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Date:   Wed, 22 Jul 2020 08:10:44 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Christoph Hellwig <hch@lst.de>, mcgrof@kernel.org,
        linux-kernel@vger.kernel.org,
        "Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH] kernel: add a kernel_wait helper
Message-ID: <20200722061044.GA24678@lst.de>
References: <20200721130449.5008-1-hch@lst.de> <20200721141838.12d19fce025c842138140324@linux-foundation.org>
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On Tue, Jul 21, 2020 at 02:18:38PM -0700, Andrew Morton wrote:
> On Tue, 21 Jul 2020 15:04:49 +0200 Christoph Hellwig <hch@lst.de> wrote:
> 
> > Add a helper that waits for a pid and stores the status in the passed
> > in kernel pointer.  Use it to fix the usage of kernel_wait4 in
> > call_usermodehelper_exec_sync that only happens to work due to the
> > implicit set_fs(KERNEL_DS) for kernel threads.
> 
> I guess it's cleaner, although it's a bit sad to be adding code to
> address a non-problem.
> 
> Did you consider a simpler kernel_wait() which just wraps a
> set_fs(KERNEL_DS) around a call to kernel_wait4()?

I'm about to kill set_fs and this one of the last users in linux-next..