linux-kernel - Re: [PATCH] arm64/efi: efi

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Message-ID: <c57dfbbe-a2a7-e8af-7d94-20f86126053c@huawei.com>
Date:   Wed, 7 Sep 2016 19:15:48 +0800
From:   Yisheng Xie <xieyisheng1@...wei.com>
To:     Matt Fleming <matt@...eblueprint.co.uk>,
        Will Deacon <will.deacon@....com>
CC:     <mingo@...nel.org>, <guohanjun@...wei.com>, <mark.rutland@....com>,
        <catalin.marinas@....com>, <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-efi@...r.kernel.org>, <ard.biesheuvel@...aro.org>
Subject: Re: [PATCH] arm64/efi: efi_init error handling fix



On 2016/9/5 21:57, Matt Fleming wrote:
> On Fri, 02 Sep, at 11:26:18AM, Will Deacon wrote:
>> On Fri, Sep 02, 2016 at 06:18:39PM +0800, Xie Yisheng wrote:
>>> From: Yisheng Xie <xieyisheng1@...wei.com>
>>>
>>> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
>>> index c49d50e..5080e40 100644
>>> --- a/drivers/firmware/efi/arm-init.c
>>> +++ b/drivers/firmware/efi/arm-init.c
>>> @@ -243,8 +243,10 @@ void __init efi_init(void)
>>>  	     "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
>>>  	      efi.memmap.desc_version);
>>>  
>>> -	if (uefi_init() < 0)
>>> +	if (uefi_init() < 0) {
>>> +		early_memunmap(efi.memmap.map, params.mmap_size);
>>>  		return;
>>> +	}
> 
> This should be a call to efi_memmap_unmap() because the EFI_MEMMAP
> flag also needs clearing.
> 
Hi Matt,
Thanks for your reply.
You mean call the function efi_unmap_memmap() like x86?

however, it seems no need to clear EFI_MEMMAP here. For arm*, the flag
EFI_MEMMAP is set in function reserve_regions(), which is called
only when uefi_init() return 0:

efi_init()
   -> reserve_regions()
       -> set_bit(EFI_MEMMAP, &efi.flags);
Thanks
Xie Yisheng.

> .
>