kernel: delete separate logic for priv stacks

This never needed to be put in a separate gperf table.
Privilege mode stacks can be generated by the main
gen_kobject_list.py logic, which we do here.

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

CMakeLists.txt

@@ -351,9 +351,6 @@ endif()
 if(CONFIG_USERSPACE)
   set(APP_SMEM_ALIGNED_DEP app_smem_aligned_linker)
   set(APP_SMEM_UNALIGNED_DEP app_smem_unaligned_linker)
-  if(CONFIG_ARM)
-    set(PRIV_STACK_DEP priv_stacks_prebuilt)
-  endif()
 endif()
 
 get_property(TOPT GLOBAL PROPERTY TOPT)
@@ -706,7 +703,6 @@ endif() # CONFIG_CODE_DATA_RELOCATION
 configure_linker_script(
   linker.cmd
   ""
-  ${PRIV_STACK_DEP}
   ${APP_SMEM_ALIGNED_DEP}
   ${CODE_RELOCATION_DEP}
   zephyr_generated_headers
@@ -786,147 +782,7 @@ if(CONFIG_USERSPACE)
 
   get_property(compile_definitions_interface TARGET zephyr_interface
     PROPERTY INTERFACE_COMPILE_DEFINITIONS)
-endif()
 
-
-# Warning most of this gperf code is duplicated below for
-# gen_kobject_list.py / output_lib
-if(CONFIG_ARM AND CONFIG_USERSPACE)
-  set(GEN_PRIV_STACKS $ENV{ZEPHYR_BASE}/scripts/gen_priv_stacks.py)
-  set(PROCESS_PRIV_STACKS_GPERF $ENV{ZEPHYR_BASE}/scripts/process_gperf.py)
-
-  set(PRIV_STACKS                    priv_stacks_hash.gperf)
-  set(PRIV_STACKS_OUTPUT_SRC_PRE     priv_stacks_hash_preprocessed.c)
-  set(PRIV_STACKS_OUTPUT_SRC         priv_stacks_hash.c)
-  set(PRIV_STACKS_OUTPUT_OBJ         priv_stacks_hash.c.obj)
-  set(PRIV_STACKS_OUTPUT_OBJ_RENAMED priv_stacks_hash_renamed.o)
-
-  # Essentially what we are doing here is extracting some information
-  # out of the nearly finished elf file, generating the source code
-  # for a hash table based on that information, and then compiling and
-  # linking the hash table back into a now even more nearly finished
-  # elf file.
-
-  # Use the script GEN_PRIV_STACKS to scan the kernel binary's
-  # (${ZEPHYR_PREBUILT_EXECUTABLE}) DWARF information to produce a table of kernel
-  # objects (PRIV_STACKS) which we will then pass to gperf
-  add_custom_command(
-    OUTPUT ${PRIV_STACKS}
-    COMMAND
-    ${PYTHON_EXECUTABLE}
-    ${GEN_PRIV_STACKS}
-    --kernel $<TARGET_FILE:priv_stacks_prebuilt>
-    --output ${PRIV_STACKS}
-    $<$<BOOL:${CMAKE_VERBOSE_MAKEFILE}>:--verbose>
-    DEPENDS priv_stacks_prebuilt
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-    )
-  add_custom_target(priv_stacks DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS})
-
-  if(${GPERF} STREQUAL GPERF-NOTFOUND)
-    message(FATAL_ERROR "Unable to find gperf")
-  endif()
-
-  # Use gperf to generate C code (PRIV_STACKS_OUTPUT_SRC_PRE) which implements a
-  # perfect hashtable based on PRIV_STACKS
-  add_custom_command(
-    OUTPUT ${PRIV_STACKS_OUTPUT_SRC_PRE}
-    COMMAND
-    ${GPERF} -C
-    --output-file ${PRIV_STACKS_OUTPUT_SRC_PRE}
-    ${PRIV_STACKS}
-    DEPENDS priv_stacks ${PRIV_STACKS}
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-    )
-  add_custom_target(priv_stacks_output_src_pre DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_SRC_PRE})
-
-  # For our purposes the code/data generated by gperf is not optimal.
-  #
-  # The script PROCESS_GPERF creates a new c file OUTPUT_SRC based on
-  # OUTPUT_SRC_PRE to greatly reduce the amount of code/data generated
-  # since we know we are always working with pointer values
-  add_custom_command(
-    OUTPUT ${PRIV_STACKS_OUTPUT_SRC}
