Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH] efi/libstub/arm64: Enable __efistub_global define in
 .data section
To:     Ard Biesheuvel <ardb@kernel.org>,
        Arvind Sankar <nivedita@alum.mit.edu>
Cc:     linux-efi <linux-efi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <1586468669-21456-1-git-send-email-victor.erminpour@oracle.com>
 <CAMj1kXGgYYx=9rq-Ficw3vS6FX_0nb-hRStXijh7H4zdD=+Gaw@mail.gmail.com>
 <aee6c7cc-24c7-2822-47d5-1e05413a8024@oracle.com>
 <CAMj1kXFF3gR+LyE1VbLuwnRA3CzQtF90mv7rpw9x2RcyugO1JA@mail.gmail.com>
From:   Victor Erminpour <victor.erminpour@oracle.com>
Organization: Oracle America
Message-ID: <95f421ad-6ba7-b968-d605-c464bc1df4e2@oracle.com>
Date:   Mon, 13 Apr 2020 15:56:40 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.6.0
MIME-Version: 1.0
In-Reply-To: <CAMj1kXFF3gR+LyE1VbLuwnRA3CzQtF90mv7rpw9x2RcyugO1JA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 4/10/20 11:39 PM, Ard Biesheuvel wrote:
> On Sat, 11 Apr 2020 at 00:12, Victor Erminpour
> <victor.erminpour@oracle.com> wrote:
>>
>>
>>
>> On 4/10/20 1:09 AM, Ard Biesheuvel wrote:
>>> On Thu, 9 Apr 2020 at 23:44, Victor Erminpour
>>> <victor.erminpour@oracle.com> wrote:
>>>>
>>>> Enable the __efistub_global define to place variables in the
>>>> .data section for both CONFIG_ARM and CONFIG_ARM64.
>>>>
>>>> This places the EFIstub sys_table variable and other EFIstub
>>>> static variables in the .data section for both CONFIG_ARM and
>>>> CONFIG_ARM64.
>>>>
>>>
>>> What does that achieve?
>>
>> Hi Ard,
>>
>> Without placing these global variables in .data, I get the
>> following errors when booting an ARM64 EFI system:
>>
>> EFI stub: ERROR: Exit boot services failed.
>> EFI stub: ERROR: Failed to update FDT and exit boot services
>>
> 
> Which boot loader are you using? Does this involve shim?
> 

grub2-efi-aa64-2.02-0.80.0.4.el7.aarch64
shim-aa64-15-1.0.4.el7.aarch64

> Also, does it help if you add 'efi=no_disable_early_pci_dma'?
> 

Tried this boot time option, but to no effect.

> 
>>
>> I know that the ARM64 linker script is supposed to put the
>> .init.bss into the .init.data section, but I don't think this
>> is happening for all systems.
>>
>> Having it explicitly enabled for CONFIG_ARM64 worked for me.
>>
> 
> OK, thanks for the report. However, we will be removing
> __efistub_global entirely during the next cycle, so this is not the
> right fix.

Thanks Ard, this sounds promising!

Regards,
--Victor


> 

-- 
Victor Hugo Erminpour
Principal Member of Technical Staff
Oracle America