![Sowmini Varadhan](/assets/img/avatar_default.png)
An rds_connection can get added during netns deletion between lines 528
and 529 of
506 static void rds_tcp_kill_sock(struct net *net)
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/* code to pull out all the rds_connections that should be destroyed */
:
528 spin_unlock_irq(&rds_tcp_conn_lock);
529 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
530 rds_conn_destroy(tc->t_cpath->cp_conn);
Such an rds_connection would miss out the rds_conn_destroy()
loop (that cancels all pending work) and (if it was scheduled
after netns deletion) could trigger the use-after-free.
A similar race-window exists for the module unload path
in rds_tcp_exit -> rds_tcp_destroy_conns
Concurrency with netns deletion (rds_tcp_kill_sock()) must be handled
by checking check_net() before enqueuing new work or adding new
connections.
Concurrency with module-unload is handled by maintaining a module
specific flag that is set at the start of the module exit function,
and must be checked before enqueuing new work or adding new connections.
This commit refactors existing RDS_DESTROY_PENDING checks added by
commit 3db6e0d172
("rds: use RCU to synchronize work-enqueue with
connection teardown") and consolidates all the concurrency checks
listed above into the function rds_destroy_pending().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
476 lines
14 KiB
C
476 lines
14 KiB
C
/*
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* Copyright (c) 2006 Oracle. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/in.h>
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#include <linux/if.h>
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#include <linux/netdevice.h>
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#include <linux/inetdevice.h>
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#include <linux/if_arp.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include "rds_single_path.h"
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#include "rds.h"
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#include "ib.h"
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#include "ib_mr.h"
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static unsigned int rds_ib_mr_1m_pool_size = RDS_MR_1M_POOL_SIZE;
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static unsigned int rds_ib_mr_8k_pool_size = RDS_MR_8K_POOL_SIZE;
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unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
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static atomic_t rds_ib_unloading;
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module_param(rds_ib_mr_1m_pool_size, int, 0444);
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MODULE_PARM_DESC(rds_ib_mr_1m_pool_size, " Max number of 1M mr per HCA");
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module_param(rds_ib_mr_8k_pool_size, int, 0444);
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MODULE_PARM_DESC(rds_ib_mr_8k_pool_size, " Max number of 8K mr per HCA");
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module_param(rds_ib_retry_count, int, 0444);
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MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
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/*
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* we have a clumsy combination of RCU and a rwsem protecting this list
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* because it is used both in the get_mr fast path and while blocking in
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* the FMR flushing path.
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*/
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DECLARE_RWSEM(rds_ib_devices_lock);
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struct list_head rds_ib_devices;
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/* NOTE: if also grabbing ibdev lock, grab this first */
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DEFINE_SPINLOCK(ib_nodev_conns_lock);
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LIST_HEAD(ib_nodev_conns);
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static void rds_ib_nodev_connect(void)
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{
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struct rds_ib_connection *ic;
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spin_lock(&ib_nodev_conns_lock);
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list_for_each_entry(ic, &ib_nodev_conns, ib_node)
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rds_conn_connect_if_down(ic->conn);
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spin_unlock(&ib_nodev_conns_lock);
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}
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static void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
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{
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struct rds_ib_connection *ic;
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unsigned long flags;
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spin_lock_irqsave(&rds_ibdev->spinlock, flags);
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list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
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rds_conn_drop(ic->conn);
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spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
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}
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/*
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* rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
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* from interrupt context so we push freing off into a work struct in krdsd.
