[PATCH v3 6/6] kselftest/arm64: mte: user_mem: test a wider range of values

[Joey Gouly]

Instead of hard coding a small amount of tests, generate a wider
range of tests to try catch any corner cases that could show up.

These new tests test different MTE tag lengths and offsets, which
previously would have caused infinite loops in the kernel. This was
fixed by 295cf156231c ("arm64: Avoid premature usercopy failure"),
so these are regressions tests for that corner case.

Signed-off-by: Joey Gouly <joey.gouly at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will at kernel.org>
Cc: Mark Brown <broonie at kernel.org>
Cc: Shuah Khan <shuah at kernel.org>
Reviewed-by: Mark Brown <broonie at kernel.org>
Tested-by: Mark Brown <broonie at kernel.org>
Reviewed-by: Shuah Khan <skhan at linuxfoundation.org>
---
 .../selftests/arm64/mte/check_user_mem.c      | 94 ++++++++++++++++---
 1 file changed, 83 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/arm64/mte/check_user_mem.c b/tools/testing/selftests/arm64/mte/check_user_mem.c
index bb4974c437f8..f4ae5f87a3b7 100644
--- a/tools/testing/selftests/arm64/mte/check_user_mem.c
+++ b/tools/testing/selftests/arm64/mte/check_user_mem.c
@@ -3,6 +3,7 @@
 
 #define _GNU_SOURCE
 
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
@@ -20,6 +21,8 @@
 
 static size_t page_sz;
 
+#define TEST_NAME_MAX 100
+
 enum test_type {
 	READ_TEST,
 	WRITE_TEST,
@@ -136,9 +139,67 @@ static int check_usermem_access_fault(int mem_type, int mode, int mapping,
 	return err;
 }
 
+void format_test_name(char* name, int name_len, int type, int sync, int map, int len, int offset) {
+	const char* test_type;
+	const char* mte_type;
+	const char* map_type;
+
+	switch (type) {
+	case READ_TEST:
+		test_type = "read";
+		break;
+	case WRITE_TEST:
+		test_type = "write";
+		break;
+	case READV_TEST:
+		test_type = "readv";
+		break;
+	case WRITEV_TEST:
+		test_type = "writev";
+		break;
+	default:
+		assert(0);
+		break;
+	}
+
+	switch (sync) {
+	case MTE_SYNC_ERR:
+		mte_type = "MTE_SYNC_ERR";
+		break;
+	case MTE_ASYNC_ERR:
+		mte_type = "MTE_ASYNC_ERR";
+		break;
+	default:
+		assert(0);
+		break;
+	}
+
+	switch (map) {
+	case MAP_SHARED:
+		map_type = "MAP_SHARED";
+		break;
+	case MAP_PRIVATE:
+		map_type = "MAP_PRIVATE";
+		break;
+	default:
+		assert(0);
+		break;
+	}
+
+	snprintf(name, name_len,
+	         "test type: %s, %s, %s, tag len: %d, tag offset: %d\n",
+	         test_type, mte_type, map_type, len, offset);
+}
+
 int main(int argc, char *argv[])
 {
 	int err;
+	int t, s, m, l, o;
+	int mte_sync[] = {MTE_SYNC_ERR, MTE_ASYNC_ERR};
+	int maps[] = {MAP_SHARED, MAP_PRIVATE};
+	int tag_lens[] = {0, MT_GRANULE_SIZE};
+	int tag_offsets[] = {page_sz, MT_GRANULE_SIZE};
+	char test_name[TEST_NAME_MAX];
 
 	page_sz = getpagesize();
 	if (!page_sz) {
@@ -153,17 +214,28 @@ int main(int argc, char *argv[])
 	mte_register_signal(SIGSEGV, mte_default_handler);
 
 	/* Set test plan */
-	ksft_set_plan(4);
-
-	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE, page_sz, 0, READ_TEST),
-		"Check memory access from kernel in sync mode, private mapping and mmap memory\n");
-	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED, page_sz, 0, READ_TEST),
-		"Check memory access from kernel in sync mode, shared mapping and mmap memory\n");
-
-	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE, page_sz, 0, READ_TEST),
-		"Check memory access from kernel in async mode, private mapping and mmap memory\n");
-	evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED, page_sz, 0, READ_TEST),
-		"Check memory access from kernel in async mode, shared mapping and mmap memory\n");
+	ksft_set_plan(64);
+
+	for (t = 0; t < LAST_TEST; t++) {
+		for (s = 0; s < ARRAY_SIZE(mte_sync); s++) {
+			for (m = 0; m < ARRAY_SIZE(maps); m++) {
+				for (l = 0; l < ARRAY_SIZE(tag_lens); l++) {
+					for (o = 0; o < ARRAY_SIZE(tag_offsets); o++) {
+						int sync = mte_sync[s];
+						int map = maps[m];
+						int offset = tag_offsets[o];
+						int tag_len = tag_lens[l];
+						int res = check_usermem_access_fault(USE_MMAP, sync,
+						                                     map, offset,
+						                                     tag_len, t);
+						format_test_name(test_name, TEST_NAME_MAX,
+						                 t, sync, map, tag_len, offset);
+						evaluate_test(res, test_name);
+					}
+				}
+			}
+		}
+	}
 
 	mte_restore_setup();
 	ksft_print_cnts();
-- 
2.17.1