Re: PING: [PATCH] i386: Insert ENDBR after __morestack call

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, Apr 18, 2018 at 7:00 AM, Tsimbalist, Igor V
<igor.v.tsimbalist@intel.com> wrote:
>> -----Original Message-----
>> From: gcc-patches-owner@gcc.gnu.org [mailto:gcc-patches-
>> owner@gcc.gnu.org] On Behalf Of H.J. Lu
>> Sent: Wednesday, April 18, 2018 3:25 PM
>> To: GCC Patches <gcc-patches@gcc.gnu.org>; Tsimbalist, Igor V
>> <igor.v.tsimbalist@intel.com>
>> Cc: Uros Bizjak <ubizjak@gmail.com>
>> Subject: PING: [PATCH] i386: Insert ENDBR after __morestack call
>>
>> On Fri, Apr 13, 2018 at 5:56 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
>> > Since __morestack will jump back to its callee via indirect call, we
>> > need to insert ENDBR after calling __morestack.
>> >
>> > OK for trunk?
>> >
>> > H.J.
>> > ----
>> > gcc/
>> >
>> >         PR target/85388
>> >         * config/i386/i386.c (ix86_expand_split_stack_prologue): Insert
>> >         ENDBR after calling __morestack.
>> >
>> > gcc/testsuite/
>> >
>> >         PR target/85388
>> >         * gcc.dg/pr85388-1.c: New test.
>> >         * gcc.dg/pr85388-2.c: Likewise.
>> >         * gcc.dg/pr85388-3.c: Likewise.
>> >         * gcc.dg/pr85388-4.c: Likewise.
>> >         * gcc.dg/pr85388-5.c: Likewise.
>> >         * gcc.dg/pr85388-6.c: Likewise.
>> > ---
>> >  gcc/config/i386/i386.c           | 11 ++++++-
>> >  gcc/testsuite/gcc.dg/pr85388-1.c | 50
>> +++++++++++++++++++++++++++++
>> >  gcc/testsuite/gcc.dg/pr85388-2.c | 56
>> ++++++++++++++++++++++++++++++++
>> >  gcc/testsuite/gcc.dg/pr85388-3.c | 65
>> +++++++++++++++++++++++++++++++++++++
>> >  gcc/testsuite/gcc.dg/pr85388-4.c | 69
>> ++++++++++++++++++++++++++++++++++++++++
>> >  gcc/testsuite/gcc.dg/pr85388-5.c | 54
>> +++++++++++++++++++++++++++++++
>> >  gcc/testsuite/gcc.dg/pr85388-6.c | 56
>> ++++++++++++++++++++++++++++++++
>> >  7 files changed, 360 insertions(+), 1 deletion(-)
>> >  create mode 100644 gcc/testsuite/gcc.dg/pr85388-1.c
>> >  create mode 100644 gcc/testsuite/gcc.dg/pr85388-2.c
>> >  create mode 100644 gcc/testsuite/gcc.dg/pr85388-3.c
>> >  create mode 100644 gcc/testsuite/gcc.dg/pr85388-4.c
>> >  create mode 100644 gcc/testsuite/gcc.dg/pr85388-5.c
>> >  create mode 100644 gcc/testsuite/gcc.dg/pr85388-6.c
>> >
>> > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>> > index 03e5c433574..8b4fd8ae30b 100644
>> > --- a/gcc/config/i386/i386.c
>> > +++ b/gcc/config/i386/i386.c
>> > @@ -15242,7 +15242,16 @@ ix86_expand_split_stack_prologue (void)
>> >       instruction--we need control flow to continue at the subsequent
>> >       label.  Therefore, we use an unspec.  */
>> >    gcc_assert (crtl->args.pops_args < 65536);
>> > -  emit_insn (gen_split_stack_return (GEN_INT (crtl->args.pops_args)));
>> > +  rtx_insn *ret_insn
>> > +    = emit_insn (gen_split_stack_return (GEN_INT (crtl->args.pops_args)));
>> > +
>> > +  if ((flag_cf_protection & CF_BRANCH) && TARGET_IBT)
>> > +    {
>> > +      /* Insert ENDBR since __morestack will jump back here via indirect
>> > +        call.  */
>> > +      rtx cet_eb = gen_nop_endbr ();
>> > +      emit_insn_after (cet_eb, ret_insn);
>> > +    }
>> >
>> >    /* If we are in 64-bit mode and this function uses a static chain,
>> >       we saved %r10 in %rax before calling _morestack.  */
>>
>> PING:
>>
>> https://gcc.gnu.org/ml/gcc-patches/2018-04/msg00669.html
>>
>
> OK.

I am going to check it in.

Thanks.

-- 
H.J.