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*/
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static void rds_ib_dev_free(struct work_struct *work)
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{
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struct rds_ib_ipaddr *i_ipaddr, *i_next;
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struct rds_ib_device *rds_ibdev = container_of(work,
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struct rds_ib_device, free_work);
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if (rds_ibdev->mr_8k_pool)
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rds_ib_destroy_mr_pool(rds_ibdev->mr_8k_pool);
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if (rds_ibdev->mr_1m_pool)
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rds_ib_destroy_mr_pool(rds_ibdev->mr_1m_pool);
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if (rds_ibdev->pd)
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ib_dealloc_pd(rds_ibdev->pd);
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list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
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list_del(&i_ipaddr->list);
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kfree(i_ipaddr);
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}
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kfree(rds_ibdev->vector_load);
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kfree(rds_ibdev);
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}
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void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
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{
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BUG_ON(refcount_read(&rds_ibdev->refcount) == 0);
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if (refcount_dec_and_test(&rds_ibdev->refcount))
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queue_work(rds_wq, &rds_ibdev->free_work);
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}
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static void rds_ib_add_one(struct ib_device *device)
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{
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struct rds_ib_device *rds_ibdev;
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bool has_fr, has_fmr;
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/* Only handle IB (no iWARP) devices */
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if (device->node_type != RDMA_NODE_IB_CA)
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return;
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rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
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ibdev_to_node(device));
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if (!rds_ibdev)
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return;
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spin_lock_init(&rds_ibdev->spinlock);
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refcount_set(&rds_ibdev->refcount, 1);
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INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
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rds_ibdev->max_wrs = device->attrs.max_qp_wr;
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rds_ibdev->max_sge = min(device->attrs.max_sge, RDS_IB_MAX_SGE);
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has_fr = (device->attrs.device_cap_flags &
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IB_DEVICE_MEM_MGT_EXTENSIONS);
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has_fmr = (device->alloc_fmr && device->dealloc_fmr &&
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device->map_phys_fmr && device->unmap_fmr);
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rds_ibdev->use_fastreg = (has_fr && !has_fmr);
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rds_ibdev->fmr_max_remaps = device->attrs.max_map_per_fmr?: 32;
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rds_ibdev->max_1m_mrs = device->attrs.max_mr ?
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min_t(unsigned int, (device->attrs.max_mr / 2),
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rds_ib_mr_1m_pool_size) : rds_ib_mr_1m_pool_size;
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rds_ibdev->max_8k_mrs = device->attrs.max_mr ?
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min_t(unsigned int, ((device->attrs.max_mr / 2) * RDS_MR_8K_SCALE),
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rds_ib_mr_8k_pool_size) : rds_ib_mr_8k_pool_size;
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rds_ibdev->max_initiator_depth = device->attrs.max_qp_init_rd_atom;
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rds_ibdev->max_responder_resources = device->attrs.max_qp_rd_atom;
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rds_ibdev->vector_load = kzalloc(sizeof(int) * device->num_comp_vectors,
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GFP_KERNEL);
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if (!rds_ibdev->vector_load) {
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pr_err("RDS/IB: %s failed to allocate vector memory\n",
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__func__);
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goto put_dev;
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}
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rds_ibdev->dev = device;
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rds_ibdev->pd = ib_alloc_pd(device, 0);
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if (IS_ERR(rds_ibdev->pd)) {
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rds_ibdev->pd = NULL;
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goto put_dev;
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}
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rds_ibdev->mr_1m_pool =
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rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_1M_POOL);
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if (IS_ERR(rds_ibdev->mr_1m_pool)) {
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rds_ibdev->mr_1m_pool = NULL;
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goto put_dev;
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}
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rds_ibdev->mr_8k_pool =
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rds_ib_create_mr_pool(rds_ibdev, RDS_IB_MR_8K_POOL);
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if (IS_ERR(rds_ibdev->mr_8k_pool)) {
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rds_ibdev->mr_8k_pool = NULL;
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goto put_dev;
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}
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rdsdebug("RDS/IB: max_mr = %d, max_wrs = %d, max_sge = %d, fmr_max_remaps = %d, max_1m_mrs = %d, max_8k_mrs = %d\n",
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device->attrs.max_fmr, rds_ibdev->max_wrs, rds_ibdev->max_sge,
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rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_mrs,
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rds_ibdev->max_8k_mrs);
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pr_info("RDS/IB: %s: %s supported and preferred\n",
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device->name,
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rds_ibdev->use_fastreg ? "FRMR" : "FMR");
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INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
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INIT_LIST_HEAD(&rds_ibdev->conn_list);
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down_write(&rds_ib_devices_lock);
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list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
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up_write(&rds_ib_devices_lock);
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refcount_inc(&rds_ibdev->refcount);
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ib_set_client_data(device, &rds_ib_client, rds_ibdev);
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refcount_inc(&rds_ibdev->refcount);
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rds_ib_nodev_connect();
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put_dev:
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rds_ib_dev_put(rds_ibdev);
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}
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/*
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* New connections use this to find the device to associate with the
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* connection. It's not in the fast path so we're not concerned about the
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* performance of the IB call. (As of this writing, it uses an interrupt
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* blocking spinlock to serialize walking a per-device list of all registered
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* clients.)
