[BUG/REGRESSION] Kernel 4.5-rc1 on Acube Sam460ex AMCC 460ex Power PC motherboards

[Julian Margetson]

On 1/27/2016 3:34 PM, Dan Williams wrote:
> On Wed, Jan 27, 2016 at 2:18 AM, Julian Margetson <runaway at candw.ms> wrote:
>> On 1/26/2016 9:43 PM, Dan Williams wrote:
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 30991f83d0bf..c44e387130b2 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -1521,6 +1521,8 @@ static int insert_pfn(struct vm_area_struct
>> *vma, unsigned long addr,
>>                 entry = pte_mkdevmap(pfn_t_pte(pfn, prot));
>>         else
>>                 entry = pte_mkspecial(pfn_t_pte(pfn, prot));
>> +       pr_info("%s: entry: %#llx pfn: %#lx\n", __func__,
>> +                       (unsigned long long) entry, pfn_t_to_pfn(pfn));
>>         set_pte_at(mm, addr, pte, entry);
>>         update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
>>
>> ...of course for the passing case you'll need to drop the call to
>> pfn_t_to_pfn() and just print the pfn directly.
>>
>> Thank you for the help tracking this down, it's much appreciated.
>>
>> Happy to help out. Just need some guidance sometimes as I am relatively new
>> at this.
> No worries.
>
> So, below is the failing case, what does insert_pfn print in the
> passing case?  No need for the full log just the first few lines after
> starting X when running the commit before this failing one... (commit
> 69660fd797c3 "x86, mm: introduce _PAGE_DEVMAP").
>
> I'm still stumped given that PTE_RPN_SHIFT==PAGE_SHIFT in this
> configuration, so there's no 64-bit to 32-bit truncation to worry
> about...
Having a problem building .

   CALL    scripts/checksyscalls.sh
<stdin>:1307:2: warning: #warning syscall copy_file_range not implemented [-Wcpp]
   CHK     include/generated/compile.h
   CALL    arch/powerpc/kernel/systbl_chk.sh
   CC      mm/memory.o
   CHK     kernel/config_data.h
mm/memory.c: In function ‘insert_pfn’:
mm/memory.c:1520:9: error: implicit declaration of function ‘pfn_t_to_pfn’ [-Werror=implicit-function-declaration]
          pr_info("%s: entry: %#llx pfn: %#lx\n", __func__,
          ^
mm/memory.c:1520:9: warning: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 4 has type ‘int’ [-Wformat=]
cc1: some warnings being treated as errors
make[1]: *** [mm/memory.o] Error 1
make: *** [mm] Error 2
make: *** Waiting for unfinished jobs....


-----------------------------------------------------------------------------------------------------------------------------
15.802615] systemd[1]: Started Journal Service.
[   44.263074] Oops: Machine check, sig: 7 [#1]
[   44.267603] PREEMPT Canyonlands
[   44.270938] Modules linked in:
[   44.274182] CPU: 0 PID: 586 Comm: Xorg Tainted: G        W
4.5.0-rc1-Sam460ex #2
[   44.282538] task: ecd505c0 ti: efff2000 task.ti: ecd76000
[   44.288239] NIP: c0000cec LR: 1fb81404 CTR: 1fb814d0
[   44.293483] REGS: efff3f10 TRAP: 0214   Tainted: G        W
(4.5.0-rc1-Sam460ex)
[   44.301926] MSR: 00021000 <CE,ME>  CR: 84004242  XER: 00000000
[   44.308185]
GPR00: 1f045134 bfd0ce80 b7e7b6f0 b763dffc b6e54008 00000780 00000004
00000000
GPR08: 00000000 b763dffc b6e54010 ecf50000 ecf50000 00000009 00000000
00000780
GPR16: 00000000 00000020 00000000 00000000 00001e00 2079b638 00000438
b6e54008
GPR24: 00000780 bfd0ced8 20785770 b763e000 b763e000 b6e54008 1fc89ff4
00001e00
[   44.340039] NIP [c0000cec] DataTLBError44x+0x6c/0x90
[   44.345279] LR [1fb81404] 0x1fb81404
[   44.349053] Call Trace:
[   44.351631] Instruction dump:
[   44.354776] 7d7342a6 816b0040 7d92eaa6 7db00aa6 51ac063e 7d92eba6
7d9e0aa6 39a00009
[   44.363081] 518d57bc 554c6cfa 7d6c582e 556c0029 <4182003c> 514cbd38
816c0000 818c0004
[   44.524699] ---[ end trace 439fa29153308785 ]---
[   44.529322]
[   47.216536] insert_pfn: entry: 0x80ed246b pfn: 0x80ed2
[   47.221777] insert_pfn: entry: 0x80ed346b pfn: 0x80ed3
[   47.228485] insert_pfn: entry: 0x80ed446b pfn: 0x80ed4
[   47.237798] insert_pfn: entry: 0x80ed546b pfn: 0x80ed5
[   47.249809] insert_pfn: entry: 0x80ed646b pfn: 0x80ed6
[   47.257588] insert_pfn: entry: 0x80ed746b pfn: 0x80ed7
[   47.265879] insert_pfn: entry: 0x80ed846b pfn: 0x80ed8
[   47.275825] insert_pfn: entry: 0x80ed946b pfn: 0x80ed9
[   47.281437] insert_pfn: entry: 0x80eda46b pfn: 0x80eda
[   47.288113] insert_pfn: entry: 0x80edb46b pfn: 0x80edb
[   47.293660] insert_pfn: entry: 0x80edc46b pfn: 0x80edc
[   47.299834] insert_pfn: entry: 0x80edd46b pfn: 0x80edd
[   47.305223] insert_pfn: entry: 0x80ede46b pfn: 0x80ede
[   47.314891] insert_pfn: entry: 0x80edf46b pfn: 0x80edf
[   47.329777] insert_pfn: entry: 0x80ee046b pfn: 0x80ee0
[   47.339769] insert_pfn: entry: 0x80ee146b pfn: 0x80ee1
[   47.349777] Machine check in kernel mode.
[   47.353814] Data Write PLB Error

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