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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2015-11-09 09:55:46 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2015-11-09 14:26:36 +0000
commitfb226c3d7c77b4f99cee675795cc0e70937c56ee (patch)
tree08f88c1b14952e03fdf797f0ec233923463cfa56 /arch/arm64/include/asm/pgtable.h
parentarm64: fix STRICT_MM_TYPECHECKS issue in PTE_CONT manipulation (diff)
downloadlinux-dev-fb226c3d7c77b4f99cee675795cc0e70937c56ee.tar.xz
linux-dev-fb226c3d7c77b4f99cee675795cc0e70937c56ee.zip
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>
Diffstat (limited to '')
-rw-r--r--arch/arm64/include/asm/pgtable.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c3d22a507648..1c99d5610bc7 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -78,6 +78,7 @@ extern void __pgd_error(const char *file, int line, unsigned long val);
#define _PAGE_DEFAULT (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
#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_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)