KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 878 insertions, 0 deletions

diff --git a/lib/tests/printf_kunit.c b/lib/tests/printf_kunit.c
new file mode 100644
index 000000000..eccf041eb
--- /dev/null
+++ b/lib/tests/printf_kunit.c
@@ -0,0 +1,878 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test cases for printf facility.
+ */
+
+#include <kunit/test.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/sprintf.h>
+#include <linux/string.h>
+
+#include <linux/bitmap.h>
+#include <linux/dcache.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+
+#include <linux/gfp.h>
+#include <linux/mm.h>
+
+#include <linux/property.h>
+
+#define BUF_SIZE 256
+#define PAD_SIZE 16
+#define FILL_CHAR '$'
+
+#define NOWARN(option, comment, block) \
+	__diag_push(); \
+	__diag_ignore_all(#option, comment); \
+	block \
+	__diag_pop();
+
+static unsigned int total_tests;
+
+static char *test_buffer;
+static char *alloced_buffer;
+
+static void __printf(7, 0)
+do_test(struct kunit *kunittest, const char *file, const int line, 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) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: vsnprintf(buf, %d, \"%s\", ...) returned %d, expected %d\n",
+			   file, line, bufsize, fmt, ret, elen);
+		return;
+	}
+
+	if (memchr_inv(alloced_buffer, FILL_CHAR, PAD_SIZE)) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: vsnprintf(buf, %d, \"%s\", ...) wrote before buffer\n",
+			   file, line, bufsize, fmt);
+		return;
+	}
+
+	if (!bufsize) {
+		if (memchr_inv(test_buffer, FILL_CHAR, BUF_SIZE + PAD_SIZE)) {
+			KUNIT_FAIL(kunittest,
+				   "%s:%d: vsnprintf(buf, 0, \"%s\", ...) wrote to buffer\n",
+				   file, line, fmt);
+		}
+		return;
+	}
+
+	written = min(bufsize-1, elen);
+	if (test_buffer[written]) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: vsnprintf(buf, %d, \"%s\", ...) did not nul-terminate buffer\n",
+			   file, line, bufsize, fmt);
+		return;
+	}
+
+	if (memchr_inv(test_buffer + written + 1, FILL_CHAR, bufsize - (written + 1))) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: vsnprintf(buf, %d, \"%s\", ...) wrote beyond the nul-terminator\n",
+			   file, line, bufsize, fmt);
+		return;
+	}
+
+	if (memchr_inv(test_buffer + bufsize, FILL_CHAR, BUF_SIZE + PAD_SIZE - bufsize)) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: vsnprintf(buf, %d, \"%s\", ...) wrote beyond buffer\n",
+			   file, line, bufsize, fmt);
+		return;
+	}
+
+	if (memcmp(test_buffer, expect, written)) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: vsnprintf(buf, %d, \"%s\", ...) wrote '%s', expected '%.*s'\n",
+			   file, line, bufsize, fmt, test_buffer, written, expect);
+		return;
+	}
+}
+
+static void __printf(6, 7)
+__test(struct kunit *kunittest, const char *file, const int line, const char *expect, int elen,
+	const char *fmt, ...)
+{
+	va_list ap;
+	int rand;
+	char *p;
+
+	if (elen >= BUF_SIZE) {
+		KUNIT_FAIL(kunittest,
+			   "%s:%d: error in test suite: expected length (%d) >= BUF_SIZE (%d). fmt=\"%s\"\n",
+			   file, line, elen, BUF_SIZE, fmt);
+		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 kvasprintf would
+	 * be able to print it as expected.
