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From:   David Laight <David.Laight@ACULAB.COM>
To:     "'Matthew Wilcox (Oracle)'" <willy@infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>
CC:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Andrew Morton" <akpm@linux-foundation.org>,
        Christoph Lameter <cl@linux.com>,
        "Pekka Enberg" <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        "Joonsoo Kim" <iamjoonsoo.kim@lge.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Uladzislau Rezki" <urezki@gmail.com>,
        Nicholas Piggin <npiggin@gmail.com>
Subject: RE: [PATCH v2 0/4] vmalloc: Improve vmalloc(4MB) performance
Thread-Topic: [PATCH v2 0/4] vmalloc: Improve vmalloc(4MB) performance
Thread-Index: AQHXIL93smWggbtuakOz/LFGaMnBoqqU3Ndw
Date:   Thu, 25 Mar 2021 15:59:56 +0000
Message-ID: <38da93959bc948c992fc7fc1efd4d25c@AcuMS.aculab.com>
References: <20210324150518.2734402-1-willy@infradead.org>
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From: Matthew Wilcox
> Sent: 24 March 2021 15:05
> 
> I may have gone a little too far with the first patch.  It turns out we
> have a lot of code using the vmalloc caller functionality, and I decided
> to convert it all to unsigned long instead of leaving some paths as void *
> and casting later.

What is the 'address of the caller' needed for?
If it gets printed anywhere it ought to be a pointer type
throughout so that it will get hashed and not leak the
real address.

Even then it is probably better to use a typed pointer
(eg to an undefined structure) than 'void *'.
That might also pick up more incorrect uses.

Of course things like _RET_IP_ would need changing to return
the same pointer type.

	David

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