Re: [parisc-linux] Re: Kernel faults on boot

[Richard Hirst <rhirst@linuxcare.com>]

Just tried my new installer that tries to run the second stage installer
automatically on reboot.  Crashed the kernel in kfree(), called from
vc_resize() again.  I'm guessing there is something screwy about the
screenbuf allocation.  Possibly due to the first ones being allocated
from the bootmem allocator?

Richard


On Mon, Jun 11, 2001 at 01:16:36PM +0100, Richard Hirst wrote:
> On Mon, Jun 11, 2001 at 01:17:39PM +0200, Peter Weilbacher wrote:
> > Hmm, it seems that the numbers change every time, but here are the
> > ones from the last instance:
> > 
> > 	Kernel Fault: Code=15 regs=1051ca80 (Addr=1dc0ce18)
> > 
> > 	     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
> > 	PSW: 00000000000001000000000000001111
> > 	r0-3o 00000000 10236000 10193d70 1dc0cd18
> > 	r4-7o 146fc000 102fe13c 00000001 00000100
> > 	r8-11o 4020b1a8 00000000 00000004 146ff000
> > 	r12-15o 00000100 00000030 00003000 102fe138
> > 	r16-19o 00000080 1051c908 00000001 14786000
> > 	r20-23o 146fc000 102959f8 101da1d4 00000000
> > 	r24-27o 000000ff 1dc0ce18 146fc000 10268010
> > 	r28-31o 00001920 00000004 1051ccc0 10192c78
> > 	sr0-3o 00000000 0000012a 00000000 0000012a
> > 	sr4-7o 00000000 00000000 00000000 00000000
> > 
> > 	IASQ: 00000000 00000000 IAOQ: 10236234 10236238
> > 	 IIR: 0f221033    ISR: 00000000  IOR: 1dc0ce18
> > 	 ORIG_R28: 1005f210
> > 
> > Phew, quite a work to type all this stuff, I am glad that you are
> > not interested in the stack... Perhaps this is useful.
> 
> The 'o' chars are actually tabs, which are supposed to make the register
> dump line up.
> 
> IAOQ is the most important.  You can look up the value in the
> sti/sys_map file on the CD:
> 
> ...
> 10236204 T bcopy
> 10236228 T memcpy
> 1023624c T memmove
> ...
> 
> so it crashed in memcpy.  r2 is often the return address, so back to sys_map:
> 
> ...
> 10193a98 T vc_allocate
> 10193bc8 T vc_resize
> 10193ed8 t .L1003
> 10193f40 t .L1043
> 10193fcc T vc_disallocate
> ...
> 
> looks like memcpy was called from vc_resize().
> 
> r236,r25,r24,r23 are the call params, if they havn't been overwritten.
> 
> memcpy() disassembles as
> 
> 00000000 <memcpy>:
>    0:   37 18 3f ff     ldo -1(r24),r24
>    4:   87 1f 20 20     cmpib,= -1,r24,1c <memcpy+0x1c>
>    8:   08 1a 02 54     copy r26,r20
>    c:   0f 22 10 33     ldb,ma  1(sr0,r25),r19
>   10:   37 18 3f ff     ldo -1(r24),r24
>   14:   8f 1f 3f e5     cmpib,<> -1,r24,c <memcpy+0xc>
>   18:   0e 93 12 22     stb,ma  r19,1(sr0,r20)
>   1c:   e8 40 c0 00     bv r0(rp)
>   20:   08 1a 02 5c     copy r26,ret0
> 
> r26 = r20, so it failed on the first byte of the move, so call was
> 
>   memcpy(0x146fc000,0x1dc0ce18,0x100);
> 
> with 0x1dc0ce18 being an invalid address.
> 
> I guess that comes from this loop in drivers/char/screen.c:
> 
>   while (ol < scr_end) {
>           scr_memcpyw((unsigned short *) nl, (unsigned short *) ol, rlth);
>           if (rrem)
>                   scr_memsetw((void *)(nl + rlth), video_erase_char, rrem);
>           ol += osr;
>           nl += sr;
>   }
> 
> 
> At this point I'll stop and hope Helge can comment...
> 
> 
> > In the meantime I noticed that about every 6th time it boots up
> > without crashing, but the keyboard setting from the installation
> > (German) was obviously not saved.
> 
> Correct, keyboard config is broken in the release sti image.  If you
> manage to boot you could try
> 
> mv /bin/loadkeys /bin/loadkeys.old
> mv /bin/dumpkeys /bin/dumpkeys.old
> mv /etc/console-tools /etc/console-tools.old
> apt-get install console-data console-common console-tools console-tools-libs
> 
> 
> If that works, let me know and I'll add it to the errata.
> 
> Richard
>