Re: RFC: remove set_fs for m68k

Michael Schmitz
2021-07-12T19:04:49Z

On 11/07/21 7:20 pm, Michael Schmitz wrote:

> Hi Christoph,
>
> Am 09.07.2021 um 19:01 schrieb Christoph Hellwig:
>> Hi all,
>>
>> this series converts m68k to the new world where set_fs is gone to make
>> the uaccess routines work on kernel pointers.  Note that it is compile
>> tested only and thus needs to be handled with care.
>
> Testing your series, I've got this in the console log:
>
> [16534.130000] *** FORMAT ERROR ***   FORMAT=0
> [16534.150000] Current process id is 1347
> [16534.160000] BAD KERNEL TRAP: 00000000
> [16534.180000] Modules linked in: atari_scsi ne 8390p
> [16534.210000] PC: [<00002a8c>] resume_userspace+0x14/0x16
> [16534.230000] SR: 2200  SP: d1b6e0e8  a2: 00000000
> [16534.240000] d0: 0000001e    d1: 00000003    d2: 00000578    d3:
> 00000000
> [16534.270000] d4: ffffffff    d5: 00000001    a0: 00000578    a1:
> 00000080
> [16534.300000] Process savelog (pid: 1347, task=e3955528)
> [16534.310000] Frame format=0
> [16534.330000] Stack from 005e9fa4:
> [16534.330000]         02108005 0d06b008 1eeeb649 007e0001 00aea040
> 003ec318 005e9e68 000279a2
> [16534.330000]         000b0000 00000000 00000000 030dfffb 0044fffa
> 0e000000 fffa1a00 fffa1c00
> [16534.330000]         fffa1e00 fffb0e40 fffb0e80 00049e02 00000040
> 0085a800 00000001
> [16534.430000] Call Trace: [<000279a2>] warn_slowpath_fmt+0x0/0x62
> [16534.460000]  [<000b0000>] vm_map_ram+0x144/0x5ae
> [16534.490000]  [<00049e02>] __handle_irq_event_percpu+0x38/0xce
> [16534.520000]
> [16534.540000] Code: 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 <9f38>
> 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38 9f38
> 9f38
>
> Never seen the like of it before...
>
Now the good news is, the IO test I ran at that time continued OK and
completed normally (aside from the OOM killer hitting another process).
I'm using IO to three 24 MB files each on five partitions concurrently
with 14 MB of RAM (9,7 MB total RAM remaining once the kernel has
loaded) so memory may be a little tight.

Any reason to assume the warn_slowpath_fmt() here is related to the
warning you stuck in set_segment()?

Cheers,

Michael