxnet;
634  	unsigned int debug_id = call->debug_id;
635  	bool dead;
636  	int r;
637  
638  	ASSERT(call != NULL);
639  
640  	dead = __refcount_dec_and_test(&call->ref, &r);
641  	trace_rxrpc_call(debug_id, r - 1, 0, why);
642  	if (dead) {
643  		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
644  
645  		if (!list_empty(&call->link)) {
646  			spin_lock(&rxnet->call_lock);
647  			list_del_init(&call->link);
648  			spin_unlock(&rxnet->call_lock);
649  		}
650  
651  		rxrpc_cleanup_call(call);
652  	}
653  }
654  
655  /*
656   * Free up the call under RCU.
657   */
rxrpc_rcu_free_call(struct rcu_head * rcu)658  static void rxrpc_rcu_free_call(struct rcu_head *rcu)
659  {
660  	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
661  	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
662  
663  	kmem_cache_free(rxrpc_call_jar, call);
664  	if (atomic_dec_and_test(&rxnet->nr_calls))
665  		wake_up_var(&rxnet->nr_calls);
666  }
667  
668  /*
669   * Final call destruction - but must be done in process context.
670   */
rxrpc_destroy_call(struct work_struct * work)671  static void rxrpc_destroy_call(struct work_struct *work)
672  {
673  	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
674  	struct rxrpc_txbuf *txb;
675  
676  	del_timer_sync(&call->timer);
677  
678  	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
679  	rxrpc_cleanup_ring(call);
680  	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
681  					       struct rxrpc_txbuf, call_link))) {
682  		list_del(&txb->call_link);
683  		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
684  	}
685  	while ((txb = list_first_entry_or_null(&call->tx_buffer,
686  					       struct rxrpc_txbuf, call_link))) {
687  		list_del(&txb->call_link);
688  		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
689  	}
690  
691  	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
692  	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
693  	rxrpc_deactivate_bundle(call->bundle);
694  	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
695  	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
696  	rxrpc_put_local(call->local, rxrpc_local_put_call);
697  	call_rcu(&call->rcu, rxrpc_rcu_free_call);
698  }
699  
700  /*
701   * clean up a call
702   */
rxrpc_cleanup_call(struct rxrpc_call * call)703  void rxrpc_cleanup_call(struct rxrpc_call *call)
704  {
705  	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
706  
707  	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
708  	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
709  
710  	del_timer(&call->timer);
711  
712  	if (rcu_read_lock_held())
713  		/* Can't use the rxrpc workqueue as we need to cancel/flush
714  		 * something that may be running/waiting there.
715  		 */
716  		schedule_work(&call->destroyer);
717  	else
718  		rxrpc_destroy_call(&call->destroyer);
719  }
720  
721  /*
722   * Make sure that all calls are gone from a network namespace.  To reach this
723   * point, any open UDP sockets in that namespace must have been closed, so any
724   * outstanding calls cannot be doing I/O.
725   */
rxrpc_destroy_all_calls(struct rxrpc_net * rxnet)726  void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
727  {
728  	struct rxrpc_call *call;
729  
730  	_enter("");
731  
732  	if (!list_empty(&rxnet->calls)) {
733  		spin_lock(&rxnet->call_lock);
734  
735  		while (!list_empty(&rxnet->calls)) {
736  			call = list_entry(rxnet->calls.next,
737  					  struct rxrpc_call, link);
738  			_debug("Zapping call %p", call);
739  
740  			rxrpc_see_call(call, rxrpc_call_see_zap);
741  			list_del_init(&call->link);
742  
743  			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
744  			       call, refcount_read(&call->ref),
745  			       rxrpc_call_states[__rxrpc_call_state(call)],
746  			       call->flags, call->events);
747  
748  			spin_unlock(&rxnet->call_lock);
749  			cond_resched();
750  			spin_lock(&rxnet->call_lock);
751  		}
752  
753  		spin_unlock(&rxnet->call_lock);
754  	}
755  
756  	atomic_dec(&rxnet->nr_calls);
757  	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
758  }
759