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Date:   Fri, 26 Apr 2019 10:07:50 +0200 (CEST)
From:   Jiri Kosina <jikos@kernel.org>
To:     Andy Lutomirski <luto@kernel.org>
cc:     Mike Rapoport <rppt@linux.ibm.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Alexandre Chartre <alexandre.chartre@oracle.com>,
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        Linux-MM <linux-mm@kvack.org>,
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Subject: Re: [RFC PATCH 0/7] x86: introduce system calls addess space
 isolation
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On Thu, 25 Apr 2019, Andy Lutomirski wrote:

> The benefit seems to come from making sure that the RET instruction 
> actually goes somewhere that's already been faulted in.

Which doesn't seem to be really compatible with things like retpolines or 
anyone using FTRACE_WITH_REGS to modify stored instruction pointer.

-- 
Jiri Kosina
SUSE Labs