[PATCH] fixups

[Lorenzo Stoakes]

Signed-off-by: Lorenzo Stoakes <ljs@xxxxxxxxxx>
---
 mm/madvise.c | 55 +++++++++++++++++++++-------------------------------
 1 file changed, 22 insertions(+), 33 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index ce238dd96f15..865fe7fb3d81 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1834,45 +1834,31 @@ static void madvise_finish_tlb(struct madvise_behavior *madv_behavior)
 		tlb_finish_mmu(madv_behavior->tlb);
 }

-static bool is_valid_madvise_range(unsigned long start, size_t len_in)
+/**
+ * check_input_range() - Check if the requested range is valid.
+ * @start:	Start address of madvise-requested address range.
+ * @len_in:	Length of madvise-requested address range.
+ *
+ * Returns: 0 if the input range is valid, otherwise an error code.
+ */
+static int check_input_range(unsigned long start, size_t len_in)
 {
 	size_t len;

 	if (!PAGE_ALIGNED(start))
-		return false;
+		return -EINVAL;
+
 	len = PAGE_ALIGN(len_in);

 	/* Check to see whether len was rounded up from small -ve to zero */
 	if (len_in && !len)
-		return false;
+		return -EINVAL;

+	/* Overflow? */
 	if (start + len < start)
-		return false;
-
-	return true;
-}
+		return -EINVAL;

-/*
- * madvise_should_skip() - Return if the request is invalid or nothing.
- * @start:	Start address of madvise-requested address range.
- * @len_in:	Length of madvise-requested address range.
- * @err:	Pointer to store an error code from the check.
- *
- * If the specified range is invalid or nothing would occur, we skip the
- * operation.  This function returns true in these cases, otherwise false.  In
- * the former case we store an error in @err.
- */
-static bool madvise_should_skip(unsigned long start, size_t len_in, int *err)
-{
-	if (!is_valid_madvise_range(start, len_in)) {
-		*err = -EINVAL;
-		return true;
-	}
-	if (start + PAGE_ALIGN(len_in) == start) {
-		*err = 0;
-		return true;
-	}
-	return false;
+	return 0;
 }

 static bool is_madvise_populate(struct madvise_behavior *madv_behavior)
@@ -2010,12 +1996,13 @@ int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int beh

 	if (!madvise_behavior_valid(behavior))
 		return -EINVAL;
-
-	if (madvise_should_skip(start, len_in, &error))
+	error = check_input_range(start, len_in);
+	if (error || !len_in)
 		return error;
 	error = madvise_lock(&madv_behavior);
 	if (error)
 		return error;
+
 	madvise_init_tlb(&madv_behavior);
 	error = madvise_do_behavior(start, len_in, &madv_behavior);
 	madvise_finish_tlb(&madv_behavior);
@@ -2054,10 +2041,12 @@ static ssize_t vector_madvise(struct mm_struct *mm, struct iov_iter *iter,
 		size_t len_in = iter_iov_len(iter);
 		int error;

-		if (madvise_should_skip(start, len_in, &error))
-			ret = error;
-		else
+		error = check_input_range(start, len_in);
+		if (len_in && !error)
 			ret = madvise_do_behavior(start, len_in, &madv_behavior);
+		else
+			ret = error;
+
 		/*
 		 * An madvise operation is attempting to restart the syscall,
 		 * but we cannot proceed as it would not be correct to repeat
--
2.54.0