#include "packet.h"
struct sk_buff;
void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
bool dropped);
struct batadv_forw_packet *
batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing,
atomic_t *queue_left,
struct batadv_priv *bat_priv);
bool batadv_forw_packet_steal(struct batadv_forw_packet *packet, spinlock_t *l);
void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
struct batadv_forw_packet *forw_packet,
unsigned long send_time);
int batadv_send_skb_to_orig(struct sk_buff *skb,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if);
int batadv_send_skb_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
const u8 *dst_addr);
int batadv_send_broadcast_skb(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface);
int batadv_send_unicast_skb(struct sk_buff *skb,
struct batadv_neigh_node *neigh_node);
int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
const struct sk_buff *skb,
unsigned long delay,
bool own_packet);
void
batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
const struct batadv_hard_iface *hard_iface);
bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
struct sk_buff *skb,
struct batadv_orig_node *orig_node,
int packet_subtype);
int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
struct sk_buff *skb, int packet_type,
int packet_subtype,
struct batadv_orig_node *orig_node,
unsigned short vid);
int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
struct sk_buff *skb, int packet_type,
int packet_subtype, u8 *dst_hint,
unsigned short vid);
int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid);
/**
* batadv_send_skb_via_tt - send an skb via TT lookup
* @bat_priv: the bat priv with all the soft interface information
* @skb: the payload to send
* @dst_hint: can be used to override the destination contained in the skb
* @vid: the vid to be used to search the translation table
*
* Look up the recipient node for the destination address in the ethernet
* header via the translation table. Wrap the given skb into a batman-adv
* unicast header. Then send this frame to the according destination node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
static inline int batadv_send_skb_via_tt(struct batadv_priv *bat_priv,
struct sk_buff *skb, u8 *dst_hint,
unsigned short vid)
{
return batadv_send_skb_via_tt_generic(bat_priv, skb, BATADV_UNICAST, 0,
dst_hint, vid);
}
/**
* batadv_send_skb_via_tt_4addr - send an skb via TT lookup
* @bat_priv: the bat priv with all the soft interface information
* @skb: the payload to send
* @packet_subtype: the unicast 4addr packet subtype to use
* @dst_hint: can be used to override the destination contained in the skb
* @vid: the vid to be used to search the translation table
*
* Look up the recipient node for the destination address in the ethernet
* header via the translation table. Wrap the given skb into a batman-adv
* unicast-4addr header. Then send this frame to the according destination
* node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
static inline int batadv_send_skb_via_tt_4addr(struct batadv_priv *bat_priv,
struct sk_buff *skb,
int packet_subtype,
u8 *dst_hint,
unsigned short vid)
{
return batadv_send_skb_via_tt_generic(bat_priv, skb,
BATADV_UNICAST_4ADDR,
packet_subtype, dst_hint, vid);
}
#endif /* _NET_BATMAN_ADV_SEND_H_ */
h>Douglas Miller <dougmill@linux.vnet.ibm.com> | 2017-01-28 06:42:20 -0600 |
committer | Tejun Heo <tj@kernel.org> | 2017-01-28 07:49:42 -0500 |
commit | 966d2b04e070bc040319aaebfec09e0144dc3341 (patch) |
tree | 4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /net/openvswitch/vport-geneve.c |
parent | 1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff) |
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return
"true" IFF they acquire a reference. But the return value from
atomic_long_inc_not_zero() is a long and may have high bits set,
e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines
is bool so the reference may actually be acquired but the routines
return "false" which results in a reference leak since the caller
assumes it does not need to do a corresponding percpu_ref_put().
This was seen when performing CPU hotplug during I/O, as hangs in
blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start)
raced with percpu_ref_tryget (blk_mq_timeout_work).
Sample stack trace:
__switch_to+0x2c0/0x450
__schedule+0x2f8/0x970
schedule+0x48/0xc0
blk_mq_freeze_queue_wait+0x94/0x120
blk_mq_queue_reinit_work+0xb8/0x180
blk_mq_queue_reinit_prepare+0x84/0xa0
cpuhp_invoke_callback+0x17c/0x600
cpuhp_up_callbacks+0x58/0x150
_cpu_up+0xf0/0x1c0
do_cpu_up+0x120/0x150
cpu_subsys_online+0x64/0xe0
device_online+0xb4/0x120
online_store+0xb4/0xc0
dev_attr_store+0x68/0xa0
sysfs_kf_write+0x80/0xb0
kernfs_fop_write+0x17c/0x250
__vfs_write+0x6c/0x1e0
vfs_write+0xd0/0x270
SyS_write+0x6c/0x110
system_call+0x38/0xe0
Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS,
and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests.
However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0
and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set.
The fix is to make the tryget routines use an actual boolean internally instead
of the atomic long result truncated to a int.
Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints
Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751
Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Reviewed-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+