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Date: Mon, 6 Apr 2020 14:02:38 +0100
From: Al Viro <viro@zeniv.linux.org.uk>
To: Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 3/6] binfmt_elf: remove the set_fs(KERNEL_DS) in
 elf_core_dump
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Cc: Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org,
 Jeremy Kerr <jk@ozlabs.org>, linux-fsdevel@vger.kernel.org,
 Andrew Morton <akpm@linux-foundation.org>, linuxppc-dev@lists.ozlabs.org
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 <linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org>

On Mon, Apr 06, 2020 at 02:03:09PM +0200, Christoph Hellwig wrote:
> There is no logic in elf_core_dump itself that uses uaccess routines
> on kernel pointers, the file writes are nicely encapsulated in dump_emit
> which does its own set_fs.

... assuming you've checked the asm/elf.h to see that nobody is playing
silly buggers in these forests of macros and the stuff called from those.
Which is a feat that ought to be mentioned in commit message...