From bca7aacfe8be121ecefb3be609420220b0820c2c Mon Sep 17 00:00:00 2001
From: Ram Pai <linuxram@us.ibm.com>
Date: Thu, 18 Jan 2018 17:50:38 -0800
Subject: [PATCH] powerpc: check key protection for user page access
Make sure that the kernel does not access user pages without
checking their key-protection.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Integrate with upstream version of pte_access_permitted()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 449b797f8b7b5..1c495068bcfa9 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -571,7 +571,14 @@ static inline int pte_present(pte_t pte)
return !!(pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT));
}
+#ifdef CONFIG_PPC_MEM_KEYS
extern bool arch_pte_access_permitted(u64 pte, bool write, bool execute);
+#else
+static inline bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
+{
+ return true;
+}
+#endif /* CONFIG_PPC_MEM_KEYS */
#define pte_access_permitted pte_access_permitted
static inline bool pte_access_permitted(pte_t pte, bool write)
@@ -593,7 +600,8 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
if ((pteval & clear_pte_bits) == clear_pte_bits)
return false;
- return true;
+
+ return arch_pte_access_permitted(pte_val(pte), write, 0);
}
/*
--
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