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

From: Christophe Leroy
Date: Thu Sep 12 2019 - 11:52:35 EST




Le 12/09/2019 Ã 17:36, Christophe Leroy a ÃcritÂ:


Le 12/09/2019 Ã 17:00, Christophe Leroy a ÃcritÂ:


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