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

[Nicholas Piggin]

On Thu, 26 Apr 2018 17:12:03 +0530
Mahesh J Salgaonkar <mahesh at linux.vnet.ibm.com> wrote:

> From: Mahesh Salgaonkar <mahesh at 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?

> 
> Signed-off-by: Mahesh Salgaonkar <mahesh at 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);
>  	}
>  }
>  
>