On Wed, 05 Jan 2011 14:52:17 -0800 Roland Dreier wrote: > > More excitement from https://bugzilla.kernel.org/show_bug.cgi?id=20702 > > > > Anyone want to take a stab at it? I know I'd be appreciative. I am > > running a debug kernel with everything I could find and enable I even > > remotely thought might prove helpful. Nothing has jumped out yet though. > > A little late, but perhaps running with the patch below might help us > make a bit of progress. The idea is to dump the last /proc/net file > opened and closed, so we can at least have a clue as to where the crash > is coming from. This should add lines like > > last procfs open: /proc/2443/net/arp > last procfs close: /proc/2443/net/arp > > to the oops output, so maybe we can zero in on things after you get a > crash with this applied. > > - R. > > diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c > index 6e8752c..c67b8d6 100644 > --- a/arch/x86/kernel/dumpstack.c > +++ b/arch/x86/kernel/dumpstack.c > @@ -18,6 +18,7 @@ > > #include <asm/stacktrace.h> > > +void procfs_printk_last_file(void); > > int panic_on_unrecovered_nmi; > int panic_on_io_nmi; > @@ -283,6 +284,7 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err) > #endif > printk("\n"); > sysfs_printk_last_file(); > + procfs_printk_last_file(); > if (notify_die(DIE_OOPS, str, regs, err, > current->thread.trap_no, SIGSEGV) == NOTIFY_STOP) > return 1; > diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c > index 9020ac1..1801cc1 100644 > --- a/fs/proc/proc_net.c > +++ b/fs/proc/proc_net.c > @@ -26,6 +26,14 @@ > > #include "internal.h" > > +/* used in crash dumps to help with debugging */ > +static char last_procfs_open[PATH_MAX]; > +static char last_procfs_close[PATH_MAX]; > +void procfs_printk_last_file(void) > +{ > + printk(KERN_EMERG "last procfs open: %s\n", last_procfs_open); > + printk(KERN_EMERG "last procfs close: %s\n", last_procfs_close); Let's not mislead the reader of a crash dump, please. How about: + printk(KERN_EMERG "last /proc..net open: %s\n", last_procfs_open); + printk(KERN_EMERG "last /proc..net close: %s\n", last_procfs_close); > +} > > static struct net *get_proc_net(const struct inode *inode) > { > @@ -37,9 +45,14 @@ int seq_open_net(struct inode *ino, struct file *f, > { > struct net *net; > struct seq_net_private *p; > + char *n; > > BUG_ON(size < sizeof(*p)); > > + n = d_path(&f->f_path, last_procfs_open, sizeof(last_procfs_open)); > + if (!IS_ERR(n)) > + memmove(last_procfs_open, n, strlen(n) + 1); > + > net = get_proc_net(ino); > if (net == NULL) > return -ENXIO; > @@ -83,6 +96,11 @@ EXPORT_SYMBOL_GPL(single_open_net); > int seq_release_net(struct inode *ino, struct file *f) > { > struct seq_file *seq; > + char *n; > + > + n = d_path(&f->f_path, last_procfs_close, sizeof(last_procfs_close)); > + if (!IS_ERR(n)) > + memmove(last_procfs_close, n, strlen(n) + 1); > > seq = f->private_data; > > -- --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
