Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Peter Zijlstra <peterz@infradead.org>,
        Sami Tolvanen <samitolvanen@google.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Joao Moreira <joao@overdrivepizza.com>,
        LKML <linux-kernel@vger.kernel.org>,
        the arch/x86 maintainers <x86@kernel.org>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        "Cooper, Andrew" <andrew.cooper3@citrix.com>,
        Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
        Johannes Wikner <kwikner@ethz.ch>,
        Alyssa Milburn <alyssa.milburn@linux.intel.com>,
        Jann Horn <jannh@google.com>, "H.J. Lu" <hjl.tools@gmail.com>,
        "Moreira, Joao" <joao.moreira@intel.com>,
        "Nuzman, Joseph" <joseph.nuzman@intel.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        "Gross, Jurgen" <jgross@suse.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Peter Collingbourne <pcc@google.com>,
        Kees Cook <keescook@chromium.org>
Subject: Re: [patch 00/38] x86/retbleed: Call depth tracking mitigation
In-Reply-To: <Ytl2vg15Hc0fh8Dl@worktop.programming.kicks-ass.net>
References: <2f7f899cb75b79b08b0662ff4d2cb877@overdrivepizza.com>
 <CABCJKudvSv9bAOrDLHki5XPYNJK6=PS-x8v=E08es8w4LJpxBw@mail.gmail.com>
 <87fsiyuhyz.ffs@tglx>
 <CAHk-=wjEDJ4+xg0CWR7CaCKnO6Nhzn+vjJy7CjaVmf9R+g_3ag@mail.gmail.com>
 <CAHk-=wj6U3UamfLLV+rPu1WmKG_w3p0Bg=YbQcG1DxHpmP40Ag@mail.gmail.com>
 <YtXzgWnbTQH48JGR@worktop.programming.kicks-ass.net>
 <CAHk-=wiJNViWKCCrDPByGWmVVXuEKhRGykx4q8diXSxEqGfOMw@mail.gmail.com>
 <CAHk-=wjmUeB=_s6jcBUNoAT4GHv-aF1Mzqa6G1X4k+dcHDs1Mg@mail.gmail.com>
 <Ytbnlms90+LBLbrY@google.com>
 <Ythv7NqofIAHp3bf@worktop.programming.kicks-ass.net>
 <Ytl2vg15Hc0fh8Dl@worktop.programming.kicks-ass.net>
Date:   Sat, 23 Jul 2022 11:50:53 +0200
Message-ID: <87ilnotawy.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Thu, Jul 21 2022 at 17:54, Peter Zijlstra wrote:
> On Wed, Jul 20, 2022 at 11:13:16PM +0200, Peter Zijlstra wrote:
> The idea is the above callthunk that makes any offset work by not having
> the full hash as an immediate and allow kCFI along with
> -fpatchable-function-entry=N,M and include M in the offset.
>
> Specifically, I meant to use -fpatchable-function-entry=16,16, but alas,
> I never got that far.

That's embarrasing. I missed that option in the maze of gcc
options. That would have spared me to stare at gcc code :)