Juno: Initialize stack protector canary from the trusted entropy source
Change-Id: I7f3e4bfd46613c6311ba4015d56705414fd6feab
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
diff --git a/plat/arm/board/juno/juno_def.h b/plat/arm/board/juno/juno_def.h
index d7e2ac6..a8e9872 100644
--- a/plat/arm/board/juno/juno_def.h
+++ b/plat/arm/board/juno/juno_def.h
@@ -83,6 +83,7 @@
#define TRNG_INTMASK 0x14
#define TRNG_CONFIG 0x18
#define TRNG_CONTROL 0x1C
+#define TRNG_NBYTES 16 /* Number of bytes generated per round. */
/*******************************************************************************
* MMU-401 related constants
diff --git a/plat/arm/board/juno/juno_stack_protector.c b/plat/arm/board/juno/juno_stack_protector.c
new file mode 100644
index 0000000..720a522
--- /dev/null
+++ b/plat/arm/board/juno/juno_stack_protector.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <arch_helpers.h>
+#include <debug.h>
+#include <utils.h>
+#include "juno_decl.h"
+#include "juno_def.h"
+
+u_register_t plat_get_stack_protector_canary(void)
+{
+ u_register_t c[TRNG_NBYTES / sizeof(u_register_t)];
+ u_register_t ret = 0;
+ size_t i;
+
+ if (juno_getentropy(c, sizeof(c)) != 0) {
+ ERROR("Not enough entropy to initialize canary value\n");
+ panic();
+ }
+
+ /*
+ * On Juno we get 128-bits of entropy in one round.
+ * Fuse the values together to form the canary.
+ */
+ for (i = 0; i < ARRAY_SIZE(c); i++)
+ ret ^= c[i];
+ return ret;
+}
diff --git a/plat/arm/board/juno/platform.mk b/plat/arm/board/juno/platform.mk
index 924a402..161443b 100644
--- a/plat/arm/board/juno/platform.mk
+++ b/plat/arm/board/juno/platform.mk
@@ -42,6 +42,9 @@
plat/arm/board/juno/juno_trng.c \
plat/arm/common/arm_tzc400.c
+ifneq (${ENABLE_STACK_PROTECTOR}, 0)
+JUNO_SECURITY_SOURCES += plat/arm/board/juno/juno_stack_protector.c
+endif
PLAT_INCLUDES := -Iplat/arm/board/juno/include
@@ -52,7 +55,8 @@
lib/cpus/aarch64/cortex_a72.S \
plat/arm/board/juno/juno_bl1_setup.c \
plat/arm/board/juno/juno_err.c \
- ${JUNO_INTERCONNECT_SOURCES}
+ ${JUNO_INTERCONNECT_SOURCES} \
+ ${JUNO_SECURITY_SOURCES}
BL2_SOURCES += plat/arm/board/juno/juno_err.c \
${JUNO_SECURITY_SOURCES}