xref: /linux/drivers/infiniband/core/restrack.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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 <linux/mutex.h>
10 #include <linux/sched/task.h>
11 #include <linux/pid_namespace.h>
12 
13 #include "cma_priv.h"
14 #include "restrack.h"
15 
16 /**
17  * rdma_restrack_init() - initialize and allocate resource tracking
18  * @dev:  IB device
19  *
20  * Return: 0 on success
21  */
22 int rdma_restrack_init(struct ib_device *dev)
23 {
24 	struct rdma_restrack_root *rt;
25 	int i;
26 
27 	dev->res = kcalloc(RDMA_RESTRACK_MAX, sizeof(*rt), GFP_KERNEL);
28 	if (!dev->res)
29 		return -ENOMEM;
30 
31 	rt = dev->res;
32 
33 	for (i = 0; i < RDMA_RESTRACK_MAX; i++)
34 		xa_init_flags(&rt[i].xa, XA_FLAGS_ALLOC);
35 
36 	return 0;
37 }
38 
39 static const char *type2str(enum rdma_restrack_type type)
40 {
41 	static const char * const names[RDMA_RESTRACK_MAX] = {
42 		[RDMA_RESTRACK_PD] = "PD",
43 		[RDMA_RESTRACK_CQ] = "CQ",
44 		[RDMA_RESTRACK_QP] = "QP",
45 		[RDMA_RESTRACK_CM_ID] = "CM_ID",
46 		[RDMA_RESTRACK_MR] = "MR",
47 		[RDMA_RESTRACK_CTX] = "CTX",
48 	};
49 
50 	return names[type];
51 };
52 
53 /**
54  * rdma_restrack_clean() - clean resource tracking
55  * @dev:  IB device
56  */
57 void rdma_restrack_clean(struct ib_device *dev)
58 {
59 	struct rdma_restrack_root *rt = dev->res;
60 	struct rdma_restrack_entry *e;
61 	char buf[TASK_COMM_LEN];
62 	bool found = false;
63 	const char *owner;
64 	int i;
65 
66 	for (i = 0 ; i < RDMA_RESTRACK_MAX; i++) {
67 		struct xarray *xa = &dev->res[i].xa;
68 
69 		if (!xa_empty(xa)) {
70 			unsigned long index;
71 
72 			if (!found) {
73 				pr_err("restrack: %s", CUT_HERE);
74 				dev_err(&dev->dev, "BUG: RESTRACK detected leak of resources\n");
75 			}
76 			xa_for_each(xa, index, e) {
77 				if (rdma_is_kernel_res(e)) {
78 					owner = e->kern_name;
79 				} else {
80 					/*
81 					 * There is no need to call get_task_struct here,
82 					 * because we can be here only if there are more
83 					 * get_task_struct() call than put_task_struct().
84 					 */
85 					get_task_comm(buf, e->task);
86 					owner = buf;
87 				}
88 
89 				pr_err("restrack: %s %s object allocated by %s is not freed\n",
90 				       rdma_is_kernel_res(e) ? "Kernel" :
91 							       "User",
92 				       type2str(e->type), owner);
93 			}
94 			found = true;
95 		}
96 		xa_destroy(xa);
97 	}
98 	if (found)
99 		pr_err("restrack: %s", CUT_HERE);
100 
101 	kfree(rt);
102 }
103 
104 /**
105  * rdma_restrack_count() - the current usage of specific object
106  * @dev:  IB device
107  * @type: actual type of object to operate
108  * @ns:   PID namespace
109  */
110 int rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type,
111 			struct pid_namespace *ns)
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 (ns == &init_pid_ns ||
121 		    (!rdma_is_kernel_res(e) &&
122 		     ns == task_active_pid_ns(e->task)))
123 			cnt++;
124 	}
125 	xa_unlock(&rt->xa);
126 	return cnt;
127 }
128 EXPORT_SYMBOL(rdma_restrack_count);
129 
130 static void set_kern_name(struct rdma_restrack_entry *res)
131 {
132 	struct ib_pd *pd;
133 
134 	switch (res->type) {
135 	case RDMA_RESTRACK_QP:
136 		pd = container_of(res, struct ib_qp, res)->pd;
137 		if (!pd) {
138 			WARN_ONCE(true, "XRC QPs are not supported\n");
139 			/* Survive, despite the programmer's error */
140 			res->kern_name = " ";
141 		}
142 		break;
143 	case RDMA_RESTRACK_MR:
144 		pd = container_of(res, struct ib_mr, res)->pd;
145 		break;
146 	default:
147 		/* Other types set kern_name directly */
148 		pd = NULL;
149 		break;
150 	}
151 
152 	if (pd)
153 		res->kern_name = pd->res.kern_name;
154 }
155 
156 static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
157 {
158 	switch (res->type) {
159 	case RDMA_RESTRACK_PD:
160 		return container_of(res, struct ib_pd, res)->device;
161 	case RDMA_RESTRACK_CQ:
162 		return container_of(res, struct ib_cq, res)->device;
163 	case RDMA_RESTRACK_QP:
164 		return container_of(res, struct ib_qp, res)->device;
165 	case RDMA_RESTRACK_CM_ID:
166 		return container_of(res, struct rdma_id_private,
