linux-kernel - Re: [PATCH v2 1/4] highmem: Enhance is_kmap_addr() to check kmap_local

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Message-ID: <63dea5f637532_f9c512941c@iweiny-mobl.notmuch>
Date:   Sat, 4 Feb 2023 10:37:42 -0800
From:   Ira Weiny <ira.weiny@...el.com>
To:     Christoph Hellwig <hch@....de>, Ira Weiny <ira.weiny@...el.com>
CC:     Sumit Garg <sumit.garg@...aro.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Al Viro <viro@...iv.linux.org.uk>,
        "Christoph Hellwig" <hch@....de>, <linux-kernel@...r.kernel.org>,
        <op-tee@...ts.trustedfirmware.org>, <linux-mm@...ck.org>,
        Jens Wiklander <jens.wiklander@...aro.org>,
        "Fabio M. De Francesco" <fmdefrancesco@...il.com>,
        John Hubbard <jhubbard@...dia.com>,
        Matthew Wilcox <willy@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v2 1/4] highmem: Enhance is_kmap_addr() to check
 kmap_local_page() mappings

Christoph Hellwig wrote:
> On Fri, Feb 03, 2023 at 08:06:32PM -0800, Ira Weiny wrote:
> > -	return addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP);
> > +
> > +	return (addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP)) ||
> > +		(addr >= __fix_to_virt(FIX_KMAP_END) &&
> > +		 addr < __fix_to_virt(FIX_KMAP_BEGIN));
> 
> Isn't the second check inverted?
> 

The enum map runs from top down.  So I believe this is correct.  I tested
it with a different series and it worked.

Ira