-    COMMAND
-    ${PYTHON_EXECUTABLE}
-    ${PROCESS_PRIV_STACKS_GPERF}
-    -i ${PRIV_STACKS_OUTPUT_SRC_PRE}
-    -o ${PRIV_STACKS_OUTPUT_SRC}
-    -p "struct _k_priv_stack_map"
-    $<$<BOOL:${CMAKE_VERBOSE_MAKEFILE}>:--verbose>
-    DEPENDS priv_stacks_output_src_pre ${PRIV_STACKS_OUTPUT_SRC_PRE}
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-    )
-  add_custom_target(priv_stacks_output_src DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_SRC})
-
-  set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_SRC}
-    PROPERTIES COMPILE_DEFINITIONS "${compile_definitions_interface}")
-
-  set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_SRC}
-    PROPERTIES COMPILE_FLAGS
-    "${NO_COVERAGE_FLAGS} -fno-function-sections -fno-data-sections ")
-
-  # We need precise control of where generated text/data ends up in the final
-  # kernel image. Disable function/data sections and use objcopy to move
-  # generated data into special section names
-  add_library(priv_stacks_output_lib STATIC
-    ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_SRC}
-    )
-
-  # Turn off -ffunction-sections, etc.
-  # NB: Using a library instead of target_compile_options(priv_stacks_output_lib
-  # [...]) because a library's options have precedence
-  add_library(priv_stacks_output_lib_interface INTERFACE)
-  foreach(incl ${include_dir_in_interface})
-    target_include_directories(priv_stacks_output_lib_interface INTERFACE ${incl})
-  endforeach()
-
-  foreach(incl ${sys_include_dir_in_interface})
-    target_include_directories(priv_stacks_output_lib_interface SYSTEM INTERFACE ${incl})
-  endforeach()
-
-  target_link_libraries(priv_stacks_output_lib priv_stacks_output_lib_interface)
-
-  set(PRIV_STACKS_OUTPUT_OBJ_PATH ${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/priv_stacks_output_lib.dir/${PRIV_STACKS_OUTPUT_OBJ})
-
-  set(obj_copy_cmd "")
-  set(obj_copy_sections_rename
-    .bss=.priv_stacks.noinit
-    .data=.priv_stacks.data
-    .text=.priv_stacks.text
-    .rodata=.priv_stacks.rodata
-    )
-  bintools_objcopy(
-    RESULT_CMD_LIST obj_copy_cmd
-    SECTION_RENAME  ${obj_copy_sections_rename}
-    FILE_INPUT      ${PRIV_STACKS_OUTPUT_OBJ_PATH}
-    FILE_OUTPUT     ${PRIV_STACKS_OUTPUT_OBJ_RENAMED}
-    )
-  add_custom_command(
-    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_OBJ_RENAMED}
-    ${obj_copy_cmd}
-    DEPENDS priv_stacks_output_lib
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
-    )
-  add_custom_target(priv_stacks_output_obj_renamed DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_OBJ_RENAMED})
-
-  add_library(priv_stacks_output_obj_renamed_lib STATIC IMPORTED GLOBAL)
-  set_property(
-    TARGET priv_stacks_output_obj_renamed_lib
-    PROPERTY
-    IMPORTED_LOCATION ${CMAKE_CURRENT_BINARY_DIR}/${PRIV_STACKS_OUTPUT_OBJ_RENAMED}
-    )
-  add_dependencies(
-    priv_stacks_output_obj_renamed_lib
-    priv_stacks_output_obj_renamed
-    )
-
-  set_property(GLOBAL APPEND PROPERTY GENERATED_KERNEL_OBJECT_FILES priv_stacks_output_obj_renamed_lib)
-endif()
-
-# Warning: most of this gperf code is duplicated above for
-# gen_priv_stacks.py / priv_stacks_output_lib
-if(CONFIG_USERSPACE)
   set(GEN_KOBJ_LIST ${ZEPHYR_BASE}/scripts/gen_kobject_list.py)
   set(PROCESS_GPERF ${ZEPHYR_BASE}/scripts/process_gperf.py)
 
@@ -1168,42 +1024,6 @@ if(CONFIG_USERSPACE)
     )
 endif()
 
