selftests/mm: mremap_test: use sscanf to parse /proc/self/maps

Enforce consistency across files by avoiding two separate functions to
parse /proc/self/maps, replacing them with a simple sscanf().

Link: https://lkml.kernel.org/r/20240330173557.2697684-4-dev.jain@arm.comSigned-off-by: Dev Jain <dev.jain@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/mm/mremap_test.c

@@ -148,19 +148,21 @@ static unsigned long long get_mmap_min_addr(void)
  * Using /proc/self/maps, assert that the specified address range is contained
  * within a single mapping.
  */
-static bool is_range_mapped(FILE *maps_fp, void *start, void *end)
+static bool is_range_mapped(FILE *maps_fp, unsigned long start,
+			    unsigned long end)
 {
 	char *line = NULL;
 	size_t len = 0;
 	bool success = false;
+	unsigned long first_val, second_val;
 
 	rewind(maps_fp);
 
 	while (getline(&line, &len, maps_fp) != -1) {
-		char *first = strtok(line, "- ");
-		void *first_val = (void *)strtol(first, NULL, 16);
-		char *second = strtok(NULL, "- ");
-		void *second_val = (void *) strtol(second, NULL, 16);
+		if (sscanf(line, "%lx-%lx", &first_val, &second_val) != 2) {
+			ksft_exit_fail_msg("cannot parse /proc/self/maps\n");
+			break;
+		}
 
 		if (first_val <= start && second_val >= end) {
 			success = true;
@@ -255,7 +257,8 @@ static void mremap_expand_merge(FILE *maps_fp, unsigned long page_size)
 		goto out;
 	}
 
-	success = is_range_mapped(maps_fp, start, start + 3 * page_size);
+	success = is_range_mapped(maps_fp, (unsigned long)start,
+				  (unsigned long)(start + 3 * page_size));
 	munmap(start, 3 * page_size);
 
 out:
@@ -294,7 +297,8 @@ static void mremap_expand_merge_offset(FILE *maps_fp, unsigned long page_size)
 		goto out;
 	}
 
-	success = is_range_mapped(maps_fp, start, start + 3 * page_size);
+	success = is_range_mapped(maps_fp, (unsigned long)start,
+				  (unsigned long)(start + 3 * page_size));
 	munmap(start, 3 * page_size);
 
 out: