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RE: [PATCH] i386: Don't generate ENDBR if function is only called directly
- From: "Tsimbalist, Igor V" <igor dot v dot tsimbalist at intel dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Uros Bizjak <ubizjak at gmail dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, "Tsimbalist, Igor V" <igor dot v dot tsimbalist at intel dot com>
- Date: Mon, 23 Oct 2017 22:01:56 +0000
- Subject: RE: [PATCH] i386: Don't generate ENDBR if function is only called directly
- Authentication-results: sourceware.org; auth=none
- Dlp-product: dlpe-windows
- Dlp-reaction: no-action
- Dlp-version: 11.0.0.116
- References: <20171022141359.GA15671@gmail.com> <CAFULd4ZGKa-XvobU45zuXCUz+N8HY8GvST=zqHjUYTbnF74ptQ@mail.gmail.com> <D511F25789BA7F4EBA64C8A63891A00291F4796D@IRSMSX102.ger.corp.intel.com> <CAMe9rOpjR2u=EdFEBvOpJy+nV5QYfXRttAi1Xxaitm8xVGWjhQ@mail.gmail.com>
Existing tests cet-label.c cet-switch-2.c cet-sjlj-1.c cet-sjlj-3.c should catch this.
Igor
> -----Original Message-----
> From: H.J. Lu [mailto:hjl.tools@gmail.com]
> Sent: Monday, October 23, 2017 11:50 PM
> To: Tsimbalist, Igor V <igor.v.tsimbalist@intel.com>
> Cc: Uros Bizjak <ubizjak@gmail.com>; gcc-patches@gcc.gnu.org
> Subject: Re: [PATCH] i386: Don't generate ENDBR if function is only called
> directly
>
> On Mon, Oct 23, 2017 at 2:44 PM, Tsimbalist, Igor V
> <igor.v.tsimbalist@intel.com> wrote:
> > The change will skip a whole function from endbr processing by
> rest_of_insert_endbranch,
> > which inserts endbr not only at the beginning of the function but inside the
> function's
> > body also. For example, tests with setjmp should fail.
> >
> > I would suggest to insert the check in rest_of_insert_endbranch function,
> something like this
> >
> > if (!(lookup_attribute ("nocf_check",
> > TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl)))
> > || cgraph_node::get (fun->decl)->only_called_directly_p ())
> >
> > Igor
>
> Can you provide one test for each case to cover all of them?
>
>
> >
> >> -----Original Message-----
> >> From: Uros Bizjak [mailto:ubizjak@gmail.com]
> >> Sent: Monday, October 23, 2017 9:26 PM
> >> To: H.J. Lu <hjl.tools@gmail.com>
> >> Cc: gcc-patches@gcc.gnu.org; Tsimbalist, Igor V
> >> <igor.v.tsimbalist@intel.com>
> >> Subject: Re: [PATCH] i386: Don't generate ENDBR if function is only called
> >> directly
> >>
> >> On Sun, Oct 22, 2017 at 4:13 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> >> > There is no need to insert ENDBR instruction if function is only called
> >> > directly.
> >> >
> >> > OK for trunk if there is no regressions?
> >>
> >> Patch needs to be OK'd by Igor first.
> >>
> >> Uros.
> >>
> >> > H.J.
> >> > ----
> >> > gcc/
> >> >
> >> > PR target/82659
> >> > * config/i386/i386.c (pass_insert_endbranch::gate): Return
> >> > false if function is only called directly.
> >> >
> >> > gcc/testsuite/
> >> >
> >> > PR target/82659
> >> > * gcc.target/i386/pr82659-1.c: New test.
> >> > * gcc.target/i386/pr82659-2.c: Likewise.
> >> > * gcc.target/i386/pr82659-3.c: Likewise.
> >> > * gcc.target/i386/pr82659-4.c: Likewise.
> >> > * gcc.target/i386/pr82659-5.c: Likewise.
> >> > * gcc.target/i386/pr82659-6.c: Likewise.
