On Thu, Aug 18, 2011 at 5:50 PM, Garrett Cooper <yaneg...@gmail.com> wrote: > When loading if_alc as a module on my netbook and running > /etc/rc.d/netif restart, I can deterministically panic my netbook with > the following message: > > ) at _bus_dmamap_sync+0x51 > alc_stop(c3dbb000,0,c0c51844,93a,80206910,...) at alc_stop+0x24e > alc_ioctl(c3d07400,80206910,c40423c0,c06a7935,c0914e3c,...) at alc_ioctl+0x22e > ifioctl(c45029c0,80206910,c40423c0,c40505c0,c4528c00,...) at ifioctl+0xc98 > soo_ioctl(c4574e00,80206910,c40423c0,c413e680,c40505c0,...) at soo_ioctl+0x401 > kern_ioctl(c40505c0,3,80206910,c40423c0,c40423c0,...) at kern_ioctl+0x1d7 > ioctl(c40505c0,e6ca3cec,e6ca3d28,c08e929d,0,...) at ioctl+0x118 > syscallenter(c40505c0,e6ca3ce4,e6ca3ce4,0,0,...) at syscallenter+0x23f > syscall(e6ca3d28) at syscall+0x2e > Xint0x80_syscall() at Xint0x80_syscall+0x21 > --- syscall (54kernel trap 12 with interrupts disabled > Kernel page fault with the following non-sleepable locks held: > exclusive sleep mutex alc0 (network driver) r = 0 (0xc3dbc608) locked > @ /usr/src/sys/modules/alc/../../dev/alc/if_alc.c:2362 > KDB: stack backtrace: > db_trace_self_wrapper(c08e727a,80,6e726500,74206c65,20706172,...) at > db_trace_self_wrapper+0x26 > kdb_backtrace(93a,0,ffffffff,c0ad6114,e6ca323c,...) at kdb_backtrace+0x2a > _witness_debugger(c08e9f67,e6ca3250,4,1,0,...) at _witness_debugger+0x1e > witness_warn(5,0,c0924fe1,c097df50,c3e42b00,...) at witness_warn+0x1f1 > trap(e6ca32dc) at trap+0x15a > calltrap() at calltrap+0x6 > > I tried to track down what the exact issue was, but I got lost > (the locking sort of looks ok to me, but I'm still not an expert with > mutex(9)). > I still have the vmcore and can provide more helpful details when > requested.
The locking itself is almost certainly fine. The error message is not very helpful, but what went wrong was the page fault. You just happen to panic on a witness warning before vm_fault can panic due to a bad address. The alc(4) maintainer would probably like info on the trap (line of code and where the bad pointer came from). Cheers, matthew _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