-if(CONFIG_USERSPACE AND CONFIG_ARM)
-  configure_linker_script(
-    linker_priv_stacks.cmd
-    ""
-    ${CODE_RELOCATION_DEP}
-    ${APP_SMEM_ALIGNED_DEP}
-    ${APP_SMEM_ALIGNED_LD}
-    zephyr_generated_headers
-    )
-
-  add_custom_target(
-    linker_priv_stacks_script
-    DEPENDS
-    linker_priv_stacks.cmd
-    )
-
-  set_property(TARGET
-    linker_priv_stacks_script
-    PROPERTY INCLUDE_DIRECTORIES
-    ${ZEPHYR_INCLUDE_DIRS}
-    )
-
-  set(PRIV_STACK_LIB priv_stacks_output_obj_renamed_lib)
-  add_executable(       priv_stacks_prebuilt misc/empty_file.c)
-  toolchain_ld_link_elf(
-    TARGET_ELF            priv_stacks_prebuilt
-    OUTPUT_MAP            ${PROJECT_BINARY_DIR}/priv_stacks_prebuilt.map
-    LIBRARIES_PRE_SCRIPT  ""
-    LINKER_SCRIPT         ${PROJECT_BINARY_DIR}/linker_priv_stacks.cmd
-    LIBRARIES_POST_SCRIPT ""
-    DEPENDENCIES          ${CODE_RELOCATION_DEP}
-  )
-  set_property(TARGET   priv_stacks_prebuilt PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker_priv_stacks.cmd)
-  add_dependencies(     priv_stacks_prebuilt linker_priv_stacks_script ${OFFSETS_LIB})
-endif()
-
 # FIXME: Is there any way to get rid of empty_file.c?
 add_executable(       ${ZEPHYR_PREBUILT_EXECUTABLE} misc/empty_file.c)
 toolchain_ld_link_elf(
@@ -1211,11 +1031,10 @@ toolchain_ld_link_elf(
   OUTPUT_MAP            ${PROJECT_BINARY_DIR}/${ZEPHYR_PREBUILT_EXECUTABLE}.map
   LIBRARIES_PRE_SCRIPT  ""
   LINKER_SCRIPT         ${PROJECT_BINARY_DIR}/linker.cmd
-  LIBRARIES_POST_SCRIPT ${PRIV_STACK_LIB}
   DEPENDENCIES          ${CODE_RELOCATION_DEP}
 )
 set_property(TARGET   ${ZEPHYR_PREBUILT_EXECUTABLE} PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker.cmd)
-add_dependencies(     ${ZEPHYR_PREBUILT_EXECUTABLE} ${PRIV_STACK_DEP} ${LINKER_SCRIPT_TARGET} ${OFFSETS_LIB})
+add_dependencies(     ${ZEPHYR_PREBUILT_EXECUTABLE} ${LINKER_SCRIPT_TARGET} ${OFFSETS_LIB})
 
 
 set(generated_kernel_files ${GKSF} ${GKOF})
@@ -1230,7 +1049,6 @@ else()
   configure_linker_script(
     linker_pass_final.cmd
     "-DLINKER_PASS2"
-    ${PRIV_STACK_DEP}
     ${CODE_RELOCATION_DEP}
     ${ZEPHYR_PREBUILT_EXECUTABLE}
     zephyr_generated_headers
@@ -1258,7 +1076,7 @@ else()
     DEPENDENCIES          ${CODE_RELOCATION_DEP}
   )
   set_property(TARGET   ${ZEPHYR_FINAL_EXECUTABLE} PROPERTY LINK_DEPENDS ${PROJECT_BINARY_DIR}/linker_pass_final.cmd)
-  add_dependencies(     ${ZEPHYR_FINAL_EXECUTABLE} ${PRIV_STACK_DEP} ${LINKER_PASS_FINAL_SCRIPT_TARGET})
+  add_dependencies(     ${ZEPHYR_FINAL_EXECUTABLE} ${LINKER_PASS_FINAL_SCRIPT_TARGET})
 
   # Use the pass2 elf as the final elf
   set(logical_target_for_zephyr_elf ${ZEPHYR_FINAL_EXECUTABLE})

CODEOWNERS

@@ -383,7 +383,6 @@
 /arch/x86/gen_gdt.py                      @andrewboie
 /arch/x86/gen_idt.py                      @andrewboie
 /scripts/gen_kobject_list.py              @andrewboie
-/scripts/gen_priv_stacks.py               @andrewboie @agross-oss @ioannisg
 /scripts/gen_syscalls.py                  @andrewboie
 /scripts/net/                             @jukkar @pfl
 /scripts/process_gperf.py                 @andrewboie

arch/Kconfig

@@ -27,6 +27,9 @@ config ARM
 	bool
 	select ARCH_IS_SET
 	select HAS_DTS
+	# FIXME: current state of the code for all ARM requires this, but
+	# is really only necessary for Cortex-M with ARM MPU!
+	select GEN_PRIV_STACKS
 	help
 	  ARM architecture
 
@@ -218,15 +221,8 @@ config PRIVILEGED_STACK_SIZE
 	  This option sets the privileged stack region size that will be used
 	  in addition to the user mode thread stack.  During normal execution,
 	  this region will be inaccessible from user mode.  During system calls,
-	  this region will be utilized by the system call.
+	  this region will be utilized by the system call. This value must be
-
+	  a multiple of the minimum stack alignment.
-config PRIVILEGED_STACK_TEXT_AREA
-	int "Privileged stacks text area"
-	default 512 if COVERAGE_GCOV
-	default 256
-	depends on ARCH_HAS_USERSPACE
-	help
-	  Stack text area size for privileged stacks.
 
 config KOBJECT_TEXT_AREA
 	int "Size if kobject text area"
@@ -237,6 +233,17 @@ config KOBJECT_TEXT_AREA
 	help
 	  Size of kernel object text area. Used in linker script.
 
+config GEN_PRIV_STACKS
+	bool
+	help
+	  Selected if the architecture requires that privilege elevation stacks
+	  be allocated in a separate memory area. This is typical of arches
+	  whose MPUs require regions to be power-of-two aligned/sized.
+
+	  FIXME: This should be removed and replaced with checks against
+	  CONFIG_MPU_REQUIRES_POWER_OF_TWO_ALIGNMENT, but both ARM and ARC
+	  changes will be necessary for this.
+
 config STACK_GROWS_UP
 	bool "Stack grows towards higher memory addresses"
 	help

arch/arm/core/aarch32/thread.c

@@ -16,10 +16,6 @@
 #include <ksched.h>
 #include <wait_q.h>
 
-#ifdef CONFIG_USERSPACE
-extern u8_t *z_priv_stack_find(void *obj);
-#endif
-
 /* An initial context, to be "restored" by z_arm_pendsv(), is put at the other
  * end of the stack, and thus reusable by the stack when not needed anymore.
  *

doc/guides/build/index.rst

@@ -230,15 +230,6 @@ The following is a detailed description of the scripts used during the build pro
    :start-after: """
    :end-before: """
 
-.. _gen_priv_stacks.py:
-
-:zephyr_file:`scripts/gen_priv_stacks.py`
-==========================================
-
-.. include:: ../../../scripts/gen_priv_stacks.py
-   :start-after: """
-   :end-before: """
-
 .. _gen_idt.py:
 
 :zephyr_file:`arch/x86/gen_idt.py`

doc/reference/usermode/mpu_userspace.rst

@@ -8,7 +8,7 @@ set of stacks.  These stacks exist in a 1:1 relationship with each thread stack
 defined in the system.  The privileged stacks are created as a part of the
 build process.
 
-A post-build script :ref:`gen_priv_stacks.py` scans the generated
+A post-build script :ref:`gen_kobject_list.py` scans the generated
 ELF file and finds all of the thread stack objects.  A set of privileged
 stacks, a lookup table, and a set of helper functions are created and added
 to the image.

include/arch/arm/aarch32/cortex_m/scripts/linker.ld

@@ -156,7 +156,6 @@ SECTIONS
 	{
 	_image_text_start = .;
 
-#include <linker/priv_stacks-text.ld>
 #include <linker/kobject-text.ld>
 
 	*(.text)
@@ -221,7 +220,6 @@ SECTIONS
 #include <custom-rodata.ld>
 #endif
 
-#include <linker/priv_stacks-rom.ld>
 #include <linker/kobject-rom.ld>
 
 	/*
@@ -373,10 +371,8 @@ SECTIONS
     __data_rom_start = LOADADDR(_DATA_SECTION_NAME);
 
 #include <linker/common-ram.ld>
-#include <linker/priv_stacks.ld>
 #include <linker/kobject.ld>
 
-#include <linker/priv_stacks-noinit.ld>
 #include <linker/cplusplus-ram.ld>
 
     __data_ram_end = .;

include/arch/arm/aarch32/cortex_r/scripts/linker.ld

@@ -143,7 +143,6 @@ SECTIONS
          */
         *(.glue_7t) *(.glue_7) *(.vfp11_veneer) *(.v4_bx)
 
-#include <linker/priv_stacks-text.ld>
 #include <linker/kobject-text.ld>
 
     } GROUP_LINK_IN(ROMABLE_REGION)
@@ -198,7 +197,6 @@ SECTIONS
 #include <custom-rodata.ld>
 #endif
 
-#include <linker/priv_stacks-rom.ld>
 #include <linker/kobject-rom.ld>
 
         /*
@@ -333,11 +331,7 @@ SECTIONS
     __data_rom_start = LOADADDR(_DATA_SECTION_NAME);
 
 #include <linker/common-ram.ld>
-#include <linker/priv_stacks.ld>
 #include <linker/kobject.ld>
-
-#include <linker/priv_stacks-noinit.ld>
-
 #include <linker/cplusplus-ram.ld>
 
