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| author | Jeremy Linton <jeremy.linton@arm.com> | 2016-02-19 20:50:32 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-02-26 18:08:04 +0300 |
| commit | 2f39b5f91eb4bccd786d194e70db1dccad784755 (patch) | |
| tree | 726713a839445a87a77fa05fb369cd0107e60346 /arch/arm64/mm/mmu.c | |
| parent | b7dc8d16e76c25409d93ff3aceda42fc386efc4e (diff) | |
| download | linux-2f39b5f91eb4bccd786d194e70db1dccad784755.tar.xz | |
arm64: mm: Mark .rodata as RO
Currently the .rodata section is actually still executable when DEBUG_RODATA
is enabled. This changes that so the .rodata is actually read only, no execute.
It also adds the .rodata section to the mem_init banner.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
[catalin.marinas@arm.com: added vm_struct vmlinux_rodata in map_kernel()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm/mmu.c')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 00d166465ff4..d2d8b8c2e17f 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -449,12 +449,18 @@ static void __init map_mem(pgd_t *pgd) void mark_rodata_ro(void) { - if (!IS_ENABLED(CONFIG_DEBUG_RODATA)) - return; + unsigned long section_size; + section_size = (unsigned long)__start_rodata - (unsigned long)_stext; create_mapping_late(__pa(_stext), (unsigned long)_stext, - (unsigned long)_etext - (unsigned long)_stext, - PAGE_KERNEL_ROX); + section_size, PAGE_KERNEL_ROX); + /* + * mark .rodata as read only. Use _etext rather than __end_rodata to + * cover NOTES and EXCEPTION_TABLE. + */ + section_size = (unsigned long)_etext - (unsigned long)__start_rodata; + create_mapping_late(__pa(__start_rodata), (unsigned long)__start_rodata, + section_size, PAGE_KERNEL_RO); } void fixup_init(void) @@ -493,9 +499,10 @@ static void __init map_kernel_chunk(pgd_t *pgd, void *va_start, void *va_end, */ static void __init map_kernel(pgd_t *pgd) { - static struct vm_struct vmlinux_text, vmlinux_init, vmlinux_data; + static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_init, vmlinux_data; - map_kernel_chunk(pgd, _stext, _etext, PAGE_KERNEL_EXEC, &vmlinux_text); + map_kernel_chunk(pgd, _stext, __start_rodata, PAGE_KERNEL_EXEC, &vmlinux_text); + map_kernel_chunk(pgd, __start_rodata, _etext, PAGE_KERNEL, &vmlinux_rodata); map_kernel_chunk(pgd, __init_begin, __init_end, PAGE_KERNEL_EXEC, &vmlinux_init); map_kernel_chunk(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data); |