[PATCH RFCv2 4/6] powerpc/powernv: hold device_hotplug_lock when calling device_online()

[Pasha Tatashin]

Reviewed-by: Pavel Tatashin <pavel.tatashin at microsoft.com>

On 8/21/18 6:44 AM, David Hildenbrand wrote:
> device_online() should be called with device_hotplug_lock() held.
> 
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Rashmica Gupta <rashmica.g at gmail.com>
> Cc: Balbir Singh <bsingharora at gmail.com>
> Cc: Michael Neuling <mikey at neuling.org>
> Signed-off-by: David Hildenbrand <david at redhat.com>
> ---
>  arch/powerpc/platforms/powernv/memtrace.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
> index 8f1cd4f3bfd5..ef7181d4fe68 100644
> --- a/arch/powerpc/platforms/powernv/memtrace.c
> +++ b/arch/powerpc/platforms/powernv/memtrace.c
> @@ -229,9 +229,11 @@ static int memtrace_online(void)
>  		 * we need to online the memory ourselves.
>  		 */
>  		if (!memhp_auto_online) {
> +			lock_device_hotplug();
>  			walk_memory_range(PFN_DOWN(ent->start),
>  					  PFN_UP(ent->start + ent->size - 1),
>  					  NULL, online_mem_block);
> +			unlock_device_hotplug();
>  		}
>  
>  		/*
>