On Sun, May 13, 2007 at 11:39:37PM -0700, David Miller wrote:
> From: Jarek Poplawski <[EMAIL PROTECTED]>
> Date: Mon, 14 May 2007 08:07:00 +0200
>
> > After sending this patch I was a little confused, when next
> > lockdep warning report appeared, and I thought - since this is
> > not enough, this patch could be dumped. But now I changed my
> > mind: there are really many possibilities of strange connections
> > between locks taken from vlans, ppp (with pppoe), multicasts etc.
> > - that every one possibility less is a gain here.
> ...
> > Of course, later, if somebody will find better solution, they could
> > be removed,
>
> I already suggested a better fix, you ignored it.
>
> For each unique netdev type, use a different locking class.
>
> That will fix this forever, anything else is a situation specific
> band-aid (but then again isn't that what every lockdep annotation is
> :-).
So, I guess, you thought about something like this, plus
additional annotations in specific situations like vlan
(but some hint is needed, how much of this should be
considered).
Jarek P.
--->
After initializing dev->_xmit_lock register_netdevice()
sets lockdep class according to dev->type.
Idea of this patch - by David Miller.
Signed-off-by: Jarek Poplawski <[EMAIL PROTECTED]>
---
diff -Nurp 2.6.22-/net/core/dev.c 2.6.22/net/core/dev.c
--- 2.6.22-/net/core/dev.c 2007-05-14 20:26:16.000000000 +0200
+++ 2.6.22/net/core/dev.c 2007-05-14 21:22:10.000000000 +0200
@@ -116,6 +116,7 @@
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/ctype.h>
+#include <linux/if_arp.h>
/*
* The list of packet types we will receive (as opposed to discard)
@@ -217,6 +218,73 @@ extern void netdev_unregister_sysfs(stru
#define netdev_unregister_sysfs(dev) do { } while(0)
#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+/*
+ * register_netdevice() inits dev->_xmit_lock and sets lockdep class
+ * according to dev->type
+ */
+static const unsigned short netdev_lock_type[] =
+ {ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
+ ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
+ ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
+ ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
+ ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
+ ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
+ ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
+ ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
+ ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
+ ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
+ ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
+ ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
+ ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
+ ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_VOID,
+ ARPHRD_NONE};
+
+static const char *netdev_lock_name[] =
+ {"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
+ "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
+ "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
+ "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
+ "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
+ "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
+ "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
+ "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
+ "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
+ "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
+ "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
+ "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
+ "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
+ "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_VOID",
+ "_xmit_NONE"};
+
+static struct lock_class_key
netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
+
+static inline unsigned short netdev_lock_pos(unsigned short dev_type)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
+ if (netdev_lock_type[i] == dev_type)
+ return i;
+ /* the last key is used by default */
+ return --i;
+}
+
+static inline void netdev_set_lockdep_class(spinlock_t *lock,
+ unsigned short dev_type)
+{
+ int i;
+
+ i = netdev_lock_pos(dev_type);
+ lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
+ netdev_lock_name[i]);
+}
+#else
+static inline void netdev_set_lockdep_class(spinlock_t *lock,
+ unsigned short dev_type)
+{
+}
+#endif
/*******************************************************************************
@@ -3001,6 +3069,7 @@ int register_netdevice(struct net_device
spin_lock_init(&dev->queue_lock);
spin_lock_init(&dev->_xmit_lock);
+ netdev_set_lockdep_class(&dev->_xmit_lock, dev->type);
dev->xmit_lock_owner = -1;
spin_lock_init(&dev->ingress_lock);
-
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