From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 9D07D385840D; Wed, 27 Oct 2021 19:59:21 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9D07D385840D
From: "peterz at infradead dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/102952] New code-gen options for retpolines and straight
 line speculation
Date: Wed, 27 Oct 2021 19:59:21 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: peterz at infradead dot org
X-Bugzilla-Status: WAITING
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: hjl.tools at gmail dot com
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cc
Message-ID: <bug-102952-4-ahJGnLPtPs@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-102952-4@http.gcc.gnu.org/bugzilla/>
References: <bug-102952-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Wed, 27 Oct 2021 19:59:21 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102952

peterz at infradead dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |peterz at infradead dot org

--- Comment #7 from peterz at infradead dot org ---
(In reply to H.J. Lu from comment #3)
> Created attachment 51678 [details]
> A patch to add -mharden-sls=3D
>=20
> x86: Add -mharden-sls=3D[none|all|return|indirect-branch]
>=20
> Generate code to mitigate against straight line speculation.

I'm getting (a lot) spurious int3 instructions with this, for example:

0000000000000280 <do_SYSENTER_32>:
 280:   48 81 8f 90 00 00 00 00 02 00 00        orq    $0x200,0x90(%rdi)
 28b:   48 8b 47 20             mov    0x20(%rdi),%rax
 28f:   48 89 87 98 00 00 00    mov    %rax,0x98(%rdi)
 296:   e9 75 ff ff ff          jmp    210 <do_fast_syscall_32>
 29b:   cc                      int3

That's not an *indirect* jump there.=