[PATCH v10 17/27] powerpc: check key protection for user page access
From: Ram Pai <hidden>
Date: 2018-01-19 01:55:44
Also in:
linux-arch, linux-kselftest, linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Make sure that the kernel does not access user pages without checking their key-protection. Signed-off-by: Ram Pai <redacted> --- arch/powerpc/include/asm/book3s/64/pgtable.h | 19 +++++++++++++++++++ 1 files changed, 19 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index e785c68..3d8186e 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h@@ -464,6 +464,25 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm, #ifdef CONFIG_PPC_MEM_KEYS extern bool arch_pte_access_permitted(u64 pte, bool write, bool execute); + +#define pte_access_permitted(pte, write) \ + (pte_present(pte) && \ + ((!(write) || pte_write(pte)) && \ + arch_pte_access_permitted(pte_val(pte), !!write, 0))) + +/* + * We store key in pmd/pud for huge pages. Need to check for key protection. + */ +#define pmd_access_permitted(pmd, write) \ + (pmd_present(pmd) && \ + ((!(write) || pmd_write(pmd)) && \ + arch_pte_access_permitted(pmd_val(pmd), !!write, 0))) + +#define pud_access_permitted(pud, write) \ + (pud_present(pud) && \ + ((!(write) || pud_write(pud)) && \ + arch_pte_access_permitted(pud_val(pud), !!write, 0))) + #endif /* CONFIG_PPC_MEM_KEYS */ #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
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1.7.1