From: Jarkko Sakkinen <jarkko@kernel.org>
To: "Yu, Yu-cheng" <yu-cheng.yu@intel.com>
Cc: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-api@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Andy Lutomirski <luto@kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Borislav Petkov <bp@alien8.de>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Eugene Syromiatnikov <esyr@redhat.com>,
Florian Weimer <fweimer@redhat.com>,
"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadav Amit <nadav.amit@gmail.com>,
Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
Dave Martin <Dave.Martin@arm.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Pengfei Xu <pengfei.xu@intel.com>,
Haitao Huang <haitao.huang@intel.com>
Subject: Re: [PATCH v23 9/9] x86/vdso: Add ENDBR to __vdso_sgx_enter_enclave
Date: Wed, 17 Mar 2021 03:42:15 +0200 [thread overview]
Message-ID: <YFFedzHcV/zL883v@kernel.org> (raw)
In-Reply-To: <b523b794-3553-f7bb-3a69-24d936f0fefa@intel.com>
On Tue, Mar 16, 2021 at 12:27:19PM -0700, Yu, Yu-cheng wrote:
> On 3/16/2021 12:22 PM, Jarkko Sakkinen wrote:
> > On Tue, Mar 16, 2021 at 08:13:19AM -0700, Yu-cheng Yu wrote:
> > > ENDBR is a special new instruction for the Indirect Branch Tracking (IBT)
> > > component of CET. IBT prevents attacks by ensuring that (most) indirect
> > > branches and function calls may only land at ENDBR instructions. Branches
> > > that don't follow the rules will result in control flow (#CF) exceptions.
> > >
> > > ENDBR is a noop when IBT is unsupported or disabled. Most ENDBR
> > > instructions are inserted automatically by the compiler, but branch
> > > targets written in assembly must have ENDBR added manually.
> > >
> > > Add ENDBR to __vdso_sgx_enter_enclave() branch targets.
> > >
> > > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
> > > Cc: Andy Lutomirski <luto@kernel.org>
> > > Cc: Borislav Petkov <bp@alien8.de>
> > > Cc: Dave Hansen <dave.hansen@linux.intel.com>
> > > Cc: Jarkko Sakkinen <jarkko@kernel.org>
> > > Cc: Peter Zijlstra <peterz@infradead.org>
> > > ---
> > > arch/x86/entry/vdso/vsgx.S | 4 ++++
> > > 1 file changed, 4 insertions(+)
> > >
> > > diff --git a/arch/x86/entry/vdso/vsgx.S b/arch/x86/entry/vdso/vsgx.S
> > > index 86a0e94f68df..1baa9b49053e 100644
> > > --- a/arch/x86/entry/vdso/vsgx.S
> > > +++ b/arch/x86/entry/vdso/vsgx.S
> > > @@ -6,6 +6,7 @@
> > > #include <asm/enclu.h>
> > > #include "extable.h"
> > > +#include "../calling.h"
> > > /* Relative to %rbp. */
> > > #define SGX_ENCLAVE_OFFSET_OF_RUN 16
> > > @@ -27,6 +28,7 @@
> > > SYM_FUNC_START(__vdso_sgx_enter_enclave)
> > > /* Prolog */
> > > .cfi_startproc
> > > + ENDBR
> > > push %rbp
> > > .cfi_adjust_cfa_offset 8
> > > .cfi_rel_offset %rbp, 0
> > > @@ -62,6 +64,7 @@ SYM_FUNC_START(__vdso_sgx_enter_enclave)
> > > .Lasync_exit_pointer:
> > > .Lenclu_eenter_eresume:
> > > enclu
> > > + ENDBR
> > > /* EEXIT jumps here unless the enclave is doing something fancy. */
> > > mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rbx
> > > @@ -91,6 +94,7 @@ SYM_FUNC_START(__vdso_sgx_enter_enclave)
> > > jmp .Lout
> > > .Lhandle_exception:
> > > + ENDBR
> > > mov SGX_ENCLAVE_OFFSET_OF_RUN(%rbp), %rbx
> > > /* Set the exception info. */
> > > --
> > > 2.21.0
> > >
> > >
> >
> > Looks good to me.
> >
> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
>
> Thanks for reviewing. In response to Dave's and Boris' comments, I will
> replace ENDBR macro with _CET_ENDBR that comes from the compiler. Can I
> still keep the Reviewed-by?
I'll rather re-ack, thanks. Most likely give reviewed-by but I always
prefer to see the code change before doing that.
/Jarkko
prev parent reply other threads:[~2021-03-17 1:43 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 15:13 [PATCH v23 0/9] Control-flow Enforcement: Indirect Branch Tracking Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 1/9] x86/cet/ibt: Update Kconfig for user-mode " Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 2/9] x86/cet/ibt: User-mode Indirect Branch Tracking support Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 3/9] x86/cet/ibt: Handle signals for Indirect Branch Tracking Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 4/9] x86/cet/ibt: Update ELF header parsing " Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 5/9] x86/cet/ibt: Update arch_prctl functions " Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 6/9] x86/entry: Introduce ENDBR macro Yu-cheng Yu
2021-03-16 15:49 ` Dave Hansen
2021-03-16 17:12 ` Yu, Yu-cheng
2021-03-16 17:28 ` Dave Hansen
2021-03-16 17:44 ` Yu, Yu-cheng
2021-03-16 17:46 ` Dave Hansen
2021-03-16 17:30 ` Borislav Petkov
2021-03-16 17:42 ` Yu, Yu-cheng
2021-03-16 19:57 ` Peter Zijlstra
2021-03-16 20:05 ` Yu, Yu-cheng
2021-03-16 20:15 ` Peter Zijlstra
2021-03-16 20:26 ` Yu, Yu-cheng
2021-03-16 21:01 ` Yu, Yu-cheng
2021-03-16 21:01 ` Peter Zijlstra
2021-03-16 15:13 ` [PATCH v23 7/9] x86/vdso/32: Add ENDBR to __kernel_vsyscall entry point Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 8/9] x86/vdso: Insert endbr32/endbr64 to vDSO Yu-cheng Yu
2021-03-16 15:13 ` [PATCH v23 9/9] x86/vdso: Add ENDBR to __vdso_sgx_enter_enclave Yu-cheng Yu
2021-03-16 19:22 ` Jarkko Sakkinen
2021-03-16 19:27 ` Yu, Yu-cheng
2021-03-17 1:42 ` Jarkko Sakkinen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YFFedzHcV/zL883v@kernel.org \
--to=jarkko@kernel.org \
--cc=Dave.Martin@arm.com \
--cc=arnd@arndb.de \
--cc=bp@alien8.de \
--cc=bsingharora@gmail.com \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=esyr@redhat.com \
--cc=fweimer@redhat.com \
--cc=gorcunov@gmail.com \
--cc=haitao.huang@intel.com \
--cc=hjl.tools@gmail.com \
--cc=hpa@zytor.com \
--cc=jannh@google.com \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mike.kravetz@oracle.com \
--cc=mingo@redhat.com \
--cc=nadav.amit@gmail.com \
--cc=oleg@redhat.com \
--cc=pavel@ucw.cz \
--cc=pengfei.xu@intel.com \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=rdunlap@infradead.org \
--cc=tglx@linutronix.de \
--cc=vedvyas.shanbhogue@intel.com \
--cc=weijiang.yang@intel.com \
--cc=x86@kernel.org \
--cc=yu-cheng.yu@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).