test: self: port Linux printf kselftest

Port over the Linux v5.11 selftest for printf sans the parts we don't
support. This can be used to catch regressions if changes affecting the
printf code are made.

Acked-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20210604084704.17410-9-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

4 files changed, 314 insertions, 0 deletions

diff --git a/include/stdlib.h b/include/stdlib.h
index d405608724..8eb419e111 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -25,4 +25,9 @@ static inline u32 random32(void)
 	return ret;
 }
 
+static inline u32 prandom_u32_max(u32 ep_ro)
+{
+	return (u32)(((u64) random32() * ep_ro) >> 32);
+}
+
 #endif /* __STDLIB_H */
diff --git a/test/self/Kconfig b/test/self/Kconfig
index 720abeffc5..73dc6c7b4f 100644
--- a/test/self/Kconfig
+++ b/test/self/Kconfig
@@ -27,7 +27,13 @@ config SELFTEST_AUTORUN
 
 config SELFTEST_ENABLE_ALL
 	bool "Enable all self-tests"
+	select SELFTEST_PRINTF
 	help
 	  Selects all self-tests compatible with current configuration
 
+config SELFTEST_PRINTF
+	bool "printf selftest"
+	help
+	  Tests barebox vsnprintf() functionality
+
 endif
diff --git a/test/self/Makefile b/test/self/Makefile
index 78f738c8e2..b4aa49d6f8 100644
--- a/test/self/Makefile
+++ b/test/self/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_SELFTEST) += core.o
+obj-$(CONFIG_SELFTEST_PRINTF) += printf.o
diff --git a/test/self/printf.c b/test/self/printf.c
new file mode 100644
index 0000000000..52fe6ac0fa
--- /dev/null
+++ b/test/self/printf.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test cases for printf facility.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <common.h>
+#include <bselftest.h>
+#include <linux/kernel.h>
+#include <module.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <linux/string.h>
+#include <errno.h>
+
+#include <linux/bitmap.h>
+
+#define BUF_SIZE 256
+#define PAD_SIZE 16
+#define FILL_CHAR '$'
+
+BSELFTEST_GLOBALS();
+
+static char *test_buffer __initdata;
+static char *alloced_buffer __initdata;
+
+static int __printf(4, 0) __init
+do_test(int bufsize, const char *expect, int elen,
+	const char *fmt, va_list ap)
+{
+	va_list aq;
+	int ret, written;
+
+	total_tests++;
+
+	memset(alloced_buffer, FILL_CHAR, BUF_SIZE + 2*PAD_SIZE);
+	va_copy(aq, ap);
+	ret = vsnprintf(test_buffer, bufsize, fmt, aq);
+	va_end(aq);
+
+	if (ret != elen) {
+		pr_warn("vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
+			bufsize, fmt, ret, elen);
+		pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
+			bufsize, fmt, test_buffer, ret, expect);
+		return 1;
+	}
+
+	if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
+		pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n", bufsize, fmt);
+		return 1;
+	}
+
+	if (!bufsize) {
+		if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
+			pr_warn("vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
+				fmt);
+			return 1;
+		}
+		return 0;
+	}
+
+	written = min(bufsize-1, elen);
+	if (test_buffer[written]) {
+		pr_warn("vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
+			bufsize, fmt);
+		return 1;
+	}
+
+	if (memchr_inv(test_buffer + written + 1, FILL_CHAR, BUF_SIZE + PAD_SIZE - (written + 1))) {
+		pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
+			bufsize, fmt);
+		return 1;
+	}
+
+	if (memcmp(test_buffer, expect, written)) {
+		pr_warn("vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
+			bufsize, fmt, test_buffer, written, expect);
+		return 1;
+	}
+	return 0;
+}
+
+static void __printf(3, 4) __init
+__test(const char *expect, int elen, const char *fmt, ...)
+{
+	va_list ap;
+	int rand;
+	char *p;
+
+	if (elen >= BUF_SIZE) {
+		pr_err("error in test suite: expected output length %d too long. Format was '%s'.\n",
+		       elen, fmt);
+		failed_tests++;
+		return;
+	}
+
+	va_start(ap, fmt);
+
+	/*
+	 * Every fmt+args is subjected to four tests: Three where we
+	 * tell vsnprintf varying buffer sizes (plenty, not quite
+	 * enough and 0), and then we also test that bvasprintf would
+	 * be able to print it as expected.
+	 */
+	failed_tests += do_test(BUF_SIZE, expect, elen, fmt, ap);
+	rand = 1 + prandom_u32_max(elen+1);
+	/* Since elen < BUF_SIZE, we have 1 <= rand <= BUF_SIZE. */
+	failed_tests += do_test(rand, expect, elen, fmt, ap);
+	failed_tests += do_test(0, expect, elen, fmt, ap);
+
+	p = bvasprintf(fmt, ap);
+	if (p) {
+		total_tests++;
+		if (memcmp(p, expect, elen+1)) {
+			pr_warn("bvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
