diff options
Diffstat (limited to 'arch/riscv/mm/init.c')
| -rw-r--r-- | arch/riscv/mm/init.c | 108 |
1 files changed, 49 insertions, 59 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 3a5190a09987..12f956b3a674 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -455,6 +455,43 @@ asmlinkage void __init __copy_data(void) } #endif +#ifdef CONFIG_STRICT_KERNEL_RWX +static __init pgprot_t pgprot_from_va(uintptr_t va) +{ + if (is_va_kernel_text(va)) + return PAGE_KERNEL_READ_EXEC; + + /* + * In 64-bit kernel, the kernel mapping is outside the linear mapping so + * we must protect its linear mapping alias from being executed and + * written. + * And rodata section is marked readonly in mark_rodata_ro. + */ + if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va)) + return PAGE_KERNEL_READ; + + return PAGE_KERNEL; +} + +void mark_rodata_ro(void) +{ + set_kernel_memory(__start_rodata, _data, set_memory_ro); + if (IS_ENABLED(CONFIG_64BIT)) + set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data), + set_memory_ro); + + debug_checkwx(); +} +#else +static __init pgprot_t pgprot_from_va(uintptr_t va) +{ + if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va)) + return PAGE_KERNEL; + + return PAGE_KERNEL_EXEC; +} +#endif /* CONFIG_STRICT_KERNEL_RWX */ + /* * setup_vm() is called from head.S with MMU-off. * @@ -474,7 +511,7 @@ asmlinkage void __init __copy_data(void) #endif static uintptr_t load_pa __initdata; -static uintptr_t load_sz __initdata; +uintptr_t load_sz; #ifdef CONFIG_XIP_KERNEL #define load_pa (*((uintptr_t *)XIP_FIXUP(&load_pa))) #define load_sz (*((uintptr_t *)XIP_FIXUP(&load_sz))) @@ -486,7 +523,8 @@ static uintptr_t xiprom_sz __initdata; #define xiprom_sz (*((uintptr_t *)XIP_FIXUP(&xiprom_sz))) #define xiprom (*((uintptr_t *)XIP_FIXUP(&xiprom))) -static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) +static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, + __always_unused bool early) { uintptr_t va, end_va; @@ -505,7 +543,8 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) map_size, PAGE_KERNEL); } #else -static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) +static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, + bool early) { uintptr_t va, end_va; @@ -513,7 +552,9 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size) for (va = kernel_virt_addr; va < end_va; va += map_size) create_pgd_mapping(pgdir, va, load_pa + (va - kernel_virt_addr), - map_size, PAGE_KERNEL_EXEC); + map_size, + early ? + PAGE_KERNEL_EXEC : pgprot_from_va(va)); } #endif @@ -590,7 +631,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) * us to reach paging_init(). We map all memory banks later * in setup_vm_final() below. */ - create_kernel_page_table(early_pg_dir, map_size); + create_kernel_page_table(early_pg_dir, map_size, true); #ifndef __PAGETABLE_PMD_FOLDED /* Setup early PMD for DTB */ @@ -666,22 +707,6 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #endif } -#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX) -void __init protect_kernel_linear_mapping_text_rodata(void) -{ - unsigned long text_start = (unsigned long)lm_alias(_start); - unsigned long init_text_start = (unsigned long)lm_alias(__init_text_begin); - unsigned long rodata_start = (unsigned long)lm_alias(__start_rodata); - unsigned long data_start = (unsigned long)lm_alias(_data); - - set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT); - set_memory_nx(text_start, (init_text_start - text_start) >> PAGE_SHIFT); - - set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); - set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); -} -#endif - static void __init setup_vm_final(void) { uintptr_t va, map_size; @@ -714,21 +739,15 @@ static void __init setup_vm_final(void) map_size = best_map_size(start, end - start); for (pa = start; pa < end; pa += map_size) { va = (uintptr_t)__va(pa); - create_pgd_mapping(swapper_pg_dir, va, pa, - map_size, -#ifdef CONFIG_64BIT - PAGE_KERNEL -#else - PAGE_KERNEL_EXEC -#endif - ); + create_pgd_mapping(swapper_pg_dir, va, pa, map_size, + pgprot_from_va(va)); } } #ifdef CONFIG_64BIT /* Map the kernel */ - create_kernel_page_table(swapper_pg_dir, PMD_SIZE); + create_kernel_page_table(swapper_pg_dir, PMD_SIZE, false); #endif /* Clear fixmap PTE and PMD mappings */ @@ -759,35 +778,6 @@ static inline void setup_vm_final(void) } #endif /* CONFIG_MMU */ -#ifdef CONFIG_STRICT_KERNEL_RWX -void __init protect_kernel_text_data(void) -{ - unsigned long text_start = (unsigned long)_start; - unsigned long init_text_start = (unsigned long)__init_text_begin; - unsigned long init_data_start = (unsigned long)__init_data_begin; - unsigned long rodata_start = (unsigned long)__start_rodata; - unsigned long data_start = (unsigned long)_data; - unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn))); - - set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT); - set_memory_ro(init_text_start, (init_data_start - init_text_start) >> PAGE_SHIFT); - set_memory_nx(init_data_start, (rodata_start - init_data_start) >> PAGE_SHIFT); - /* rodata section is marked readonly in mark_rodata_ro */ - set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); - set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT); -} - -void mark_rodata_ro(void) -{ - unsigned long rodata_start = (unsigned long)__start_rodata; - unsigned long data_start = (unsigned long)_data; - - set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); - - debug_checkwx(); -} -#endif - #ifdef CONFIG_KEXEC_CORE /* * reserve_crashkernel() - reserves memory for crash kernel |