app_shmem: create generic libc partition

We need a generic name for the partition containing
essential C library globals. We're going to need to
add the stack canary guard to this area so user mode
can read it.

Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

CMakeLists.txt

@@ -1157,7 +1157,7 @@ if(CONFIG_APP_SHARED_MEM AND CONFIG_USERSPACE)
     )
 
   if(CONFIG_NEWLIB_LIBC)
-    set(NEWLIB_PART -l libc.a z_newlib_partition)
+    set(NEWLIB_PART -l libc.a z_libc_partition)
   endif()
   add_custom_command(
     OUTPUT ${APP_SMEM_LD}

include/misc/libc-hooks.h

@@ -27,13 +27,6 @@ __syscall int _zephyr_read(char *buf, int nbytes);
 
 __syscall int _zephyr_write(const void *buf, int nbytes);
 
-#ifdef CONFIG_APP_SHARED_MEM
-/* Memory partition containing newlib's globals. This includes all the globals
- * within libc.a and the supporting zephyr hooks, but not the malloc arena.
- */
-extern struct k_mem_partition z_newlib_partition;
-#endif /* CONFIG_APP_SHARED_MEM */
-
 #else
 /* Minimal libc */
 
@@ -46,6 +39,9 @@ __syscall size_t _zephyr_fwrite(const void *_MLIBC_RESTRICT ptr, size_t size,
 #ifdef CONFIG_APP_SHARED_MEM
 /* Memory partition containing the libc malloc arena */
 extern struct k_mem_partition z_malloc_partition;
+
+/* C library globals, except the malloc arena */
+extern struct k_mem_partition z_libc_partition;
 #endif
 
 #include <syscalls/libc-hooks.h>

kernel/userspace.c

@@ -17,6 +17,9 @@
 #include <device.h>
 #include <init.h>
 #include <stdbool.h>
+#include <app_memory/app_memdomain.h>
+
+K_APPMEM_PARTITION_DEFINE(z_libc_partition);
 
 #define LOG_LEVEL CONFIG_KERNEL_LOG_LEVEL
 #include <logging/log.h>

lib/libc/newlib/libc-hooks.c

@@ -17,22 +17,14 @@
 #include <app_memory/app_memdomain.h>
 #include <init.h>
 
-#ifdef CONFIG_APP_SHARED_MEM
-K_APPMEM_PARTITION_DEFINE(z_newlib_partition);
-#define LIBC_BSS	K_APP_BMEM(z_newlib_partition)
-#define LIBC_DATA	K_APP_DMEM(z_newlib_partition)
+#define LIBC_BSS	K_APP_BMEM(z_libc_partition)
+#define LIBC_DATA	K_APP_DMEM(z_libc_partition)
 
 #if CONFIG_NEWLIB_LIBC_ALIGNED_HEAP_SIZE
 K_APPMEM_PARTITION_DEFINE(z_malloc_partition);
 #define MALLOC_BSS	K_APP_BMEM(z_malloc_partition)
 #endif /* CONFIG_NEWLIB_LIBC_ALIGNED_HEAP_SIZE */
 
-#else
-#define LIBC_BSS
-#define LIBC_DATA
-#define MALLOC_BSS
-#endif /* CONFIG_APP_SHARED_MEM */
-
 #define USED_RAM_END_ADDR   POINTER_TO_UINT(&_end)
 
 #if CONFIG_NEWLIB_LIBC_ALIGNED_HEAP_SIZE

subsys/testsuite/ztest/src/ztest.c

@@ -302,11 +302,9 @@ void main(void)
 #ifdef CONFIG_APP_SHARED_MEM
 	struct k_mem_partition *parts[] = {
 		&ztest_mem_partition,
-#ifdef CONFIG_NEWLIB_LIBC
-		/* Newlib libc.a library and hooks globals */
-		&z_newlib_partition,
-#endif
-		/* Both minimal and newlib libc expose this for malloc arena */
+		/* C library globals, stack canary storage, etc */
+		&z_libc_partition,
+		/* Required for access to malloc arena */
 		&z_malloc_partition
 	};