[patch 7/7] net_device list cleanup: debugging
From: Andrey Savochkin <hidden>
Date: 2006-07-03 16:32:01
Optional code to catch cases when loop cursor is used after for_each_netdev loop: often it's a sign of a bug, since it isn't guaranteed to point to a device. Signed-off-by: Andrey Savochkin <redacted> --- If anyone wants to keep this under some debug config option, let me know which one. netdevice.h | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletion(-)
--- ./include/linux/netdevice.h.vedevbase-dbg Mon Jul 3 16:16:51 2006
+++ ./include/linux/netdevice.h Mon Jul 3 16:16:51 2006@@ -560,7 +560,13 @@ extern struct net_device loopback_dev; extern struct list_head dev_base_head; /* All devices */ extern rwlock_t dev_base_lock; /* Device list lock */ -#define for_each_netdev(p) list_for_each_entry(p, &dev_base_head, dev_list) +#define for_each_netdev(pos) \ +for (pos = list_entry(dev_base_head.next, typeof(*pos), dev_list); \ + prefetch(pos->dev_list.next), \ + &pos->dev_list != &dev_base_head ? : \ + ({ void *__check_dev_use_after_for_each_netdev; \ + pos = __check_dev_use_after_for_each_netdev; 0; }); \ + pos = list_entry(pos->dev_list.next, typeof(*pos), dev_list)) /* * When possible, it is preferrable to use for_each_netdev() loop