[18/25] powerpc: check key protection for user page access

Message ID 1504910713-7094-27-git-send-email-linuxram@us.ibm.com
State New
Headers show
Series
  • powerpc: Free up RPAGE_RSV bits
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Commit Message

Ram Pai Sept. 8, 2017, 10:45 p.m.
Make sure that the kernel does not access user pages without
checking their key-protection.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/pgtable.h |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

Patch

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index bd244b3..d22bb4d 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -494,6 +494,20 @@  static inline void write_uamor(u64 value)
 
 #ifdef CONFIG_PPC64_MEMORY_PROTECTION_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 for huge tlb pages. So 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)))
 #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
 
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR