asm-generic: sections: refactor memory_intersects

stable inclusion
from stable-v4.19.257
commit b5cc57e43f2e5c51ef6ee6d45d97ff7844e9d4ba
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5UQH4
CVE: NA

--------------------------------

commit 0c7d7cc2b4fe2e74ef8728f030f0f1674f9f6aee upstream.

There are two problems with the current code of memory_intersects:

First, it doesn't check whether the region (begin, end) falls inside the
region (virt, vend), that is (virt < begin && vend > end).

The second problem is if vend is equal to begin, it will return true but
this is wrong since vend (virt + size) is not the last address of the
memory region but (virt + size -1) is.  The wrong determination will
trigger the misreporting when the function check_for_illegal_area calls
memory_intersects to check if the dma region intersects with stext region.

The misreporting is as below (stext is at 0x80100000):
 WARNING: CPU: 0 PID: 77 at kernel/dma/debug.c:1073 check_for_illegal_area+0x130/0x168
 D...

include/asm-generic/sections.h

@@ -97,7 +97,7 @@ static inline bool memory_contains(void *begin, void *end, void *virt,
 /**
  * memory_intersects - checks if the region occupied by an object intersects
  *                     with another memory region
- * @begin: virtual address of the beginning of the memory regien
+ * @begin: virtual address of the beginning of the memory region
  * @end: virtual address of the end of the memory region
  * @virt: virtual address of the memory object
  * @size: size of the memory object
@@ -110,7 +110,10 @@ static inline bool memory_intersects(void *begin, void *end, void *virt,
 {
 	void *vend = virt + size;
 
-	return (virt >= begin && virt < end) || (vend >= begin && vend < end);
+	if (virt < end && vend > begin)
+		return true;
+
+	return false;
 }
 
 /**