Re: [PATCH V2 2/2] mm/pgtable/debug: Add test validating architecture page table helpers

Christophe Leroy
2019-09-12T15:52:21Z

Le 12/09/2019 à 17:36, Christophe Leroy a écrit :
>
>
> Le 12/09/2019 à 17:00, Christophe Leroy a écrit :
>>
>>
>> On 09/12/2019 06:02 AM, Anshuman Khandual wrote:
>>> This adds a test module which will validate architecture page table
>>> helpers
>>> and accessors regarding compliance with generic MM semantics
>>> expectations.
>>> This will help various architectures in validating changes to the
>>> existing
>>> page table helpers or addition of new ones.
>>>
>>> Test page table and memory pages creating it's entries at various
>>> level are
>>> all allocated from system memory with required alignments. If memory
>>> pages
>>> with required size and alignment could not be allocated, then all
>>> depending
>>> individual tests are skipped.
>>
>> Build failure on powerpc book3s/32. This is because asm/highmem.h is
>> missing. It can't be included from asm/book3s/32/pgtable.h because it
>> creates circular dependency. So it has to be included from
>> mm/arch_pgtable_test.c
>
> In fact it is <linux/highmem.h> that needs to be added, adding
> <asm/highmem.h> directly provokes build failure at link time.
>

I get the following failure,

[ 0.704685] ------------[ cut here ]------------
[ 0.709239] initcall arch_pgtable_tests_init+0x0/0x228 returned with
preemption imbalance
[ 0.717539] WARNING: CPU: 0 PID: 1 at init/main.c:952
do_one_initcall+0x18c/0x1d4
[ 0.724922] CPU: 0 PID: 1 Comm: swapper Not tainted
5.3.0-rc7-s3k-dev-00880-g28fd02a838e5-dirty #2307
[ 0.734070] NIP: c070e674 LR: c070e674 CTR: c001292c
[ 0.739084] REGS: df4a5dd0 TRAP: 0700 Not tainted
(5.3.0-rc7-s3k-dev-00880-g28fd02a838e5-dirty)
[ 0.747975] MSR: 00029032 <EE,ME,IR,DR,RI> CR: 28000222 XER: 00000000
[ 0.754628]
[ 0.754628] GPR00: c070e674 df4a5e88 df4a0000 0000004e 0000000a
00000000 000000ca 38207265
[ 0.754628] GPR08: 00001032 00000800 00000000 00000000 22000422
00000000 c0004a7c 00000000
[ 0.754628] GPR16: 00000000 00000000 00000000 00000000 00000000
c0810000 c0800000 c0816f30
[ 0.754628] GPR24: c070dc20 c074702c 00000006 0000009c 00000000
c0724494 c074e140 00000000
[ 0.789339] NIP [c070e674] do_one_initcall+0x18c/0x1d4
[ 0.794435] LR [c070e674] do_one_initcall+0x18c/0x1d4
[ 0.799437] Call Trace:
[ 0.801867] [df4a5e88] [c070e674] do_one_initcall+0x18c/0x1d4
(unreliable)
[ 0.808694] [df4a5ee8] [c070e8c0] kernel_init_freeable+0x204/0x2dc
[ 0.814830] [df4a5f28] [c0004a94] kernel_init+0x18/0x110
[ 0.820107] [df4a5f38] [c00122ac] ret_from_kernel_thread+0x14/0x1c
[ 0.826220] Instruction dump:
[ 0.829161] 4beb1069 7d2000a6 61298000 7d200124 89210008 2f890000
41be0048 3c60c06a
[ 0.836849] 38a10008 7fa4eb78 3863cacc 4b915115 <0fe00000> 4800002c
81220070 712a0004
[ 0.844723] ---[ end trace 969d686308d40b33 ]---

Then starting init fails:

[ 3.894074] Run /init as init process
[ 3.898403] Failed to execute /init (error -14)
[ 3.903009] Run /sbin/init as init process
[ 3.907172] Run /etc/init as init process
[ 3.911251] Run /bin/init as init process
[ 3.915513] Run /bin/sh as init process
[ 3.919471] Starting init: /bin/sh exists but couldn't execute it
(error -14)
[ 3.926732] Kernel panic - not syncing: No working init found. Try
passing init= option to kernel. See Linux
Documentation/admin-guide/init.rst for guidance.
[ 3.940864] CPU: 0 PID: 1 Comm: init Tainted: G W
5.3.0-rc7-s3k-dev-00880-g28fd02a838e5-dirty #2307
[ 3.951165] Call Trace:
[ 3.953617] [df4a5ec8] [c002392c] panic+0x12c/0x320 (unreliable)
[ 3.959621] [df4a5f28] [c0004b8c] rootfs_mount+0x0/0x2c
[ 3.964849] [df4a5f38] [c00122ac] ret_from_kernel_thread+0x14/0x1c

Christophe