     __data_ram_end = .;

include/arch/arm/aarch64/scripts/linker.ld

@@ -132,7 +132,6 @@ SECTIONS
          */
         *(.glue_7t) *(.glue_7) *(.vfp11_veneer) *(.v4_bx)
 
-#include <linker/priv_stacks-text.ld>
 #include <linker/kobject-text.ld>
 
         MMU_ALIGN;
@@ -194,7 +193,6 @@ SECTIONS
 #include <custom-rodata.ld>
 #endif
 
-#include <linker/priv_stacks-rom.ld>
 #include <linker/kobject-rom.ld>
 
     } GROUP_LINK_IN(ROMABLE_REGION)
@@ -319,11 +317,7 @@ SECTIONS
     __data_rom_start = LOADADDR(_DATA_SECTION_NAME);
 
 #include <linker/common-ram.ld>
-#include <linker/priv_stacks.ld>
 #include <linker/kobject.ld>
-
-#include <linker/priv_stacks-noinit.ld>
-
 #include <linker/cplusplus-ram.ld>
 
     __data_ram_end = .;

include/kernel.h

@@ -166,6 +166,17 @@ enum k_objects {
  */
 
 #ifdef CONFIG_USERSPACE
+#ifdef CONFIG_GEN_PRIV_STACKS
+/* Metadata struct for K_OBJ_THREAD_STACK_ELEMENT */
+struct z_stack_data {
+	/* Size of the entire stack object, including reserved areas */
+	size_t size;
+
+	/* Stack buffer for privilege mode elevations */
+	u8_t *priv;
+};
+#endif /* CONFIG_GEN_PRIV_STACKS */
+
 /* Object extra data. Only some objects use this, determined by object type */
 union z_object_data {
 	/* Backing mutex for K_OBJ_SYS_MUTEX */
@@ -174,8 +185,13 @@ union z_object_data {
 	/* Numerical thread ID for K_OBJ_THREAD */
 	unsigned int thread_id;
 
+#ifdef CONFIG_GEN_PRIV_STACKS
+	/* Metadata for K_OBJ_THREAD_STACK_ELEMENT */
+	struct z_stack_data *stack_data;
+#else
 	/* Stack buffer size for K_OBJ_THREAD_STACK_ELEMENT */
 	size_t stack_size;
+#endif /* CONFIG_GEN_PRIV_STACKS */
 
 	/* Futex wait queue and spinlock for K_OBJ_FUTEX */
 	struct z_futex_data *futex_data;

include/linker/kobject.ld

@@ -39,5 +39,13 @@
 	*(".kobject_data.rodata*")
 #endif
         } GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
-#endif /* CONFIG_USERSPACE */
 
+#ifdef CONFIG_GEN_PRIV_STACKS
+	SECTION_DATA_PROLOGUE(priv_stacks_noinit,,)
+	{
+	z_priv_stacks_ram_start = .;
+	*(".priv_stacks.noinit")
+	z_priv_stacks_ram_end = .;
+	} GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
+#endif /* CONFIG_GEN_PRIV_STACKS */
+#endif /* CONFIG_USERSPACE */

include/linker/priv_stacks-noinit.ld

@@ -1,12 +0,0 @@
-/*
- * Copyright (c) 2017 Linaro Limited.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-     SECTION_DATA_PROLOGUE(priv_stacks_noinit,,)
-        {
-        z_priv_stacks_ram_start = .;
-        *(".priv_stacks.noinit")
-        z_priv_stacks_ram_end = .;
-        } GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)

include/linker/priv_stacks-rom.ld

@@ -1,13 +0,0 @@
-/*
- * Copyright (c) 2017 Linaro Limited.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#ifdef CONFIG_USERSPACE
-        /* Kept in RAM on non-XIP */
-#ifdef CONFIG_XIP
-	*(".priv_stacks.rodata*")
-#endif
-#endif /* CONFIG_USERSPACE */
-

