Currently, set_pte_at() only checks the software PTE_WRITE bit for user mappings when it sets or clears the hardware PTE_RDONLY accordingly. The kernel ptes are written directly without any modification, relying solely on the protection bits in macros like PAGE_KERNEL. However, modifying kernel pte attributes via pte_wrprotect() would be ignored by set_pte_at(). Since pte_wrprotect() does not set PTE_RDONLY (it only clears PTE_WRITE), the new permission is not taken into account. This patch changes set_pte_at() to adjust the read-only permission for kernel ptes as well. As a side effect, existing PROT_* definitions used for kernel ioremap*() need to include PTE_DIRTY | PTE_WRITE. (additionally, white space fix for PTE_KERNEL_ROX) Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> |
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boot | ||
configs | ||
crypto | ||
include | ||
kernel | ||
kvm | ||
lib | ||
mm | ||
net | ||
xen | ||
Kconfig | ||
Kconfig.debug | ||
Kconfig.platforms | ||
Makefile |