> >> > ---
> >> > gcc/config/i386/i386.c | 6 ++++--
> >> > gcc/testsuite/gcc.target/i386/pr82659-1.c | 19 +++++++++++++++++++
> >> > gcc/testsuite/gcc.target/i386/pr82659-2.c | 18 ++++++++++++++++++
> >> > gcc/testsuite/gcc.target/i386/pr82659-3.c | 21
> +++++++++++++++++++++
> >> > gcc/testsuite/gcc.target/i386/pr82659-4.c | 15 +++++++++++++++
> >> > gcc/testsuite/gcc.target/i386/pr82659-5.c | 10 ++++++++++
> >> > gcc/testsuite/gcc.target/i386/pr82659-6.c | 19 +++++++++++++++++++
> >> > 7 files changed, 106 insertions(+), 2 deletions(-)
> >> > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-1.c
> >> > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-2.c
> >> > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-3.c
> >> > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-4.c
> >> > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-5.c
> >> > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-6.c
> >> >
> >> > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> >> > index fb0b7e71469..b86504378ae 100644
> >> > --- a/gcc/config/i386/i386.c
> >> > +++ b/gcc/config/i386/i386.c
> >> > @@ -2693,9 +2693,11 @@ public:
> >> > {}
> >> >
> >> > /* opt_pass methods: */
> >> > - virtual bool gate (function *)
> >> > + virtual bool gate (function *fun)
> >> > {
> >> > - return ((flag_cf_protection & CF_BRANCH) && TARGET_IBT);
> >> > + return ((flag_cf_protection & CF_BRANCH)
> >> > + && TARGET_IBT
> >> > + && !cgraph_node::get (fun->decl)->only_called_directly_p ());
> >> > }
> >> >
> >> > virtual unsigned int execute (function *)
> >> > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-1.c
> >> b/gcc/testsuite/gcc.target/i386/pr82659-1.c
> >> > new file mode 100644
> >> > index 00000000000..8f0a6906815
> >> > --- /dev/null
> >> > +++ b/gcc/testsuite/gcc.target/i386/pr82659-1.c
> >> > @@ -0,0 +1,19 @@
> >> > +/* { dg-do compile } */
> >> > +/* { dg-options "-O2 -fcf-protection -mcet" } */
> >> > +/* { dg-final { scan-assembler-times "endbr32" 1 { target ia32 } } } */
> >> > +/* { dg-final { scan-assembler-times "endbr64" 1 { target { ! ia32 } } } } */
> >> > +
> >> > +extern int x;
> >> > +
> >> > +static void
> >> > +__attribute__ ((noinline, noclone))
> >> > +test (int i)
> >> > +{
> >> > + x = i;
> >> > +}
> >> > +
> >> > +void
> >> > +bar (int i)
> >> > +{
> >> > + test (i);
> >> > +}
> >> > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-2.c
> >> b/gcc/testsuite/gcc.target/i386/pr82659-2.c
> >> > new file mode 100644
> >> > index 00000000000..228a20006b6
> >> > --- /dev/null
> >> > +++ b/gcc/testsuite/gcc.target/i386/pr82659-2.c
> >> > @@ -0,0 +1,18 @@
> >> > +/* { dg-do compile } */
> >> > +/* { dg-options "-O2 -fcf-protection -mcet" } */
> >> > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */
> >> > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } */
> >> > +
> >> > +extern int x;
> >> > +
> >> > +void
> >> > +test (int i)
> >> > +{
> >> > + x = i;
> >> > +}
> >> > +
> >> > +void
> >> > +bar (int i)
> >> > +{
> >> > + test (i);
> >> > +}
> >> > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-3.c
> >> b/gcc/testsuite/gcc.target/i386/pr82659-3.c
> >> > new file mode 100644
> >> > index 00000000000..6ae23e40abc
> >> > --- /dev/null
> >> > +++ b/gcc/testsuite/gcc.target/i386/pr82659-3.c
> >> > @@ -0,0 +1,21 @@
> >> > +/* { dg-do compile } */
> >> > +/* { dg-options "-O2 -fcf-protection -mcet" } */
> >> > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */
> >> > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } */
> >> > +
> >> > +extern int x;
> >> > +
> >> > +static void
> >> > +__attribute__ ((noinline, noclone))
> >> > +test (int i)
> >> > +{
> >> > + x = i;
> >> > +}
> >> > +
> >> > +extern __typeof (test) foo __attribute__ ((alias ("test")));
> >> > +
> >> > +void
> >> > +bar (int i)
> >> > +{
> >> > + test (i);
> >> > +}
> >> > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-4.c
> >> b/gcc/testsuite/gcc.target/i386/pr82659-4.c
> >> > new file mode 100644
> >> > index 00000000000..ca87264e98b
> >> > --- /dev/null
> >> > +++ b/gcc/testsuite/gcc.target/i386/pr82659-4.c
> >> > @@ -0,0 +1,15 @@
> >> > +/* { dg-do compile } */
> >> > +/* { dg-options "-O2 -fcf-protection -mcet" } */
> >> > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */
> >> > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } */
> >> > +
> >> > +static void
> >> > +test (void)
> >> > +{
> >> > +}
> >> > +
> >> > +void *
> >> > +bar (void)
> >> > +{
> >> > + return test;
> >> > +}
> >> > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-5.c
> >> b/gcc/testsuite/gcc.target/i386/pr82659-5.c
> >> > new file mode 100644
> >> > index 00000000000..c34eade0f90
> >> > --- /dev/null
> >> > +++ b/gcc/testsuite/gcc.target/i386/pr82659-5.c
> >> > @@ -0,0 +1,10 @@
> >> > +/* { dg-do compile } */
> >> > +/* { dg-options "-O2 -fcf-protection -mcet" } */
> >> > +/* { dg-final { scan-assembler-times "endbr32" 1 { target ia32 } } } */
> >> > +/* { dg-final { scan-assembler-times "endbr64" 1 { target { ! ia32 } } } } */
> >> > +static void
> >> > +test (void)
> >> > +{
> >> > +}
> >> > +
> >> > +void (*test_p) (void) = test;
> >> > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-6.c
> >> b/gcc/testsuite/gcc.target/i386/pr82659-6.c
> >> > new file mode 100644
> >> > index 00000000000..b4ffd65c74f
> >> > --- /dev/null
> >> > +++ b/gcc/testsuite/gcc.target/i386/pr82659-6.c
> >> > @@ -0,0 +1,19 @@
> >> > +/* { dg-do compile } */
> >> > +/* { dg-options "-O2 -fcf-protection -mcet" } */
> >> > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */
> >> > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } */
> >> > +
> >> > +extern int x;
> >> > +
> >> > + __attribute__ ((visibility ("hidden")))
> >> > +void
> >> > +test (int i)
> >> > +{
> >> > + x = i;
> >> > +}
> >> > +
> >> > +void
> >> > +bar (int i)
> >> > +{
> >> > + test (i);
> >> > +}
> >> > --
> >> > 2.13.6
> >> >
>
>
>
> --
> H.J.