+	 */
+	do_test(kunittest, file, line, 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(kunittest, file, line, rand, expect, elen, fmt, ap);
+	do_test(kunittest, file, line, 0, expect, elen, fmt, ap);
+
+	p = kvasprintf(GFP_KERNEL, fmt, ap);
+	if (p) {
+		total_tests++;
+		if (memcmp(p, expect, elen+1)) {
+			KUNIT_FAIL(kunittest,
+				   "%s:%d: kvasprintf(..., \"%s\", ...) returned '%s', expected '%s'\n",
+				   file, line, fmt, p, expect);
+		}
+		kfree(p);
+	}
+	va_end(ap);
+}
+
+#define test(expect, fmt, ...)					\
+	__test(kunittest, __FILE__, __LINE__, expect, strlen(expect), fmt, ##__VA_ARGS__)
+
+static void
+test_basic(struct kunit *kunittest)
+{
+	/* Work around annoying "warning: zero-length gnu_printf format string". */
+	char nul = '\0';
+
+	test("", &nul);
+	test("100%", "100%%");
+	test("xxx%yyy", "xxx%cyyy", '%');
+	__test(kunittest, __FILE__, __LINE__, "xxx\0yyy", 7, "xxx%cyyy", '\0');
+}
+
+static void
+test_number(struct kunit *kunittest)
+{
+	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);
+	NOWARN(-Wformat, "Intentionally test narrowing conversion specifiers.", {
+		test("0|1|1|128|255", "%hhu|%hhu|%hhu|%hhu|%hhu", 0, 1, 257, 128, -1);
+		test("0|1|1|-128|-1", "%hhd|%hhd|%hhd|%hhd|%hhd", 0, 1, 257, 128, -1);
+		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);
+}
+
+static void
+test_string(struct kunit *kunittest)
+{
+	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");
+	/*
+	 * POSIX and C99 say that a negative precision (which is only
+	 * possible to pass via a * argument) should be treated as if
+	 * the precision wasn't present, and that if the precision is
+	 * omitted (as in %.s), the precision should be taken to be
+	 * 0. However, the kernel's printf behave exactly opposite,
+	 * treating a negative precision as 0 and treating an omitted
+	 * precision specifier as if no precision was given.
+	 *
+	 * These test cases document the current behaviour; should
+	 * anyone ever feel the need to follow the standards more
+	 * closely, this can be revisited.
+	 */
+	test("    ", "%4.*s", -5, "123456");
+	test("123456", "%.s", "123456");
+	test("a||", "%.s|%.0s|%.*s", "a", "b", 0, "c");
+	test("a  |   |   ", "%-3.s|%-3.0s|%-3.*s", "a", "b", 0, "c");
+}
+
+#define PLAIN_BUF_SIZE 64	/* leave some space so we don't oops */
+
+#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 */
+
+static void
+plain_hash_to_buffer(struct kunit *kunittest, const void *p, char *buf, size_t len)
+{
+	KUNIT_ASSERT_EQ(kunittest, snprintf(buf, len, "%p", p), PTR_WIDTH);
+
+	if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) {
+		kunit_skip(kunittest,
+			   "crng possibly not yet initialized. plain 'p' buffer contains \"%s\"\n",
+			   PTR_VAL_NO_CRNG);
+	}
+}
+
+static void
+hash_pointer(struct kunit *kunittest)
+{
+	if (no_hash_pointers)
+		kunit_skip(kunittest, "hash pointers disabled");
+
+	char buf[PLAIN_BUF_SIZE];
+
+	plain_hash_to_buffer(kunittest, PTR, buf, PLAIN_BUF_SIZE);
+
+	/*
+	 * The hash of %p is unpredictable, therefore test() cannot be used.
+	 *
+	 * Instead verify that the first 32 bits are zeros on a 64-bit system
+	 * and that the non-hashed value is not printed.
+	 */
+
+	KUNIT_EXPECT_MEMEQ(kunittest, buf, ZEROS, strlen(ZEROS));
+	KUNIT_EXPECT_MEMNEQ(kunittest, buf, PTR_STR, PTR_WIDTH);
+}
+
+/*
+ * This is a macro so that the compiler can compare its arguments to the
+ * __printf() attribute on __test(). This cannot be a function with a __printf()
+ * attribute because GCC requires __printf() functions to be variadic.
+ */
+#define test_hashed(kunittest, fmt, p)						\
+	do {									\
+		char buf[PLAIN_BUF_SIZE];					\
+		plain_hash_to_buffer(kunittest, p, buf, PLAIN_BUF_SIZE);	\
+		test(buf, fmt, p);						\
+	} while (0)
+
+/*
+ * NULL pointers aren't hashed.
+ */
+static void
+null_pointer(struct kunit *kunittest)
+{
+	test(ZEROS "00000000", "%p", NULL);
+	test(ZEROS "00000000", "%px", NULL);
+	test("(null)", "%pE", NULL);
+}
+
+/*
+ * Error pointers aren't hashed.
+ */
+static void
+error_pointer(struct kunit *kunittest)
+{
+	test(ONES "fffffff5", "%p", ERR_PTR(-11));
+	test(ONES "fffffff5", "%px", ERR_PTR(-11));
+	test("(efault)", "%pE", ERR_PTR(-11));
+}
+
+#define PTR_INVALID ((void *)0x000000ab)
+
+static void
+invalid_pointer(struct kunit *kunittest)
+{
+	test_hashed(kunittest, "%p", PTR_INVALID);
+	test(ZEROS "000000ab", "%px", PTR_INVALID);
+	test("(efault)", "%pE", PTR_INVALID);
+}
+
+static void
+symbol_ptr(struct kunit *kunittest)
+{
+}
+
+static void
+kernel_ptr(struct kunit *kunittest)
+{
+	switch (kptr_restrict) {
+	case 0:
+		if (no_hash_pointers) {
+			test(PTR_STR, "%pK", PTR);
+		} else {
+			char buf[PLAIN_BUF_SIZE];
+
+			plain_hash_to_buffer(kunittest, PTR, buf, PLAIN_BUF_SIZE);
+			/* %pK behaves the same as hashing */
+			test(buf, "%pK", PTR);
+		}
+		break;
+	case 1:
+		/* The KUnit kthread has all capabilities, including CAP_SYSLOG */
+		test(PTR_STR, "%pK", PTR);
+		break;
+	case 2:
+	default:
+		test(ZEROS "00000000", "%pK", PTR);
+		break;
+	}
+}
+
+static void
+struct_resource(struct kunit *kunittest)
+{
+	struct resource test_resource = {
+		.start = 0xc0ffee00,
+		.end = 0xc0ffee00,
+		.flags = IORESOURCE_MEM,
+	};
+
+	test("[mem 0xc0ffee00 flags 0x200]",
+	     "%pr", &test_resource);
+
+	test_resource = (struct resource) {
+		.start = 0xc0ffee,
+		.end = 0xba5eba11,
+		.flags = IORESOURCE_MEM,
+	};
+	test("[mem 0x00c0ffee-0xba5eba11 flags 0x200]",
+	     "%pr", &test_resource);
+
+	test_resource = (struct resource) {
+		.start = 0xba5eba11,
+		.end = 0xc0ffee,
+		.flags = IORESOURCE_MEM,
+	};
+	test("[mem 0xba5eba11-0x00c0ffee flags 0x200]",
+	     "%pr", &test_resource);
+
+	test_resource = (struct resource) {
+		.start = 0xba5eba11,
+		.end = 0xba5eca11,
+		.flags = IORESOURCE_MEM,
+	};
+
+	test("[mem 0xba5eba11-0xba5eca11 flags 0x200]",
+	     "%pr", &test_resource);
+
+	test_resource = (struct resource) {
+		.start = 0xba11,
+		.end = 0xca10,
+		.flags = IORESOURCE_IO |
+			 IORESOURCE_DISABLED |
+			 IORESOURCE_UNSET,
+	};
+
+	test("[io  size 0x1000 disabled]",
+	     "%pR", &test_resource);
+}
+
+static void
+struct_range(struct kunit *kunittest)
+{
+	struct range test_range = DEFINE_RANGE(0xc0ffee00ba5eba11,
+					       0xc0ffee00ba5eba11);
+	test("[range 0xc0ffee00ba5eba11]", "%pra", &test_range);
+
+	test_range = DEFINE_RANGE(0xc0ffee, 0xba5eba11);
+	test("[range 0x0000000000c0ffee-0x00000000ba5eba11]",
+	     "%pra", &test_range);
+
+	test_range = DEFINE_RANGE(0xba5eba11, 0xc0ffee);
+	test("[range 0x00000000ba5eba11-0x0000000000c0ffee]",
+	     "%pra", &test_range);
+}
+
+static void
+addr(struct kunit *kunittest)
+{
+}
+
+static void
+escaped_str(struct kunit *kunittest)
+{
+}
+
+static void
+hex_string(struct kunit *kunittest)
+{
+	const char buf[3] = {0xc0, 0xff, 0xee};
+
+	test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
+	     "%3ph|%3phC|%3phD|%3phN", buf, buf, buf, buf);
+	test("c0 ff ee|c0:ff:ee|c0-ff-ee|c0ffee",
+	     "%*ph|%*phC|%*phD|%*phN", 3, buf, 3, buf, 3, buf, 3, buf);
+}
+
+static void
+mac(struct kunit *kunittest)
+{
+	const u8 addr[6] = {0x2d, 0x48, 0xd6, 0xfc, 0x7a, 0x05};
+
+	test("2d:48:d6:fc:7a:05", "%pM", addr);
+	test("05:7a:fc:d6:48:2d", "%pMR", addr);
+	test("05:7A:FC:D6:48:2D", "%pMRU", addr);
