Revision 78c906e430b13d30a8cfbdef4ccbbe1686841a9e authored by Vlad Buslov on 31 August 2020, 13:17:29 UTC, committed by Saeed Mahameed on 05 November 2020, 20:17:05 UTC
In functions mlx5e_route_lookup_ipv{4|6}() route_dev can be arbitrary net device and not necessary mlx5 eswitch port representor. As such, in order to ensure that route_dev is not destroyed concurrent the code needs either explicitly take reference to the device before releasing reference to rtable instance or ensure that caller holds rtnl lock. First approach is chosen as a fix since rtnl lock dependency was intentionally removed from mlx5 TC layer. To prevent unprotected usage of route_dev in encap code take a reference to the device before releasing rt. Don't save direct pointer to the device in mlx5_encap_entry structure and use ifindex instead. Modify users of route_dev pointer to properly obtain the net device instance from its ifindex. Fixes: 61086f391044 ("net/mlx5e: Protect encap hash table with mutex") Fixes: 6707f74be862 ("net/mlx5e: Update hw flows when encap source mac changed") Signed-off-by: Vlad Buslov <vladbu@nvidia.com> Reviewed-by: Roi Dayan <roid@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
1 parent e68e28b
netprio_cgroup.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/core/netprio_cgroup.c Priority Control Group
*
* Authors: Neil Horman <nhorman@tuxdriver.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/cgroup.h>
#include <linux/rcupdate.h>
#include <linux/atomic.h>
#include <linux/sched/task.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
#include <net/sock.h>
#include <net/netprio_cgroup.h>
#include <linux/fdtable.h>
/*
* netprio allocates per-net_device priomap array which is indexed by
* css->id. Limiting css ID to 16bits doesn't lose anything.
*/
#define NETPRIO_ID_MAX USHRT_MAX
#define PRIOMAP_MIN_SZ 128
/*
* Extend @dev->priomap so that it's large enough to accommodate
* @target_idx. @dev->priomap.priomap_len > @target_idx after successful
* return. Must be called under rtnl lock.
*/
static int extend_netdev_table(struct net_device *dev, u32 target_idx)
{
struct netprio_map *old, *new;
size_t new_sz, new_len;
/* is the existing priomap large enough? */
old = rtnl_dereference(dev->priomap);
if (old && old->priomap_len > target_idx)
return 0;
/*
* Determine the new size. Let's keep it power-of-two. We start
* from PRIOMAP_MIN_SZ and double it until it's large enough to
* accommodate @target_idx.
*/
new_sz = PRIOMAP_MIN_SZ;
while (true) {
new_len = (new_sz - offsetof(struct netprio_map, priomap)) /
sizeof(new->priomap[0]);
if (new_len > target_idx)
break;
new_sz *= 2;
/* overflowed? */
if (WARN_ON(new_sz < PRIOMAP_MIN_SZ))
return -ENOSPC;
}
/* allocate & copy */
new = kzalloc(new_sz, GFP_KERNEL);
if (!new)
return -ENOMEM;
if (old)
memcpy(new->priomap, old->priomap,
old->priomap_len * sizeof(old->priomap[0]));
new->priomap_len = new_len;
/* install the new priomap */
rcu_assign_pointer(dev->priomap, new);
if (old)
kfree_rcu(old, rcu);
return 0;
}
/**
* netprio_prio - return the effective netprio of a cgroup-net_device pair
* @css: css part of the target pair
* @dev: net_device part of the target pair
*
* Should be called under RCU read or rtnl lock.
*/
static u32 netprio_prio(struct cgroup_subsys_state *css, struct net_device *dev)
{
struct netprio_map *map = rcu_dereference_rtnl(dev->priomap);
int id = css->id;
if (map && id < map->priomap_len)
return map->priomap[id];
return 0;
}
/**
* netprio_set_prio - set netprio on a cgroup-net_device pair
* @css: css part of the target pair
* @dev: net_device part of the target pair
* @prio: prio to set
*
* Set netprio to @prio on @css-@dev pair. Should be called under rtnl
* lock and may fail under memory pressure for non-zero @prio.
