[PATCH v2 01/13] mm/vma: remove __private sparse decoration from vma_flags_t

[Lorenzo Stoakes]

We need to pass around these values and access them in a way that sparse
does not allow, as __private implies noderef, i.e. disallowing dereference
of the value, which manifests as sparse warnings even when passed around
benignly.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes at oracle.com>
---
 include/linux/mm.h       |  4 ++--
 include/linux/mm_types.h | 14 ++++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index d7ca837dd8a5..776a7e03f88b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -943,7 +943,7 @@ static inline void vm_flags_reset_once(struct vm_area_struct *vma,
 	 * system word.
 	 */
 	if (NUM_VMA_FLAG_BITS > BITS_PER_LONG) {
-		unsigned long *bitmap = ACCESS_PRIVATE(&vma->flags, __vma_flags);
+		unsigned long *bitmap = vma->flags.__vma_flags;
 
 		bitmap_zero(&bitmap[1], NUM_VMA_FLAG_BITS - BITS_PER_LONG);
 	}
@@ -1006,7 +1006,7 @@ static inline bool __vma_flag_atomic_valid(struct vm_area_struct *vma,
 static inline void vma_flag_set_atomic(struct vm_area_struct *vma,
 				       vma_flag_t bit)
 {
-	unsigned long *bitmap = ACCESS_PRIVATE(&vma->flags, __vma_flags);
+	unsigned long *bitmap = vma->flags.__vma_flags;
 
 	vma_assert_stabilised(vma);
 	if (__vma_flag_atomic_valid(vma, bit))
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index e5ee66f84d9a..592ad065fa75 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -866,7 +866,7 @@ struct mmap_action {
 #define NUM_VMA_FLAG_BITS BITS_PER_LONG
 typedef struct {
 	DECLARE_BITMAP(__vma_flags, NUM_VMA_FLAG_BITS);
-} __private vma_flags_t;
+} vma_flags_t;
 
 /*
  * Describes a VMA that is about to be mmap()'ed. Drivers may choose to
@@ -1056,7 +1056,7 @@ struct vm_area_struct {
 /* Clears all bits in the VMA flags bitmap, non-atomically. */
 static inline void vma_flags_clear_all(vma_flags_t *flags)
 {
-	bitmap_zero(ACCESS_PRIVATE(flags, __vma_flags), NUM_VMA_FLAG_BITS);
+	bitmap_zero(flags->__vma_flags, NUM_VMA_FLAG_BITS);
 }
 
 /*
@@ -1067,7 +1067,9 @@ static inline void vma_flags_clear_all(vma_flags_t *flags)
  */
 static inline void vma_flags_overwrite_word(vma_flags_t *flags, unsigned long value)
 {
-	*ACCESS_PRIVATE(flags, __vma_flags) = value;
+	unsigned long *bitmap = flags->__vma_flags;
+
+	bitmap[0] = value;
 }
 
 /*
@@ -1078,7 +1080,7 @@ static inline void vma_flags_overwrite_word(vma_flags_t *flags, unsigned long va
  */
 static inline void vma_flags_overwrite_word_once(vma_flags_t *flags, unsigned long value)
 {
-	unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags);
+	unsigned long *bitmap = flags->__vma_flags;
 
 	WRITE_ONCE(*bitmap, value);
 }
@@ -1086,7 +1088,7 @@ static inline void vma_flags_overwrite_word_once(vma_flags_t *flags, unsigned lo
 /* Update the first system word of VMA flags setting bits, non-atomically. */
 static inline void vma_flags_set_word(vma_flags_t *flags, unsigned long value)
 {
-	unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags);
+	unsigned long *bitmap = flags->__vma_flags;
 
 	*bitmap |= value;
 }
@@ -1094,7 +1096,7 @@ static inline void vma_flags_set_word(vma_flags_t *flags, unsigned long value)
 /* Update the first system word of VMA flags clearing bits, non-atomically. */
 static inline void vma_flags_clear_word(vma_flags_t *flags, unsigned long value)
 {
-	unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags);
+	unsigned long *bitmap = flags->__vma_flags;
 
 	*bitmap &= ~value;
 }
-- 
2.52.0