drivers/infiniband/core/restrack.c

   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);