From: Christoph Hellwig <hch@lst.de>
To: Matthew Wilcox <willy@infradead.org>
Cc: Arnd Bergmann <arnd@kernel.org>,
Grygorii Strashko <grygorii.strashko@ti.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Ilias Apalodimas <ilias.apalodimas@linaro.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
David Laight <David.Laight@aculab.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
Matteo Croce <mcroce@linux.microsoft.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
Christoph Hellwig <hch@lst.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/1] mm: Fix struct page layout on 32-bit systems
Date: Mon, 19 Apr 2021 08:34:41 +0200 [thread overview]
Message-ID: <20210419063441.GA18787@lst.de> (raw)
In-Reply-To: <20210416152755.GL2531743@casper.infradead.org>
On Fri, Apr 16, 2021 at 04:27:55PM +0100, Matthew Wilcox wrote:
> On Thu, Apr 15, 2021 at 08:08:32PM +0200, Jesper Dangaard Brouer wrote:
> > See below patch. Where I swap32 the dma address to satisfy
> > page->compound having bit zero cleared. (It is the simplest fix I could
> > come up with).
>
> I think this is slightly simpler, and as a bonus code that assumes the
> old layout won't compile.
So, why do we even do this crappy overlay of a dma address? This just
all seems like a giant hack. Random subsystems should not just steal
a few struct page fields as that just turns into the desasters like the
one we've seen here or probably something worse next time.
next prev parent reply other threads:[~2021-04-19 6:35 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-10 20:52 [PATCH 0/1] Fix struct page layout on 32-bit systems Matthew Wilcox (Oracle)
2021-04-10 20:52 ` [PATCH 1/1] mm: " Matthew Wilcox (Oracle)
2021-04-11 9:43 ` Jesper Dangaard Brouer
2021-04-11 10:33 ` Matthew Wilcox
2021-04-12 1:15 ` Matthew Wilcox
2021-04-14 8:10 ` Jesper Dangaard Brouer
2021-04-14 11:50 ` Matthew Wilcox
2021-04-14 11:56 ` Ilias Apalodimas
2021-04-14 15:52 ` David Laight
2021-04-14 19:13 ` Jesper Dangaard Brouer
2021-04-14 21:35 ` Matthew Wilcox
2021-04-14 21:56 ` David Laight
2021-04-15 18:08 ` Jesper Dangaard Brouer
2021-04-15 18:21 ` Matthew Wilcox
2021-04-15 21:11 ` David Laight
2021-04-15 22:22 ` Matthew Wilcox
2021-04-16 7:32 ` David Laight
2021-04-16 11:05 ` Matthew Wilcox
2021-04-16 15:27 ` Matthew Wilcox
2021-04-16 17:08 ` Jesper Dangaard Brouer
2021-04-17 3:19 ` Matthew Wilcox
2021-04-17 10:31 ` Arnd Bergmann
2021-04-17 13:56 ` Matthew Wilcox
2021-04-17 17:30 ` Arnd Bergmann
2021-04-17 10:59 ` David Laight
2021-04-19 6:34 ` Christoph Hellwig [this message]
2021-04-19 7:15 ` Ilias Apalodimas
2021-04-12 18:23 ` Matthew Wilcox
2021-04-13 8:21 ` David Laight
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