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[91.219.245.39]) by mx.google.com with ESMTPS id 22si16639103wmi.44.2019.04.26.01.08.12 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 26 Apr 2019 01:08:13 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning jikos@kernel.org does not designate 91.219.245.39 as permitted sender) client-ip=91.219.245.39; Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning jikos@kernel.org does not designate 91.219.245.39 as permitted sender) smtp.mailfrom=jikos@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from twin.jikos.cz (jikos@[127.0.0.1]) by twin.jikos.cz (8.13.6/8.13.6) with ESMTP id x3Q87p6T000940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 26 Apr 2019 10:07:52 +0200 Received: from localhost (jikos@localhost) by twin.jikos.cz (8.13.6/8.13.6/Submit) with ESMTP id x3Q87oY9000925; Fri, 26 Apr 2019 10:07:50 +0200 X-Authentication-Warning: twin.jikos.cz: jikos owned process doing -bs Date: Fri, 26 Apr 2019 10:07:50 +0200 (CEST) From: Jiri Kosina To: Andy Lutomirski cc: Mike Rapoport , LKML , Alexandre Chartre , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , James Bottomley , Jonathan Adams , Kees Cook , Paul Turner , Peter Zijlstra , Thomas Gleixner , Linux-MM , LSM List , X86 ML Subject: Re: [RFC PATCH 0/7] x86: introduce system calls addess space isolation In-Reply-To: Message-ID: References: <1556228754-12996-1-git-send-email-rppt@linux.ibm.com> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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