[patch] 26_all_enable-cet.patch (fixed)

file_828400.txt (text/plain), 1.90 KB, created by Sam James on 2021-12-28 03:48:51 UTC

From 83efc6ce009021f27b602c1dfcf65338f761b095 Mon Sep 17 00:00:00 2001
From: Sam James <[e-mail]>
Date: Tue, 28 Dec 2021 03:42:53 +0000
Subject: [PATCH] Enable CET (-fcf-protection=full) by default

Needs:
- CET to be enabled for GCC
- -DEXTRA_OPTIONS_CF to be passed during build (via toolchain.eclass)
  for now to avoid accidentally enabling it on other arches.

  Only supported on amd64.

---
 gcc/config/i386/i386-options.c |  3 +++
 gcc/defaults.h                 | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/gcc/config/i386/i386-options.c b/gcc/config/i386/i386-options.c
index 19632b5..fac61af 100644
--- a/gcc/config/i386/i386-options.c
+++ b/gcc/config/i386/i386-options.c
@@ -3049,6 +3049,9 @@ ix86_option_override_internal (bool main_args_p,
         = build_target_option_node (opts, opts_set);
     }
 
+  if (TARGET_64BIT && TARGET_CMOV)
+    SET_OPTION_IF_UNSET (opts, opts_set, flag_cf_protection, DEFAULT_FLAG_CF);
+
   if (opts->x_flag_cf_protection != CF_NONE)
     {
       if ((opts->x_flag_cf_protection & CF_BRANCH) == CF_BRANCH
diff --git a/gcc/defaults.h b/gcc/defaults.h
index 0f6cd78..5694412 100644
--- a/gcc/defaults.h
+++ b/gcc/defaults.h
@@ -1463,6 +1463,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define DEFAULT_FLAG_SCP 0
 #endif
 
+/* Default value for flag_cf_protection when flag_cf_protection is
+   initialized to CF_FULL.
+
+   We use a new option (EXTRA_OPTIONS_CF) here to avoid turning
+   this on accidentally for other arches. */
+#ifdef EXTRA_OPTIONS_CF
+#define DEFAULT_FLAG_CF CF_FULL
+#endif
+#ifndef DEFAULT_FLAG_CF
+#define DEFAULT_FLAG_CF CF_NONE
+#endif
+
+
 /* By default, the C++ compiler will use function addresses in the
    vtable entries.  Setting this nonzero tells the compiler to use
    function descriptors instead.  The value of this macro says how
-- 
2.34.1