[PATCH v5 2/3] printf: break kunit into test cases

Tamir Duberstein
2025-02-21T20:34:41Z

Move all tests into `printf_test_cases`. This gives us nicer output in
the event of a failure.

Combine `plain_format` and `plain_hash` into `hash_pointer` since
they're testing the same scenario.

Signed-off-by: Tamir Duberstein <tamird@gmail.com>
---
lib/tests/printf_kunit.c | 331 +++++++++++++++++------------------------------
1 file changed, 121 insertions(+), 210 deletions(-)

diff --git a/lib/tests/printf_kunit.c b/lib/tests/printf_kunit.c
index 287bbfb61148..013df6f6dd49 100644
--- a/lib/tests/printf_kunit.c
+++ b/lib/tests/printf_kunit.c
@@ -38,13 +38,8 @@ static unsigned int total_tests;
static char *test_buffer;
static char *alloced_buffer;

-static struct kunit *kunittest;
-
-#define tc_fail(fmt, ...) \
- KUNIT_FAIL(kunittest, fmt, ##__VA_ARGS__)
-
-static void __printf(4, 0)
-do_test(int bufsize, const char *expect, int elen,
+static void __printf(5, 0)
+do_test(struct kunit *kunittest, int bufsize, const char *expect, int elen,
const char *fmt, va_list ap)
{
va_list aq;
@@ -58,59 +53,64 @@ do_test(int bufsize, const char *expect, int elen,
va_end(aq);

if (ret != elen) {
- tc_fail("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d",
- bufsize, fmt, ret, elen);
+ KUNIT_FAIL(kunittest, "vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d",
+ bufsize, fmt, ret, elen);
return;
}

if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
- tc_fail("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer",
- bufsize, fmt);
+ KUNIT_FAIL(kunittest, "vsnprintf(buf, %d, \"%s\", ...) wrote before buffer",
+ bufsize, fmt);
return;
}

if (!bufsize) {
if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
- tc_fail("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer", fmt);
+ KUNIT_FAIL(kunittest, "vsnprintf(buf, 0, \"%s\", ...) wrote to buffer",
+ fmt);
}
return;
}

written = min(bufsize-1, elen);
if (test_buffer[written]) {
- tc_fail("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer",
- bufsize, fmt);
+ KUNIT_FAIL(kunittest,
+ "vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer",
+ bufsize, fmt);
return;
}

if (memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) {
- tc_fail("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator",
- bufsize, fmt);
+ KUNIT_FAIL(kunittest,
+ "vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator",
+ bufsize, fmt);
return;
}

if (memchr_inv(test_buffer + bufsize, FILL_CHAR, BUF_SIZE + PAD_SIZE - bufsize)) {
- tc_fail("vsnprintf(buf, %d, \"%s\", ...) wrote beyond buffer", bufsize, fmt);
+ KUNIT_FAIL(kunittest, "vsnprintf(buf, %d, \"%s\", ...) wrote beyond buffer",
+ bufsize, fmt);
return;
}

if (memcmp(test_buffer, expect, written)) {
- tc_fail("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'",
- bufsize, fmt, test_buffer, written, expect);
+ KUNIT_FAIL(kunittest, "vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'",
+ bufsize, fmt, test_buffer, written, expect);
return;
}
}

-static void __printf(3, 4)
-__test(const char *expect, int elen, const char *fmt, ...)
+static void __printf(4, 0)
+__test(struct kunit *kunittest, const char *expect, int elen, const char *fmt, ...)
{
va_list ap;
int rand;
char *p;

if (elen >= BUF_SIZE) {
- tc_fail("error in test suite: expected output length %d too long. Format was '%s'.",
- elen, fmt);
+ KUNIT_FAIL(kunittest,
+ "error in test suite: expected length (%d) >= BUF_SIZE (%d). fmt=\"%s\"",
+ elen, BUF_SIZE, fmt);
return;
}

@@ -122,18 +122,19 @@ __test(const char *expect, int elen, const char *fmt, ...)
* enough and 0), and then we also test that kvasprintf would
* be able to print it as expected.
*/
- do_test(BUF_SIZE, expect, elen, fmt, ap);
+ do_test(kunittest, BUF_SIZE, expect, elen, fmt, ap);
rand = get_random_u32_inclusive(1, elen + 1);
/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
- do_test(rand, expect, elen, fmt, ap);
- do_test(0, expect, elen, fmt, ap);
+ do_test(kunittest, rand, expect, elen, fmt, ap);
+ do_test(kunittest, 0, expect, elen, fmt, ap);

p = kvasprintf(GFP_KERNEL, fmt, ap);
if (p) {
total_tests++;
if (memcmp(p, expect, elen+1)) {
- tc_fail("kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'",
- fmt, p, expect);
+ KUNIT_FAIL(kunittest,
+ "kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'",
+ fmt, p, expect);
}
kfree(p);
}
@@ -141,10 +142,10 @@ __test(const char *expect, int elen, const char *fmt, ...)
}

#define test(expect, fmt, ...) \
- __test(expect, strlen(expect), fmt, ##__VA_ARGS__)
+ __test(kunittest, expect, strlen(expect), fmt, ##__VA_ARGS__)

static void
-test_basic(void)
+test_basic(struct kunit *kunittest)
{
/* Work around annoying "warning: zero-length gnu_printf format string". */
char nul = '\0';
@@ -152,11 +153,11 @@ test_basic(void)
test("", &nul);
test("100%", "100%%");
test("xxx%yyy", "xxx%cyyy", '%');
- __test("xxx\0yyy", 7, "xxx%cyyy", '\0');
+ __test(kunittest, "xxx\0yyy", 7, "xxx%cyyy", '\0');
}

static void
-test_number(void)
+test_number(struct kunit *kunittest)
{
test("0x1234abcd ", "%#-12x", 0x1234abcd);
test(" 0x1234abcd", "%#12x", 0x1234abcd);
@@ -178,7 +179,7 @@ test_number(void)
}

static void
-test_string(void)
+test_string(struct kunit *kunittest)
{
test("", "%s%.0s", "", "123");
test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
@@ -215,29 +216,6 @@ test_string(void)
#define ZEROS "00000000" /* hex 32 zero bits */
#define ONES "ffffffff" /* hex 32 one bits */

-static int
-plain_format(void)
-{
- char buf[PLAIN_BUF_SIZE];
- int nchars;
-
- nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR);
-
- if (nchars != PTR_WIDTH)
- return -1;
-
- if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
- kunit_warn(kunittest, "crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
- PTR_VAL_NO_CRNG);
- return 0;
- }
-
- if (strncmp(buf, ZEROS, strlen(ZEROS)) != 0)
- return -1;
-
- return 0;
-}
-
#else

#define PTR_WIDTH 8
@@ -247,89 +225,44 @@ plain_format(void)
#define ZEROS ""
#define ONES ""

-static int
-plain_format(void)
-{
- /* Format is implicitly tested for 32 bit machines by plain_hash() */
- return 0;
-}
-
#endif /* BITS_PER_LONG == 64 */

-static int
-plain_hash_to_buffer(const void *p, char *buf, size_t len)
+static void
+plain_hash_to_buffer(struct kunit *kunittest, const void *p, char *buf, size_t len)
{
- int nchars;
-
- nchars = snprintf(buf, len, "%p", p);
-
- if (nchars != PTR_WIDTH)
- return -1;
+ KUNIT_ASSERT_EQ(kunittest, snprintf(buf, len, "%p", p), PTR_WIDTH);

if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
kunit_warn(kunittest, "crng possibly not yet initialized. plain 'p' buffer contains \"%s\"",
PTR_VAL_NO_CRNG);
- return 0;
}
-
- return 0;
}

-static int
-plain_hash(void)
-{
- char buf[PLAIN_BUF_SIZE];
- int ret;
-
- ret = plain_hash_to_buffer(PTR, buf, PLAIN_BUF_SIZE);
- if (ret)
- return ret;
-
- if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0)
- return -1;
-
- return 0;
-}
-
-/*
- * We can't use test() to test %p because we don't know what output to expect
- * after an address is hashed.
- */
static void
-plain(void)
+hash_pointer(struct kunit *kunittest)
{
- int err;
+ if (no_hash_pointers)
+ kunit_skip(kunittest, "hash pointers disabled");

