restrack.c
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
* Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
*/
#include <rdma/rdma_cm.h>
#include <rdma/ib_verbs.h>
#include <rdma/restrack.h>
#include <rdma/rdma_counter.h>
#include <linux/mutex.h>
#include <linux/sched/task.h>
#include <linux/pid_namespace.h>
#include "cma_priv.h"
#include "restrack.h"
/**
* rdma_restrack_init() - initialize and allocate resource tracking
* @dev: IB device
*
* Return: 0 on success
*/
int rdma_restrack_init(struct ib_device *dev)
{
struct rdma_restrack_root *rt;
int i;
dev->res = kcalloc(RDMA_RESTRACK_MAX, sizeof(*rt), GFP_KERNEL);
if (!dev->res)
return -ENOMEM;
rt = dev->res;
for (i = 0; i < RDMA_RESTRACK_MAX; i++)
xa_init_flags(&rt[i].xa, XA_FLAGS_ALLOC);
return 0;
}
static const char *type2str(enum rdma_restrack_type type)
{
static const char * const names[RDMA_RESTRACK_MAX] = {
[RDMA_RESTRACK_PD] = "PD",
[RDMA_RESTRACK_CQ] = "CQ",
[RDMA_RESTRACK_QP] = "QP",
[RDMA_RESTRACK_CM_ID] = "CM_ID",
[RDMA_RESTRACK_MR] = "MR",
[RDMA_RESTRACK_CTX] = "CTX",
[RDMA_RESTRACK_COUNTER] = "COUNTER",
};
return names[type];
};
/**
* rdma_restrack_clean() - clean resource tracking
* @dev: IB device
*/
void rdma_restrack_clean(struct ib_device *dev)
{
struct rdma_restrack_root *rt = dev->res;
struct rdma_restrack_entry *e;
char buf[TASK_COMM_LEN];
bool found = false;
const char *owner;
int i;
for (i = 0 ; i < RDMA_RESTRACK_MAX; i++) {
struct xarray *xa = &dev->res[i].xa;
if (!xa_empty(xa)) {
unsigned long index;
if (!found) {
pr_err("restrack: %s", CUT_HERE);
dev_err(&dev->dev, "BUG: RESTRACK detected leak of resources\n");
}
xa_for_each(xa, index, e) {
if (rdma_is_kernel_res(e)) {
owner = e->kern_name;
} else {
/*
* There is no need to call get_task_struct here,
* because we can be here only if there are more
* get_task_struct() call than put_task_struct().
*/
get_task_comm(buf, e->task);
owner = buf;
}
pr_err("restrack: %s %s object allocated by %s is not freed\n",
rdma_is_kernel_res(e) ? "Kernel" :
"User",
type2str(e->type), owner);
}
found = true;
}
xa_destroy(xa);
}
if (found)
pr_err("restrack: %s", CUT_HERE);
kfree(rt);
}
/**
* rdma_restrack_count() - the current usage of specific object
* @dev: IB device
* @type: actual type of object to operate
*/
int rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type)
{
struct rdma_restrack_root *rt = &dev->res[type];
struct rdma_restrack_entry *e;
XA_STATE(xas, &rt->xa, 0);
u32 cnt = 0;
xa_lock(&rt->xa);
xas_for_each(&xas, e, U32_MAX)
cnt++;
xa_unlock(&rt->xa);
return cnt;
}
EXPORT_SYMBOL(rdma_restrack_count);
static void set_kern_name(struct rdma_restrack_entry *res)
{
struct ib_pd *pd;
switch (res->type) {
case RDMA_RESTRACK_QP:
pd = container_of(res, struct ib_qp, res)->pd;
if (!pd) {
WARN_ONCE(true, "XRC QPs are not supported\n");
/* Survive, despite the programmer's error */
res->kern_name = " ";
}
break;
case RDMA_RESTRACK_MR:
pd = container_of(res, struct ib_mr, res)->pd;
break;
default:
/* Other types set kern_name directly */
pd = NULL;
break;
}
if (pd)
res->kern_name = pd->res.kern_name;
}
static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
{
switch (res->type) {
case RDMA_RESTRACK_PD:
return container_of(res, struct ib_pd, res)->device;
case RDMA_RESTRACK_CQ:
return container_of(res, struct ib_cq, res)->device;
case RDMA_RESTRACK_QP:
return container_of(res, struct ib_qp, res)->device;
case RDMA_RESTRACK_CM_ID:
return container_of(res, struct rdma_id_private,
res)->id.device;
case RDMA_RESTRACK_MR:
return container_of(res, struct ib_mr, res)->device;
case RDMA_RESTRACK_CTX:
return container_of(res, struct ib_ucontext, res)->device;
case RDMA_RESTRACK_COUNTER:
return container_of(res, struct rdma_counter, res)->device;
default:
WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
return NULL;
}
}
void rdma_restrack_set_task(struct rdma_restrack_entry *res,
const char *caller)
{
if (caller) {
res->kern_name = caller;
return;
}
if (res->task)
put_task_struct(res->task);
get_task_struct(current);
res->task = current;
}
EXPORT_SYMBOL(rdma_restrack_set_task);
/**
* rdma_restrack_attach_task() - attach the task onto this resource
* @res: resource entry
* @task: the task to attach, the current task will be used if it is NULL.
