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 		if (!rdma_is_visible_in_pid_ns(e))
121 			continue;
122 		cnt++;
123 	}
124 	xa_unlock(&rt->xa);
125 	return cnt;
126 }
127 EXPORT_SYMBOL(rdma_restrack_count);
128 
129 static void set_kern_name(struct rdma_restrack_entry *res)
130 {
131 	struct ib_pd *pd;
132 
133 	switch (res->type) {
134 	case RDMA_RESTRACK_QP:
135 		pd = container_of(res, struct ib_qp, res)->pd;
136 		if (!pd) {
137 			WARN_ONCE(true, "XRC QPs are not supported\n");
138 			/* Survive, despite the programmer's error */
139 			res->kern_name = " ";
140 		}
141 		break;
142 	case RDMA_RESTRACK_MR:
143 		pd = container_of(res, struct ib_mr, res)->pd;
144 		break;
145 	default:
146 		/* Other types set kern_name directly */
147 		pd = NULL;
148 		break;
149 	}
150 
151 	if (pd)
152 		res->kern_name = pd->res.kern_name;
153 }
154 
155 static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
156 {
157 	switch (res->type) {
158 	case RDMA_RESTRACK_PD:
159 		return container_of(res, struct ib_pd, res)->device;
160 	case RDMA_RESTRACK_CQ:
161 		return container_of(res, struct ib_cq, res)->device;
162 	case RDMA_RESTRACK_QP:
163 		return container_of(res, struct ib_qp, res)->device;
164 	case RDMA_RESTRACK_CM_ID:
165 		return container_of(res, struct rdma_id_private,
166 				    res)->id.device;
167 	case RDMA_RESTRACK_MR:
168 		return container_of(res, struct ib_mr, res)->device;
169 	case RDMA_RESTRACK_CTX:
170 		return container_of(res, struct ib_ucontext, res)->device;
171 	case RDMA_RESTRACK_COUNTER:
172 		return container_of(res, struct rdma_counter, res)->device;
173 	default:
174 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
175 		return NULL;
176 	}
177 }
178 
179 void rdma_restrack_set_task(struct rdma_restrack_entry *res,
180 			    const char *caller)
181 {
182 	if (caller) {
183 		res->kern_name = caller;
184 		return;
185 	}
186 
187 	if (res->task)
188 		put_task_struct(res->task);
189 	get_task_struct(current);
190 	res->task = current;
191 }
192 EXPORT_SYMBOL(rdma_restrack_set_task);
193 
194 /**
195  * rdma_restrack_attach_task() - attach the task onto this resource
196  * @res:  resource entry
197  * @task: the task to attach, the current task will be used if it is NULL.
198  */
199 void rdma_restrack_attach_task(struct rdma_restrack_entry *res,
200 			       struct task_struct *task)
201 {
202 	if (res->task)
203 		put_task_struct(res->task);
204 	get_task_struct(task);
205 	res->task = task;
206 }
207 
208 static void rdma_restrack_add(struct rdma_restrack_entry *res)
209 {
210 	struct ib_device *dev = res_to_dev(res);
211 	struct rdma_restrack_root *rt;
212 	int ret;
213 
214 	if (!dev)
215 		return;
216 
217 	rt = &dev->res[res->type];
218 
219 	kref_init(&res->kref);
220 	init_completion(&res->comp);
221 	if (res->type == RDMA_RESTRACK_QP) {
222 		/* Special case to ensure that LQPN points to right QP */
223 		struct ib_qp *qp = container_of(res, struct ib_qp, res);
224 
225 		ret = xa_insert(&rt->xa, qp->qp_num, res, GFP_KERNEL);
226 		res->id = ret ? 0 : qp->qp_num;
227 	} else if (res->type == RDMA_RESTRACK_COUNTER) {
228 		/* Special case to ensure that cntn points to right counter */
229 		struct rdma_counter *counter;
230 
231 		counter = container_of(res, struct rdma_counter, res);
232 		ret = xa_insert(&rt->xa, counter->id, res, GFP_KERNEL);
233 		res->id = ret ? 0 : counter->id;
234 	} else {
235 		ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
236 				      &rt->next_id, GFP_KERNEL);
237 	}
238 
239 	if (!ret)
240 		res->valid = true;
241 }
242 
243 /**
244  * rdma_restrack_kadd() - add kernel object to the reource tracking database
245  * @res:  resource entry
246  */
247 void rdma_restrack_kadd(struct rdma_restrack_entry *res)
248 {
249 	res->task = NULL;
250 	set_kern_name(res);
251 	res->user = false;
252 	rdma_restrack_add(res);
253 }
254 EXPORT_SYMBOL(rdma_restrack_kadd);
255 
256 /**
257  * rdma_restrack_uadd() - add user object to the reource tracking database
258  * @res:  resource entry
259  */
260 void rdma_restrack_uadd(struct rdma_restrack_entry *res)
261 {
262 	if ((res->type != RDMA_RESTRACK_CM_ID) &&
263 	    (res->type != RDMA_RESTRACK_COUNTER))
264 		res->task = NULL;
265 
266 	if (!res->task)
267 		rdma_restrack_set_task(res, NULL);
268 	res->kern_name = NULL;
269 
270 	res->user = true;
271 	rdma_restrack_add(res);
272 }
273 EXPORT_SYMBOL(rdma_restrack_uadd);
274 
275 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
276 {
277 	return kref_get_unless_zero(&res->kref);
278 }
279 EXPORT_SYMBOL(rdma_restrack_get);
280 
281 /**
282  * rdma_restrack_get_byid() - translate from ID to restrack object
283  * @dev: IB device
284  * @type: resource track type
285  * @id: ID to take a look
286  *
287  * Return: Pointer to restrack entry or -ENOENT in case of error.
288  */
289 struct rdma_restrack_entry *
290 rdma_restrack_get_byid(struct ib_device *dev,
291 		       enum rdma_restrack_type type, u32 id)
292 {
293 	struct rdma_restrack_root *rt = &dev->res[type];
294 	struct rdma_restrack_entry *res;
295 
296 	xa_lock(&rt->xa);
297 	res = xa_load(&rt->xa, id);
298 	if (!res || !rdma_restrack_get(res))
299 		res = ERR_PTR(-ENOENT);
300 	xa_unlock(&rt->xa);
301 
302 	return res;
303 }
304 EXPORT_SYMBOL(rdma_restrack_get_byid);
305 
306 static void restrack_release(struct kref *kref)
307 {
308 	struct rdma_restrack_entry *res;
309 
310 	res = container_of(kref, struct rdma_restrack_entry, kref);
311 	complete(&res->comp);
312 }
313 
314 int rdma_restrack_put(struct rdma_restrack_entry *res)
315 {
316 	return kref_put(&res->kref, restrack_release);
317 }
318 EXPORT_SYMBOL(rdma_restrack_put);
319 
320 void rdma_restrack_del(struct rdma_restrack_entry *res)
321 {
322 	struct rdma_restrack_entry *old;
323 	struct rdma_restrack_root *rt;
324 	struct ib_device *dev;
325 
326 	if (!res->valid)
327 		goto out;
328 
329 	dev = res_to_dev(res);
330 	if (WARN_ON(!dev))
331 		return;
332 
333 	rt = &dev->res[res->type];
334 
335 	old = xa_erase(&rt->xa, res->id);
336 	WARN_ON(old != res);
337 	res->valid = false;
338 
339 	rdma_restrack_put(res);
340 	wait_for_completion(&res->comp);
341 
342 out:
343 	if (res->task) {
344 		put_task_struct(res->task);
345 		res->task = NULL;
346 	}
347 }
348 EXPORT_SYMBOL(rdma_restrack_del);
349 
350 bool rdma_is_visible_in_pid_ns(struct rdma_restrack_entry *res)
351 {
352 	/*
353 	 * 1. Kern resources should be visible in init
354 	 *    namespace only
355 	 * 2. Present only resources visible in the current
356 	 *     namespace
357 	 */
358 	if (rdma_is_kernel_res(res))
359 		return task_active_pid_ns(current) == &init_pid_ns;
360 
361 	/* PID 0 means that resource is not found in current namespace */
362 	return task_pid_vnr(res->task);
363 }
364