linux-kernel - Re: [PATCH RFC V2 12/17] memremap: Add zone device access protection

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200718050650.GT3008823@iweiny-DESK2.sc.intel.com>
Date:   Fri, 17 Jul 2020 22:06:50 -0700
From:   Ira Weiny <ira.weiny@...el.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Andy Lutomirski <luto@...nel.org>, x86@...nel.org,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Fenghua Yu <fenghua.yu@...el.com>, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-nvdimm@...ts.01.org,
        linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        linux-kselftest@...r.kernel.org
Subject: Re: [PATCH RFC V2 12/17] memremap: Add zone device access protection

On Fri, Jul 17, 2020 at 11:10:53AM +0200, Peter Zijlstra wrote:
> On Fri, Jul 17, 2020 at 12:20:51AM -0700, ira.weiny@...el.com wrote:
> > +static pgprot_t dev_protection_enable_get(struct dev_pagemap *pgmap, pgprot_t prot)
> > +{
> > +	if (pgmap->flags & PGMAP_PROT_ENABLED && dev_page_pkey != PKEY_INVALID) {
> > +		pgprotval_t val = pgprot_val(prot);
> > +
> > +		static_branch_inc(&dev_protection_static_key);
> > +		prot = __pgprot(val | _PAGE_PKEY(dev_page_pkey));
> > +	}
> > +	return prot;
> > +}
> 
> Every other pgprot modifying function is called pgprot_*(), although I
> suppose we have the exceptions phys_mem_access_prot() and dma_pgprot().

Yea...  this function kind of morphed.  The issue is that this is also a 'get'
with a corresponding 'put'.  So I'm at a loss for what makes sense between the
2 functions.

> 
> How about we call this one devm_pgprot() ?

Dan Williams mentioned to me that the devm is not an appropriate prefix.  Thus
the 'dev' prefix instead.

How about dev_pgprot_{get,put}()?

Ira