+				fmt, p, expect);
+			failed_tests++;
+		}
+		kfree(p);
+	}
+	va_end(ap);
+}
+
+#define test(expect, fmt, ...)					\
+	__test(expect, strlen(expect), fmt, ##__VA_ARGS__)
+
+static void __init
+test_basic(void)
+{
+	/* Work around annoying "warning: zero-length gnu_printf format string". */
+	char nul = '\0';
+
+	test("", &nul);
+	test("100%", "100%%");
+	test("xxx%yyy", "xxx%cyyy", '%');
+	__test("xxx\0yyy", 7, "xxx%cyyy", '\0');
+}
+
+static void __init
+test_number(void)
+{
+	signed char val;
+
+	test("0x1234abcd  ", "%#-12x", 0x1234abcd);
+	test("  0x1234abcd", "%#12x", 0x1234abcd);
+	test("0|001| 12|+123| 1234|-123|-1234", "%d|%03d|%3d|%+d|% d|%+d|% d", 0, 1, 12, 123, 1234, -123, -1234);
+	test("0|1|1|32768|65535", "%hu|%hu|%hu|%hu|%hu", 0, 1, 65537, 32768, -1);
+	test("0|1|1|-32768|-1", "%hd|%hd|%hd|%hd|%hd", 0, 1, 65537, 32768, -1);
+	test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
+
+	test("2015122420151225", "%ho%ho%#ho", 1037, 5282, -11627);
+
+	/*
+	 * POSIX/C99: »The result of converting zero with an explicit
+	 * precision of zero shall be no characters.« Hence the output
+	 * from the below test should really be "00|0||| ". However,
+	 * the kernel's printf also produces a single 0 in that
+	 * case. This test case simply documents the current
+	 * behaviour.
+	 */
+	test("00|0|0|0|0", "%.2d|%.1d|%.0d|%.*d|%1.0d", 0, 0, 0, 0, 0, 0);
+
+	val = -16;
+	test("0xfffffff0|0xf0|0xf0", "%#02x|%#02x|%#02x", val, val & 0xff, (u8)val);
+
+	/* On some platforms, test failure here indicates a misaligned stack */
+	test("0x0807060504030201", "0x%016llx", 0x0807060504030201ULL);
+}
+
+static void __init
+test_string(void)
+{
+	test("", "%s%.0s", "", "123");
+	test("ABCD|abc|123", "%s|%.3s|%.*s", "ABCD", "abcdef", 3, "123456");
+	test("1  |  2|3  |  4|5  ", "%-3s|%3s|%-*s|%*s|%*s", "1", "2", 3, "3", 3, "4", -3, "5");
+	test("1234      ", "%-10.4s", "123456");
+	test("      1234", "%10.4s", "123456");
+}
+
+#if BITS_PER_LONG == 64
+
+#define PTR_WIDTH 16
+#define PTR ((void *)0xffff0123456789abUL)
+#define PTR_STR "ffff0123456789ab"
+#define PTR_VAL_NO_CRNG "(____ptrval____)"
+#define ZEROS "00000000"	/* hex 32 zero bits */
+#define ONES "ffffffff"		/* hex 32 one bits */
+
+#else
+
+#define PTR_WIDTH 8
+#define PTR ((void *)0x456789ab)
+#define PTR_STR "456789ab"
+#define PTR_VAL_NO_CRNG "(ptrval)"
+#define ZEROS ""
+#define ONES ""
+
+#endif	/* BITS_PER_LONG == 64 */
+
+/*
+ * NULL pointers aren't hashed.
+ */
+static void __init
+null_pointer(void)
+{
+	test(ZEROS "00000000", "%p", NULL);
+	test(ZEROS "00000000", "%px", NULL);
+}
+
+/*
+ * Error pointers aren't hashed.
+ */
+static void __init
+error_pointer(void)
+{
+	test(ONES "fffffff5", "%p", ERR_PTR(-11));
+	test(ONES "fffffff5", "%px", ERR_PTR(-11));
+}
+
+#define PTR_INVALID ((void *)0x000000ab)
+
+static void __init
+invalid_pointer(void)
+{
+	test(ZEROS "000000ab", "%px", PTR_INVALID);
+}
+
+static void __init
+ip4(void)
+{
+	IPaddr_t ip = cpu_to_be32(0x7f000001);
+
+	test("127.0.0.1", "%pI4", &ip);
+}
+
+static void __init
+ip(void)
+{
+	ip4();
+}
+
+static void __init
+uuid(void)
+{
+	const char uuid[16] = {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
+			       0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf};
+
+	if (!IS_ENABLED(CONFIG_PRINTF_UUID))
+		return;
+
+	test("00010203-0405-0607-0809-0a0b0c0d0e0f", "%pUb", uuid);
+	test("00010203-0405-0607-0809-0A0B0C0D0E0F", "%pUB", uuid);
+	test("03020100-0504-0706-0809-0a0b0c0d0e0f", "%pUl", uuid);
+	test("03020100-0504-0706-0809-0A0B0C0D0E0F", "%pUL", uuid);
+}
+
+static void __init
+errptr(void)
+{
+	test("error 1234", "%pe", ERR_PTR(-1234));
+	test(sizeof(void *) == 8 ? "00000000000004d2" : "000004d2", "%pe", ERR_PTR(1234));
+
+	/* Check that %pe with a non-ERR_PTR gets treated as ordinary %p. */
+	BUILD_BUG_ON(IS_ERR(PTR));
+
+	if (!IS_ENABLED(CONFIG_ERRNO_MESSAGES))
+		return;
+	test("(Operation not permitted)", "(%pe)", ERR_PTR(-EPERM));
+	test("Requested probe deferral", "%pe", ERR_PTR(-EPROBE_DEFER));
+}
+
+static void __init
+test_pointer(void)
+{
+	null_pointer();
+	error_pointer();
+	invalid_pointer();
+	ip();
+	uuid();
+	errptr();
+}
+
+static void __init test_printf(void)
+{
+	alloced_buffer = malloc(BUF_SIZE + 2*PAD_SIZE);
+	if (!alloced_buffer)
+		return;
+	test_buffer = alloced_buffer + PAD_SIZE;
+
+	test_basic();
+	test_number();
+	test_string();
+	test_pointer();
+
+	free(alloced_buffer);
+}
+
+bselftest(core, test_printf);
+MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
+MODULE_LICENSE("GPL");