From bbbab5ca835fb7676434815a47add8f2c696bec7 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 24 Oct 2007 13:58:57 +0200 Subject: [PATCH] natsemi: fix oops, link back netdevice from private-struct * Andrew Nelless wrote: > Hi, > > I booted up 2.6.24-rc1 this morning [Real early over a brew ;-)] and > was having a problems with multiple ~5 second hangs on SATA/drive init > (Something to do with "EH" something-or-other and resets but I'll > email in separately about it later unless its fixed by the time I get > the chance). > > Anyway, I went to fire up netconsole to get a decent log dump and hit > across the following nasty. Netconsole works fine in 2.6.23.1 with a > similar config and the same kernel parameters. > > A shot of the screen is the only method I could come up with to > capture the log, I hope that is OK, it is pretty readable. > > > The nasty: > http://andotnet.nfshost.com/linux/2.6.24-rc1-netconsole-nullderef.jpg the NULL dereference is here: (gdb) list *0xffffffff804a9504 0xffffffff804a9504 is in natsemi_poll (drivers/net/natsemi.c:717). 712 return count; 713 } 714 715 static inline void __iomem *ns_ioaddr(struct net_device *dev) 716 { 717 return (void __iomem *) dev->base_addr; 718 } 719 which is this code from natsemi.c: 2227 struct net_device *dev = np->dev; 2228 void __iomem * ioaddr = ns_ioaddr(dev); 2229 int work_done = 0; seems like the NAPI changes in -rc1 added an np->dev field but forgot to initialize it ... does the patch below fix the oops for you? Ingo --------------------> Subject: natsemi: fix oops, link back netdevice from private-struct From: Ingo Molnar this commit: commit bea3348eef27e6044b6161fd04c3152215f96411 Author: Stephen Hemminger Date: Wed Oct 3 16:41:36 2007 -0700 [NET]: Make NAPI polling independent of struct net_device objects. added np->dev to drivers/net/natsemi.c's struct netdev_private, but forgot to initialize that new field upon driver init. The result was a predictable NULL dereference oops the first time the hardware generated an interrupt. Reported-by: Andrew Nelless Signed-off-by: Ingo Molnar Signed-off-by: Jeff Garzik --- drivers/net/natsemi.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c index 953117152bbd..87cde062fd63 100644 --- a/drivers/net/natsemi.c +++ b/drivers/net/natsemi.c @@ -864,6 +864,7 @@ static int __devinit natsemi_probe1 (struct pci_dev *pdev, np = netdev_priv(dev); netif_napi_add(dev, &np->napi, natsemi_poll, 64); + np->dev = dev; np->pci_dev = pdev; pci_set_drvdata(pdev, dev);