Message-ID: <1437491241.3214.211.camel@hp.com>
Subject: Re: [PATCH RESEND 2/3] mm, x86: Remove region_is_ram() call from
 ioremap
From: Toshi Kani <toshi.kani@hp.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: mingo@redhat.com, hpa@zytor.com, akpm@linux-foundation.org, travis@sgi.com,
        roland@purestorage.com, dan.j.williams@intel.com, mcgrof@suse.com,
        x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Borislav Petkov <bp@alien8.de>
Date: Tue, 21 Jul 2015 09:07:21 -0600
In-Reply-To: <alpine.DEB.2.11.1507211620250.18576@nanos>
References: <1437088996-28511-1-git-send-email-toshi.kani@hp.com>
	 <1437088996-28511-3-git-send-email-toshi.kani@hp.com>
	 <alpine.DEB.2.11.1507211620250.18576@nanos>
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On Tue, 2015-07-21 at 16:31 +0200, Thomas Gleixner wrote:
> On Thu, 16 Jul 2015, Toshi Kani wrote:
> > Note, removing the call to region_is_ram() is also necessary to
> > fix bugs in region_is_ram().  walk_system_ram_range() requires
> > RAM ranges be page-aligned in the iomem_resource table to work
> > properly.  This restriction has allowed multiple ioremaps to RAM
> > (setup_data) which are page-unaligned.  Using fixed region_is_ram()
> > will cause these callers to start failing.
> 
> Which callers? 

They are the callers I noticed.

 - Multiple ioremap calls from arch/x86/kernel/kdebugfs.c.
 - Multiple ioremap calls from arch/x86/kernel/ksysfs.c.
 - pcibios_add_device()

Thanks,
-Toshi


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