- if (no_hash_pointers) {
- kunit_warn(kunittest, "skipping plain 'p' tests");
- return;
- }
+ char buf[PLAIN_BUF_SIZE];

- err = plain_hash();
- if (err) {
- tc_fail("plain 'p' does not appear to be hashed");
- return;
- }
+ plain_hash_to_buffer(kunittest, PTR, buf, PLAIN_BUF_SIZE);

- err = plain_format();
- if (err) {
- tc_fail("hashing plain 'p' has unexpected format");
- }
+ /*
+ * We can't use test() to test %p because we don't know what output to expect
+ * after an address is hashed.
+ */
+
+ KUNIT_EXPECT_MEMEQ(kunittest, buf, ZEROS, strlen(ZEROS));
+ KUNIT_EXPECT_MEMNEQ(kunittest, buf+strlen(ZEROS), PTR_STR, PTR_WIDTH);
}

static void
-test_hashed(const char *fmt, const void *p)
+test_hashed(struct kunit *kunittest, const char *fmt, const void *p)
{
char buf[PLAIN_BUF_SIZE];
- int ret;

- /*
- * No need to increase failed test counter since this is assumed
- * to be called after plain().
- */
- ret = plain_hash_to_buffer(p, buf, PLAIN_BUF_SIZE);
- if (ret)
- return;
+ plain_hash_to_buffer(kunittest, p, buf, PLAIN_BUF_SIZE);

test(buf, fmt, p);
}
@@ -338,7 +271,7 @@ test_hashed(const char *fmt, const void *p)
* NULL pointers aren't hashed.
*/
static void
-null_pointer(void)
+null_pointer(struct kunit *kunittest)
{
test(ZEROS "00000000", "%p", NULL);
test(ZEROS "00000000", "%px", NULL);
@@ -349,7 +282,7 @@ null_pointer(void)
* Error pointers aren't hashed.
*/
static void
-error_pointer(void)
+error_pointer(struct kunit *kunittest)
{
test(ONES "fffffff5", "%p", ERR_PTR(-11));
test(ONES "fffffff5", "%px", ERR_PTR(-11));
@@ -359,26 +292,26 @@ error_pointer(void)
#define PTR_INVALID ((void *)0x000000ab)

static void
-invalid_pointer(void)
+invalid_pointer(struct kunit *kunittest)
{
- test_hashed("%p", PTR_INVALID);
+ test_hashed(kunittest, "%p", PTR_INVALID);
test(ZEROS "000000ab", "%px", PTR_INVALID);
test("(efault)", "%pE", PTR_INVALID);
}

static void
-symbol_ptr(void)
+symbol_ptr(struct kunit *kunittest)
{
}

static void
-kernel_ptr(void)
+kernel_ptr(struct kunit *kunittest)
{
/* We can't test this without access to kptr_restrict. */
}

static void
-struct_resource(void)
+struct_resource(struct kunit *kunittest)
{
struct resource test_resource = {
.start = 0xc0ffee00,
@@ -427,7 +360,7 @@ struct_resource(void)
}

static void
-struct_range(void)
+struct_range(struct kunit *kunittest)
{
struct range test_range = DEFINE_RANGE(0xc0ffee00ba5eba11,
0xc0ffee00ba5eba11);
@@ -443,17 +376,17 @@ struct_range(void)
}

static void
-addr(void)
+addr(struct kunit *kunittest)
{
}

static void
-escaped_str(void)
+escaped_str(struct kunit *kunittest)
{
}

static void
-hex_string(void)
+hex_string(struct kunit *kunittest)
{
const char buf[3] = {0xc0, 0xff, 0xee};

@@ -464,7 +397,7 @@ hex_string(void)
}

static void
-mac(void)
+mac(struct kunit *kunittest)
{
const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};

