[PATCH] powerpc/mm: Remove DEBUG_VM_PGTABLE support on ppc64

[Christophe Leroy]

Le 01/09/2020 à 10:15, Christophe Leroy a écrit :
> 
> 
> Le 01/09/2020 à 10:12, Aneesh Kumar K.V a écrit :
>> On 9/1/20 1:40 PM, Christophe Leroy wrote:
>>>
>>>
>>> Le 01/09/2020 à 10:02, Aneesh Kumar K.V a écrit :
>>>> The test is broken w.r.t page table update rules and results in kernel
>>>> crash as below. Disable the support untill we get the tests updated.
>>>>
>>>>
>>>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
>>>
>>> Any Fixes: tag ?
>>>
>>>> ---
>>>>   arch/powerpc/Kconfig | 1 -
>>>>   1 file changed, 1 deletion(-)
>>>>
>>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>>> index 65bed1fdeaad..787e829b6f25 100644
>>>> --- a/arch/powerpc/Kconfig
>>>> +++ b/arch/powerpc/Kconfig
>>>> @@ -116,7 +116,6 @@ config PPC
>>>>       #
>>>>       select ARCH_32BIT_OFF_T if PPC32
>>>>       select ARCH_HAS_DEBUG_VIRTUAL
>>>> -    select ARCH_HAS_DEBUG_VM_PGTABLE
>>>
>>>
>>> You say you remove support for ppc64 but you are removing it for both 
>>> PPC64 and PPC32. Should you replace the line by:
>>
>> Does it work on PPC32 with DEBUG_VM enabled? I was expecting it will 
>> be broken there too.
> 
> I was wondering. I have just started a build to test that on my 8xx. 
> I'll tell you before noon (Paris).
> 

There are warnings but it boots OK. So up to you, but if you deactivate 
it for both PPC32 and PPC64, say so in the subject like.

