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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2017-03-09 21:52:03 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2017-03-23 14:54:50 +0100 |
| commit | 2ebe088b73a87c8fc70231b468c719337f258bf0 (patch) | |
| tree | 35b2361b9bd6cbd9668cd0562b77bcc076c7a893 /arch/arm64/mm | |
| parent | arm64: mmu: map .text as read-only from the outset (diff) | |
| download | linux-2ebe088b73a87c8fc70231b468c719337f258bf0.tar.xz linux-2ebe088b73a87c8fc70231b468c719337f258bf0.zip | |
arm64: mmu: apply strict permissions to .init.text and .init.data
To avoid having mappings that are writable and executable at the same
time, split the init region into a .init.text region that is mapped
read-only, and a .init.data region that is mapped non-executable.
This is possible now that the alternative patching occurs via the linear
mapping, and the linear alias of the init region is always mapped writable
(but never executable).
Since the alternatives descriptions themselves are read-only data, move
those into the .init.text region.
Reviewed-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 300e98e8cd63..75e21c33caff 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -459,7 +459,8 @@ early_param("rodata", parse_rodata); */ static void __init map_kernel(pgd_t *pgd) { - static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_init, vmlinux_data; + static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext, + vmlinux_initdata, vmlinux_data; /* * External debuggers may need to write directly to the text @@ -469,9 +470,12 @@ static void __init map_kernel(pgd_t *pgd) pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; map_kernel_segment(pgd, _text, _etext, text_prot, &vmlinux_text); - map_kernel_segment(pgd, __start_rodata, __init_begin, PAGE_KERNEL, &vmlinux_rodata); - map_kernel_segment(pgd, __init_begin, __init_end, PAGE_KERNEL_EXEC, - &vmlinux_init); + map_kernel_segment(pgd, __start_rodata, __inittext_begin, PAGE_KERNEL, + &vmlinux_rodata); + map_kernel_segment(pgd, __inittext_begin, __inittext_end, text_prot, + &vmlinux_inittext); + map_kernel_segment(pgd, __initdata_begin, __initdata_end, PAGE_KERNEL, + &vmlinux_initdata); map_kernel_segment(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data); if (!pgd_val(*pgd_offset_raw(pgd, FIXADDR_START))) { |