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Date:   Tue, 1 Sep 2020 16:46:41 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Mark Rutland <mark.rutland@arm.com>
Cc:     Josh Poimboeuf <jpoimboe@redhat.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
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        Andrea Arcangeli <aarcange@redhat.com>,
        Waiman Long <longman@redhat.com>,
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        Andrew Cooper <andrew.cooper3@citrix.com>,
        Andy Lutomirski <luto@kernel.org>,
        Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] x86/uaccess: Use pointer masking to limit uaccess
 speculation
Message-ID: <20200901144641.GA28580@lst.de>
References: <f12e7d3cecf41b2c29734ea45a393be21d4a8058.1597848273.git.jpoimboe@redhat.com> <20200901140208.GA95447@C02TD0UTHF1T.local>
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On Tue, Sep 01, 2020 at 03:02:08PM +0100, Mark Rutland wrote:
> One thing to consider is whether you need a speculation barrier after
> set_fs(). Otherwise for code like:

FYI, at least for x86 and powerpc I have a pending series to kill
set_fs().  I'd love to see someone help with the arm/arm64 side, otherwise
I'll try to get to it eventually.