Merge pull request #1325 from michpappas/tf-issues#568_qemu_add_ENABLE_STACK_PROTECTOR

qemu: Add support for stack canary protection

plat/qemu/include/platform_def.h

@@ -75,7 +75,7 @@
 #define NS_DRAM0_SIZE			0x3de00000
 
 #define SEC_SRAM_BASE			0x0e000000
-#define SEC_SRAM_SIZE			0x00040000
+#define SEC_SRAM_SIZE			0x00060000
 
 #define SEC_DRAM_BASE			0x0e100000
 #define SEC_DRAM_SIZE			0x00f00000
@@ -123,7 +123,7 @@
  * Put BL2 just below BL3-1. BL2_BASE is calculated using the current BL2 debug
  * size plus a little space for growth.
  */
-#define BL2_BASE			(BL31_BASE - 0x1D000)
+#define BL2_BASE			(BL31_BASE - 0x25000)
 #define BL2_LIMIT			BL31_BASE
 
 /*

plat/qemu/platform.mk

@@ -169,6 +169,10 @@ $(eval $(call TOOL_ADD_IMG,bl32_extra2,--tos-fw-extra2))
 endif
 
 SEPARATE_CODE_AND_RODATA := 1
+ENABLE_STACK_PROTECTOR	 := 0
+ifneq ($(ENABLE_STACK_PROTECTOR), 0)
+	PLAT_BL_COMMON_SOURCES += plat/qemu/qemu_stack_protector.c
+endif
 
 # Use MULTI_CONSOLE_API by default only on AArch64
 # as it is not yet supported on AArch32

plat/qemu/qemu_stack_protector.c

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <platform.h>
+#include <stdint.h>
+
+#define RANDOM_CANARY_VALUE ((u_register_t) 3288484550995823360ULL)
+
+u_register_t plat_get_stack_protector_canary(void)
+{
+	/*
+	 * Ideally, a random number should be returned instead of the
+	 * combination of a timer's value and a compile-time constant.
+	 * As the virt platform does not have any random number generator,
+	 * this is better than nothing but not necessarily really secure.
+	 */
+	return RANDOM_CANARY_VALUE ^ read_cntpct_el0();
+}
+