include/linker/priv_stacks-text.ld

@@ -1,38 +0,0 @@
-/*
- * Copyright (c) 2017 Linaro Limited.
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-#ifdef CONFIG_USERSPACE
-	/* We need to reserve room for the gperf generated hash functions.
-	 * Fortunately, unlike the data tables, the size of the code is
-	 * reasonably predictable.
-	 */
-	_priv_stacks_text_area_start = .;
-	*(".priv_stacks.text*")
-	_priv_stacks_text_area_end = .;
-
-	_priv_stacks_text_area_used = _priv_stacks_text_area_end - _priv_stacks_text_area_start;
-
-#ifndef LINKER_PASS2
-	PROVIDE(z_priv_stack_find = .);
-#endif
-
-	/* In a valid build the MAX function will always evaluate to the
-	second argument below, but to give the user a good error message
-	when the area overflows we need to temporarily corrupt the
-	location counter, and then detect the overflow with an assertion
-	later on. */
-
-	. = MAX(., _priv_stacks_text_area_start + CONFIG_PRIVILEGED_STACK_TEXT_AREA);
-
-	ASSERT(
-		CONFIG_PRIVILEGED_STACK_TEXT_AREA >= _priv_stacks_text_area_used,
-"The configuration system has incorrectly set
-'CONFIG_PRIVILEGED_STACK_TEXT_AREA' to
-CONFIG_PRIVILEGED_STACK_TEXT_AREA, which is not big enough. You must
-through Kconfig either disable 'CONFIG_USERSPACE', or set
-'CONFIG_PRIVILEGED_STACK_TEXT_AREA' to a value larger than
-CONFIG_PRIVILEGED_STACK_TEXT_AREA."
-		);
-#endif /* CONFIG_USERSPACE */

include/linker/priv_stacks.ld

@@ -1,36 +0,0 @@
-/*
- * Copyright (c) 2017 Linaro Limited
- *
- * SPDX-License-Identifier: Apache-2.0
- */
-
-#ifdef CONFIG_USERSPACE
-	/* Constraints:
-         *
-         * - changes to the size of this section between build phases
-         *   *must not* shift the memory address of any kernel objects,
-         *   since it contains a hashtable of the memory addresses of those
-         *   kernel objects
-         *
-         * - It is OK if this section itself is shifted in between builds; for
-         *   example some arches may precede this section with generated MMU
-         *    page tables which are also unpredictable in size.
-         *
-         * The size of the
-	 * gperf tables is both a function of the number of kernel objects,
-	 * *and* the specific memory addresses being hashed. It is not something
-	 * that can be predicted without actually building and compiling it.
-         */
-	SECTION_DATA_PROLOGUE(priv_stacks,,)
-	{
-	*(".priv_stacks.data*")
-
-        /* This is also unpredictable in size, and has the same constraints.
-         * On XIP systems this will get put at the very end of ROM.
-         */
-#ifndef CONFIG_XIP
-	*(".priv_stacks.rodata*")
-#endif
-        } GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
-#endif /* CONFIG_USERSPACE */
-

kernel/include/kernel_internal.h

@@ -124,6 +124,10 @@ extern struct k_thread z_idle_threads[CONFIG_MP_NUM_CPUS];
 extern K_THREAD_STACK_ARRAY_DEFINE(z_interrupt_stacks, CONFIG_MP_NUM_CPUS,
 				   CONFIG_ISR_STACK_SIZE);
 
+#ifdef CONFIG_GEN_PRIV_STACKS
+extern u8_t *z_priv_stack_find(k_thread_stack_t *stack);
+#endif
+
 #ifdef __cplusplus
 }
 #endif

kernel/thread.c

@@ -641,7 +641,7 @@ k_tid_t z_vrfy_k_thread_create(struct k_thread *new_thread,
 			       void *p1, void *p2, void *p3,
 			       int prio, u32_t options, s32_t delay)
 {
-	size_t total_size;
+	size_t total_size, stack_obj_size;
 	struct z_object *stack_object;
 
 	/* The thread and stack objects *must* be in an uninitialized state */
@@ -664,9 +664,14 @@ k_tid_t z_vrfy_k_thread_create(struct k_thread *new_thread,
 	/* Testing less-than-or-equal since additional room may have been
 	 * allocated for alignment constraints
 	 */
-	Z_OOPS(Z_SYSCALL_VERIFY_MSG(total_size <= stack_object->data.stack_size,
+#ifdef CONFIG_GEN_PRIV_STACKS
+	stack_obj_size = stack_object->data.stack_data->size;
+#else
+	stack_obj_size = stack_object->data.stack_size;
+#endif
+	Z_OOPS(Z_SYSCALL_VERIFY_MSG(total_size <= stack_obj_size,
 				    "stack size %zu is too big, max is %zu",
-				    total_size, stack_object->data.stack_size));
+				    total_size, stack_obj_size));
 
 	/* User threads may only create other user threads and they can't
 	 * be marked as essential

kernel/userspace.c

@@ -90,6 +90,25 @@ struct perm_ctx {
 	struct k_thread *parent;
 };
 