+	test("2d-48-d6-fc-7a-05", "%pMF", addr);
+	test("2d48d6fc7a05", "%pm", addr);
+	test("2D48D6FC7A05", "%pmU", addr);
+	test("057afcd6482d", "%pmR", addr);
+}
+
+static void
+ip4(struct kunit *kunittest)
+{
+	struct sockaddr_in sa;
+
+	sa.sin_family = AF_INET;
+	sa.sin_port = cpu_to_be16(12345);
+	sa.sin_addr.s_addr = cpu_to_be32(0x7f000001);
+
+	test("127.000.000.001|127.0.0.1", "%pi4|%pI4", &sa.sin_addr, &sa.sin_addr);
+	test("127.000.000.001|127.0.0.1", "%piS|%pIS", &sa, &sa);
+	sa.sin_addr.s_addr = cpu_to_be32(0x01020304);
+	test("001.002.003.004:12345|1.2.3.4:12345", "%piSp|%pISp", &sa, &sa);
+}
+
+static void
+ip6(struct kunit *kunittest)
+{
+	const struct in6_addr addr = {
+		.s6_addr = { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04,
+			     0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }
+	};
+	const struct in6_addr single_zero = {
+		.s6_addr = { 0x00, 0x01, 0x00, 0x00, 0x00, 0x03, 0x00, 0x04,
+			     0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }
+	};
+	struct sockaddr_in6 sa = {
+		.sin6_family = AF_INET6,
+		.sin6_port = cpu_to_be16(12345),
+		.sin6_addr = addr,
+	};
+
+	test("00010002000300040005000600070008|0001:0002:0003:0004:0005:0006:0007:0008",
+	     "%pi6|%pI6", &addr, &addr);
+	test("00010002000300040005000600070008|0001:0002:0003:0004:0005:0006:0007:0008",
+	     "%piS|%pIS", &sa, &sa);
+	test("1:2:3:4:5:6:7:8", "%pI6c", &addr);
+	test("1:0:3:4:5:6:7:8", "%pI6c", &single_zero);
+	test("[1:2:3:4:5:6:7:8]:12345", "%pISpc", &sa);
+}
+
+static 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};
+
+	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 struct dentry test_dentry[4] = {
+	{ .d_parent = &test_dentry[0],
+	  .d_name = QSTR_INIT(test_dentry[0].d_iname, 3),
+	  .d_iname = "foo" },
+	{ .d_parent = &test_dentry[0],
+	  .d_name = QSTR_INIT(test_dentry[1].d_iname, 5),
+	  .d_iname = "bravo" },
+	{ .d_parent = &test_dentry[1],
+	  .d_name = QSTR_INIT(test_dentry[2].d_iname, 4),
+	  .d_iname = "alfa" },
+	{ .d_parent = &test_dentry[2],
+	  .d_name = QSTR_INIT(test_dentry[3].d_iname, 5),
+	  .d_iname = "romeo" },
+};
+
+static void
+dentry(struct kunit *kunittest)
+{
+	test("foo", "%pd", &test_dentry[0]);
+	test("foo", "%pd2", &test_dentry[0]);
+
+	test("(null)", "%pd", NULL);
+	test("(efault)", "%pd", PTR_INVALID);
+	test("(null)", "%pD", NULL);
+	test("(efault)", "%pD", PTR_INVALID);
+
+	test("romeo", "%pd", &test_dentry[3]);
+	test("alfa/romeo", "%pd2", &test_dentry[3]);
+	test("bravo/alfa/romeo", "%pd3", &test_dentry[3]);
+	test("/bravo/alfa/romeo", "%pd4", &test_dentry[3]);
+	test("/bravo/alfa", "%pd4", &test_dentry[2]);
+
+	test("bravo/alfa  |bravo/alfa  ", "%-12pd2|%*pd2", &test_dentry[2], -12, &test_dentry[2]);
+	test("  bravo/alfa|  bravo/alfa", "%12pd2|%*pd2", &test_dentry[2], 12, &test_dentry[2]);
+}
+
+static void
+struct_va_format(struct kunit *kunittest)
+{
+}
+
+static void
+time_and_date(struct kunit *kunittest)
+{
+	/* 1543210543 */
+	const struct rtc_time tm = {
+		.tm_sec = 43,
+		.tm_min = 35,
+		.tm_hour = 5,
+		.tm_mday = 26,
+		.tm_mon = 10,
+		.tm_year = 118,
+	};
+	/* 2019-01-04T15:32:23 */
+	time64_t t = 1546615943;
+	struct timespec64 ts = { .tv_sec = t, .tv_nsec = 11235813 };
+
+	test("(%pt?)", "%pt", &tm);
+	test("2018-11-26T05:35:43", "%ptR", &tm);