*/
static int netprio_set_prio(struct cgroup_subsys_state *css,
struct net_device *dev, u32 prio)
{
struct netprio_map *map;
int id = css->id;
int ret;
/* avoid extending priomap for zero writes */
map = rtnl_dereference(dev->priomap);
if (!prio && (!map || map->priomap_len <= id))
return 0;
ret = extend_netdev_table(dev, id);
if (ret)
return ret;
map = rtnl_dereference(dev->priomap);
map->priomap[id] = prio;
return 0;
}
static struct cgroup_subsys_state *
cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct cgroup_subsys_state *css;
css = kzalloc(sizeof(*css), GFP_KERNEL);
if (!css)
return ERR_PTR(-ENOMEM);
return css;
}
static int cgrp_css_online(struct cgroup_subsys_state *css)
{
struct cgroup_subsys_state *parent_css = css->parent;
struct net_device *dev;
int ret = 0;
if (css->id > NETPRIO_ID_MAX)
return -ENOSPC;
if (!parent_css)
return 0;
rtnl_lock();
/*
* Inherit prios from the parent. As all prios are set during
* onlining, there is no need to clear them on offline.
*/
for_each_netdev(&init_net, dev) {
u32 prio = netprio_prio(parent_css, dev);
ret = netprio_set_prio(css, dev, prio);
if (ret)
break;
}
rtnl_unlock();
return ret;
}
static void cgrp_css_free(struct cgroup_subsys_state *css)
{
kfree(css);
}
static u64 read_prioidx(struct cgroup_subsys_state *css, struct cftype *cft)
{
return css->id;
}
static int read_priomap(struct seq_file *sf, void *v)
{
struct net_device *dev;
rcu_read_lock();
for_each_netdev_rcu(&init_net, dev)
seq_printf(sf, "%s %u\n", dev->name,
netprio_prio(seq_css(sf), dev));
rcu_read_unlock();
return 0;
}
static ssize_t write_priomap(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
char devname[IFNAMSIZ + 1];
struct net_device *dev;
u32 prio;
int ret;
if (sscanf(buf, "%"__stringify(IFNAMSIZ)"s %u", devname, &prio) != 2)
return -EINVAL;
dev = dev_get_by_name(&init_net, devname);
if (!dev)
return -ENODEV;
cgroup_sk_alloc_disable();
rtnl_lock();
ret = netprio_set_prio(of_css(of), dev, prio);
rtnl_unlock();
dev_put(dev);
return ret ?: nbytes;
}
static int update_netprio(const void *v, struct file *file, unsigned n)
{
int err;
struct socket *sock = sock_from_file(file, &err);
if (sock) {
spin_lock(&cgroup_sk_update_lock);
sock_cgroup_set_prioidx(&sock->sk->sk_cgrp_data,
(unsigned long)v);
spin_unlock(&cgroup_sk_update_lock);
}
return 0;
}
static void net_prio_attach(struct cgroup_taskset *tset)
{
struct task_struct *p;
struct cgroup_subsys_state *css;
cgroup_sk_alloc_disable();
cgroup_taskset_for_each(p, css, tset) {
void *v = (void *)(unsigned long)css->id;
task_lock(p);
iterate_fd(p->files, 0, update_netprio, v);
task_unlock(p);
}
}
static struct cftype ss_files[] = {
{
.name = "prioidx",
.read_u64 = read_prioidx,
},
{
.name = "ifpriomap",
.seq_show = read_priomap,
.write = write_priomap,
},
{ } /* terminate */
};
struct cgroup_subsys net_prio_cgrp_subsys = {
.css_alloc = cgrp_css_alloc,
.css_online = cgrp_css_online,
.css_free = cgrp_css_free,
.attach = net_prio_attach,
.legacy_cftypes = ss_files,
};
static int netprio_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct netprio_map *old;
/*
* Note this is called with rtnl_lock held so we have update side
* protection on our rcu assignments
*/
switch (event) {
case NETDEV_UNREGISTER:
old = rtnl_dereference(dev->priomap);
RCU_INIT_POINTER(dev->priomap, NULL);
if (old)
kfree_rcu(old, rcu);
break;
}
return NOTIFY_DONE;
}
static struct notifier_block netprio_device_notifier = {
.notifier_call = netprio_device_event
};
static int __init init_cgroup_netprio(void)
{
register_netdevice_notifier(&netprio_device_notifier);
return 0;
}
subsys_initcall(init_cgroup_netprio);
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