BL2: Enable pointer authentication support

The size increase after enabling options related to ARMv8.3-PAuth is:

+----------------------------+-------+-------+-------+--------+
|                            |  text |  bss  |  data | rodata |
+----------------------------+-------+-------+-------+--------+
| CTX_INCLUDE_PAUTH_REGS = 1 |   +40 |   +0  |   +0  |   +0   |
|                            |  0.2% |       |       |        |
+----------------------------+-------+-------+-------+--------+
| ENABLE_PAUTH = 1           |  +664 |   +0  |  +16  |   +0   |
|                            |  3.1% |       |  0.9% |        |
+----------------------------+-------+-------+-------+--------+

Results calculated with the following build configuration:

    make PLAT=fvp SPD=tspd DEBUG=1 \
    SDEI_SUPPORT=1                 \
    EL3_EXCEPTION_HANDLING=1       \
    TSP_NS_INTR_ASYNC_PREEMPT=1    \
    CTX_INCLUDE_PAUTH_REGS=1       \
    ENABLE_PAUTH=1

The changes for BL2_AT_EL3 aren't done in this commit.

Change-Id: I8c803b40c7160525a06173bc6cdca21c4505837d
Signed-off-by: Antonio Nino Diaz <[email protected]>

diff --git a/bl2/aarch32/bl2_entrypoint.S b/bl2/aarch32/bl2_entrypoint.S
index e7b98af32fe77fef41fcbf7b6e5032711fc93032..23d151356512ef17ad2fba83cf923e7443dd1288 100644 (file)
--- a/bl2/aarch32/bl2_entrypoint.S
+++ b/bl2/aarch32/bl2_entrypoint.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -108,16 +108,15 @@ func bl2_entrypoint
 #endif
 
        /* ---------------------------------------------
-        * Perform early platform setup & platform
-        * specific early arch. setup e.g. mmu setup
+        * Perform BL2 setup
         * ---------------------------------------------
         */
        mov     r0, r9
        mov     r1, r10
        mov     r2, r11
        mov     r3, r12
-       bl      bl2_early_platform_setup2
-       bl      bl2_plat_arch_setup
+
+       bl      bl2_setup
 
        /* ---------------------------------------------
         * Jump to main function.

diff --git a/bl2/aarch64/bl2_entrypoint.S b/bl2/aarch64/bl2_entrypoint.S
index d938947c1c55b0e8fc42a766cb012f4b4cb51137..611b8076df14764d1ec5e72090e05b5feb2badde 100644 (file)
--- a/bl2/aarch64/bl2_entrypoint.S
+++ b/bl2/aarch64/bl2_entrypoint.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -106,17 +106,25 @@ func bl2_entrypoint
 #endif
 
        /* ---------------------------------------------
-        * Perform early platform setup & platform
-        * specific early arch. setup e.g. mmu setup
+        * Perform BL2 setup
         * ---------------------------------------------
         */
        mov     x0, x20
        mov     x1, x21
        mov     x2, x22
        mov     x3, x23
-       bl      bl2_early_platform_setup2
+       bl      bl2_setup
 
-       bl      bl2_plat_arch_setup
+       /* ---------------------------------------------
+        * Enable pointer authentication
+        * ---------------------------------------------
+        */
+#if ENABLE_PAUTH
+       mrs     x0, sctlr_el1
+       orr     x0, x0, #SCTLR_EnIA_BIT
+       msr     sctlr_el1, x0
+       isb
+#endif /* ENABLE_PAUTH */
 
        /* ---------------------------------------------
         * Jump to main function.

diff --git a/bl2/bl2.mk b/bl2/bl2.mk
index f905bc2354da671b6991d870d571f41506c624de..9523918bccf3f8d84bfaac659e0871302fbca656 100644 (file)
--- a/bl2/bl2.mk
+++ b/bl2/bl2.mk
@@ -1,10 +1,11 @@
 #
-# Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
-BL2_SOURCES            +=      bl2/bl2_main.c                          \
+BL2_SOURCES            +=      bl2/bl2_image_load_v2.c                 \
+                               bl2/bl2_main.c                          \
                                bl2/${ARCH}/bl2_arch_setup.c            \
                                lib/locks/exclusive/${ARCH}/spinlock.S  \
                                plat/common/${ARCH}/platform_up_stack.S \
@@ -14,7 +15,9 @@ ifeq (${ARCH},aarch64)
 BL2_SOURCES            +=      common/aarch64/early_exceptions.S
 endif
 
-BL2_SOURCES            +=      bl2/bl2_image_load_v2.c
+ifeq (${ENABLE_PAUTH},1)
+BL2_CFLAGS             +=      -msign-return-address=non-leaf
+endif
 
 ifeq (${BL2_AT_EL3},0)
 BL2_SOURCES            +=      bl2/${ARCH}/bl2_entrypoint.S

diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index 019088dc128f2279e8ef655798cd748cdc932e11..e7ab7bb71e541b0bd562e7645ac52778cea3bf52 100644 (file)
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -21,6 +21,29 @@
 #define NEXT_IMAGE     "BL31"
 #endif
 
+/*******************************************************************************
+ * Setup function for BL2.
+ ******************************************************************************/
+void bl2_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
+              u_register_t arg3)
+{
+       /* Perform early platform-specific setup */
+       bl2_early_platform_setup2(arg0, arg1, arg2, arg3);
+
+#ifdef AARCH64
+       /*
+        * Update pointer authentication key before the MMU is enabled. It is
+        * saved in the rodata section, that can be writen before enabling the
+        * MMU. This function must be called after the console is initialized
+        * in the early platform setup.
+        */
+       bl_handle_pauth();
+#endif /* AARCH64 */
+
+       /* Perform late platform-specific setup */
+       bl2_plat_arch_setup();
+}
+
 /*******************************************************************************
  * The only thing to do in BL2 is to load further images and pass control to
  * next BL. The memory occupied by BL2 will be reclaimed by BL3x stages. BL2

diff --git a/include/bl2/bl2.h b/include/bl2/bl2.h
index 8ec080c0a5406fd6e368b9afd2e49f25a30d6131..b3f9a879acbf9be2644d43b79b7354785614db3e 100644 (file)
--- a/include/bl2/bl2.h
+++ b/include/bl2/bl2.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,6 +7,10 @@
 #ifndef BL2_H
 #define BL2_H
 
+#include <stdint.h>
+
+void bl2_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
+              u_register_t arg3);
 void bl2_main(void);
 
 #endif /* BL2_H */