WARNING: CPU: 0 PID: 1 at arch/powerpc/lib/feature-fixups.c:109 do_feature_fixups+0xb0/0xf0

[Christophe Leroy]

Le 30/03/2021 à 12:42, Christophe Leroy a écrit :
> 
> 
> Le 30/03/2021 à 12:37, Paul Menzel a écrit :
>> Dear Linux folks,
>>
>>
>> On the POWER8 system IBM S822LC, Linux 5.12-rc5+ logs the warning below.
>>
>> ```
>> [    0.723485] ------------[ cut here ]------------
>> [    0.723491] WARNING: CPU: 0 PID: 1 at arch/powerpc/lib/feature-fixups.c:109 
>> do_feature_fixups+0xb0/0xf0
>> [    0.723512] Modules linked in:
>> [    0.723524] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc5+ #3
>> [    0.723537] NIP:  c0000000000bbc70 LR: c0000000000bbc3c CTR: 0000000000000000
>> [    0.723547] REGS: c00000800d48b800 TRAP: 0700   Not tainted (5.12.0-rc5+)
>> [    0.723556] MSR:  9000000002029033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE>  CR: 42008244  XER: 20000000
>> [    0.723613] CFAR: c0000000000bbc40 IRQMASK: 0
>>                 GPR00: c000000001707610 c00000800d48baa0 c0000000021bb200 0000000000000001
>>                 GPR04: c0000000021d0d88 aaaaaaaaaaaaaaab 00000000ffffffc0 c0000000021c0034
>>                 GPR08: 0000000c000003a0 0000000000000000 0000000000000000 0000000080000000
>>                 GPR12: c000000001211458 c0000000028e0000 c0000000000129f8 0000000000000000
>>                 GPR16: 0000000000000000 0000000000000000 0000000000000000 c000000001f003f0
>>                 GPR20: c000000001f003d0 c000000001f003b0 c000000001f00390 c000000001703520
>>                 GPR24: 0000000000000004 c0000000016ddfe0 c000000001791048 c000000001791088
>>                 GPR28: c0000000014fd870 000000fb8f5db187 c0000000021d0d88 0000000000000001
>> [    0.723822] NIP [c0000000000bbc70] do_feature_fixups+0xb0/0xf0
>> [    0.723835] LR [c0000000000bbc3c] do_feature_fixups+0x7c/0xf0
>> [    0.723848] Call Trace:
>> [    0.723854] [c00000800d48baa0] [c0000000001b4f4c] parse_one+0x11c/0x3c0 (unreliable)
>> [    0.723875] [c00000800d48bb20] [c000000001707610] vdso_fixup_features+0xbc/0x11c
>> [    0.723896] [c00000800d48bb60] [c0000000017078bc] vdso_init+0x154/0x1b0
>> [    0.723914] [c00000800d48bb90] [c0000000000123c0] do_one_initcall+0x60/0x2c0
>> [    0.723933] [c00000800d48bc60] [c000000001704944] do_initcalls+0x1e0/0x248
>> [    0.723951] [c00000800d48bd40] [c000000001704c38] kernel_init_freeable+0x1f0/0x25c
>> [    0.723969] [c00000800d48bda0] [c000000000012a14] kernel_init+0x24/0x170
>> [    0.723987] [c00000800d48be10] [c00000000000d6ec] ret_from_kernel_thread+0x5c/0x70
>> [    0.724005] Instruction dump:
>> [    0.724014] 40820030 37ffffff 3bde0030 4082ffe4 38210080 e8010010 eb81ffe0 eba1ffe8
>> [    0.724057] ebc1fff0 ebe1fff8 7c0803a6 4e800020 <0fe00000> e8fe0028 e8de0020 e8be0018
>> [    0.724102] ---[ end trace 9bbb55f5cd8ca2ba ]---
>> [    0.724118] Unable to patch feature section at (____ptrval____) - (____ptrval____) with 
>> (____ptrval____) - (____ptrval____)
>> [    0.724185] pstore: Registered nvram as persistent store backend
>> ```
>>
>> Please find the output of `dmesg` attached.
> 
> I saw something similar yesterday. Never seen that before.
> 

With no_hash_pointers.

[    0.000000] Kernel virtual memory layout:
[    0.000000]   * 0xffafc000..0xffffc000  : fixmap
[    0.000000]   * 0xc9000000..0xffafc000  : vmalloc & ioremap


[    0.468026] ------------[ cut here ]------------
[    0.472416] WARNING: CPU: 0 PID: 1 at arch/powerpc/lib/feature-fixups.c:109 
do_feature_fixups+0x140/0x228
[    0.481880] Modules linked in:
[    0.484896] CPU: 0 PID: 1 Comm: swapper Not tainted 5.12.0-rc5-s3k-dev-01664-gca8e05f05062-dirty 
#4823
[    0.494102] NIP:  c0016630 LR: c0896b88 CTR: 00000000
[    0.499092] REGS: c9023d60 TRAP: 0700   Not tainted  (5.12.0-rc5-s3k-dev-01664-gca8e05f05062-dirty)
[    0.508041] MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 42000244  XER: 00000000
[    0.514755]
[    0.514755] GPR00: c0896b88 c9023e20 c20f8000 00000100 c0b18f58 c0b18f70 cfffff60 c07141b5
[    0.514755] GPR08: c0048ddc e3196feb 11e31570 0000006e 00000000 00000000 c00048a0 00000000
[    0.514755] GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 c07f00d8 00000100
[    0.514755] GPR24: c0b18f70 60000000 c7230f5a c6d4eb68 d8b800d8 c0b18f58 e4099f6f c0b18000
[    0.550642] NIP [c0016630] do_feature_fixups+0x140/0x228
[    0.555892] LR [c0896b88] vdso_init+0x90/0x15c
[    0.560283] Call Trace:
[    0.562691] [c9023e20] [c08c7034] 0xc08c7034 (unreliable)
[    0.568027] [c9023e70] [c0896b88] vdso_init+0x90/0x15c
[    0.573105] [c9023e90] [c000442c] do_one_initcall+0x38/0x214
[    0.578699] [c9023ef0] [c0894db0] kernel_init_freeable+0x164/0x208
[    0.584809] [c9023f20] [c00048b4] kernel_init+0x14/0x10c
[    0.590059] [c9023f30] [c00110c0] ret_from_kernel_thread+0x14/0x1c
[    0.596173] Instruction dump:
[    0.599098] 40bcff98 4bfffe0d 2c030000 4182ff8c 839d0014 837d0010 835d000c 83dd0008
[    0.606929] 7f9de214 7f7dda14 7f5dd214 7fddf214 <0fe00000> 7f87e378 7f66db78 7f45d378
[    0.614955] ---[ end trace 5ee29eb875be947f ]---
[    0.619594] Unable to patch feature section at e4099f6f - c7230f5a with c6d4eb68 - d8b800d8

Looks like it points in the weed.