+#ifdef CONFIG_GEN_PRIV_STACKS
+/* See write_gperf_table() in scripts/gen_kobject_list.py. The privilege
+ * mode stacks are allocated as an array. The base of the array is
+ * aligned to Z_PRIVILEGE_STACK_ALIGN, and all members must be as well.
+ */
+BUILD_ASSERT(CONFIG_PRIVILEGED_STACK_SIZE % Z_PRIVILEGE_STACK_ALIGN == 0);
+
+u8_t *z_priv_stack_find(k_thread_stack_t *stack)
+{
+	struct z_object *obj = z_object_find(stack);
+
+	__ASSERT(obj != NULL, "stack object not found");
+	__ASSERT(obj->type == K_OBJ_THREAD_STACK_ELEMENT,
+		 "bad stack object");
+
+	return obj->data.stack_data->priv;
+}
+#endif /* CONFIG_GEN_PRIV_STACKS */
+
 #ifdef CONFIG_DYNAMIC_OBJECTS
 struct dyn_obj {
 	struct z_object kobj;

scripts/elf_helper.py

@@ -38,6 +38,7 @@ STACK_TYPE = "z_thread_stack_element"
 thread_counter = 0
 sys_mutex_counter = 0
 futex_counter = 0
+stack_counter = 0
 
 # Global type environment. Populated by pass 1.
 type_env = {}
@@ -57,6 +58,7 @@ class KobjectInstance:
         global thread_counter
         global sys_mutex_counter
         global futex_counter
+        global stack_counter
 
         self.addr = addr
         self.type_obj = type_obj
@@ -76,6 +78,8 @@ class KobjectInstance:
         elif self.type_obj.name == "k_futex":
             self.data = "&futex_data[%d]" % futex_counter
             futex_counter += 1
+        elif self.type_obj.name == STACK_TYPE:
+            stack_counter += 1
         else:
             self.data = 0
 
@@ -604,3 +608,8 @@ class ElfHelper:
     @staticmethod
     def get_futex_counter():
         return futex_counter
+
+    @staticmethod
+    def get_stack_counter():
+        return stack_counter
+

scripts/gen_kobject_list.py

@@ -144,14 +144,10 @@ void z_object_wordlist_foreach(_wordlist_cb_func_t func, void *context)
 #endif
 """
 
-metadata_names = {
-    "K_OBJ_THREAD" : "thread_id",
-    "K_OBJ_THREAD_STACK_ELEMENT" : "stack_size",
-    "K_OBJ_SYS_MUTEX" : "mutex",
-    "K_OBJ_FUTEX" : "futex_data"
-}
 
 def write_gperf_table(fp, eh, objs, static_begin, static_end):
+    syms = eh.get_symbols()
+
     fp.write(header)
     num_mutexes = eh.get_sys_mutex_counter()
     if num_mutexes != 0:
@@ -171,9 +167,46 @@ def write_gperf_table(fp, eh, objs, static_begin, static_end):
                 fp.write(", ")
         fp.write("};\n")
 
+    metadata_names = {
+        "K_OBJ_THREAD" : "thread_id",
+        "K_OBJ_SYS_MUTEX" : "mutex",
+        "K_OBJ_FUTEX" : "futex_data"
+    }
+
+    if "CONFIG_GEN_PRIV_STACKS" in syms:
+        metadata_names["K_OBJ_THREAD_STACK_ELEMENT"] = "stack_data"
+        num_stack = eh.get_stack_counter()
+        if num_stack != 0:
+            fp.write("static u8_t Z_GENERIC_SECTION(.priv_stacks.noinit) "
+                     " __aligned(Z_PRIVILEGE_STACK_ALIGN)"
+                     " priv_stacks[%d][CONFIG_PRIVILEGED_STACK_SIZE];\n"
+                     % num_stack);
+
+            fp.write("static struct z_stack_data stack_data[%d] = {\n"
+                     % num_stack)
+            counter = 0
+            for _, ko in objs.items():
+                if ko.type_name != "K_OBJ_THREAD_STACK_ELEMENT":
+                    continue
+
+                # ko.data currently has the stack size. fetch the value to
+                # populate the appropriate entry in stack_data, and put
+                # a reference to the entry in stack_data into the data value
+                # instead
+                size = ko.data
+                ko.data = "&stack_data[%d]" % counter
+                fp.write("\t{ %d, (u8_t *)(&priv_stacks[%d]) }"
+                         % (size, counter))
+                if counter != (num_stack - 1):
+                    fp.write(",")
+                fp.write("\n")
+                counter += 1
+            fp.write("};\n")
+    else:
+        metadata_names["K_OBJ_THREAD_STACK_ELEMENT"] = "stack_size"
+
     fp.write("%%\n")
     # Setup variables for mapping thread indexes
-    syms = eh.get_symbols()
     thread_max_bytes = syms["CONFIG_MAX_THREAD_BYTES"]
     thread_idx_map = {}
 

