From: Barry Song <v-songbaohua@oppo.com>
Date: Wed, 14 Aug 2024 22:34:16 +0000 (+1200)
Subject: mm: use get_oder() and check size is is_power_of_2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8bfb09a8be669eac93ea0149b897ce32d4e2dcd7;p=users%2Fjedix%2Flinux-maple.git

mm: use get_oder() and check size is is_power_of_2

Using get_order() is more robust according to Baolin.  It is also better
to filter illegal size such as 3KB, 16KB according to David.

Link: https://lkml.kernel.org/r/20240814224635.43272-1-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Suggested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d32ade990059..cf8e34f62976 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -929,14 +929,17 @@ static inline int get_order_from_str(const char *size_str)
 	int order;
 
 	size = memparse(size_str, &endptr);
-	order = fls(size >> PAGE_SHIFT) - 1;
-	if ((1 << order) & ~THP_ORDERS_ALL_ANON) {
-		pr_err("invalid size %s(order %d) in thp_anon boot parameter\n",
-			size_str, order);
-		return -EINVAL;
-	}
+
+	if (!is_power_of_2(size >> PAGE_SHIFT))
+		goto err;
+	order = get_order(size);
+	if ((1 << order) & ~THP_ORDERS_ALL_ANON)
+		goto err;
 
 	return order;
+err:
+	pr_err("invalid size %s in thp_anon boot parameter\n", size_str);
+	return -EINVAL;
 }
 
 static char str_dup[PAGE_SIZE] __meminitdata;