linux-kernel - Re: [tip:x86/asm] x86/asm/msr: Make wrmsrl() a function

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Message-ID: <55DA1DCE.60401@zytor.com>
Date:	Sun, 23 Aug 2015 12:23:58 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	linux-kernel@...r.kernel.org, luto@...capital.net,
	peterz@...radead.org, w@....eu, mingo@...nel.org,
	torvalds@...ux-foundation.org, tglx@...utronix.de, bp@...en8.de,
	dvlasenk@...hat.com, brgerst@...il.com, luto@...nel.org,
	rostedt@...dmis.org, linux-tip-commits@...r.kernel.org
Subject: Re: [tip:x86/asm] x86/asm/msr: Make wrmsrl() a function

On 08/23/2015 04:45 AM, tip-bot for Andy Lutomirski wrote:
> Commit-ID:  47edb65178cb7056c2eea0b6c41a7d8c84547192
> Gitweb:     http://git.kernel.org/tip/47edb65178cb7056c2eea0b6c41a7d8c84547192
> Author:     Andy Lutomirski <luto@...nel.org>
> AuthorDate: Thu, 23 Jul 2015 12:14:40 -0700
> Committer:  Ingo Molnar <mingo@...nel.org>
> CommitDate: Sun, 23 Aug 2015 13:25:38 +0200
> 
> x86/asm/msr: Make wrmsrl() a function
> 
> As of cf991de2f614 ("x86/asm/msr: Make wrmsrl_safe() a
> function"), wrmsrl_safe is a function, but wrmsrl is still a
> macro.  The wrmsrl macro performs invalid shifts if the value
> argument is 32 bits. This makes it unnecessarily awkward to
> write code that puts an unsigned long into an MSR.
> 

Looking at this: where do you see an invalid shift?  Everywhere I can
see we do the proper casting.  Still not side effect free, though.

	-hpa

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