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| author | Zong Li <zong.li@sifive.com> | 2020-03-09 19:55:41 +0300 |
|---|---|---|
| committer | Palmer Dabbelt <palmerdabbelt@google.com> | 2020-03-26 19:24:45 +0300 |
| commit | d27c3c90817e4c5ea655714065a725b4abd576f9 (patch) | |
| tree | 6ab698bef5704fa108f5454047f6cf92cc196c07 /arch/riscv/mm | |
| parent | 00cb41d5ad3189f52a59f42766918557693f94fa (diff) | |
| download | linux-d27c3c90817e4c5ea655714065a725b4abd576f9.tar.xz | |
riscv: add STRICT_KERNEL_RWX support
The commit contains that make text section as non-writable, rodata
section as read-only, and data section as non-executable.
The init section should be changed to non-executable.
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/mm')
| -rw-r--r-- | arch/riscv/mm/init.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 965a8cf4829c..0c625a5e98db 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -12,6 +12,7 @@ #include <linux/sizes.h> #include <linux/of_fdt.h> #include <linux/libfdt.h> +#include <linux/set_memory.h> #include <asm/fixmap.h> #include <asm/tlbflush.h> @@ -477,6 +478,17 @@ static void __init setup_vm_final(void) csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE); local_flush_tlb_all(); } + +void free_initmem(void) +{ + unsigned long init_begin = (unsigned long)__init_begin; + unsigned long init_end = (unsigned long)__init_end; + + /* Make the region as non-execuatble. */ + set_memory_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT); + free_initmem_default(POISON_FREE_INITMEM); +} + #else asmlinkage void __init setup_vm(uintptr_t dtb_pa) { @@ -488,6 +500,38 @@ static inline void setup_vm_final(void) } #endif /* CONFIG_MMU */ +#ifdef CONFIG_STRICT_KERNEL_RWX +void set_kernel_text_rw(void) +{ + unsigned long text_start = (unsigned long)_text; + unsigned long text_end = (unsigned long)_etext; + + set_memory_rw(text_start, (text_end - text_start) >> PAGE_SHIFT); +} + +void set_kernel_text_ro(void) +{ + unsigned long text_start = (unsigned long)_text; + unsigned long text_end = (unsigned long)_etext; + + set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT); +} + +void mark_rodata_ro(void) +{ + unsigned long text_start = (unsigned long)_text; + unsigned long text_end = (unsigned long)_etext; + 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, (text_end - 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); + set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT); +} +#endif + void __init paging_init(void) { setup_vm_final(); |