From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 03 Jun 2019 07:44:55 +0000
Subject: Re: [PATCH 10/16] sparc64: use the generic get_user_pages_fast code
Message-Id: <20190603074455.GC22920@lst.de>
List-Id: <linux-sh.vger.kernel.org>
References: <20190601074959.14036-1-hch@lst.de> <20190601074959.14036-11-hch@lst.de>
In-Reply-To: <20190601074959.14036-11-hch@lst.de>
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To: Hillf Danton <hdanton@sina.com>
Cc: Christoph Hellwig <hch@lst.de>, Linus Torvalds <torvalds@linux-foundation.org>, Paul Burton <paul.burton@mips.com>, James Hogan <jhogan@kernel.org>, Yoshinori Sato <ysato@users.sourceforge.jp>, Rich Felker <dalias@libc.org>, "David S. Miller" <davem@davemloft.net>, Nicholas Piggin <npiggin@gmail.com>, Khalid Aziz <khalid.aziz@oracle.com>, Andrey Konovalov <andreyknvl@google.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>, linux-mips@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org

On Sun, Jun 02, 2019 at 03:39:48PM +0800, Hillf Danton wrote:
> 
> Hi Christoph 
> 
> On Sat,  1 Jun 2019 09:49:53 +0200 Christoph Hellwig wrote:
> > 
> > diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
> > index a93eca29e85a..2301ab5250e4 100644
> > --- a/arch/sparc/include/asm/pgtable_64.h
> > +++ b/arch/sparc/include/asm/pgtable_64.h
> > @@ -1098,6 +1098,24 @@ static inline unsigned long untagged_addr(unsigned long start)
> >  }
> >  #define untagged_addr untagged_addr
> >  
> > +static inline bool pte_access_permitted(pte_t pte, bool write)
> > +{
> > +	u64 prot;
> > +
> > +	if (tlb_type = hypervisor) {
> > +		prot = _PAGE_PRESENT_4V | _PAGE_P_4V;
> > +		if (prot)
> 
> Feel free to correct me if I misread or miss anything.
> It looks like a typo: s/prot/write/, as checking _PAGE_PRESENT_4V and
> _PAGE_P_4V makes prot always have _PAGE_WRITE_4V set, regardless of write.

True, the if prot should be if write.