Tmpfs panic in -current

[Kevin Lo]

Konstantin Belousov wrote:
> On Mon, Jun 25, 2012 at 10:03:28AM +0800, Kevin Lo wrote:
> > I've observed a panic in recent -current several times but I only
> > have a picture of the backtrace:
> > http://people.freebsd.org/~kevlo/panic_tmpfs.jpg
> > 
> > Does this look at all familiar to anyone?
> 
> Can you look up the line corresponding to tmpfs_reg_resize + 0x627 address
> in your kernel ?

Sure.

> The screenshot looks strange. The instruction on which the kernel trapped
> is int 0x28 which should not appear in the compiled code.

# gdb tmpfs.ko
(gdb) l *tmpfs_reg_resize+0x627
0xbf37 is in tmpfs_reg_resize (/usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_subr.c:1005).
1000    in /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_subr.c

In tmpfs_subr.c:
 999                         if (m != NULL) {
1000                                 if ((m->oflags & VPO_BUSY) != 0 ||
1001                                     m->busy != 0) {
1002                                         vm_page_sleep(m, "tmfssz");
1003                                         goto retry;
1004                                 }
1005                                 MPASS(m->valid == VM_PAGE_BITS_ALL);
1006                         } else if (vm_pager_has_page(uobj, idx, NULL, NU
LL)) {

Thanks!

	Kevin