Re: [PATCH v12 16/37] x86/ptrace: Add FRED additional information to the pt_regs structure

H. Peter Anvin
2023-11-28T17:19:17Z

On November 28, 2023 12:51:22 AM PST, Borislav Petkov <bp@alien8.de> wrote:
>On Mon, Oct 02, 2023 at 11:24:37PM -0700, Xin Li wrote:
>> FRED defines additional information in the upper 48 bits of cs/ss
>> fields. Therefore add the information definitions into the pt_regs
>> structure.
>>
>> Specially introduce a new structure fred_ss to denote the FRED flags
>> above SS selector, which avoids FRED_SSX_ macros and makes the code
>> simpler and easier to read.
>>
>> Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
>
>You and hpa need to go through all the patches and figure out who's the
>author that's going to land in git.
>
>Because this and others have hpa's SOB first, suggesting he's the
>author. However, the mail doesn't start with
>
>From: H. Peter Anvin (Intel) <hpa@zytor.com>
>
>and then git will make *you* the author.
>
>> Tested-by: Shan Kang <shan.kang@intel.com>
>> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>> Signed-off-by: Xin Li <xin3.li@intel.com>
>
>...
>
>> union {
>> - u64 ssx; // The full 64-bit data slot containing SS
>> - u16 ss; // SS selector
>> + /* SS selector */
>> + u16 ss;
>> + /* The extended 64-bit data slot containing SS */
>> + u64 ssx;
>> + /* The FRED SS extension */
>> + struct fred_ss fred_ss;
>
>Aha, sanity about the right comments has come to your mind in this next
>patch. :-P
>
>Just do them right in the previous one.
>
>> /*
>> - * Top of stack on IDT systems.
>> + * Top of stack on IDT systems, while FRED systems have extra fields
>> + * defined above for storing exception related information, e.g. CR2 or
>> + * DR6.
>
>Btw, I really appreciate the good commenting - thanks for that!
>

For Xin, mainly:

Standard practice is:

1. For a patch with relatively small modifications, or where the changes are mainly in comments or the patch message:

Keep the authorship, but put a description of what you have changed in brackets with your username at the bottom of the description, immediately before Signed-off-by:

[ xin: changed foo, bar, baz ]

2. For a patch with major rewrites:

Take authorship on the From: line, but have an Originally-by: tag (rather than a Signed-off-by: by the original author):

Originally-by: Someone Else <someone@elsewhere.dom>

3. For a patch which is fully or nearly fully your own work (a total rewrite, or based on a concept idea rather than actual code), credit the original in the patch comment:

Based on an idea by Someone Else <someone@elsewhere.dom> (optional link to lore.kernel.org).