kselftest/arm64: mte: user_mem: test a wider range of values

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 <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Mark Brown <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Reviewed-by: Mark Brown <[e-mail]>
Tested-by: Mark Brown <[e-mail]>
Reviewed-by: Shuah Khan <[e-mail]>
Reviewed-by: Catalin Marinas <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

tools/testing/selftests/arm64/mte/check_user_mem.c

···
 
 #define _GNU_SOURCE
 
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
···
 #include "mte_def.h"
 
 static size_t page_sz;
+
+#define TEST_NAME_MAX 100
 
 enum test_type {
 	READ_TEST,
···
 	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) {
···
 	mte_register_signal(SIGSEGV, mte_default_handler);
 
 	/* Set test plan */
-	ksft_set_plan(4);
+	ksft_set_plan(64);
 
-	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");
+	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();