Re: [RFC][CFT][PATCHSET v1] uaccess unification

From: Al Viro <viro@ZenIV.linux.org.uk>
To: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Richard Henderson <rth@twiddle.net>,
	Russell King <linux@armlinux.org.uk>,
	Will Deacon <will.deacon@arm.com>,
	Haavard Skinnemoen <hskinnemoen@gmail.com>,
	Vineet Gupta <vgupta@synopsys.com>,
	Steven Miao <realmz6@gmail.com>,
	Jesper Nilsson <jesper.nilsson@axis.com>,
	Mark Salter <msalter@redhat.com>,
	Yoshinori Sato <ysato@users.sourceforge.jp>,
	Richard Kuo <rkuo@codeaurora.org>,
	Tony Luck <tony.luck@intel.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	James Hogan <james.hogan@imgtec.com>,
	Michal Simek <monstr@monstr.eu>,
	David Howells <dhowells@redhat.com>,
	Ley Foon Tan <lftan@altera.com>, Jonas Bonn <jonas@southpole.se>,
	Helge Deller <deller@gmx.de>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Ralf Baechle <ralf@linux-mips.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Chen Liqin <liqin.linux@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Chris Metcalf <cmetcalf@mellanox.com>,
	Richard Weinberger <richard@nod.at>,
	Guan Xuetao <gxt@mprc.pku.edu.cn>,
	Thomas Gleixner <tglx@linutronix.de>,
	Chris Zankel <chris@zankel.net>
Subject: Re: [RFC][CFT][PATCHSET v1] uaccess unification
Date: Tue, 4 Apr 2017 21:52:38 +0100	[thread overview]
Message-ID: <20170404205238.GP29622@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20170404202629.GA31611@octofox.metropolis>

On Tue, Apr 04, 2017 at 01:26:29PM -0700, Max Filippov wrote:
> On Wed, Mar 29, 2017 at 06:57:06AM +0100, Al Viro wrote:
> > I hope that infrastructure part is stable enough to put it into never-rebased
> > state.  Some of per-architecture branches might be even done right; however,
> > most of them got no testing whatsoever, so any help with testing (as well
> > as "Al, for fuck sake, dump that garbage of yours, here's the correct patch"
> > from maintainers) would be very welcome.  So would the review, of course.
> 
> For the xtensa part:
> Tested-by: Max Filippov <jcmvbkbc@gmail.com>
> 
> I believe that the xtensa part needs the following correction:

Applied.

> ---8<---
> >From 4505d69c3514fb12405409a7943e45831d037960 Mon Sep 17 00:00:00 2001
> From: Max Filippov <jcmvbkbc@gmail.com>
> Date: Tue, 4 Apr 2017 13:20:34 -0700
> Subject: [PATCH] xtensa: fix prefetch in the raw_copy_to_user
> 
> 'from' is the input buffer, it should be prefetched with prefetch, not
> prefetchw.
> 
> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
> ---
>  arch/xtensa/include/asm/uaccess.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
> index 8e93ed8..2e7bac0 100644
> --- a/arch/xtensa/include/asm/uaccess.h
> +++ b/arch/xtensa/include/asm/uaccess.h
> @@ -245,7 +245,7 @@ raw_copy_from_user(void *to, const void __user *from, unsigned long n)
>  static inline unsigned long
>  raw_copy_to_user(void __user *to, const void *from, unsigned long n)
>  {
> -	prefetchw(from);
> +	prefetch(from);
>  	return __xtensa_copy_user((__force void *)to, from, n);
>  }
>  #define INLINE_COPY_FROM_USER
> ---8<---
> 
> -- 
> Thanks.
> -- Max