On Wed, Apr 8, 2020 at 9:41 AM Jeff Law <l...@redhat.com> wrote:
>
> On Wed, 2020-04-08 at 09:23 -0700, H.J. Lu wrote:
> > On Wed, Apr 8, 2020 at 9:16 AM Jeff Law <l...@redhat.com> wrote:
> > > On Tue, 2020-03-31 at 08:11 -0700, H.J. Lu via Gcc-patches wrote:
> > > > Since constant_call_address_operand has
> > > >
> > > > ;; Test for a pc-relative call operand
> > > > (define_predicate "constant_call_address_operand"
> > > > (match_code "symbol_ref")
> > > > {
> > > > if (ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC
> > > > || flag_force_indirect_call)
> > > > return false;
> > > > if (TARGET_DLLIMPORT_DECL_ATTRIBUTES && SYMBOL_REF_DLLIMPORT_P (op))
> > > > return false;
> > > > return true;
> > > > })
> > > >
> > > > even if cgraph_node::get (cfun->decl)->only_called_directly_p () returns
> > > > false, the fuction may still be called indirectly. Copy the logic from
> > > > constant_call_address_operand to rest_of_insert_endbranch to insert
> > > > ENDBR
> > > > at function entry if function will be called indirectly.
> > > >
> > > > gcc/
> > > >
> > > > PR target/94417
> > > > * config/i386/i386-features.c (rest_of_insert_endbranch): Insert
> > > > ENDBR at function entry if function will be called indirectly.
> > > Can you just call constant_call_address_operand rather than copying its
> > > contents?
> >
> > I wish I could. constant_call_address_operand uses SYMBOL_REF_DLLIMPORT_P
> > (op)
> > But I need to use DECL_DLLIMPORT_P (cfun->decl)).
> Sigh. In that case I guess the patch is OK as-is.
>
I'd like to backport this wrong code fix to GCC 9/8 branches.
Is it OK for GCC 9/8 branches?
Thanks.
--
H.J.
From f86e27e71fb963aaa95b1da31515f888f6e146f8 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Wed, 8 Apr 2020 09:47:35 -0700
Subject: [PATCH] x86: Insert ENDBR if function will be called indirectly
Since constant_call_address_operand has
;; Test for a pc-relative call operand
(define_predicate "constant_call_address_operand"
(match_code "symbol_ref")
{
if (ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC
|| flag_force_indirect_call)
return false;
if (TARGET_DLLIMPORT_DECL_ATTRIBUTES && SYMBOL_REF_DLLIMPORT_P (op))
return false;
return true;
})
even if cgraph_node::get (cfun->decl)->only_called_directly_p () returns
false, the fuction may still be called indirectly. Copy the logic from
constant_call_address_operand to rest_of_insert_endbranch to insert ENDBR
at function entry if function will be called indirectly.
NB: gcc.target/i386/pr94417-2.c is updated to expect 4 ENDBRs, instead
of 2, since only GCC 10 has the fix for PR target/89355 not to insert
ENDBR after NOTE_INSN_DELETED_LABEL.
gcc/
Backport from master
PR target/94417
* config/i386/i386.c (rest_of_insert_endbranch): Insert ENDBR at
function entry if function will be called indirectly.
gcc/testsuite/
PR target/94417
* gcc.target/i386/pr94417-1.c: New test.
* gcc.target/i386/pr94417-2.c: Likewise.
* gcc.target/i386/pr94417-3.c: Likewise.
(cherry picked from commit c5f379653964a1d2c7037b2de3e947a48370a198)
---
gcc/config/i386/i386.c | 7 ++++++-
gcc/testsuite/gcc.target/i386/pr94417-1.c | 20 ++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr94417-2.c | 21 +++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr94417-3.c | 19 +++++++++++++++++++
4 files changed, 66 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr94417-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr94417-2.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr94417-3.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 5d12d82db5b..3891d44ce85 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -2535,7 +2535,12 @@ rest_of_insert_endbranch (void)
&& (!flag_manual_endbr
|| lookup_attribute ("cf_check",
DECL_ATTRIBUTES (cfun->decl)))
- && !cgraph_node::get (cfun->decl)->only_called_directly_p ())
+ && (!cgraph_node::get (cfun->decl)->only_called_directly_p ()
+ || ix86_cmodel == CM_LARGE
+ || ix86_cmodel == CM_LARGE_PIC
+ || flag_force_indirect_call
+ || (TARGET_DLLIMPORT_DECL_ATTRIBUTES
+ && DECL_DLLIMPORT_P (cfun->decl))))
{
/* Queue ENDBR insertion to x86_function_profiler. */
if (crtl->profile && flag_fentry)
diff --git a/gcc/testsuite/gcc.target/i386/pr94417-1.c b/gcc/testsuite/gcc.target/i386/pr94417-1.c
new file mode 100644
index 00000000000..5bbe057fa8f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr94417-1.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-options "-O2 -fcf-protection -mcmodel=large" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+extern void ext (void);
+
+__attribute((noclone, noinline))
+static
+void
+foo (void)
+{
+ ext ();
+}
+
+void
+bar (void)
+{
+ foo ();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr94417-2.c b/gcc/testsuite/gcc.target/i386/pr94417-2.c
new file mode 100644
index 00000000000..9e9c277e07f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr94417-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target lp64 } */
+/* { dg-require-effective-target fpic } */
+/* { dg-options "-O2 -fpic -mcmodel=large -fcf-protection" } */
+/* { dg-final { scan-assembler-times {\mendbr} 4 } } */
+
+extern void ext (void);
+
+__attribute((noclone, noinline))
+static
+void
+foo (void)
+{
+ ext ();
+}
+
+void
+bar (void)
+{
+ foo ();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr94417-3.c b/gcc/testsuite/gcc.target/i386/pr94417-3.c
new file mode 100644
index 00000000000..07c451796c2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr94417-3.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcf-protection -mforce-indirect-call" } */
+/* { dg-final { scan-assembler-times {\mendbr} 2 } } */
+
+extern void ext (void);
+
+__attribute((noclone, noinline))
+static
+void
+foo (void)
+{
+ ext ();
+}
+
+void
+bar (void)
+{
+ foo ();
+}
--
2.25.2