*/
void rdma_restrack_attach_task(struct rdma_restrack_entry *res,
struct task_struct *task)
{
if (res->task)
put_task_struct(res->task);
get_task_struct(task);
res->task = task;
}
static void rdma_restrack_add(struct rdma_restrack_entry *res)
{
struct ib_device *dev = res_to_dev(res);
struct rdma_restrack_root *rt;
int ret;
if (!dev)
return;
rt = &dev->res[res->type];
kref_init(&res->kref);
init_completion(&res->comp);
if (res->type == RDMA_RESTRACK_QP) {
/* Special case to ensure that LQPN points to right QP */
struct ib_qp *qp = container_of(res, struct ib_qp, res);
ret = xa_insert(&rt->xa, qp->qp_num, res, GFP_KERNEL);
res->id = ret ? 0 : qp->qp_num;
} else if (res->type == RDMA_RESTRACK_COUNTER) {
/* Special case to ensure that cntn points to right counter */
struct rdma_counter *counter;
counter = container_of(res, struct rdma_counter, res);
ret = xa_insert(&rt->xa, counter->id, res, GFP_KERNEL);
res->id = ret ? 0 : counter->id;
} else {
ret = xa_alloc_cyclic(&rt->xa, &res->id, res, xa_limit_32b,
&rt->next_id, GFP_KERNEL);
}
if (!ret)
res->valid = true;
}
/**
* rdma_restrack_kadd() - add kernel object to the reource tracking database
* @res: resource entry
*/
void rdma_restrack_kadd(struct rdma_restrack_entry *res)
{
res->task = NULL;
set_kern_name(res);
res->user = false;
rdma_restrack_add(res);
}
EXPORT_SYMBOL(rdma_restrack_kadd);
/**
* rdma_restrack_uadd() - add user object to the reource tracking database
* @res: resource entry
*/
void rdma_restrack_uadd(struct rdma_restrack_entry *res)
{
if ((res->type != RDMA_RESTRACK_CM_ID) &&
(res->type != RDMA_RESTRACK_COUNTER))
res->task = NULL;
if (!res->task)
rdma_restrack_set_task(res, NULL);
res->kern_name = NULL;
res->user = true;
rdma_restrack_add(res);
}
EXPORT_SYMBOL(rdma_restrack_uadd);
int __must_check rdma_restrack_get(struct rdma_restrack_entry *res)
{
return kref_get_unless_zero(&res->kref);
}
EXPORT_SYMBOL(rdma_restrack_get);
/**
* rdma_restrack_get_byid() - translate from ID to restrack object
* @dev: IB device
* @type: resource track type
* @id: ID to take a look
*
* Return: Pointer to restrack entry or -ENOENT in case of error.
*/
struct rdma_restrack_entry *
rdma_restrack_get_byid(struct ib_device *dev,
enum rdma_restrack_type type, u32 id)
{
struct rdma_restrack_root *rt = &dev->res[type];
struct rdma_restrack_entry *res;
xa_lock(&rt->xa);
res = xa_load(&rt->xa, id);
if (!res || !rdma_restrack_get(res))
res = ERR_PTR(-ENOENT);
xa_unlock(&rt->xa);
return res;
}
EXPORT_SYMBOL(rdma_restrack_get_byid);
static void restrack_release(struct kref *kref)
{
struct rdma_restrack_entry *res;
res = container_of(kref, struct rdma_restrack_entry, kref);
complete(&res->comp);
}
int rdma_restrack_put(struct rdma_restrack_entry *res)
{
return kref_put(&res->kref, restrack_release);
}
EXPORT_SYMBOL(rdma_restrack_put);
void rdma_restrack_del(struct rdma_restrack_entry *res)
{
struct rdma_restrack_entry *old;
struct rdma_restrack_root *rt;
struct ib_device *dev;
if (!res->valid)
goto out;
dev = res_to_dev(res);
if (WARN_ON(!dev))
return;
rt = &dev->res[res->type];
old = xa_erase(&rt->xa, res->id);
WARN_ON(old != res);
res->valid = false;
rdma_restrack_put(res);
wait_for_completion(&res->comp);
out:
if (res->task) {
put_task_struct(res->task);
res->task = NULL;
}
}
EXPORT_SYMBOL(rdma_restrack_del);