[    7.065399] debug_vm_pgtable: [debug_vm_pgtable         ]: Validating 
architecture page table helpers
[    7.075155] ------------[ cut here ]------------
[    7.079590] WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:185 
set_pte_at+0x20/0xf4
[    7.087542] CPU: 0 PID: 1 Comm: swapper Not tainted 
5.9.0-rc2-s3k-dev-01348-g283e890ee4ad #3933
[    7.096122] NIP:  c000f634 LR: c07440f8 CTR: 00000000
[    7.101124] REGS: c9023c50 TRAP: 0700   Not tainted 
(5.9.0-rc2-s3k-dev-01348-g283e890ee4ad)
[    7.109445] MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 53000339  XER: 80006100
[    7.116072]
[    7.116072] GPR00: c07440f8 c9023d08 c60e4000 c6ba4000 1efac000 
c6ba8eb0 c9023da8 00000001
[    7.116072] GPR08: 00000004 007346c9 c6ba8ebc 00000000 93000333 
00000000 c000390c 00000000
[    7.116072] GPR16: c0840000 00000ec9 000001ec 00734000 06ba8000 
c6bb0000 c05f43e8 1efac000
[    7.116072] GPR24: fffffff0 c6b96d08 c6ba8eac c6ba4000 1efac000 
007346c9 c6ba8eb0 007346c9
[    7.150796] NIP [c000f634] set_pte_at+0x20/0xf4
[    7.155274] LR [c07440f8] pte_advanced_tests+0xec/0x2bc
[    7.160401] Call Trace:
[    7.162831] [c9023d08] [c080db94] 0xc080db94 (unreliable)
[    7.168183] [c9023d28] [c07440f8] pte_advanced_tests+0xec/0x2bc
[    7.174036] [c9023dd8] [c0744498] debug_vm_pgtable+0x1d0/0x668
[    7.179827] [c9023e98] [c0734cd4] do_one_initcall+0x8c/0x1cc
[    7.185405] [c9023ef8] [c0735008] kernel_init_freeable+0x178/0x1d0
[    7.191511] [c9023f28] [c0003920] kernel_init+0x14/0x114
[    7.196763] [c9023f38] [c000e184] ret_from_kernel_thread+0x14/0x1c
[    7.202818] Instruction dump:
[    7.205754] bba10014 7c0803a6 38210020 4e800020 7c0802a6 9421ffe0 
bfc10018 90010024
[    7.213412] 83e60000 81250000 71270001 41820008 <0fe00000> 73e90040 
41820080 73ea0001
[    7.221249] ---[ end trace 95bbebcafa22d0f7 ]---
[    7.226049] ------------[ cut here ]------------
[    7.230438] WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:185 
set_pte_at+0x20/0xf4
[    7.238410] CPU: 0 PID: 1 Comm: swapper Tainted: G        W 
5.9.0-rc2-s3k-dev-01348-g283e890ee4ad #3933
[    7.248363] NIP:  c000f634 LR: c0744218 CTR: 00000000
[    7.253368] REGS: c9023c50 TRAP: 0700   Tainted: G        W 
(5.9.0-rc2-s3k-dev-01348-g283e890ee4ad)
[    7.263064] MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 53000335  XER: a0006100
[    7.269690]
[    7.269690] GPR00: c0744218 c9023d08 c60e4000 c6ba4000 1efac000 
c6ba8eb0 c9023da8 00000001
[    7.269690] GPR08: 00000000 007341c9 00000000 007341c9 93000333 
00000000 c000390c 00000000
[    7.269690] GPR16: c0840000 00000ec9 000001ec 00734000 06ba8000 
c6bb0000 c05f43e8 1efac000
[    7.269690] GPR24: fffffff0 c6b96d08 c6ba8eac c6ba4000 1efac000 
007346c9 c6ba8eb0 007346c9
[    7.304418] NIP [c000f634] set_pte_at+0x20/0xf4
[    7.308892] LR [c0744218] pte_advanced_tests+0x20c/0x2bc
[    7.314105] Call Trace:
[    7.316535] [c9023d08] [c080db94] 0xc080db94 (unreliable)
[    7.321888] [c9023d28] [c0744218] pte_advanced_tests+0x20c/0x2bc
[    7.327826] [c9023dd8] [c0744498] debug_vm_pgtable+0x1d0/0x668
[    7.333613] [c9023e98] [c0734cd4] do_one_initcall+0x8c/0x1cc
[    7.339196] [c9023ef8] [c0735008] kernel_init_freeable+0x178/0x1d0
[    7.345300] [c9023f28] [c0003920] kernel_init+0x14/0x114
[    7.350551] [c9023f38] [c000e184] ret_from_kernel_thread+0x14/0x1c
[    7.356609] Instruction dump:
[    7.359545] bba10014 7c0803a6 38210020 4e800020 7c0802a6 9421ffe0 
bfc10018 90010024
[    7.367203] 83e60000 81250000 71270001 41820008 <0fe00000> 73e90040 
41820080 73ea0001
[    7.375039] ---[ end trace 95bbebcafa22d0f8 ]---
[    7.379783] ------------[ cut here ]------------
[    7.384228] WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:276 
set_huge_pte_at+0x104/0x134
[    7.392803] CPU: 0 PID: 1 Comm: swapper Tainted: G        W 
5.9.0-rc2-s3k-dev-01348-g283e890ee4ad #3933
[    7.402756] NIP:  c000f8fc LR: c074465c CTR: 00000000
[    7.407761] REGS: c9023d00 TRAP: 0700   Tainted: G        W 
(5.9.0-rc2-s3k-dev-01348-g283e890ee4ad)
[    7.417456] MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 53000339  XER: a0006100
[    7.424082]
[    7.424082] GPR00: c074465c c9023db8 c60e4000 c6ba4000 000001ec 
c6ba8eb0 c9023e48 00000001
[    7.424082] GPR08: c6ba90ac 0000000b 007346c9 007341c9 93000333 
00000000 c000390c 00000000
[    7.424082] GPR16: c0840000 c6ba8eac 000001ec 00734000 06ba8000 
c6bb0000 c05f43e8 1efac000
[    7.424082] GPR24: c7fb39a0 c6ba8000 c6b96d08 000001cd 000006c9 
c0840000 007346c9 00000080
[    7.458810] NIP [c000f8fc] set_huge_pte_at+0x104/0x134
[    7.463885] LR [c074465c] debug_vm_pgtable+0x394/0x668
[    7.468928] Call Trace:
[    7.471358] [c9023db8] [c6ba8000] 0xc6ba8000 (unreliable)
[    7.476709] [c9023dd8] [c074465c] debug_vm_pgtable+0x394/0x668
[    7.482497] [c9023e98] [c0734cd4] do_one_initcall+0x8c/0x1cc
[    7.488081] [c9023ef8] [c0735008] kernel_init_freeable+0x178/0x1d0
[    7.494182] [c9023f28] [c0003920] kernel_init+0x14/0x114
[    7.499436] [c9023f38] [c000e184] ret_from_kernel_thread+0x14/0x1c
[    7.505494] Instruction dump:
[    7.508429] 7d2a482e 712a0800 40a2ff78 812204b4 2f890000 419e0014 
812900a0 55290034
[    7.516088] 2b890400 419e0014 57de06b0 4bffff54 <0fe00000> 4bffff3c 
7fa3eb78 90a10008
[    7.523925] ---[ end trace 95bbebcafa22d0f9 ]---


Christophe