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/openbmc/linux/arch/arm64/include/asm/ |
H A D | pgtable.h | fb226c3d Mon Nov 09 02:55:46 CST 2015 Ard Biesheuvel <ard.biesheuvel@linaro.org> arm64: fix R/O permissions of FDT mapping
The mapping permissions of the FDT are set to 'PAGE_KERNEL | PTE_RDONLY' in an attempt to map the FDT as read-only. However, not only does this break at build time under STRICT_MM_TYPECHECKS (since the two terms are of different types in that case), it also results in both the PTE_WRITE and PTE_RDONLY attributes to be set, which means the region is still writable under ARMv8.1 DBM (and an attempted write will simply clear the PT_RDONLY bit).
So instead, define PAGE_KERNEL_RO (which already has an established meaning across architectures) and use that instead.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> fb226c3d Mon Nov 09 02:55:46 CST 2015 Ard Biesheuvel <ard.biesheuvel@linaro.org> arm64: fix R/O permissions of FDT mapping The mapping permissions of the FDT are set to 'PAGE_KERNEL | PTE_RDONLY' in an attempt to map the FDT as read-only. However, not only does this break at build time under STRICT_MM_TYPECHECKS (since the two terms are of different types in that case), it also results in both the PTE_WRITE and PTE_RDONLY attributes to be set, which means the region is still writable under ARMv8.1 DBM (and an attempted write will simply clear the PT_RDONLY bit). So instead, define PAGE_KERNEL_RO (which already has an established meaning across architectures) and use that instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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/openbmc/linux/arch/arm64/mm/ |
H A D | mmu.c | fb226c3d Mon Nov 09 02:55:46 CST 2015 Ard Biesheuvel <ard.biesheuvel@linaro.org> arm64: fix R/O permissions of FDT mapping
The mapping permissions of the FDT are set to 'PAGE_KERNEL | PTE_RDONLY' in an attempt to map the FDT as read-only. However, not only does this break at build time under STRICT_MM_TYPECHECKS (since the two terms are of different types in that case), it also results in both the PTE_WRITE and PTE_RDONLY attributes to be set, which means the region is still writable under ARMv8.1 DBM (and an attempted write will simply clear the PT_RDONLY bit).
So instead, define PAGE_KERNEL_RO (which already has an established meaning across architectures) and use that instead.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> fb226c3d Mon Nov 09 02:55:46 CST 2015 Ard Biesheuvel <ard.biesheuvel@linaro.org> arm64: fix R/O permissions of FDT mapping The mapping permissions of the FDT are set to 'PAGE_KERNEL | PTE_RDONLY' in an attempt to map the FDT as read-only. However, not only does this break at build time under STRICT_MM_TYPECHECKS (since the two terms are of different types in that case), it also results in both the PTE_WRITE and PTE_RDONLY attributes to be set, which means the region is still writable under ARMv8.1 DBM (and an attempted write will simply clear the PT_RDONLY bit). So instead, define PAGE_KERNEL_RO (which already has an established meaning across architectures) and use that instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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