[RFC PATCH 07/16] mm/madvise: make madvise_walk_vmas() visit function receives a void pointer

[SeongJae Park <sj@kernel.org>]

madvise_walk_vmas() is used for two visit functions, namely
madvise_vma_anon_name() and madvise_walk_vmas().  The visit function
type is defined to receive an 'unsigned long' type argument.  But, both
visit functions need a pointer argument, so casting the arguments
between 'unsinged long' and the real pointer types.  It is more
idiomatic and clean to use a void pointer type for such cases.  Update
the visit function type to receive a void pointer as the argument and
cleanup the type-casting code.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/madvise.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index 8c4c128eaeb7..6fa7dabe5bad 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1253,9 +1253,9 @@ struct madvise_behavior {
 static int madvise_vma_behavior(struct vm_area_struct *vma,
 				struct vm_area_struct **prev,
 				unsigned long start, unsigned long end,
-				unsigned long behavior_arg)
+				void *behavior_arg)
 {
-	struct madvise_behavior *arg = (struct madvise_behavior *)behavior_arg;
+	struct madvise_behavior *arg = behavior_arg;
 	int behavior = arg->behavior;
 	int error;
 	struct anon_vma_name *anon_name;
@@ -1468,10 +1468,10 @@ static bool process_madvise_remote_valid(int behavior)
  */
 static
 int madvise_walk_vmas(struct mm_struct *mm, unsigned long start,
-		      unsigned long end, unsigned long arg,
+		      unsigned long end, void *arg,
 		      int (*visit)(struct vm_area_struct *vma,
 				   struct vm_area_struct **prev, unsigned long start,
-				   unsigned long end, unsigned long arg))
+				   unsigned long end, void *arg))
 {
 	struct vm_area_struct *vma;
 	struct vm_area_struct *prev;
@@ -1529,7 +1529,7 @@ int madvise_walk_vmas(struct mm_struct *mm, unsigned long start,
 static int madvise_vma_anon_name(struct vm_area_struct *vma,
 				 struct vm_area_struct **prev,
 				 unsigned long start, unsigned long end,
-				 unsigned long anon_name)
+				 void *anon_name)
 {
 	int error;
 
@@ -1538,7 +1538,7 @@ static int madvise_vma_anon_name(struct vm_area_struct *vma,
 		return -EBADF;
 
 	error = madvise_update_vma(vma, prev, start, end, vma->vm_flags,
-				   (struct anon_vma_name *)anon_name);
+				   anon_name);
 
 	/*
 	 * madvise() returns EAGAIN if kernel resources, such as
@@ -1570,7 +1570,7 @@ int madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
 	if (end == start)
 		return 0;
 
-	return madvise_walk_vmas(mm, start, end, (unsigned long)anon_name,
+	return madvise_walk_vmas(mm, start, end, anon_name,
 				 madvise_vma_anon_name);
 }
 #endif /* CONFIG_ANON_VMA_NAME */
@@ -1689,8 +1689,7 @@ static int madvise_do_behavior(struct mm_struct *mm,
 	if (is_memory_populate(behavior))
 		error = madvise_populate(mm, start, end, behavior);
 	else
-		error = madvise_walk_vmas(mm, start, end,
-					  (unsigned long)madv_behavior,
+		error = madvise_walk_vmas(mm, start, end, madv_behavior,
 					  madvise_vma_behavior);
 	blk_finish_plug(&plug);
 	return error;
-- 
2.39.5