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Subject: Re: [PATCH v26 26/30] ELF: Introduce arch_setup_elf_property()
From:   "Yu, Yu-cheng" <yu-cheng.yu@intel.com>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Borislav Petkov <bp@alien8.de>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
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        Haitao Huang <haitao.huang@intel.com>,
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References: <20210427204315.24153-1-yu-cheng.yu@intel.com>
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Date:   Thu, 20 May 2021 14:06:30 -0700
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On 5/20/2021 10:52 AM, Yu, Yu-cheng wrote:
> On 5/20/2021 10:38 AM, Matthew Wilcox wrote:
>> On Wed, May 19, 2021 at 03:14:58PM -0700, Yu, Yu-cheng wrote:
>>>>> +++ b/include/uapi/linux/elf.h
>>>>> @@ -455,4 +455,13 @@ typedef struct elf64_note {
>>>>>    /* Bits for GNU_PROPERTY_AARCH64_FEATURE_1_BTI */
>>>>>    #define GNU_PROPERTY_AARCH64_FEATURE_1_BTI    (1U << 0)
>>>>> +/* .note.gnu.property types for x86: */
>>>>> +#define GNU_PROPERTY_X86_FEATURE_1_AND        0xc0000002
>>>>
>>>> Why not 0xc0000001? ARM64 is 0xc0000000...
>>>>
>>>
>>> I just looked at the ABI document.
>>>
>>> ARM has GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
>>>
>>> X86 has:
>>>     GNU_PROPERTY_X86_ISA_1_USED    0xc0000000
>>>     GNU_PROPERTY_X86_ISA_1_NEEDED    0xc0000001
>>>     GNU_PROPERTY_X86_FEATURE_1_AND    0xc0000002
>>
>> Please add all three, not just the last one.
>>
> 
> Ok!

Just found out, I have been reading an older version.  Now 0xc0000000 
and 0xc0000001 have become reserved/not-used.  Maybe I will just put a 
note about that along with the link to the ABI document.

Yu-cheng