From a41778694806ac1ccd4b1dafed1abef8d5ba98ac Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 28 Nov 2010 21:43:02 +0000 Subject: [PATCH] xps: add __rcu annotations Avoid sparse warnings : add __rcu annotations and use rcu_dereference_protected() where necessary. Signed-off-by: Eric Dumazet Cc: Tom Herbert Signed-off-by: David S. Miller --- include/linux/netdevice.h | 4 ++-- net/core/net-sysfs.c | 24 +++++++++++++++--------- 2 files changed, 17 insertions(+), 11 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 9ae4544f0cf..4b0c7f3aa32 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -622,7 +622,7 @@ struct xps_map { */ struct xps_dev_maps { struct rcu_head rcu; - struct xps_map *cpu_map[0]; + struct xps_map __rcu *cpu_map[0]; }; #define XPS_DEV_MAPS_SIZE (sizeof(struct xps_dev_maps) + \ (nr_cpu_ids * sizeof(struct xps_map *))) @@ -1049,7 +1049,7 @@ struct net_device { spinlock_t tx_global_lock; #ifdef CONFIG_XPS - struct xps_dev_maps *xps_maps; + struct xps_dev_maps __rcu *xps_maps; #endif /* These may be needed for future network-power-down code. */ diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 35ef42fa0cf..f85cee3d869 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -899,6 +899,8 @@ static void xps_dev_maps_release(struct rcu_head *rcu) } static DEFINE_MUTEX(xps_map_mutex); +#define xmap_dereference(P) \ + rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex)) static ssize_t store_xps_map(struct netdev_queue *queue, struct netdev_queue_attribute *attribute, @@ -935,11 +937,12 @@ static ssize_t store_xps_map(struct netdev_queue *queue, mutex_lock(&xps_map_mutex); - dev_maps = dev->xps_maps; + dev_maps = xmap_dereference(dev->xps_maps); for_each_possible_cpu(cpu) { - new_map = map = dev_maps ? dev_maps->cpu_map[cpu] : NULL; - + map = dev_maps ? + xmap_dereference(dev_maps->cpu_map[cpu]) : NULL; + new_map = map; if (map) { for (pos = 0; pos < map->len; pos++) if (map->queues[pos] == index) @@ -975,13 +978,14 @@ static ssize_t store_xps_map(struct netdev_queue *queue, else new_map = NULL; } - new_dev_maps->cpu_map[cpu] = new_map; + RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], new_map); } /* Cleanup old maps */ for_each_possible_cpu(cpu) { - map = dev_maps ? dev_maps->cpu_map[cpu] : NULL; - if (map && new_dev_maps->cpu_map[cpu] != map) + map = dev_maps ? + xmap_dereference(dev_maps->cpu_map[cpu]) : NULL; + if (map && xmap_dereference(new_dev_maps->cpu_map[cpu]) != map) call_rcu(&map->rcu, xps_map_release); if (new_dev_maps->cpu_map[cpu]) nonempty = 1; @@ -1007,7 +1011,9 @@ error: if (new_dev_maps) for_each_possible_cpu(i) - kfree(new_dev_maps->cpu_map[i]); + kfree(rcu_dereference_protected( + new_dev_maps->cpu_map[i], + 1)); kfree(new_dev_maps); free_cpumask_var(mask); return -ENOMEM; @@ -1033,11 +1039,11 @@ static void netdev_queue_release(struct kobject *kobj) index = get_netdev_queue_index(queue); mutex_lock(&xps_map_mutex); - dev_maps = dev->xps_maps; + dev_maps = xmap_dereference(dev->xps_maps); if (dev_maps) { for_each_possible_cpu(i) { - map = dev_maps->cpu_map[i]; + map = xmap_dereference(dev_maps->cpu_map[i]); if (!map) continue; -- 2.11.4.GIT