Re: [PATCH 01/14] asmlinkage, kvm: Make kvm_rebooting visible

[Andrew Morton <akpm@linux-foundation.org>]

On Sat,  8 Feb 2014 08:51:57 +0100 Andi Kleen <ak@linux.intel.com> wrote:

> kvm_rebooting is referenced from assembler code, thus
> needs to be visible.

So I read the gcc page and looked at the __visible definition but I
still don't really get it.  What goes wrong if the __visible isn't
present on these referenced-from-asm identifiers?

> Cc: gleb@redhat.com
> Cc: pbonzini@redhat.com

Grumble.  Email addresses go into commits with display names and <>. 
At least, 89.3% of them do.  Some sucker has to go through these and
fix them up.  I'd prefer it not be me ;)

>
> ...
>
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -102,7 +102,7 @@ static void kvm_release_pfn_dirty(pfn_t pfn);
>  static void mark_page_dirty_in_slot(struct kvm *kvm,
>  				    struct kvm_memory_slot *memslot, gfn_t gfn);
>  
> -bool kvm_rebooting;
> +__visible bool kvm_rebooting;
>  EXPORT_SYMBOL_GPL(kvm_rebooting);
>  
>  static bool largepages_enabled = true;