scripts/gen_priv_stacks.py

@@ -1,140 +0,0 @@
-#!/usr/bin/env python3
-#
-# Copyright (c) 2017 Linaro Limited
-#
-# SPDX-License-Identifier: Apache-2.0
-
-"""
-Script to generate gperf tables mapping threads to their privileged mode stacks
-
-Some MPU devices require that memory region definitions be aligned to their
-own size, which must be a power of two. This introduces difficulties in
-reserving memory for the thread's supervisor mode stack inline with the
-K_THREAD_STACK_DEFINE() macro.
-
-Instead, the stack used when a user thread elevates privileges is allocated
-elsewhere in memory, and a gperf table is created to be able to quickly
-determine where the supervisor mode stack is in memory. This is accomplished
-by scanning the DWARF debug information in zephyr_prebuilt.elf, identifying
-instances of 'struct k_thread', and emitting a gperf configuration file which
-allocates memory for each thread's privileged stack and creates the table
-mapping thread addresses to these stacks.
-"""
-
-import sys
-import argparse
-import struct
-from elf_helper import ElfHelper
-
-kobjects = {
-        "z_thread_stack_element": (None, False)
-}
-
-
-header = """%compare-lengths
-%define lookup-function-name z_priv_stack_map_lookup
-%language=ANSI-C
-%global-table
-%struct-type
-"""
-
-
-# Each privilege stack buffer needs to respect the alignment
-# constraints as specified in arm/arch.h.
-priv_stack_decl_temp = ("static u8_t __used"
-                        " __aligned(Z_PRIVILEGE_STACK_ALIGN)"
-                        " priv_stack_%x[CONFIG_PRIVILEGED_STACK_SIZE];\n")
-
-
-includes = """#include <kernel.h>
-#include <string.h>
-"""
-
-
-structure = """struct _k_priv_stack_map {
-    char *name;
-    u8_t *priv_stack_addr;
-};
-%%
-"""
-
-
-# Different versions of gperf have different prototypes for the lookup
-# function, best to implement the wrapper here. The pointer value itself is
-# turned into a string, we told gperf to expect binary strings that are not
-# NULL-terminated.
-footer = """%%
-u8_t *z_priv_stack_find(void *obj)
-{
-    const struct _k_priv_stack_map *map =
-        z_priv_stack_map_lookup((const char *)obj, sizeof(void *));
-    return map->priv_stack_addr;
-}
-"""
-
-
-def write_gperf_table(fp, eh, objs):
-    fp.write(header)
-
-    # priv stack declarations
-    fp.write("%{\n")
-    fp.write(includes)
-    for obj_addr in objs:
-        fp.write(priv_stack_decl_temp % (obj_addr))
-    fp.write("%}\n")
-
-    # structure declaration
-    fp.write(structure)
-
-    for obj_addr in objs:
-        byte_str = struct.pack("<I" if eh.little_endian else ">I", obj_addr)
-        fp.write("\"")
-        for byte in byte_str:
-            val = "\\x%02x" % byte
-            fp.write(val)
-
-        fp.write("\",priv_stack_%x\n" % obj_addr)
-
-    fp.write(footer)
-
-
-def parse_args():
-    global args
-
-    parser = argparse.ArgumentParser(
-        description=__doc__,
-        formatter_class=argparse.RawDescriptionHelpFormatter)
-
-    parser.add_argument("-k", "--kernel", required=True,
-                        help="Input zephyr ELF binary")
-    parser.add_argument(
-        "-o", "--output", required=True,
-        help="Output list of kernel object addresses for gperf use")
-    parser.add_argument("-v", "--verbose", action="store_true",
-                        help="Print extra debugging information")
-    args = parser.parse_args()
-
-
-def main():
-    parse_args()
-
-    eh = ElfHelper(args.kernel, args.verbose, kobjects, [])
-    syms = eh.get_symbols()
-    max_threads = syms["CONFIG_MAX_THREAD_BYTES"] * 8
-    objs = eh.find_kobjects(syms)
-    if not objs:
-        sys.stderr.write("WARNING: zero kobject found in %s\n"
-                         % args.kernel)
-
-    thread_counter = eh.get_thread_counter()
-    if thread_counter > max_threads:
-        sys.exit("Too many thread objects ({})\n"
-                 "Increase CONFIG_MAX_THREAD_BYTES to {}"
-                 .format(thread_counter, -(-thread_counter // 8)))
-
-    with open(args.output, "w") as fp:
-        write_gperf_table(fp, eh, objs)
-
-
-if __name__ == "__main__":
-    main()