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From: "H. Peter Anvin" <hpa@zytor.com>
To: Andy Lutomirski <luto@amacapital.net>, Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>, X86 ML <x86@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 2/2] x86_64,signal: Remove 'fs' and 'gs' from sigcontext
Date: Fri, 11 Jul 2014 19:09:03 -0700	[thread overview]
Message-ID: <53C098BF.6010203@zytor.com> (raw)
In-Reply-To: <CALCETrWMgTET6MZwaH4D4tOg2v1kV6ozBnjGTGrecnMWJbkUEg@mail.gmail.com>

On 07/11/2014 11:39 AM, Andy Lutomirski wrote:
> On Fri, Jul 11, 2014 at 11:12 AM, Andi Kleen <andi@firstfloor.org> wrote:
>>> diff --git a/arch/x86/include/uapi/asm/sigcontext.h b/arch/x86/include/uapi/asm/sigcontext.h
>>> index 076b11f..df9908b 100644
>>> --- a/arch/x86/include/uapi/asm/sigcontext.h
>>> +++ b/arch/x86/include/uapi/asm/sigcontext.h
>>
>> I don't think renaming fields in uapi/asm is acceptable. These
>> are likely used by user programs and you'll break compiles.
> 
> Hmm.  That's a fair point.  On the other hand, any user code that uses
> these fields explicitly may already be broken, since the current names
> of these fields rather strongly imply that they do something.
> 
> Is there any clear policy on minor API breaks in the UAPI headers that
> don't affect ABI?
> 

There really isn't, and this *definitely* a boundary case: as you state,
it is very likely that anyone currently using them are doing so
incorrectly, but it does induce potential source-level breakage.

Linus, do you have any guidance here?

	-hpa


  reply	other threads:[~2014-07-12  2:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-11 16:29 [PATCH 0/2] x86_64,signal: Fix the set of saved segment registers Andy Lutomirski
2014-07-11 16:29 ` [PATCH 1/2] x86_64,signal: Save and restore SS in signal frames Andy Lutomirski
2015-03-09 20:15   ` Andy Lutomirski
2014-07-11 16:29 ` [PATCH 2/2] x86_64,signal: Remove 'fs' and 'gs' from sigcontext Andy Lutomirski
2014-07-11 18:12   ` Andi Kleen
2014-07-11 18:39     ` Andy Lutomirski
2014-07-12  2:09       ` H. Peter Anvin [this message]
2014-07-12  2:04   ` H. Peter Anvin
2014-07-12  2:21   ` Linus Torvalds
2014-07-12  2:26     ` H. Peter Anvin
2014-07-12  8:39     ` Andy Lutomirski
2014-07-12 18:37       ` Andi Kleen
2014-07-12 18:40         ` H. Peter Anvin
2014-07-12 18:52           ` Andi Kleen
2014-07-12 21:17             ` Andy Lutomirski
2014-07-18  1:13               ` Andy Lutomirski

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