diff options
Diffstat (limited to 'common')
| -rw-r--r-- | common/Kconfig | 13 | ||||
| -rw-r--r-- | common/board_r.c | 20 |
2 files changed, 33 insertions, 0 deletions
diff --git a/common/Kconfig b/common/Kconfig index a1f65559a1b..be517b80eb5 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -914,6 +914,19 @@ config STACKPROTECTOR Enable stack smash detection through compiler's stack-protector canary logic +config MMU_PGPROT + bool "Enable RO, RW and RX mappings" + help + U-Boot maps all pages as RWX. If selected pages will + be marked as RO(.rodata), RX(.text), RW(.data) right after + we relocate. Since code sections needs to be page aligned + the final binary size will increase. The mappings can be dumped + using the 'meminfo' command. + + Enabling this feature can expose bugs in U-Boot where we have + code that violates read-only permissions for example. Use this + feature with caution. + config SPL_STACKPROTECTOR bool "Stack Protector buffer overflow detection for SPL" depends on STACKPROTECTOR && SPL diff --git a/common/board_r.c b/common/board_r.c index db0c5cb8032..8d69db1875d 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -170,7 +170,27 @@ static int initr_reloc_global_data(void) efi_save_gd(); efi_runtime_relocate(gd->relocaddr, NULL); + #endif + /* + * We are done with all relocations change the permissions of the binary + * NOTE: __start_rodata etc are defined in arm64 linker scripts and + * sections.h. If you want to add support for your platform you need to + * add the symbols on your linker script, otherwise they will point to + * random addresses. + * + */ + if (IS_ENABLED(CONFIG_MMU_PGPROT)) { + pgprot_set_attrs((phys_addr_t)(uintptr_t)(__start_rodata), + (size_t)(uintptr_t)(__end_rodata - __start_rodata), + MMU_ATTR_RO); + pgprot_set_attrs((phys_addr_t)(uintptr_t)(__start_data), + (size_t)(uintptr_t)(__end_data - __start_data), + MMU_ATTR_RW); + pgprot_set_attrs((phys_addr_t)(uintptr_t)(__text_start), + (size_t)(uintptr_t)(__text_end - __text_start), + MMU_ATTR_RX); + } return 0; } |