linux-kernel - RE: [PATCH v2 0/4] vmalloc: Improve vmalloc(4MB) performance

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Message-ID: <38da93959bc948c992fc7fc1efd4d25c@AcuMS.aculab.com>
Date:   Thu, 25 Mar 2021 15:59:56 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     "'Matthew Wilcox (Oracle)'" <willy@...radead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Andrew Morton" <akpm@...ux-foundation.org>,
        Christoph Lameter <cl@...ux.com>,
        "Pekka Enberg" <penberg@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        "Joonsoo Kim" <iamjoonsoo.kim@....com>,
        Vlastimil Babka <vbabka@...e.cz>,
        "Uladzislau Rezki" <urezki@...il.com>,
        Nicholas Piggin <npiggin@...il.com>
Subject: RE: [PATCH v2 0/4] vmalloc: Improve vmalloc(4MB) performance

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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