Re: [PATCH 0/2] printk: replace ringbuffer

From: lijiang
Date: Wed Feb 05 2020 - 00:38:25 EST



> On (20/02/05 13:48), Sergey Senozhatsky wrote:
>> On (20/02/05 12:25), lijiang wrote:
>> [..]
>>> [ 42.111004] Kernel Offset: 0x1f000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
>>> [ 42.111005] general protection fault: 0000 [#1] SMP PTI
>>> [ 42.111005] CPU: 15 PID: 1395 Comm: systemd-journal Not tainted 5.5.0-rc7+ #4
>>> [ 42.111005] Hardware name: Intel Corporation S2600WTT/S2600WTT, BIOS SE5C610.86B.01.01.6024.071720181717 07/17/2018
>>> [ 42.111006] RIP: 0010:copy_data+0xf2/0x1e0
>>> [ 42.111006] Code: eb 08 49 83 c4 08 0f 84 8e 00 00 00 4c 89 74 24 08 4c 89 cd 41 89 d6 44 89 44 24 04 49 39 db 0f 87 c6 00 00 00 4d 85 c9 74 43 <41> c7 01 00 00 00 00 48 85 db 74 37 4c 89 e7 48 89 da 41 bf 01 00
>>> [ 42.111007] RSP: 0018:ffffbbe207a7bd80 EFLAGS: 00010002
>>> [ 42.111007] RAX: ffffa075d44ca000 RBX: 00000000000000a8 RCX: fffffffffff000b0
>>> [ 42.111008] RDX: 00000000000000a8 RSI: 00000fffffffff01 RDI: ffffffffa1456e00
>>> [ 42.111008] RBP: 0801364600307073 R08: 0000000000002000 R09: 0801364600307073
>>> [ 42.111008] R10: fffffffffff00000 R11: 00000000000000a8 R12: ffffffffa1e98330
>>> [ 42.111009] R13: 00000000d7efbe00 R14: 00000000000000a8 R15: 00000000ffffc000
>>> [ 42.111009] FS: 00007f7c5642a980(0000) GS:ffffa075df5c0000(0000) knlGS:0000000000000000
>>> [ 42.111010] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [ 42.111010] CR2: 00007ffe95f4c4c0 CR3: 000000084fbfc004 CR4: 00000000003606e0
>>> [ 42.111011] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> [ 42.111011] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>> [ 42.111012] Call Trace:
>>> [ 42.111012] _prb_read_valid+0xd8/0x190
>>> [ 42.111012] prb_read_valid+0x15/0x20
>>> [ 42.111013] devkmsg_read+0x9d/0x2a0
>>> [ 42.111013] vfs_read+0x91/0x140
>>> [ 42.111013] ksys_read+0x59/0xd0
>>> [ 42.111014] do_syscall_64+0x55/0x1b0
>>> [ 42.111014] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>>> [ 42.111014] RIP: 0033:0x7f7c55740b62
>>> [ 42.111015] Code: 94 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b6 0f 1f 80 00 00 00 00 f3 0f 1e fa 8b 05 e6 d8 20 00 85 c0 75 12 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 41 54 49 89 d4 55 48 89
>>> [ 42.111015] RSP: 002b:00007ffe95f4c4a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
>>> [ 42.111016] RAX: ffffffffffffffda RBX: 00007ffe95f4e500 RCX: 00007f7c55740b62
>>> [ 42.111016] RDX: 0000000000002000 RSI: 00007ffe95f4c4b0 RDI: 0000000000000008
>>> [ 42.111017] RBP: 0000000000000000 R08: 0000000000000100 R09: 0000000000000003
>>> [ 42.111017] R10: 0000000000000100 R11: 0000000000000246 R12: 00007ffe95f4c4b0
>>
>> So there is a General protection fault. That's the type of a problem that
>> kills the boot for me as well (different backtrace, tho).
>
> Do you have CONFIG_RELOCATABLE and CONFIG_RANDOMIZE_BASE (KASLR) enabled?
>

Yes. These two options are enabled.

CONFIG_RELOCATABLE=y
CONFIG_RANDOMIZE_BASE=y

Thanks.

> -ss
>