Re: [RFC v4 09/17] powerpc: call the hash functions with the correct pkey value

[Aneesh Kumar K.V]

On Tuesday 27 June 2017 03:41 PM, Ram Pai wrote:

Pass the correct protection key value to the hash functions on
page fault.

Signed-off-by: Ram Pai 
---
  arch/powerpc/include/asm/pkeys.h | 11 +++
  arch/powerpc/mm/hash_utils_64.c  |  4 
  arch/powerpc/mm/mem.c|  6 ++
  3 files changed, 21 insertions(+)

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index ef1c601..1370b3f 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -74,6 +74,17 @@ static inline bool mm_pkey_is_allocated(struct mm_struct 
*mm, int pkey)
  }

  /*
+ * return the protection key of the vma corresponding to the
+ * given effective address @ea.
+ */
+static inline int mm_pkey(struct mm_struct *mm, unsigned long ea)
+{
+   struct vm_area_struct *vma = find_vma(mm, ea);
+   int pkey = vma ? vma_pkey(vma) : 0;
+   return pkey;
+}
+
+/*



That is not going to work in hash fault path right ? We can't do a 
find_vma there without holding the mmap_sem


-aneesh

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[RFC v4 09/17] powerpc: call the hash functions with the correct pkey value

[Ram Pai]

Pass the correct protection key value to the hash functions on
page fault.

Signed-off-by: Ram Pai 
---
 arch/powerpc/include/asm/pkeys.h | 11 +++
 arch/powerpc/mm/hash_utils_64.c  |  4 
 arch/powerpc/mm/mem.c|  6 ++
 3 files changed, 21 insertions(+)

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index ef1c601..1370b3f 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -74,6 +74,17 @@ static inline bool mm_pkey_is_allocated(struct mm_struct 
*mm, int pkey)
 }
 
 /*
+ * return the protection key of the vma corresponding to the
+ * given effective address @ea.
+ */
+static inline int mm_pkey(struct mm_struct *mm, unsigned long ea)
+{
+   struct vm_area_struct *vma = find_vma(mm, ea);
+   int pkey = vma ? vma_pkey(vma) : 0;
+   return pkey;
+}
+
+/*
  * Returns a positive, 5-bit key on success, or -1 on failure.
  */
 static inline int mm_pkey_alloc(struct mm_struct *mm)
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 7e67dea..403f75d 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1319,6 +1319,10 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
goto bail;
}
 
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+   pkey = mm_pkey(mm, ea);
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
if (hugeshift) {
if (is_thp)
rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index ec890d3..0fcaa48 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -541,8 +541,14 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned 
long address,
return;
}
 
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+   hash_preload_pkey(vma->vm_mm, address, access, trap, vma_pkey(vma));
+#else
hash_preload(vma->vm_mm, address, access, trap);
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
 #endif /* CONFIG_PPC_STD_MMU */
+
 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
&& defined(CONFIG_HUGETLB_PAGE)
if (is_vm_hugetlb_page(vma))
-- 
1.8.3.1

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