1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /*
3  * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
4  */
5 
6 #include <rdma/rdma_cm.h>
7 #include <rdma/ib_verbs.h>
8 #include <rdma/restrack.h>
9 #include <rdma/rdma_counter.h>
10 #include <linux/mutex.h>
11 #include <linux/sched/task.h>
12 #include <linux/pid_namespace.h>
13 
14 #include "cma_priv.h"
15 #include "restrack.h"
16 
17 /**
18  * rdma_restrack_init() - initialize and allocate resource tracking
19  * @dev:  IB device
20  *
21  * Return: 0 on success
22  */
23 int rdma_restrack_init(struct ib_device *dev)
24 {
25 	struct rdma_restrack_root *rt;
26 	int i;
27 
28 	dev->res = kcalloc(RDMA_RESTRACK_MAX, sizeof(*rt), GFP_KERNEL);
29 	if (!dev->res)
30 		return -ENOMEM;
31 
32 	rt = dev->res;
33 
34 	for (i = 0; i < RDMA_RESTRACK_MAX; i++)
35 		xa_init_flags(&rt[i].xa, XA_FLAGS_ALLOC);
36 
37 	return 0;
38 }
39 
40 static const char *type2str(enum rdma_restrack_type type)
41 {
42 	static const char * const names[RDMA_RESTRACK_MAX] = {
43 		[RDMA_RESTRACK_PD] = "PD",
44 		[RDMA_RESTRACK_CQ] = "CQ",
45 		[RDMA_RESTRACK_QP] = "QP",
46 		[RDMA_RESTRACK_CM_ID] = "CM_ID",
47 		[RDMA_RESTRACK_MR] = "MR",
48 		[RDMA_RESTRACK_CTX] = "CTX",
49 		[RDMA_RESTRACK_COUNTER] = "COUNTER",
50 	};
51 
52 	return names[type];
53 };
54 
55 /**
56  * rdma_restrack_clean() - clean resource tracking
57  * @dev:  IB device
58  */
59 void rdma_restrack_clean(struct ib_device *dev)
60 {
61 	struct rdma_restrack_root *rt = dev->res;
62 	struct rdma_restrack_entry *e;
63 	char buf[TASK_COMM_LEN];
64 	bool found = false;
65 	const char *owner;
66 	int i;
67 
68 	for (i = 0 ; i < RDMA_RESTRACK_MAX; i++) {
69 		struct xarray *xa = &dev->res[i].xa;
70 
71 		if (!xa_empty(xa)) {
72 			unsigned long index;
73 
74 			if (!found) {
75 				pr_err("restrack: %s", CUT_HERE);
76 				dev_err(&dev->dev, "BUG: RESTRACK detected leak of resources\n");
77 			}
78 			xa_for_each(xa, index, e) {
79 				if (rdma_is_kernel_res(e)) {
80 					owner = e->kern_name;
81 				} else {
82 					/*
83 					 * There is no need to call get_task_struct here,
84 					 * because we can be here only if there are more
85 					 * get_task_struct() call than put_task_struct().
86 					 */
87 					get_task_comm(buf, e->task);
88 					owner = buf;
89 				}
90 
91 				pr_err("restrack: %s %s object allocated by %s is not freed\n",
92 				       rdma_is_kernel_res(e) ? "Kernel" :
93 							       "User",
94 				       type2str(e->type), owner);
95 			}
96 			found = true;
97 		}
98 		xa_destroy(xa);
99 	}
100 	if (found)
101 		pr_err("restrack: %s", CUT_HERE);
102 
103 	kfree(rt);
104 }
105 
106 /**
107  * rdma_restrack_count() - the current usage of specific object
108  * @dev:  IB device
109  * @type: actual type of object to operate
110  */
111 int rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type)
112 {
113 	struct rdma_restrack_root *rt = &dev->res[type];
114 	struct rdma_restrack_entry *e;
115 	XA_STATE(xas, &rt->xa, 0);
116 	u32 cnt = 0;
117 
118 	xa_lock(&rt->xa);
119 	xas_for_each(&xas, e, U32_MAX)
120 		cnt++;
121 	xa_unlock(&rt->xa);
122 	return cnt;
123 }
124 EXPORT_SYMBOL(rdma_restrack_count);
125 
126 static void set_kern_name(struct rdma_restrack_entry *res)
127 {
128 	struct ib_pd *pd;
129 
130 	switch (res->type) {
131 	case RDMA_RESTRACK_QP:
132 		pd = container_of(res, struct ib_qp, res)->pd;
133 		if (!pd) {
134 			WARN_ONCE(true, "XRC QPs are not supported\n");
135 			/* Survive, despite the programmer's error */
136 			res->kern_name = " ";
137 		}
138 		break;
139 	case RDMA_RESTRACK_MR:
140 		pd = container_of(res, struct ib_mr, res)->pd;
141 		break;
142 	default:
143 		/* Other types set kern_name directly */
144 		pd = NULL;
145 		break;
146 	}
147 
148 	if (pd)
149 		res->kern_name = pd->res.kern_name;
150 }
151 
152 static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
153 {
154 	switch (res->type) {
155 	case RDMA_RESTRACK_PD:
156 		return container_of(res, struct ib_pd, res)->device;
157 	case RDMA_RESTRACK_CQ:
158 		return container_of(res, struct ib_cq, res)->device;
159 	case RDMA_RESTRACK_QP:
160 		return container_of(res, struct ib_qp, res)->device;
161 	case RDMA_RESTRACK_CM_ID:
162 		return container_of(res, struct rdma_id_private,
163 				    res)->id.device;
164 	case RDMA_RESTRACK_MR:
165 		return container_of(res, struct ib_mr, res)->device;
166 	case RDMA_RESTRACK_CTX:
167 		return container_of(res, struct ib_ucontext, res)->device;
168 	case RDMA_RESTRACK_COUNTER:
169 		return container_of(res, struct rdma_counter, res)->device;
170 	default:
171 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
172 		return NULL;
173 	}
174 }
175 
176 void rdma_restrack_set_task(struct rdma_restrack_entry *res,
177 			    const char *caller)
178 {
179 	if (caller) {
180 		res->kern_name = caller;
181 		return;
182 	}
183 
184 	if (res->task)
185 		put_task_struct(res->task);
186 	get_task_struct(current);
187 	res->task = current;
188 }
189 EXPORT_SYMBOL(rdma_restrack_set_task);
190 
191 /**
192  * rdma_restrack_attach_task() - attach the task onto this resource
193  * @res:  resource entry
194  * @task: the task to attach, the current task will be used if it is NULL.
195  */
196 void rdma_restrack_attach_task(struct rdma_restrack_entry *res,
197 			       struct task_struct *task)
198 {
199 	if (res->task)
200 		put_task_struct(res->task);
201 	get_task_struct(task);
202 	res->task = task;
203 }
204 
205 static void rdma_restrack_add(struct rdma_restrack_entry *res)
206 {
207 	struct ib_device *dev = res_to_dev(res);
208 	struct rdma_restrack_root *rt;
209 	int ret;
210 
211 	if (!dev)
212 		return;
213 
214 	rt = &dev->res[res->type];
215 
216 	kref_init(&res->kref);
217 	init_completion(&res->comp);
218 	if (res->type == RDMA_RESTRACK_QP) {
219 		/* Special case to ensure that LQPN points to right QP */
220 		struct ib_qp *qp = container_of(res, struct ib_qp, res);
221 
222 		ret = xa_insert(&rt->xa, qp->qp_num, res, GFP_KERNEL);
223 		res->id = ret ? 0 : qp->qp_num;
224 	} else if (res->type == RDMA_RESTRACK_COUNTER) {
225 		/* Special case to ensure that cntn points to right counter */
226 		struct rdma_counter *counter;
227 
228 		counter = container_of(res, struct rdma_counter, res);
229 		ret = xa_insert(&rt->xa, counter->id, res, GFP_KERNEL);
230 		res->id = ret ? 0 : counter->id;
231 	} else {
232 		ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
233 				      &rt->next_id, GFP_KERNEL);
234 	}
235 
236 	if (!ret)
237 		res->valid = true;
238 }
239 
240 /**
241  * rdma_restrack_kadd() - add kernel object to the reource tracking database
242  * @res:  resource entry
243  */
244 void rdma_restrack_kadd(struct rdma_restrack_entry *res)
245 {
246 	res->task = NULL;
247 	set_kern_name(res);
248 	res->user = false;
249 	rdma_restrack_add(res);
250 }
251 EXPORT_SYMBOL(rdma_restrack_kadd);
252 
253 /**
254  * rdma_restrack_uadd() - add user object to the reource tracking database
255  * @res:  resource entry
256  */
257 void rdma_restrack_uadd(struct rdma_restrack_entry *res)
258 {
259 	if ((res->type != RDMA_RESTRACK_CM_ID) &&
260 	    (res->type != RDMA_RESTRACK_COUNTER))
261 		res->task = NULL;
262 
263 	if (!res->task)
264 		rdma_restrack_set_task(res, NULL);
265 	res->kern_name = NULL;
266 
267 	res->user = true;
268 	rdma_restrack_add(res);
269 }
270 EXPORT_SYMBOL(rdma_restrack_uadd);
271 
272 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
273 {
274 	return kref_get_unless_zero(&res->kref);
275 }
276 EXPORT_SYMBOL(rdma_restrack_get);
277 
278 /**
279  * rdma_restrack_get_byid() - translate from ID to restrack object
280  * @dev: IB device
281  * @type: resource track type
282  * @id: ID to take a look
283  *
284  * Return: Pointer to restrack entry or -ENOENT in case of error.
285  */
286 struct rdma_restrack_entry *
287 rdma_restrack_get_byid(struct ib_device *dev,
288 		       enum rdma_restrack_type type, u32 id)
289 {
290 	struct rdma_restrack_root *rt = &dev->res[type];
291 	struct rdma_restrack_entry *res;
292 
293 	xa_lock(&rt->xa);
294 	res = xa_load(&rt->xa, id);
295 	if (!res || !rdma_restrack_get(res))
296 		res = ERR_PTR(-ENOENT);
297 	xa_unlock(&rt->xa);
298 
299 	return res;
300 }
301 EXPORT_SYMBOL(rdma_restrack_get_byid);
302 
303 static void restrack_release(struct kref *kref)
304 {
305 	struct rdma_restrack_entry *res;
306 
307 	res = container_of(kref, struct rdma_restrack_entry, kref);
308 	complete(&res->comp);
309 }
310 
311 int rdma_restrack_put(struct rdma_restrack_entry *res)
312 {
313 	return kref_put(&res->kref, restrack_release);
314 }
315 EXPORT_SYMBOL(rdma_restrack_put);
316 
317 void rdma_restrack_del(struct rdma_restrack_entry *res)
318 {
319 	struct rdma_restrack_entry *old;
320 	struct rdma_restrack_root *rt;
321 	struct ib_device *dev;
322 
323 	if (!res->valid)
324 		goto out;
325 
326 	dev = res_to_dev(res);
327 	if (WARN_ON(!dev))
328 		return;
329 
330 	rt = &dev->res[res->type];
331 
332 	old = xa_erase(&rt->xa, res->id);
333 	WARN_ON(old != res);
334 	res->valid = false;
335 
336 	rdma_restrack_put(res);
337 	wait_for_completion(&res->comp);
338 
339 out:
340 	if (res->task) {
341 		put_task_struct(res->task);
342 		res->task = NULL;
343 	}
344 }
345 EXPORT_SYMBOL(rdma_restrack_del);
346