On Fri, 15 Apr 2005, John Baldwin wrote: > On Apr 15, 2005, at 8:27 AM, Andre Guibert de Bruet wrote: > >> (kgdb) bt <snip> >> #9 0xc0693a18 in trap_pfault (frame=0xe900c9d8, usermode=0, eva=0) >> at /usr/src/sys/i386/i386/trap.c:724 >> #10 0xc06935f8 in trap (frame= >> {tf_fs = -1068433400, tf_es = -1056636888, tf_ds = 40, tf_edi = >> -1066508002, tf_esi = 295, tf_ebp = -385824200, tf_isp = -385824252, tf_ebx >> = 0, tf_edx = 7, tf_ecx = -385824056, tf_eax = -989770368, tf_trapno = 12, >> tf_err = 0, tf_eip = -1068379561, tf_cs = 32, tf_eflags = 66178, tf_esp = >> -1067131464, tf_ss = -1056600064}) at /usr/src/sys/i386/i386/trap.c:414 >> #11 0xc067f91a in calltrap () at /usr/src/sys/i386/i386/exception.s:139 >> #12 0xc0510008 in idle_setup (dummy=0x0) at >> /usr/src/sys/kern/kern_idle.c:89 >> #13 0xc0645d6e in vm_fault (map=0xc1059000, vaddr=3222274048, >> fault_type=2 '\002', fault_flags=0) at /usr/src/sys/vm/vm_fault.c:295 > > You have a truly unique nested panic here that I haven't seen in a long time. > Somehow vm_map_lookup() is returning success, but it is setting > fs.first_object to NULL. This vm_map_lookup call would be performed before the callout that gets us here, right? >> #14 0xc06939c4 in trap_pfault (frame=0xe900cb9c, usermode=0, >> eva=3222274048) >> at /usr/src/sys/i386/i386/trap.c:713 >> #15 0xc06935f8 in trap (frame= >> {tf_fs = -989790200, tf_es = 40, tf_ds = -1068302296, tf_edi = >> -1072693248, tf_esi = -955760640, tf_ebp = -385823744, tf_isp = -385823800, >> tf_ebx = -1072988160, tf_edx = 1572864, tf_ecx = 319488, tf_eax = >> -116932608, tf_trapno = 12, tf_err = 3, tf_eip = -1066853962, tf_cs = 32, >> tf_eflags = 66054, tf_esp = 0, tf_ss = -986200024}) at >> /usr/src/sys/i386/i386/trap.c:414 >> #16 0xc067f91a in calltrap () at /usr/src/sys/i386/i386/exception.s:139 >> #17 0xc5010008 in ?? () >> #18 0x00000028 in ?? () >> #19 0xc0530028 in ogetkerninfo (td=0xc537c828, uap=0xc0100000) >> at /usr/src/sys/kern/kern_sysctl.c:1440 >> #20 0xc066da8c in vga_txtdraw (scp=0xc537c800, from=0, count=786432, >> flip=0) >> at /usr/src/sys/dev/syscons/scvgarndr.c:196 > > I'm not sure why you are bcopy'ing a bad KVA here. tf_eip in #15 points to i386/i386/support.s:490. This would seem to indicate that frame #16 is our call to generic_bcopy... (kgdb) l *0xc06919b6 0xc06919b6 is at /usr/src/sys/i386/i386/support.s:490. 485 cmpl %ecx,%eax /* overlapping && src < dst? */ 486 jb 1f 487 488 shrl $2,%ecx /* copy by 32-bit words */ 489 cld /* nope, copy forwards */ 490 rep 491 movsl 492 movl 20(%esp),%ecx 493 andl $3,%ecx /* any bytes left? */ 494 rep How do we get from ogetkerninfo to generic_bcopy? I don't see ogetkerninfo getting called anywhere in the syscons driver. As you suggested, it looks like we're overlapping a vm fault over our humble syscons code path. Where to from here? Cheers, Andy | Andre Guibert de Bruet | Enterprise Software Consultant > | Silicon Landmark, LLC. | http://siliconlandmark.com/ >Received on Fri Apr 15 2005 - 18:44:38 UTC
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