Reply-To: akpm@linux-foundation.org

> On Fri, 9 Mar 2007 11:42:32 -0800 bugme-daemon@bugzilla.kernel.org wrote:
> http://bugzilla.kernel.org/show_bug.cgi?id=8161
> 
>            Summary: Crash after "Allocating PCI resources" -- used to work
>                     in 2.6.21-rc2
>     Kernel Version: 2.6.21-rc3
>             Status: NEW
>           Severity: normal
>              Owner: other_other@kernel-bugs.osdl.org
>          Submitter: no.hope@gmail.com
> 
> 
> Most recent kernel where this bug did *NOT* occur: 2.6.21-rc2
> Distribution: Gentoo
> Hardware Environment: Soekris net4521 embedded board, i486 AMD Elan, 64MB RAM
> Software Environment: Diskless boot using NFS
> Problem Description: Apparent kernel crash on boot
> 
> 2.6.21-rc3 crashes on boot:
> 
>   Booting 'Diskless Gentoo'
> 
> root (nd)
>  Filesystem type is tftp, using whole disk
> kernel /skr/boot/bzImage ip=dhcp root=/dev/nfs nfsroot=172.16.0.1:/diskless/skr
>  console=ttyS0,19200n81 earlyprintk=ttyS0,19200n81
>    [Linux-bzImage, setup=0x1400, size=0xf6e70]
> 
> Linux version 2.6.21-rc3 (root@aces) (gcc version 4.1.1 (Gentoo 4.1.1)) #1 Fri
> Mar 9 19:13:30 Local time zone must be set--see zic manua
> BIOS-provided physical RAM map:
> sanitize start
> sanitize end
> copy_e820_map() start: 0000000000000000 size: 000000000009fc00 end:
> 000000000009fc00 type: 1
> copy_e820_map() type is E820_RAM
> copy_e820_map() start: 000000000009fc00 size: 0000000000000400 end:
> 00000000000a0000 type: 2
> copy_e820_map() start: 00000000000f0000 size: 0000000000010000 end:
> 0000000000100000 type: 2
> copy_e820_map() start: 0000000000100000 size: 0000000003f00000 end:
> 0000000004000000 type: 1
> copy_e820_map() type is E820_RAM
> copy_e820_map() start: 00000000fff00000 size: 0000000000100000 end:
> 0000000100000000 type: 2
>  BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
>  BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
>  BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
>  BIOS-e820: 0000000000100000 - 0000000004000000 (usable)
>  BIOS-e820: 00000000fff00000 - 0000000100000000 (reserved)
> 64MB LOWMEM available.
> Zone PFN ranges:
>   DMA             0 ->     4096
>   Normal       4096 ->    16384
> early_node_map[1] active PFN ranges
>     0:        0 ->    16384
> DMI not present or invalid.
> Allocating PCI resources starting at 10000000 (gap: 04000000:fbf00000)
> Int 6: CR2 00000000  err 00000000  EIP c010676a  CS c02e0060  flags 00010046
> Stack: 00000000 c02a93a0 c02cdbd0 ffffffff c02daea9 c02dae40 c02c8865 c024a000
> 
> 
> lspci:
> 00:00.0 Host bridge: Advanced Micro Devices [AMD] ELanSC520 Microcontroller
> 00:11.0 CardBus bridge: Texas Instruments PCI1420
> 00:11.1 CardBus bridge: Texas Instruments PCI1420
> 00:12.0 Ethernet controller: National Semiconductor Corporation DP83815
> (MacPhyter) Ethernet Controller
> 00:13.0 Ethernet controller: National Semiconductor Corporation DP83815
> (MacPhyter) Ethernet Controller
> 
> 
> The same .config works fine with 2.6.21-rc2.

int6?  How weird.  Maybe your hardware has always been trying to do that,
but we made some change which enables interrupts too early, and/or we're
doing something in a different order.


Can you please send the 2.6.21-rc2 dmesg?

Adrian, another regression to track please.