167 				    res)->id.device;
168 	case RDMA_RESTRACK_MR:
169 		return container_of(res, struct ib_mr, res)->device;
170 	case RDMA_RESTRACK_CTX:
171 		return container_of(res, struct ib_ucontext, res)->device;
172 	default:
173 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
174 		return NULL;
175 	}
176 }
177 
178 void rdma_restrack_set_task(struct rdma_restrack_entry *res,
179 			    const char *caller)
180 {
181 	if (caller) {
182 		res->kern_name = caller;
183 		return;
184 	}
185 
186 	if (res->task)
187 		put_task_struct(res->task);
188 	get_task_struct(current);
189 	res->task = current;
190 }
191 EXPORT_SYMBOL(rdma_restrack_set_task);
192 
193 static void rdma_restrack_add(struct rdma_restrack_entry *res)
194 {
195 	struct ib_device *dev = res_to_dev(res);
196 	struct rdma_restrack_root *rt;
197 	int ret;
198 
199 	if (!dev)
200 		return;
201 
202 	rt = &dev->res[res->type];
203 
204 	kref_init(&res->kref);
205 	init_completion(&res->comp);
206 	if (res->type != RDMA_RESTRACK_QP)
207 		ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
208 				&rt->next_id, GFP_KERNEL);
209 	else {
210 		/* Special case to ensure that LQPN points to right QP */
211 		struct ib_qp *qp = container_of(res, struct ib_qp, res);
212 
213 		ret = xa_insert(&rt->xa, qp->qp_num, res, GFP_KERNEL);
214 		res->id = ret ? 0 : qp->qp_num;
215 	}
216 
217 	if (!ret)
218 		res->valid = true;
219 }
220 
221 /**
222  * rdma_restrack_kadd() - add kernel object to the reource tracking database
223  * @res:  resource entry
224  */
225 void rdma_restrack_kadd(struct rdma_restrack_entry *res)
226 {
227 	res->task = NULL;
228 	set_kern_name(res);
229 	res->user = false;
230 	rdma_restrack_add(res);
231 }
232 EXPORT_SYMBOL(rdma_restrack_kadd);
233 
234 /**
235  * rdma_restrack_uadd() - add user object to the reource tracking database
236  * @res:  resource entry
237  */
238 void rdma_restrack_uadd(struct rdma_restrack_entry *res)
239 {
240 	if (res->type != RDMA_RESTRACK_CM_ID)
241 		res->task = NULL;
242 
243 	if (!res->task)
244 		rdma_restrack_set_task(res, NULL);
245 	res->kern_name = NULL;
246 
247 	res->user = true;
248 	rdma_restrack_add(res);
249 }
250 EXPORT_SYMBOL(rdma_restrack_uadd);
251 
252 int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
253 {
254 	return kref_get_unless_zero(&res->kref);
255 }
256 EXPORT_SYMBOL(rdma_restrack_get);
257 
258 /**
259  * rdma_restrack_get_byid() - translate from ID to restrack object
260  * @dev: IB device
261  * @type: resource track type
262  * @id: ID to take a look
263  *
264  * Return: Pointer to restrack entry or -ENOENT in case of error.
265  */
266 struct rdma_restrack_entry *
267 rdma_restrack_get_byid(struct ib_device *dev,
268 		       enum rdma_restrack_type type, u32 id)
269 {
270 	struct rdma_restrack_root *rt = &dev->res[type];
271 	struct rdma_restrack_entry *res;
272 
273 	xa_lock(&rt->xa);
274 	res = xa_load(&rt->xa, id);
275 	if (!res || !rdma_restrack_get(res))
276 		res = ERR_PTR(-ENOENT);
277 	xa_unlock(&rt->xa);
278 
279 	return res;
280 }
281 EXPORT_SYMBOL(rdma_restrack_get_byid);
282 
283 static void restrack_release(struct kref *kref)
284 {
285 	struct rdma_restrack_entry *res;
286 
287 	res = container_of(kref, struct rdma_restrack_entry, kref);
288 	complete(&res->comp);
289 }
290 
291 int rdma_restrack_put(struct rdma_restrack_entry *res)
292 {
293 	return kref_put(&res->kref, restrack_release);
294 }
295 EXPORT_SYMBOL(rdma_restrack_put);
296 
297 void rdma_restrack_del(struct rdma_restrack_entry *res)
298 {
299 	struct rdma_restrack_entry *old;
300 	struct rdma_restrack_root *rt;
301 	struct ib_device *dev;
302 
303 	if (!res->valid)
304 		goto out;
305 
306 	dev = res_to_dev(res);
307 	if (WARN_ON(!dev))
308 		return;
309 
310 	rt = &dev->res[res->type];
311 
312 	old = xa_erase(&rt->xa, res->id);
313 	WARN_ON(old != res);
314 	res->valid = false;
315 
316 	rdma_restrack_put(res);
317 	wait_for_completion(&res->comp);
318 
319 out:
320 	if (res->task) {
321 		put_task_struct(res->task);
322 		res->task = NULL;
323 	}
324 }
325 EXPORT_SYMBOL(rdma_restrack_del);
326