michaelh/zephyr
1
0
Fork 0
Code Releases Activity

mmu: ensure gperf data is mapped

Browse source 
Page tables created at build time may not include the
gperf data at the very end of RAM. Ensure this is mapped
properly at runtime to work around this.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit is contained in:
Andrew Boie 2020-12-18 15:18:04 -08:00 • committed by Anas Nashif
commit e9bfd64110
5 changed files with 31 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

1
include/linker/kobject.ld
View file

@ -5,6 +5,7 @@
*/
#ifdef CONFIG_USERSPACE
z_kobject_data_begin = .;
/* Constraints:
*
* - changes to the size of this section between build phases

1
include/linker/linker-defs.h
View file

@ -303,6 +303,7 @@ extern char z_priv_stacks_ram_start[];
extern char z_priv_stacks_ram_end[];
extern char z_user_stacks_start[];
extern char z_user_stacks_end[];
extern char z_kobject_data_begin[];
#endif /* CONFIG_USERSPACE */
#ifdef CONFIG_THREAD_LOCAL_STORAGE

3
kernel/include/kernel_internal.h
View file

@ -197,6 +197,9 @@ void z_thread_mark_switched_out(void);
*/
void z_mem_manage_init(void);
/* Workaround for build-time page table mapping of the kernel */
void z_kernel_map_fixup(void);
#ifdef __cplusplus
}
#endif

4
kernel/init.c
View file

@ -391,7 +391,9 @@ FUNC_NORETURN void z_cstart(void)
z_dummy_thread_init(&dummy_thread);
#endif
#if defined(CONFIG_MMU) && defined(CONFIG_USERSPACE)
z_kernel_map_fixup();
#endif
/* perform basic hardware initialization */
z_sys_init_run_level(_SYS_INIT_LEVEL_PRE_KERNEL_1);
z_sys_init_run_level(_SYS_INIT_LEVEL_PRE_KERNEL_2);

23
kernel/mmu.c
View file

@ -453,6 +453,29 @@ size_t k_mem_region_align(uintptr_t *aligned_phys, size_t *aligned_size,
*/
#define BOOT_VIRT_TO_PHYS(virt) ((uintptr_t)(((uint8_t *)virt) + VM_OFFSET))
#ifdef CONFIG_USERSPACE
void z_kernel_map_fixup(void)
{
/* XXX: Gperf kernel object data created at build time will not have
* visibility in zephyr_prebuilt.elf. There is a possibility that this
* data would not be memory-mapped if it shifts z_mapped_end between
* builds. Ensure this area is mapped.
*
* A third build phase for page tables would solve this.
*/
uint8_t *kobject_page_begin =
(uint8_t *)ROUND_DOWN((uintptr_t)&z_kobject_data_begin,
CONFIG_MMU_PAGE_SIZE);
size_t kobject_size = (size_t)(Z_KERNEL_VIRT_END - kobject_page_begin);
if (kobject_size != 0) {
arch_mem_map(kobject_page_begin,
BOOT_VIRT_TO_PHYS(kobject_page_begin),
kobject_size, K_MEM_PERM_RW | K_MEM_CACHE_WB);
}
}
#endif /* CONFIG_USERSPACE */
void z_mem_manage_init(void)
{
uintptr_t phys;