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*
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* RCU is used to handle incoming connections racing with device teardown.
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* Rather than use a lock to serialize removal from the client_data and
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* getting a new reference, we use an RCU grace period. The destruction
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* path removes the device from client_data and then waits for all RCU
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* readers to finish.
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*
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* A new connection can get NULL from this if its arriving on a
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* device that is in the process of being removed.
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*/
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struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
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{
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struct rds_ib_device *rds_ibdev;
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rcu_read_lock();
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rds_ibdev = ib_get_client_data(device, &rds_ib_client);
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if (rds_ibdev)
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refcount_inc(&rds_ibdev->refcount);
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rcu_read_unlock();
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return rds_ibdev;
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}
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/*
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* The IB stack is letting us know that a device is going away. This can
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* happen if the underlying HCA driver is removed or if PCI hotplug is removing
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* the pci function, for example.
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*
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* This can be called at any time and can be racing with any other RDS path.
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*/
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static void rds_ib_remove_one(struct ib_device *device, void *client_data)
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{
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struct rds_ib_device *rds_ibdev = client_data;
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if (!rds_ibdev)
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return;
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rds_ib_dev_shutdown(rds_ibdev);
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/* stop connection attempts from getting a reference to this device. */
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ib_set_client_data(device, &rds_ib_client, NULL);
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down_write(&rds_ib_devices_lock);
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list_del_rcu(&rds_ibdev->list);
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up_write(&rds_ib_devices_lock);
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/*
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* This synchronize rcu is waiting for readers of both the ib
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* client data and the devices list to finish before we drop
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* both of those references.
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*/
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synchronize_rcu();
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rds_ib_dev_put(rds_ibdev);
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rds_ib_dev_put(rds_ibdev);
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}
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struct ib_client rds_ib_client = {
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.name = "rds_ib",
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.add = rds_ib_add_one,
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.remove = rds_ib_remove_one
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};
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static int rds_ib_conn_info_visitor(struct rds_connection *conn,
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void *buffer)
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{
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struct rds_info_rdma_connection *iinfo = buffer;
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struct rds_ib_connection *ic;
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/* We will only ever look at IB transports */
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if (conn->c_trans != &rds_ib_transport)
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return 0;
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iinfo->src_addr = conn->c_laddr;
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iinfo->dst_addr = conn->c_faddr;
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memset(&iinfo->src_gid, 0, sizeof(iinfo->src_gid));
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memset(&iinfo->dst_gid, 0, sizeof(iinfo->dst_gid));
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if (rds_conn_state(conn) == RDS_CONN_UP) {
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struct rds_ib_device *rds_ibdev;
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ic = conn->c_transport_data;
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rdma_read_gids(ic->i_cm_id, (union ib_gid *)&iinfo->src_gid,
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(union ib_gid *)&iinfo->dst_gid);
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rds_ibdev = ic->rds_ibdev;
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iinfo->max_send_wr = ic->i_send_ring.w_nr;
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iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
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iinfo->max_send_sge = rds_ibdev->max_sge;
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rds_ib_get_mr_info(rds_ibdev, iinfo);
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}
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return 1;
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}
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static void rds_ib_ic_info(struct socket *sock, unsigned int len,
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struct rds_info_iterator *iter,
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struct rds_info_lengths *lens)
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{
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rds_for_each_conn_info(sock, len, iter, lens,
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rds_ib_conn_info_visitor,
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sizeof(struct rds_info_rdma_connection));
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}
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/*
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* Early RDS/IB was built to only bind to an address if there is an IPoIB
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* device with that address set.
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*
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* If it were me, I'd advocate for something more flexible. Sending and
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* receiving should be device-agnostic. Transports would try and maintain
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* connections between peers who have messages queued. Userspace would be
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* allowed to influence which paths have priority. We could call userspace
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* asserting this policy "routing".
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*/
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static int rds_ib_laddr_check(struct net *net, __be32 addr)
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{
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int ret;
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struct rdma_cm_id *cm_id;
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struct sockaddr_in sin;
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/* Create a CMA ID and try to bind it. This catches both
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* IB and iWARP capable NICs.
