linux_dsm_epyc7002/drivers/infiniband/core/restrack.c
Leon Romanovsky 60c78668ae RDMA/restrack: Rewrite PID namespace check to be reliable
task_active_pid_ns() is wrong API to check PID namespace because it
posses some restrictions and return PID namespace where the process
was allocated. It created mismatches with current namespace, which
can be different.

Rewrite whole rdma_is_visible_in_pid_ns() logic to provide reliable
results without any relation to allocated PID namespace.

Fixes: 8be565e65f ("RDMA/nldev: Factor out the PID namespace check")
Fixes: 6a6c306a09 ("RDMA/restrack: Make is_visible_in_pid_ns() as an API")
Reviewed-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Link: https://lore.kernel.org/r/20190815083834.9245-4-leon@kernel.org
Signed-off-by: Doug Ledford <dledford@redhat.com>
2019-08-20 13:44:44 -04:00

364 lines
8.3 KiB
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) {
if (!rdma_is_visible_in_pid_ns(e))
continue;
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);
bool rdma_is_visible_in_pid_ns(struct rdma_restrack_entry *res)
{
/*
* 1. Kern resources should be visible in init
* namespace only
* 2. Present only resources visible in the current
* namespace
*/
if (rdma_is_kernel_res(res))
return task_active_pid_ns(current) == &init_pid_ns;
/* PID 0 means that resource is not found in current namespace */
return task_pid_vnr(res->task);
}