@@ -476,7 +409,7 @@ mac(void)
}

static void
-ip4(void)
+ip4(struct kunit *kunittest)
{
struct sockaddr_in sa;

@@ -491,19 +424,12 @@ ip4(void)
}

static void
-ip6(void)
+ip6(struct kunit *kunittest)
{
}

static void
-ip(void)
-{
- ip4();
- ip6();
-}
-
-static void
-uuid(void)
+uuid(struct kunit *kunittest)
{
const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
@@ -530,7 +456,7 @@ static struct dentry test_dentry[4] = {
};

static void
-dentry(void)
+dentry(struct kunit *kunittest)
{
test("foo", "%pd", &test_dentry[0]);
test("foo", "%pd2", &test_dentry[0]);
@@ -551,12 +477,12 @@ dentry(void)
}

static void
-struct_va_format(void)
+struct_va_format(struct kunit *kunittest)
{
}

static void
-time_and_date(void)
+time_and_date(struct kunit *kunittest)
{
/* 1543210543 */
const struct rtc_time tm = {
@@ -590,12 +516,12 @@ time_and_date(void)
}

static void
-struct_clk(void)
+struct_clk(struct kunit *kunittest)
{
}

static void
-large_bitmap(void)
+large_bitmap(struct kunit *kunittest)
{
const int nbits = 1 << 16;
unsigned long *bits = bitmap_zalloc(nbits, GFP_KERNEL);
@@ -609,7 +535,7 @@ large_bitmap(void)
}

static void
-bitmap(void)
+bitmap(struct kunit *kunittest)
{
DECLARE_BITMAP(bits, 20);
const int primes[] = {2,3,5,7,11,13,17,19};
@@ -628,11 +554,11 @@ bitmap(void)
test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);

- large_bitmap();
+ large_bitmap(kunittest);
}

static void
-netdev_features(void)
+netdev_features(struct kunit *kunittest)
{
}

@@ -658,8 +584,8 @@ static const struct page_flags_test pft[] = {
};

static void
-page_flags_test(int section, int node, int zone, int last_cpupid,
- int kasan_tag, unsigned long flags, const char *name,
+page_flags_test(struct kunit *kunittest, int section, int node, int zone,
+ int last_cpupid, int kasan_tag, unsigned long flags, const char *name,
char *cmp_buf)
{
unsigned long values[] = {section, node, zone, last_cpupid, kasan_tag};
@@ -696,25 +622,24 @@ page_flags_test(int section, int node, int zone, int last_cpupid,
}

static void
-flags(void)
+flags(struct kunit *kunittest)
{
unsigned long flags;
char *cmp_buffer;
gfp_t gfp;

- cmp_buffer = kmalloc(BUF_SIZE, GFP_KERNEL);
- if (!cmp_buffer)
- return;
+ cmp_buffer = kunit_kmalloc(kunittest, BUF_SIZE, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(kunittest, cmp_buffer);

flags = 0;
- page_flags_test(0, 0, 0, 0, 0, flags, "", cmp_buffer);
+ page_flags_test(kunittest, 0, 0, 0, 0, 0, flags, "", cmp_buffer);

flags = 1UL << NR_PAGEFLAGS;
- page_flags_test(0, 0, 0, 0, 0, flags, "", cmp_buffer);
+ page_flags_test(kunittest, 0, 0, 0, 0, 0, flags, "", cmp_buffer);

flags |= 1UL << PG_uptodate | 1UL << PG_dirty | 1UL << PG_lru
| 1UL << PG_active | 1UL << PG_swapbacked;
- page_flags_test(1, 1, 1, 0x1fffff, 1, flags,
+ page_flags_test(kunittest, 1, 1, 1, 0x1fffff, 1, flags,
"uptodate|dirty|lru|active|swapbacked",
cmp_buffer);

@@ -739,11 +664,9 @@ flags(void)
(unsigned long) gfp);
gfp |= __GFP_HIGH;
test(cmp_buffer, "%pGg", &gfp);
-
- kfree(cmp_buffer);
}

-static void fwnode_pointer(void)
+static void fwnode_pointer(struct kunit *kunittest)
{
const struct software_node first = { .name = "first" };
const struct software_node second = { .name = "second", .parent = &first };
@@ -757,8 +680,7 @@ static void fwnode_pointer(void)

rval = software_node_register_node_group(group);
if (rval) {
- kunit_warn(kunittest, "cannot register softnodes; rval %d", rval);
- return;
+ kunit_skip(kunittest, "cannot register softnodes; rval %d", rval);
}

test(full_name_second, "%pfw", software_node_fwnode(&second));
@@ -770,7 +692,7 @@ static void fwnode_pointer(void)
software_node_unregister_node_group(group);
}

-static void fourcc_pointer(void)
+static void fourcc_pointer(struct kunit *kunittest)
{
struct {
u32 code;
@@ -788,13 +710,13 @@ static void fourcc_pointer(void)
}

static void
-errptr(void)
+errptr(struct kunit *kunittest)
{
test("-1234", "%pe", ERR_PTR(-1234));

/* Check that %pe with a non-ERR_PTR gets treated as ordinary %p. */
BUILD_BUG_ON(IS_ERR(PTR));
- test_hashed("%pe", PTR);
+ test_hashed(kunittest, "%pe", PTR);

#ifdef CONFIG_SYMBOLIC_ERRNAME
test("(-ENOTSOCK)", "(%pe)", ERR_PTR(-ENOTSOCK));
@@ -807,65 +729,54 @@ errptr(void)
#endif
}

-static void
-test_pointer(void)
-{
- plain();
- null_pointer();
- error_pointer();
- invalid_pointer();
- symbol_ptr();
- kernel_ptr();
- struct_resource();
- struct_range();
- addr();
- escaped_str();
- hex_string();
- mac();
- ip();
- uuid();
- dentry();
- struct_va_format();
- time_and_date();
- struct_clk();
- bitmap();
- netdev_features();
- flags();
- errptr();
- fwnode_pointer();
- fourcc_pointer();
-}
-
-static void printf_test(struct kunit *test)
+static int printf_suite_init(struct kunit_suite *suite)
{
+ total_tests = 0;
+
alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
if (!alloced_buffer)
- return;
+ return -ENOMEM;
test_buffer = alloced_buffer + PAD_SIZE;

- kunittest = test;
-
- test_basic();
- test_number();
- test_string();
- test_pointer();
-
- kfree(alloced_buffer);
-}
-
-static int printf_suite_init(struct kunit_suite *suite)
-{
- total_tests = 0;
return 0;
}

static void printf_suite_exit(struct kunit_suite *suite)
{
+ kfree(alloced_buffer);
+
kunit_info(suite, "ran %u tests", total_tests);
}

static struct kunit_case printf_test_cases[] = {
- KUNIT_CASE(printf_test),
+ KUNIT_CASE(test_basic),
+ KUNIT_CASE(test_number),
+ KUNIT_CASE(test_string),
+ KUNIT_CASE(hash_pointer),
+ KUNIT_CASE(null_pointer),
+ KUNIT_CASE(error_pointer),
+ KUNIT_CASE(invalid_pointer),
+ KUNIT_CASE(symbol_ptr),
+ KUNIT_CASE(kernel_ptr),
+ KUNIT_CASE(struct_resource),
+ KUNIT_CASE(struct_range),
+ KUNIT_CASE(addr),
+ KUNIT_CASE(escaped_str),
+ KUNIT_CASE(hex_string),
+ KUNIT_CASE(mac),
+ KUNIT_CASE(ip4),
+ KUNIT_CASE(ip6),
+ KUNIT_CASE(uuid),
+ KUNIT_CASE(dentry),
+ KUNIT_CASE(struct_va_format),
+ KUNIT_CASE(time_and_date),
+ KUNIT_CASE(struct_clk),
+ KUNIT_CASE(bitmap),
+ KUNIT_CASE(netdev_features),
+ KUNIT_CASE(flags),
+ KUNIT_CASE(errptr),
+ KUNIT_CASE(fwnode_pointer),
+ KUNIT_CASE(fourcc_pointer),
{}
};

--
2.48.1