[Powerpc/SLQB] Next June 06 : BUG during scsi initialization

[Sachin Sant <sachinp@in.ibm.com>]

Sachin Sant wrote:
> Today's Next tree failed to boot on a Power6 box with following BUG :
>
> BUG: spinlock bad magic on CPU#1, modprobe/63
> Unable to handle kernel paging request for data at address 0xffffc994838
> Faulting instruction address: 0xc00000000035f5a8
> Oops: Kernel access of bad area, sig: 11 [#1]
> SMP NR_CPUS=1024 DEBUG_PAGEALLOC NUMA pSeries
> Modules linked in: scsi_mod(+)
> NIP: c00000000035f5a8 LR: c00000000035f58c CTR: 0000000000136f8c
> REGS: c0000000c7d03500 TRAP: 0300   Not tainted  
> (2.6.30-rc5-autotest-next-20090511)
> MSR: 8000000000009032 <EE,ME,IR,DR>  CR: 28222484  XER: 0000000f
> DAR: 00000ffffc994838, DSISR: 0000000040000000
> TASK = c0000000c7cf0a80[63] 'modprobe' THREAD: c0000000c7d00000 CPU: 1
> GPR00: c00000000035f58c c0000000c7d03780 c000000000aaeed8 
> 0000000000000031 GPR04: 0000000000000000 00000000585cf4e0 
> 0000000000673580 80000000565a6cc0 GPR08: 0000000000000000 
> c0000000009ebf50 0000000000000000 c0000000009ebf38 GPR12: 
> 0000000028222482 c000000000b82600 0000000000000000 0000000000000000 
> GPR16: 0000000000000000 0000000000000000 0000000000000000 
> 0000000000000000 GPR20: 0000000000000018 ffffffffffffffff 
> c0000000009bbe40 0000000000000010 GPR24: 0000000000210d00 
> c0000000c6caff80 c0000000dfc732a0 c000000000f61380 GPR28: 
> c0000000007c8350 c0000000008a4280 c000000000a2f928 00000ffffc994550 
> NIP [c00000000035f5a8] .spin_bug+0x90/0xd4
> LR [c00000000035f58c] .spin_bug+0x74/0xd4
> Call Trace:
> [c0000000c7d03780] [c00000000035f58c] .spin_bug+0x74/0xd4 (unreliable)
> [c0000000c7d03810] [c00000000035f890] ._raw_spin_lock+0x48/0x184
> [c0000000c7d038b0] [c0000000005d67d8] ._spin_lock+0x10/0x24
> [c0000000c7d03920] [c00000000013fbdc] .__slab_alloc_page+0x344/0x3cc
> [c0000000c7d039e0] [c000000000141168] .kmem_cache_alloc+0x13c/0x21c
> [c0000000c7d03aa0] [c000000000141b04] .kmem_cache_create+0x294/0x2a8
> [c0000000c7d03b90] [d000000000ea14cc] .scsi_init_queue+0x38/0x170 
> [scsi_mod]
> [c0000000c7d03c20] [d000000000ea13c8] .init_scsi+0x1c/0xe8 [scsi_mod]
> [c0000000c7d03ca0] [c0000000000092c0] .do_one_initcall+0x80/0x19c
> [c0000000c7d03d90] [c0000000000c0540] .SyS_init_module+0xe0/0x244
> [c0000000c7d03e30] [c000000000008534] syscall_exit+0x0/0x40
> Instruction dump:
> 7f84e378 e87e8020 38c604d0 e8e902ea 4827fced 60000000 2fbf0000 
> 80bd0004 409e0010 e8de8028 38e0ffff 4800000c <e8ff02ea> 38df04d0 
> 7fa4eb78 811d0008 ---[ end trace f725820a6fa9dbb7 ]---
> /init: line 21:    63 Segmentation fault      modprobe $file
>
Nick, Pekka

I can still recreate this bug on a Power 6 hardware with today's next tree.
I can recreate this problem at will.
Let me know if i can help in debugging this problem.

Thanks
-Sachin

-- 

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Sachin Sant
IBM Linux Technology Center
India Systems and Technology Labs
Bangalore, India
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