Re: [PATCH v5 1/4] powerpc/fadump: un-register fadump on kexec path.

[Mahesh Jagannath Salgaonkar <mahesh@linux.vnet.ibm.com>]

On 04/26/2018 06:28 PM, Nicholas Piggin wrote:
> On Thu, 26 Apr 2018 17:12:03 +0530
> Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> wrote:
> 
>> From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>>
>> otherwise the fadump registration in new kexec-ed kernel complains that
>> fadump is already registered. This makes new kernel to continue using
>> fadump registered by previous kernel which may lead to invalid vmcore
>> generation. Hence this patch fixes this issue by un-registering fadump
>> in fadump_cleanup() which is called during kexec path so that new kernel
>> can register fadump with new valid values.
> 
> I assume this series is for 4.17, but it might be good to get this one
> into the 4.16 fixes branch? Should it go to stable kernels?

You are right. Should I send it out as separate patch ?

> 
>>
>> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
>> ---
>>  arch/powerpc/kernel/fadump.c |    3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
>> index 8ceabef40d3d..07e8396d472b 100644
>> --- a/arch/powerpc/kernel/fadump.c
>> +++ b/arch/powerpc/kernel/fadump.c
>> @@ -1180,6 +1180,9 @@ void fadump_cleanup(void)
>>  		init_fadump_mem_struct(&fdm,
>>  			be64_to_cpu(fdm_active->cpu_state_data.destination_address));
>>  		fadump_invalidate_dump(&fdm);
>> +	} else if (fw_dump.dump_registered) {
>> +		/* Un-register Firmware-assisted dump if it was registered. */
>> +		fadump_unregister_dump(&fdm);
>>  	}
>>  }
>>  
>>
>