[Crash-utility] The problems when running SuSE 12 on VirtualBox

[David Mair]

On 11/19/2015 08:37 AM, David Mair wrote:
> On 11/19/2015 07:45 AM, Dave Anderson wrote:
> 
> Hi Dave,
> 
>> ----- Original Message -----
> <snip>
>>
>>> (2) Execute "crash -d8" on physical machine will cause crash utility core
>>> dump.
>>
>> I can reproduce this, so I'll look into it.  It's related to the /dev/mem "test"
>> to determine whether the kernel was configured with CONFIG_STRICT_DEVMEM, where
>> it tries to read from pfn 257 (just above the CONFIG_STRICT_DEVMEM limit), but
>> gets into an infinite loop when used in conjunction with -d.   
>>
>> Anyway, just continue to use /proc/kcore and you should be fine.
> 
> This is the cause in readmem():
> 
> switch(READMEM(...))
> {
> 	.
> 	.
> 	.
> case READ_ERROR:
> 	if (PRINT_ERROR_MESSAGE) ********** THIS ***********
> 	{
> 		causes a nested readmem() call before the goto gives it
> 		to the caller to deal with
> 	}
> 	goto readmem_error
> }
> 	.
> 	.
> 	.
> switch(error_handle)
> {
> 	case (RETURN_ON_ERROR):
> }
> 
> The PRINT_ERROR_MESSAGE I assume is an escalation from -d 8 in this case.
> 

The whole switch_to_proc_kcore() probably shouldn't be conditional on
the presence of PRINT_ERROR_MESSAGE, only the actual error message
should be.

Patch shortly.

-- 
David.