From: Hongtao Liu <crazylht@gmail.com>
To: "H.J. Lu" <hjl.tools@gmail.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [GCC 11 PATCH 0/5] x86: Backport straight-line-speculation mitigation
Date: Wed, 16 Feb 2022 15:01:08 +0800 [thread overview]
Message-ID: <CAMZc-bxpKf_aH66=rHvbYMeVb-oBKogiC_5BHO3ZNEo2mv=9NA@mail.gmail.com> (raw)
In-Reply-To: <20220131185528.619688-1-hjl.tools@gmail.com>
On Tue, Feb 1, 2022 at 2:55 AM H.J. Lu via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Backport -mindirect-branch-cs-prefix:
>
> commit 48a4ae26c225eb018ecb59f131e2c4fd4f3cf89a
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date: Wed Oct 27 06:27:15 2021 -0700
>
> x86: Add -mindirect-branch-cs-prefix
>
> Add -mindirect-branch-cs-prefix to add CS prefix to call and jmp to
> indirect thunk with branch target in r8-r15 registers so that the call
> and jmp instruction length is 6 bytes to allow them to be replaced with
> "lfence; call *%r8-r15" or "lfence; jmp *%r8-r15" at run-time.
>
> commit 63738e176726d31953deb03f7e32cf8b760735ac
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date: Wed Oct 27 07:48:54 2021 -0700
>
> x86: Add -mharden-sls=[none|all|return|indirect-branch]
>
> Add -mharden-sls= to mitigate against straight line speculation (SLS)
> for function return and indirect branch by adding an INT3 instruction
> after function return and indirect branch.
>
> and followup commits to support Linux kernel commits:
>
> commit e463a09af2f0677b9485a7e8e4e70b396b2ffb6f
> Author: Peter Zijlstra <peterz@infradead.org>
> Date: Sat Dec 4 14:43:44 2021 +0100
>
> x86: Add straight-line-speculation mitigation
>
> commit 68cf4f2a72ef8786e6b7af6fd9a89f27ac0f520d
> Author: Peter Zijlstra <peterz@infradead.org>
> Date: Fri Nov 19 17:50:25 2021 +0100
>
> x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds
>
> H.J. Lu (5):
> x86: Remove "%!" before ret
> x86: Add -mharden-sls=[none|all|return|indirect-branch]
> x86: Add -mindirect-branch-cs-prefix
> x86: Rename -harden-sls=indirect-branch to -harden-sls=indirect-jmp
> x86: Generate INT3 for __builtin_eh_return
The patch LGTM.
>
> gcc/config/i386/i386-opts.h | 7 ++++
> gcc/config/i386/i386.c | 38 +++++++++++++------
> gcc/config/i386/i386.md | 2 +-
> gcc/config/i386/i386.opt | 24 ++++++++++++
> gcc/doc/invoke.texi | 18 ++++++++-
> gcc/testsuite/gcc.target/i386/harden-sls-1.c | 14 +++++++
> gcc/testsuite/gcc.target/i386/harden-sls-2.c | 14 +++++++
> gcc/testsuite/gcc.target/i386/harden-sls-3.c | 14 +++++++
> gcc/testsuite/gcc.target/i386/harden-sls-4.c | 16 ++++++++
> gcc/testsuite/gcc.target/i386/harden-sls-5.c | 17 +++++++++
> gcc/testsuite/gcc.target/i386/harden-sls-6.c | 18 +++++++++
> .../i386/indirect-thunk-cs-prefix-1.c | 14 +++++++
> .../i386/indirect-thunk-cs-prefix-2.c | 15 ++++++++
> 13 files changed, 198 insertions(+), 13 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/harden-sls-1.c
> create mode 100644 gcc/testsuite/gcc.target/i386/harden-sls-2.c
> create mode 100644 gcc/testsuite/gcc.target/i386/harden-sls-3.c
> create mode 100644 gcc/testsuite/gcc.target/i386/harden-sls-4.c
> create mode 100644 gcc/testsuite/gcc.target/i386/harden-sls-5.c
> create mode 100644 gcc/testsuite/gcc.target/i386/harden-sls-6.c
> create mode 100644 gcc/testsuite/gcc.target/i386/indirect-thunk-cs-prefix-1.c
> create mode 100644 gcc/testsuite/gcc.target/i386/indirect-thunk-cs-prefix-2.c
>
> --
> 2.34.1
>
--
BR,
Hongtao
next prev parent reply other threads:[~2022-02-16 6:52 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-31 18:55 H.J. Lu
2022-01-31 18:55 ` [GCC 11 PATCH 1/5] x86: Remove "%!" before ret H.J. Lu
2022-02-16 6:46 ` Hongtao Liu
2022-01-31 18:55 ` [GCC 11 PATCH 2/5] x86: Add -mharden-sls=[none|all|return|indirect-branch] H.J. Lu
2022-01-31 18:55 ` [GCC 11 PATCH 3/5] x86: Add -mindirect-branch-cs-prefix H.J. Lu
2022-01-31 18:55 ` [GCC 11 PATCH 4/5] x86: Rename -harden-sls=indirect-branch to -harden-sls=indirect-jmp H.J. Lu
2022-01-31 18:55 ` [GCC 11 PATCH 5/5] x86: Generate INT3 for __builtin_eh_return H.J. Lu
2022-02-01 7:21 ` [GCC 11 PATCH 0/5] x86: Backport straight-line-speculation mitigation Richard Biener
2022-02-01 16:59 ` H.J. Lu
2022-02-02 9:22 ` Richard Biener
2022-02-16 7:01 ` Hongtao Liu [this message]
2022-02-16 13:30 ` H.J. Lu
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