Commit 0b2aa5b8 authored by Laura Abbott's avatar Laura Abbott Committed by Catalin Marinas
Browse files

arm64: Fix R/O permissions in mark_rodata_ro 



The permissions in mark_rodata_ro trigger a build error
with STRICT_MM_TYPECHECKS. Fix this by introducing
PAGE_KERNEL_ROX for the same reasons as PAGE_KERNEL_RO.
From Ard:

"PAGE_KERNEL_EXEC has PTE_WRITE set as well, making the range
writeable under the ARMv8.1 DBM feature, that manages the
dirty bit in hardware (writing to a page with the PTE_RDONLY
and PTE_WRITE bits both set will clear the PTE_RDONLY bit in that case)"

Signed-off-by: default avatarLaura Abbott <labbott@fedoraproject.org>
Acked-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 08c6781c

arch/arm64/include/asm/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ extern void __pgd_error(const char *file, int line, unsigned long val); 


#define PAGE_KERNEL		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)

#define PAGE_KERNEL_RO		__pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_RDONLY)

#define PAGE_KERNEL_ROX	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_RDONLY)

#define PAGE_KERNEL_EXEC	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)

#define PAGE_KERNEL_EXEC_CONT	__pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_CONT)

arch/arm64/mm/mmu.c

+1 −1
Original line number Diff line number Diff line
@@ -475,7 +475,7 @@ void mark_rodata_ro(void) 
{

	create_mapping_late(__pa(_stext), (unsigned long)_stext,

				(unsigned long)_etext - (unsigned long)_stext,

				PAGE_KERNEL_EXEC | PTE_RDONLY);

				PAGE_KERNEL_ROX);



}

#endif

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