[PATCH v3 2/2] printf: break kunit into test cases

10 Feb 2025

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/printf_kunit.c | 331 ++++++++++++++++++++---------------------------------
 1 file changed, 121 insertions(+), 210 deletions(-)

diff --git a/lib/printf_kunit.c b/lib/printf_kunit.c
index 287bbfb61148..00c35eb0abdc 100644
--- a/lib/printf_kunit.c
+++ b/lib/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, 5)
+__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)
-{
-}
-
-static void
-ip(void)
+ip6(struct kunit *kunittest)
 {
-	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



    

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[PATCH v3 2/2] printf: break kunit into test cases