RE: [PATCH v7 09/10] arm64: efi: Export screen_info

From: Michael Kelley <mikelley@microsoft.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: "will@kernel.org" <will@kernel.org>,
	"ardb@kernel.org" <ardb@kernel.org>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"Mark.Rutland@arm.com" <Mark.Rutland@arm.com>,
	"maz@kernel.org" <maz@kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
	"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	"wei.liu@kernel.org" <wei.liu@kernel.org>,
	vkuznets <vkuznets@redhat.com>, KY Srinivasan <kys@microsoft.com>,
	Sunil Muthuswamy <sunilmut@microsoft.com>,
	"boqun.feng@gmail.com" <boqun.feng@gmail.com>
Subject: RE: [PATCH v7 09/10] arm64: efi: Export screen_info
Date: Mon, 24 Aug 2020 17:40:32 +0000	[thread overview]
Message-ID: <MW2PR2101MB1052C68771718B3FB47BB58BD7560@MW2PR2101MB1052.namprd21.prod.outlook.com> (raw)
In-Reply-To: <20200824173502.GA1161855@kroah.com>

From: Greg KH <gregkh@linuxfoundation.org> Sent: Monday, August 24, 2020 10:35 AM
> 
> On Mon, Aug 24, 2020 at 09:46:22AM -0700, Michael Kelley wrote:
> > The Hyper-V frame buffer driver may be built as a module, and
> > it needs access to screen_info. So export screen_info.
> >
> > Signed-off-by: Michael Kelley <mikelley@microsoft.com>
> > ---
> >  arch/arm64/kernel/efi.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
> > index d0cf596..8ff557a 100644
> > --- a/arch/arm64/kernel/efi.c
> > +++ b/arch/arm64/kernel/efi.c
> > @@ -55,6 +55,7 @@ static __init pteval_t
> create_mapping_protection(efi_memory_desc_t *md)
> >
> >  /* we will fill this structure from the stub, so don't put it in .bss */
> >  struct screen_info screen_info __section(.data);
> > +EXPORT_SYMBOL(screen_info);
> 
> EXPORT_SYMBOL_GPL()?
> 
> I have to ask :)

It's also just EXPORT_SYMBOL(screen_info) in the x86, PowerPC, and Alpha
architectures. I know that doesn't guarantee it's right, but I'll have to defer
to the appropriate subsystem maintainers for whether it really should be
EXPORT_SYMBOL_GPL.

Michael

> 
> thanks,
> 
> greg k-h