From 394df3815e8ceec750fd06583eee4896174ce808 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 24 Jul 2018 12:23:03 -0700
Subject: x86/CET: Extend arch_prctl syscall for CET control

CET arch_prctl bits should be defined in <asm/prctl.h> from Linux kernel
header files.  Add x86 <include/asm/prctl.h> for pre-CET kernel header
files.

Note: sysdeps/unix/sysv/linux/x86/include/asm/prctl.h should be removed
if <asm/prctl.h> from the required kernel header files contains CET
arch_prctl bits.

 /* CET features:
    IBT:   GNU_PROPERTY_X86_FEATURE_1_IBT
    SHSTK: GNU_PROPERTY_X86_FEATURE_1_SHSTK
  */

 /* Return CET features in unsigned long long *addr:
      features: addr[0].
      shadow stack base address: addr[1].
      shadow stack size: addr[2].
  */
 # define ARCH_CET_STATUS		0x3001
 /* Disable CET features in unsigned int features.  */
 # define ARCH_CET_DISABLE		0x3002
 /* Lock all CET features.  */
 # define ARCH_CET_LOCK			0x3003
 /* Allocate a new shadow stack with unsigned long long *addr:
      IN: requested shadow stack size: *addr.
      OUT: allocated shadow stack address: *addr.
  */
 # define ARCH_CET_ALLOC_SHSTK		0x3004
 /* Return legacy region bitmap info in unsigned long long *addr:
     address: addr[0].
     size: addr[1].
  */
 # define ARCH_CET_LEGACY_BITMAP	0x3005

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

	* sysdeps/unix/sysv/linux/x86/include/asm/prctl.h: New file.
	* sysdeps/unix/sysv/linux/x86/cpu-features.c: Include
	<sys/prctl.h> and <asm/prctl.h>.
	(get_cet_status): Call arch_prctl with ARCH_CET_STATUS.
	* sysdeps/unix/sysv/linux/x86/dl-cet.h: Include <sys/prctl.h>
	and <asm/prctl.h>.
	(dl_cet_allocate_legacy_bitmap): Call arch_prctl with
	ARCH_CET_LEGACY_BITMAP.
	(dl_cet_disable_cet): Call arch_prctl with ARCH_CET_DISABLE.
	(dl_cet_lock_cet): Call arch_prctl with ARCH_CET_LOCK.
	* sysdeps/x86/libc-start.c: Include <startup.h>.
---
 sysdeps/x86/libc-start.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'sysdeps/x86/libc-start.c')

diff --git a/sysdeps/x86/libc-start.c b/sysdeps/x86/libc-start.c
index 43aba9d061..eb5335c154 100644
--- a/sysdeps/x86/libc-start.c
+++ b/sysdeps/x86/libc-start.c
@@ -16,6 +16,9 @@
    <http://www.gnu.org/licenses/>.  */
 
 #ifndef SHARED
+/* Define I386_USE_SYSENTER to support syscall during startup in static
+   PIE.  */
+# include <startup.h>
 # include <ldsodefs.h>
 # include <cpu-features.h>
 # include <cpu-features.c>
-- 
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