Reply-To: ak@muc.de

> > Allocating PCI resources starting at 10000000 (gap: 04000000:fbf00000)
> > Int 6: CR2 00000000  err 00000000  EIP c010676a  CS c02e0060  flags 00010046
> > Stack: 00000000 c02a93a0 c02cdbd0 ffffffff c02daea9 c02dae40 c02c8865 c024a000
> > 
> > 
> > lspci:
> > 00:00.0 Host bridge: Advanced Micro Devices [AMD] ELanSC520 Microcontroller
> > 00:11.0 CardBus bridge: Texas Instruments PCI1420
> > 00:11.1 CardBus bridge: Texas Instruments PCI1420
> > 00:12.0 Ethernet controller: National Semiconductor Corporation DP83815
> > (MacPhyter) Ethernet Controller
> > 00:13.0 Ethernet controller: National Semiconductor Corporation DP83815
> > (MacPhyter) Ethernet Controller
> > 
> > 
> > The same .config works fine with 2.6.21-rc2.
> 
> int6?  How weird.  Maybe your hardware has always been trying to do that,
> but we made some change which enables interrupts too early, and/or we're
> doing something in a different order.

External hardware cannot cause such a low exception on x86. 
Int 6 is invalid op. Probably a BUG() or a stray function pointer of some sort.

gdb vmlinux
disas 0xc010676a

would be good.

-Andi

Created attachment 10682 [details]
2.6.21-rc2 dmesg

dmesg from working 2.6.21-rc2

Created attachment 10683 [details]
disas 0xc010676a (original build)

disas 0xc010676a of vmlinux in original post

I then enabled DEBUG_KERNEL, CONFIG_FRAME_POINTER, CONFIG_DEBUG_INFO and
recompiled. EIP changed and gdb disas gave me this:
0xc0107787 <sched_clock+0>:     push   %ebp
0xc0107788 <sched_clock+1>:     mov    %esp,%ebp
0xc010778a <sched_clock+3>:     push   %esi
0xc010778b <sched_clock+4>:     push   %ebx
0xc010778c <sched_clock+5>:     cmpl   $0x0,0xc02fbca8
0xc0107793 <sched_clock+12>:    je     0xc01077ba <sched_clock+51>
0xc0107795 <sched_clock+14>:    imul   $0x989680,0xc02b9804,%ecx
0xc010779f <sched_clock+24>:    mov    $0x989680,%eax
0xc01077a4 <sched_clock+29>:    mull   0xc02b9800
0xc01077aa <sched_clock+35>:    lea    (%ecx,%edx,1),%edx
0xc01077ad <sched_clock+38>:    add    $0xd964b800,%eax
0xc01077b2 <sched_clock+43>:    adc    $0xff6769c5,%edx
0xc01077b8 <sched_clock+49>:    jmp    0xc01077d3 <sched_clock+76>
0xc01077ba <sched_clock+51>:    rdtsc
0xc01077bc <sched_clock+53>:    mov    0xc02d4334,%ecx
0xc01077c2 <sched_clock+59>:    mov    %edx,%esi
0xc01077c4 <sched_clock+61>:    imul   %ecx,%esi
0xc01077c7 <sched_clock+64>:    mul    %ecx
0xc01077c9 <sched_clock+66>:    lea    (%esi,%edx,1),%edx
0xc01077cc <sched_clock+69>:    shrd   $0xa,%edx,%eax
0xc01077d0 <sched_clock+73>:    shr    $0xa,%edx
0xc01077d3 <sched_clock+76>:    pop    %ebx
0xc01077d4 <sched_clock+77>:    pop    %esi
0xc01077d5 <sched_clock+78>:    pop    %ebp
0xc01077d6 <sched_clock+79>:    ret

Then I disabled DEBUG_KERNEL and got this:
Allocating PCI resources starting at 10000000 (gap: 04000000:fbf00000)
Int 6: CR2 00000000  err 00000000  EIP c01075a2  CS c02f0060  flags 00010046
Stack: 00000000 c02ae3a0 c02da61d ffffffff c02e7aa9 c02e7a40 c02d286a c024d000

(gdb) disassemble 0xc01075a2
No function contains specified address.

I tried to use RDTSC on your CPU which it probably doesn't support
This should be already fixed in my patch queue

Cannot close the bug because I don't own it.

Andi, you should be able to "accept" it and then close it.

RDTSC is indeed unsupported by Elan

Fixed in Linus' tree (and will therefore be fixed in 2.6.21-rc5).