KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

atoi() doesn't detect errors. There is no way to know that a 0 return
is correct conversion or due to an error.

Introduce atoi_paranoid() to detect errors and provide correct
conversion. Replace all atoi() calls with atoi_paranoid().

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Suggested-by: David Matlack <dmatlack@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221103191719.1559407-4-vipinsh@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/aarch64/arch_timer.c

@@ -414,7 +414,7 @@ static bool parse_args(int argc, char *argv[])
 	while ((opt = getopt(argc, argv, "hn:i:p:m:")) != -1) {
 		switch (opt) {
 		case 'n':
-			test_args.nr_vcpus = atoi(optarg);
+			test_args.nr_vcpus = atoi_paranoid(optarg);
 			if (test_args.nr_vcpus <= 0) {
 				pr_info("Positive value needed for -n\n");
 				goto err;
@@ -425,21 +425,21 @@ static bool parse_args(int argc, char *argv[])
 			}
 			break;
 		case 'i':
-			test_args.nr_iter = atoi(optarg);
+			test_args.nr_iter = atoi_paranoid(optarg);
 			if (test_args.nr_iter <= 0) {
 				pr_info("Positive value needed for -i\n");
 				goto err;
 			}
 			break;
 		case 'p':
-			test_args.timer_period_ms = atoi(optarg);
+			test_args.timer_period_ms = atoi_paranoid(optarg);
 			if (test_args.timer_period_ms <= 0) {
 				pr_info("Positive value needed for -p\n");
 				goto err;
 			}
 			break;
 		case 'm':
-			test_args.migration_freq_ms = atoi(optarg);
+			test_args.migration_freq_ms = atoi_paranoid(optarg);
 			if (test_args.migration_freq_ms < 0) {
 				pr_info("0 or positive value needed for -m\n");
 				goto err;

tools/testing/selftests/kvm/aarch64/debug-exceptions.c

@@ -423,7 +423,7 @@ int main(int argc, char *argv[])
 	while ((opt = getopt(argc, argv, "i:")) != -1) {
 		switch (opt) {
 		case 'i':
-			ss_iteration = atoi(optarg);
+			ss_iteration = atoi_paranoid(optarg);
 			break;
 		case 'h':
 		default:

tools/testing/selftests/kvm/aarch64/vgic_irq.c

@@ -824,16 +824,16 @@ int main(int argc, char **argv)
 	while ((opt = getopt(argc, argv, "hn:e:l:")) != -1) {
 		switch (opt) {
 		case 'n':
-			nr_irqs = atoi(optarg);
+			nr_irqs = atoi_paranoid(optarg);
 			if (nr_irqs > 1024 || nr_irqs % 32)
 				help(argv[0]);
 			break;
 		case 'e':
-			eoi_split = (bool)atoi(optarg);
+			eoi_split = (bool)atoi_paranoid(optarg);
 			default_args = false;
 			break;
 		case 'l':
-			level_sensitive = (bool)atoi(optarg);
+			level_sensitive = (bool)atoi_paranoid(optarg);
 			default_args = false;
 			break;
 		case 'h':

tools/testing/selftests/kvm/access_tracking_perf_test.c

@@ -368,7 +368,7 @@ int main(int argc, char *argv[])
 			params.vcpu_memory_bytes = parse_size(optarg);
 			break;
 		case 'v':
-			params.nr_vcpus = atoi(optarg);
+			params.nr_vcpus = atoi_paranoid(optarg);
 			break;
 		case 'o':
 			overlap_memory_access = true;

tools/testing/selftests/kvm/demand_paging_test.c

@@ -427,7 +427,7 @@ int main(int argc, char *argv[])
 			p.src_type = parse_backing_src_type(optarg);
 			break;
 		case 'v':
-			nr_vcpus = atoi(optarg);
+			nr_vcpus = atoi_paranoid(optarg);
 			TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 				    "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 			break;

tools/testing/selftests/kvm/dirty_log_perf_test.c

@@ -416,7 +416,7 @@ int main(int argc, char *argv[])
 			run_vcpus_while_disabling_dirty_logging = true;
 			break;
 		case 'f':
-			p.wr_fract = atoi(optarg);
+			p.wr_fract = atoi_paranoid(optarg);
 			TEST_ASSERT(p.wr_fract >= 1,
 				    "Write fraction cannot be less than one");
 			break;
@@ -427,7 +427,7 @@ int main(int argc, char *argv[])
 			help(argv[0]);
 			break;
 		case 'i':
-			p.iterations = atoi(optarg);
+			p.iterations = atoi_paranoid(optarg);
 			break;
 		case 'm':
 			guest_modes_cmdline(optarg);
@@ -445,12 +445,12 @@ int main(int argc, char *argv[])
 			p.backing_src = parse_backing_src_type(optarg);
 			break;
 		case 'v':
-			nr_vcpus = atoi(optarg);
+			nr_vcpus = atoi_paranoid(optarg);
 			TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 				    "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 			break;
 		case 'x':
-			p.slots = atoi(optarg);
+			p.slots = atoi_paranoid(optarg);
 			break;
 		default:
 			help(argv[0]);

tools/testing/selftests/kvm/include/test_util.h

@@ -152,4 +152,6 @@ static inline void *align_ptr_up(void *x, size_t size)
 	return (void *)align_up((unsigned long)x, size);
 }
 
