mbedtls: provide user mode access

The mbedtls library has some globals which results in faults
when user mode tries to access them.

Instantiate a memory partition for mbedtls's globals.
The linker will place all globals found by building this
library into this partition.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

CMakeLists.txt

@@ -1149,13 +1149,17 @@ if(CONFIG_USERSPACE)
   if(CONFIG_NEWLIB_LIBC)
     set(NEWLIB_PART -l libc.a z_libc_partition)
   endif()
+  if(CONFIG_MBEDTLS)
+    set(MBEDTLS_PART -l libext__lib__crypto__mbedtls.a k_mbedtls_partition)
+  endif()
+
   add_custom_command(
     OUTPUT ${APP_SMEM_LD}
     COMMAND ${PYTHON_EXECUTABLE}
     ${ZEPHYR_BASE}/scripts/gen_app_partitions.py
     -d ${OBJ_FILE_DIR}
     -o ${APP_SMEM_LD}
-    ${NEWLIB_PART}
+    ${NEWLIB_PART} ${MBEDTLS_PART}
     $<$<BOOL:${CMAKE_VERBOSE_MAKEFILE}>:--verbose>
     DEPENDS
     kernel

CODEOWNERS

@@ -144,6 +144,7 @@
 /ext/lib/crypto/mbedtls/                  @nashif
 /ext/lib/crypto/tinycrypt/                @ceolin
 /include/adc.h                            @anangl
+/include/app_memory/                      @andrewboie
 /include/arch/arc/                        @vonhust @ruuddw
 /include/arch/arc/arch.h                  @andrewboie
 /include/arch/arc/v2/irq.h                @andrewboie

ext/lib/crypto/mbedtls/zephyr_init.c

@@ -11,6 +11,7 @@
  */
 
 #include <init.h>
+#include <app_memory/app_memdomain.h>
 
 #if defined(CONFIG_MBEDTLS)
 #if !defined(CONFIG_MBEDTLS_CFG_FILE)

include/app_memory/partitions.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2019 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_APP_MEMORY_PARTITIONS_H
+#define ZEPHYR_APP_MEMORY_PARTITIONS_H
+
+#ifdef CONFIG_USERSPACE
+#include <kernel.h> /* For struct k_mem_partition */
+
+#if defined(CONFIG_MBEDTLS)
+extern struct k_mem_partition k_mbedtls_partition;
+#endif /* CONFIG_MBEDTLS */
+#endif /* CONFIG_USERSPACE */
+#endif /* ZEPHYR_APP_MEMORY_PARTITIONS_H */

kernel/userspace.c

@@ -24,6 +24,14 @@
 K_APPMEM_PARTITION_DEFINE(z_libc_partition);
 #endif
 
+/* TODO: Find a better place to put this. Since we pull the entire
+ * libext__lib__crypto__mbedtls.a globals into app shared memory
+ * section, we can't put this in ext/lib/crypto/mbedtls/zephyr_init.c
+ */
+#ifdef CONFIG_MBEDTLS
+K_APPMEM_PARTITION_DEFINE(k_mbedtls_partition);
+#endif
+
 #define LOG_LEVEL CONFIG_KERNEL_LOG_LEVEL
 #include <logging/log.h>
 LOG_MODULE_DECLARE(kernel);

tests/crypto/mbedtls/src/main.c

@@ -5,12 +5,17 @@
  */
 
 #include <ztest.h>
+#include <app_memory/partitions.h>
+
 extern void test_mbedtls(void);
 
 /**test case main entry*/
 void test_main(void)
 {
+#ifdef CONFIG_USERSPACE
+	k_mem_domain_add_partition(&ztest_mem_domain, &k_mbedtls_partition);
+#endif
 	ztest_test_suite(test_mbedtls_fn,
-		ztest_unit_test(test_mbedtls));
+		ztest_user_unit_test(test_mbedtls));
 	ztest_run_test_suite(test_mbedtls_fn);
 }

tests/crypto/mbedtls/src/mbedtls.c

@@ -75,7 +75,7 @@
 #if defined(MBEDTLS_RSA_C)
 int rand(void)
 {
-	static u32_t seed = 7U;
+	static ZTEST_DMEM u32_t seed = 7U;
 
 	seed ^= seed << 13;
 	seed ^= seed >> 17;
@@ -155,7 +155,7 @@ static void create_entropy_seed_file(void)
 #endif
 
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
-unsigned char buf[16384];
+ZTEST_BMEM unsigned char buf[16000];
 #endif
 
 void test_mbedtls(void)