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*/
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cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler,
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NULL, RDMA_PS_TCP, IB_QPT_RC);
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if (IS_ERR(cm_id))
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return PTR_ERR(cm_id);
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memset(&sin, 0, sizeof(sin));
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sin.sin_family = AF_INET;
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sin.sin_addr.s_addr = addr;
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/* rdma_bind_addr will only succeed for IB & iWARP devices */
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ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
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/* due to this, we will claim to support iWARP devices unless we
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check node_type. */
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if (ret || !cm_id->device ||
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cm_id->device->node_type != RDMA_NODE_IB_CA)
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ret = -EADDRNOTAVAIL;
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rdsdebug("addr %pI4 ret %d node type %d\n",
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&addr, ret,
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cm_id->device ? cm_id->device->node_type : -1);
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rdma_destroy_id(cm_id);
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return ret;
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}
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static void rds_ib_unregister_client(void)
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{
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ib_unregister_client(&rds_ib_client);
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/* wait for rds_ib_dev_free() to complete */
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flush_workqueue(rds_wq);
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}
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static void rds_ib_set_unloading(void)
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{
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atomic_set(&rds_ib_unloading, 1);
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}
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static bool rds_ib_is_unloading(struct rds_connection *conn)
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{
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struct rds_conn_path *cp = &conn->c_path[0];
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return (test_bit(RDS_DESTROY_PENDING, &cp->cp_flags) ||
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atomic_read(&rds_ib_unloading) != 0);
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}
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void rds_ib_exit(void)
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{
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rds_ib_set_unloading();
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synchronize_rcu();
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rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
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rds_ib_unregister_client();
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rds_ib_destroy_nodev_conns();
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rds_ib_sysctl_exit();
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rds_ib_recv_exit();
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rds_trans_unregister(&rds_ib_transport);
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rds_ib_mr_exit();
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}
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struct rds_transport rds_ib_transport = {
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.laddr_check = rds_ib_laddr_check,
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.xmit_path_complete = rds_ib_xmit_path_complete,
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.xmit = rds_ib_xmit,
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.xmit_rdma = rds_ib_xmit_rdma,
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.xmit_atomic = rds_ib_xmit_atomic,
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.recv_path = rds_ib_recv_path,
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.conn_alloc = rds_ib_conn_alloc,
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.conn_free = rds_ib_conn_free,
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.conn_path_connect = rds_ib_conn_path_connect,
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.conn_path_shutdown = rds_ib_conn_path_shutdown,
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|
.inc_copy_to_user = rds_ib_inc_copy_to_user,
|
|
.inc_free = rds_ib_inc_free,
|
|
.cm_initiate_connect = rds_ib_cm_initiate_connect,
|
|
.cm_handle_connect = rds_ib_cm_handle_connect,
|
|
.cm_connect_complete = rds_ib_cm_connect_complete,
|
|
.stats_info_copy = rds_ib_stats_info_copy,
|
|
.exit = rds_ib_exit,
|
|
.get_mr = rds_ib_get_mr,
|
|
.sync_mr = rds_ib_sync_mr,
|
|
.free_mr = rds_ib_free_mr,
|
|
.flush_mrs = rds_ib_flush_mrs,
|
|
.t_owner = THIS_MODULE,
|
|
.t_name = "infiniband",
|
|
.t_unloading = rds_ib_is_unloading,
|
|
.t_type = RDS_TRANS_IB
|
|
};
|
|
|
|
int rds_ib_init(void)
|
|
{
|
|
int ret;
|
|
|
|
INIT_LIST_HEAD(&rds_ib_devices);
|
|
|
|
ret = rds_ib_mr_init();
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = ib_register_client(&rds_ib_client);
|
|
if (ret)
|
|
goto out_mr_exit;
|
|
|
|
ret = rds_ib_sysctl_init();
|
|
if (ret)
|
|
goto out_ibreg;
|
|
|
|
ret = rds_ib_recv_init();
|
|
if (ret)
|
|
goto out_sysctl;
|
|
|
|
rds_trans_register(&rds_ib_transport);
|
|
|
|
rds_info_register_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
|
|
|
|
goto out;
|
|
|
|
out_sysctl:
|
|
rds_ib_sysctl_exit();
|
|
out_ibreg:
|
|
rds_ib_unregister_client();
|
|
out_mr_exit:
|
|
rds_ib_mr_exit();
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|