linux/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h

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/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2013-2014, 2016-2018 The Linux Foundation. All rights reserved.
*
* RMNET Data configuration engine
*/
#include <linux/skbuff.h>
#include <net/gro_cells.h>
#ifndef _RMNET_CONFIG_H_
#define _RMNET_CONFIG_H_
#define RMNET_MAX_LOGICAL_EP 255
struct rmnet_endpoint {
u8 mux_id;
struct net_device *egress_dev;
struct hlist_node hlnode;
};
/* One instance of this structure is instantiated for each real_dev associated
* with rmnet.
*/
struct rmnet_port {
struct net_device *dev;
u32 data_format;
u8 nr_rmnet_devs;
u8 rmnet_mode;
struct hlist_head muxed_ep[RMNET_MAX_LOGICAL_EP];
struct net_device *bridge_ep;
};
extern struct rtnl_link_ops rmnet_link_ops;
struct rmnet_vnd_stats {
u64 rx_pkts;
u64 rx_bytes;
u64 tx_pkts;
u64 tx_bytes;
u32 tx_drops;
};
struct rmnet_pcpu_stats {
struct rmnet_vnd_stats stats;
struct u64_stats_sync syncp;
};
struct rmnet_priv_stats {
u64 csum_ok;
u64 csum_valid_unset;
u64 csum_validation_failed;
u64 csum_err_bad_buffer;
u64 csum_err_invalid_ip_version;
u64 csum_err_invalid_transport;
u64 csum_fragmented_pkt;
u64 csum_skipped;
u64 csum_sw;
};
struct rmnet_priv {
u8 mux_id;
struct net_device *real_dev;
struct rmnet_pcpu_stats __percpu *pcpu_stats;
struct gro_cells gro_cells;
struct rmnet_priv_stats stats;
};
net: rmnet: fix suspicious RCU usage rmnet_get_port() internally calls rcu_dereference_rtnl(), which checks RTNL. But rmnet_get_port() could be called by packet path. The packet path is not protected by RTNL. So, the suspicious RCU usage problem occurs. Test commands: modprobe rmnet ip netns add nst ip link add veth0 type veth peer name veth1 ip link set veth1 netns nst ip link add rmnet0 link veth0 type rmnet mux_id 1 ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1 ip netns exec nst ip link set veth1 up ip netns exec nst ip link set rmnet1 up ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1 ip link set veth0 up ip link set rmnet0 up ip a a 192.168.100.1/24 dev rmnet0 ping 192.168.100.2 Splat looks like: [ 146.630958][ T1174] WARNING: suspicious RCU usage [ 146.631735][ T1174] 5.6.0-rc1+ #447 Not tainted [ 146.632387][ T1174] ----------------------------- [ 146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() ! [ 146.634742][ T1174] [ 146.634742][ T1174] other info that might help us debug this: [ 146.634742][ T1174] [ 146.645992][ T1174] [ 146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1 [ 146.646937][ T1174] 5 locks held by ping/1174: [ 146.647609][ T1174] #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980 [ 146.662463][ T1174] #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150 [ 146.671696][ T1174] #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940 [ 146.673064][ T1174] #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150 [ 146.690358][ T1174] #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020 [ 146.699875][ T1174] [ 146.699875][ T1174] stack backtrace: [ 146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ #447 [ 146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 146.706565][ T1174] Call Trace: [ 146.707102][ T1174] dump_stack+0x96/0xdb [ 146.708007][ T1174] rmnet_get_port.part.9+0x76/0x80 [rmnet] [ 146.709233][ T1174] rmnet_egress_handler+0x107/0x420 [rmnet] [ 146.710492][ T1174] ? sch_direct_xmit+0x1e2/0x1020 [ 146.716193][ T1174] rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet] [ 146.717012][ T1174] dev_hard_start_xmit+0x160/0x740 [ 146.717854][ T1174] sch_direct_xmit+0x265/0x1020 [ 146.718577][ T1174] ? register_lock_class+0x14d0/0x14d0 [ 146.719429][ T1174] ? dev_watchdog+0xac0/0xac0 [ 146.723738][ T1174] ? __dev_queue_xmit+0x15fd/0x2940 [ 146.724469][ T1174] ? lock_acquire+0x164/0x3b0 [ 146.725172][ T1174] __dev_queue_xmit+0x20c7/0x2940 [ ... ] Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27 12:24:45 +00:00
struct rmnet_port *rmnet_get_port_rcu(struct net_device *real_dev);
struct rmnet_endpoint *rmnet_get_endpoint(struct rmnet_port *port, u8 mux_id);
int rmnet_add_bridge(struct net_device *rmnet_dev,
struct net_device *slave_dev,
struct netlink_ext_ack *extack);
int rmnet_del_bridge(struct net_device *rmnet_dev,
struct net_device *slave_dev);
#endif /* _RMNET_CONFIG_H_ */