+int atoi_paranoid(const char *num_str);
+
 #endif /* SELFTEST_KVM_TEST_UTIL_H */

tools/testing/selftests/kvm/kvm_page_table_test.c

@@ -461,7 +461,7 @@ int main(int argc, char *argv[])
 			p.test_mem_size = parse_size(optarg);
 			break;
 		case 'v':
-			nr_vcpus = atoi(optarg);
+			nr_vcpus = atoi_paranoid(optarg);
 			TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 				    "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 			break;

tools/testing/selftests/kvm/lib/test_util.c

@@ -334,3 +334,22 @@ long get_run_delay(void)
 
 	return val[1];
 }
+
+int atoi_paranoid(const char *num_str)
+{
+	char *end_ptr;
+	long num;
+
+	errno = 0;
+	num = strtol(num_str, &end_ptr, 0);
+	TEST_ASSERT(!errno, "strtol(\"%s\") failed", num_str);
+	TEST_ASSERT(num_str != end_ptr,
+		    "strtol(\"%s\") didn't find a valid integer.", num_str);
+	TEST_ASSERT(*end_ptr == '\0',
+		    "strtol(\"%s\") failed to parse trailing characters \"%s\".",
+		    num_str, end_ptr);
+	TEST_ASSERT(num >= INT_MIN && num <= INT_MAX,
+		    "%ld not in range of [%d, %d]", num, INT_MIN, INT_MAX);
+
+	return num;
+}

tools/testing/selftests/kvm/max_guest_memory_test.c

@@ -193,15 +193,15 @@ int main(int argc, char *argv[])
 	while ((opt = getopt(argc, argv, "c:h:m:s:H")) != -1) {
 		switch (opt) {
 		case 'c':
-			nr_vcpus = atoi(optarg);
+			nr_vcpus = atoi_paranoid(optarg);
 			TEST_ASSERT(nr_vcpus > 0, "number of vcpus must be >0");
 			break;
 		case 'm':
-			max_mem = atoi(optarg) * size_1gb;
+			max_mem = atoi_paranoid(optarg) * size_1gb;
 			TEST_ASSERT(max_mem > 0, "memory size must be >0");
 			break;
 		case 's':
-			slot_size = atoi(optarg) * size_1gb;
+			slot_size = atoi_paranoid(optarg) * size_1gb;
 			TEST_ASSERT(slot_size > 0, "slot size must be >0");
 			break;
 		case 'H':

tools/testing/selftests/kvm/memslot_modification_stress_test.c

@@ -158,7 +158,7 @@ int main(int argc, char *argv[])
 			guest_modes_cmdline(optarg);
 			break;
 		case 'd':
-			p.memslot_modification_delay = strtoul(optarg, NULL, 0);
+			p.memslot_modification_delay = atoi_paranoid(optarg);
 			TEST_ASSERT(p.memslot_modification_delay >= 0,
 				    "A negative delay is not supported.");
 			break;
@@ -166,7 +166,7 @@ int main(int argc, char *argv[])
 			guest_percpu_mem_size = parse_size(optarg);
 			break;
 		case 'v':
-			nr_vcpus = atoi(optarg);
+			nr_vcpus = atoi_paranoid(optarg);
 			TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 				    "Invalid number of vcpus, must be between 1 and %d",
 				    max_vcpus);
@@ -175,7 +175,7 @@ int main(int argc, char *argv[])
 			p.partition_vcpu_memory_access = false;
 			break;
 		case 'i':
-			p.nr_memslot_modifications = atoi(optarg);
+			p.nr_memslot_modifications = atoi_paranoid(optarg);
 			break;
 		case 'h':
 		default:

tools/testing/selftests/kvm/memslot_perf_test.c

@@ -885,21 +885,21 @@ static bool parse_args(int argc, char *argv[],
 			map_unmap_verify = true;
 			break;
 		case 's':
-			targs->nslots = atoi(optarg);
+			targs->nslots = atoi_paranoid(optarg);
 			if (targs->nslots <= 0 && targs->nslots != -1) {
 				pr_info("Slot count cap has to be positive or -1 for no cap\n");
 				return false;
 			}
 			break;
 		case 'f':
-			targs->tfirst = atoi(optarg);
+			targs->tfirst = atoi_paranoid(optarg);
 			if (targs->tfirst < 0) {
 				pr_info("First test to run has to be non-negative\n");
 				return false;
 			}
 			break;
 		case 'e':
-			targs->tlast = atoi(optarg);
+			targs->tlast = atoi_paranoid(optarg);
 			if (targs->tlast < 0 || targs->tlast >= NTESTS) {
 				pr_info("Last test to run has to be non-negative and less than %zu\n",
 					NTESTS);
@@ -907,14 +907,14 @@ static bool parse_args(int argc, char *argv[],
 			}
 			break;
 		case 'l':
-			targs->seconds = atoi(optarg);
+			targs->seconds = atoi_paranoid(optarg);
 			if (targs->seconds < 0) {
 				pr_info("Test length in seconds has to be non-negative\n");
 				return false;
 			}
 			break;
 		case 'r':
-			targs->runs = atoi(optarg);
+			targs->runs = atoi_paranoid(optarg);
 			if (targs->runs <= 0) {
 				pr_info("Runs per test has to be positive\n");
 				return false;

tools/testing/selftests/kvm/set_memory_region_test.c

@@ -407,7 +407,7 @@ int main(int argc, char *argv[])
 
 #ifdef __x86_64__
 	if (argc > 1)
-		loops = atoi(argv[1]);
+		loops = atoi_paranoid(argv[1]);
 	else
 		loops = 10;
 

tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c

@@ -241,10 +241,10 @@ int main(int argc, char **argv)
 	while ((opt = getopt(argc, argv, "hp:t:r")) != -1) {
 		switch (opt) {
 		case 'p':
-			reclaim_period_ms = atoi(optarg);
+			reclaim_period_ms = atoi_paranoid(optarg);
 			break;
 		case 't':
-			token = atoi(optarg);
+			token = atoi_paranoid(optarg);
 			break;
 		case 'r':
 			reboot_permissions = true;