+	test("0118-10-26T05:35:43", "%ptRr", &tm);
+	test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm);
+	test("05:35:43|0118-10-26", "%ptRtr|%ptRdr", &tm, &tm);
+	test("05:35:43|2018-11-26", "%ptRttr|%ptRdtr", &tm, &tm);
+	test("05:35:43 tr|2018-11-26 tr", "%ptRt tr|%ptRd tr", &tm, &tm);
+
+	test("2019-01-04T15:32:23", "%ptT", &t);
+	test("0119-00-04T15:32:23", "%ptTr", &t);
+	test("15:32:23|2019-01-04", "%ptTt|%ptTd", &t, &t);
+	test("15:32:23|0119-00-04", "%ptTtr|%ptTdr", &t, &t);
+
+	test("2019-01-04 15:32:23", "%ptTs", &t);
+	test("0119-00-04 15:32:23", "%ptTsr", &t);
+	test("15:32:23|2019-01-04", "%ptTts|%ptTds", &t, &t);
+	test("15:32:23|0119-00-04", "%ptTtrs|%ptTdrs", &t, &t);
+
+	test("2019-01-04T15:32:23.011235813", "%ptS", &ts);
+	test("1546615943.011235813", "%ptSp", &ts);
+}
+
+static void
+struct_clk(struct kunit *kunittest)
+{
+}
+
+static void
+large_bitmap(struct kunit *kunittest)
+{
+	const int nbits = 1 << 16;
+	unsigned long *bits = bitmap_zalloc(nbits, GFP_KERNEL);
+	if (!bits)
+		return;
+
+	bitmap_set(bits, 1, 20);
+	bitmap_set(bits, 60000, 15);
+	test("1-20,60000-60014", "%*pbl", nbits, bits);
+	bitmap_free(bits);
+}
+
+static void
+bitmap(struct kunit *kunittest)
+{
+	DECLARE_BITMAP(bits, 20);
+	const int primes[] = {2,3,5,7,11,13,17,19};
+	int i;
+
+	bitmap_zero(bits, 20);
+	test("00000|00000", "%20pb|%*pb", bits, 20, bits);
+	test("|", "%20pbl|%*pbl", bits, 20, bits);
+
+	for (i = 0; i < ARRAY_SIZE(primes); ++i)
+		set_bit(primes[i], bits);
+	test("a28ac|a28ac", "%20pb|%*pb", bits, 20, bits);
+	test("2-3,5,7,11,13,17,19|2-3,5,7,11,13,17,19", "%20pbl|%*pbl", bits, 20, bits);
+
+	bitmap_fill(bits, 20);
+	test("fffff|fffff", "%20pb|%*pb", bits, 20, bits);
+	test("0-19|0-19", "%20pbl|%*pbl", bits, 20, bits);
+
+	large_bitmap(kunittest);
+}
+
+static void
+netdev_features(struct kunit *kunittest)
+{
+}
+
+struct page_flags_test {
+	int width;
+	int shift;
+	int mask;
+	const char *fmt;
+	const char *name;
+};
+
+static const struct page_flags_test pft[] = {
+	{SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK,
+	 "%d", "section"},
+	{NODES_WIDTH, NODES_PGSHIFT, NODES_MASK,
+	 "%d", "node"},
+	{ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK,
+	 "%d", "zone"},
+	{LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK,
+	 "%#x", "lastcpupid"},
+	{KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK,
+	 "%#x", "kasantag"},
+};
+
+static void
+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};
+	unsigned long size;
+	bool append = false;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(values); i++)
+		flags |= (values[i] & pft[i].mask) << pft[i].shift;
+
+	size = scnprintf(cmp_buf, BUF_SIZE, "%#lx(", flags);
+	if (flags & PAGEFLAGS_MASK) {
+		size += scnprintf(cmp_buf + size, BUF_SIZE - size, "%s", name);
+		append = true;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(pft); i++) {
+		if (!pft[i].width)
+			continue;
+
+		if (append)
+			size += scnprintf(cmp_buf + size, BUF_SIZE - size, "|");
+
+		size += scnprintf(cmp_buf + size, BUF_SIZE - size, "%s=",
+				pft[i].name);
+		size += scnprintf(cmp_buf + size, BUF_SIZE - size, pft[i].fmt,
+				values[i] & pft[i].mask);
+		append = true;
+	}
+
+	snprintf(cmp_buf + size, BUF_SIZE - size, ")");
+
+	test(cmp_buf, "%pGp", &flags);
+}
+
+static void
+flags(struct kunit *kunittest)
+{
+	unsigned long flags;
+	char *cmp_buffer;
+	gfp_t gfp;
+
+	cmp_buffer = kunit_kmalloc(kunittest, BUF_SIZE, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(kunittest, cmp_buffer);
+
+	flags = 0;
+	page_flags_test(kunittest, 0, 0, 0, 0, 0, flags, "", cmp_buffer);
+
+	flags = 1UL << NR_PAGEFLAGS;
+	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(kunittest, 1, 1, 1, 0x1fffff, 1, flags,
+			"uptodate|dirty|lru|active|swapbacked",
+			cmp_buffer);
+
+	flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
+	test("read|exec|mayread|maywrite|mayexec", "%pGv", &flags);
+
+	gfp = GFP_TRANSHUGE;
+	test("GFP_TRANSHUGE", "%pGg", &gfp);
+
+	gfp = GFP_ATOMIC|__GFP_DMA;
+	test("GFP_ATOMIC|GFP_DMA", "%pGg", &gfp);
+
+	gfp = __GFP_HIGH;
+	test("__GFP_HIGH", "%pGg", &gfp);
+
+	/* Any flags not translated by the table should remain numeric */
+	gfp = ~__GFP_BITS_MASK;
+	snprintf(cmp_buffer, BUF_SIZE, "%#lx", (unsigned long) gfp);
+	test(cmp_buffer, "%pGg", &gfp);
+
+	snprintf(cmp_buffer, BUF_SIZE, "__GFP_HIGH|%#lx",
+							(unsigned long) gfp);
+	gfp |= __GFP_HIGH;
+	test(cmp_buffer, "%pGg", &gfp);
+}
+
+static void fwnode_pointer(struct kunit *kunittest)
+{
+	const struct software_node first = { .name = "first" };
+	const struct software_node second = { .name = "second", .parent = &first };
+	const struct software_node third = { .name = "third", .parent = &second };
+	const struct software_node *group[] = { &first, &second, &third, NULL };
+	const char * const full_name_second = "first/second";
+	const char * const full_name_third = "first/second/third";
+	const char * const second_name = "second";
+	const char * const third_name = "third";
+	int rval;
+
+	rval = software_node_register_node_group(group);
+	if (rval) {
+		kunit_skip(kunittest, "cannot register softnodes; rval %d\n", rval);
+	}
+
+	test(full_name_second, "%pfw", software_node_fwnode(&second));
+	test(full_name_third, "%pfw", software_node_fwnode(&third));
+	test(full_name_third, "%pfwf", software_node_fwnode(&third));
+	test(second_name, "%pfwP", software_node_fwnode(&second));
+	test(third_name, "%pfwP", software_node_fwnode(&third));
+
+	software_node_unregister_node_group(group);
+}
+
+struct fourcc_struct {
+	u32 code;
+	const char *str;
+};
+
+static void fourcc_pointer_test(struct kunit *kunittest, const struct fourcc_struct *fc,
+				size_t n, const char *fmt)
+{
+	size_t i;
+
+	for (i = 0; i < n; i++)
+		test(fc[i].str, fmt, &fc[i].code);
+}
+
+static void fourcc_pointer(struct kunit *kunittest)
+{
+	static const struct fourcc_struct try_cc[] = {
+		{ 0x3231564e, "NV12 little-endian (0x3231564e)", },
+		{ 0xb231564e, "NV12 big-endian (0xb231564e)", },
+		{ 0x10111213, ".... little-endian (0x10111213)", },
+		{ 0x20303159, "Y10  little-endian (0x20303159)", },
+	};
+	static const struct fourcc_struct try_ch[] = {
+		{ 0x41424344, "ABCD (0x41424344)", },
+	};
+	static const struct fourcc_struct try_chR[] = {
+		{ 0x41424344, "DCBA (0x44434241)", },
+	};
+	static const struct fourcc_struct try_cl[] = {
+		{ (__force u32)cpu_to_le32(0x41424344), "ABCD (0x41424344)", },
+	};
+	static const struct fourcc_struct try_cb[] = {
+		{ (__force u32)cpu_to_be32(0x41424344), "ABCD (0x41424344)", },
+	};
+
+	fourcc_pointer_test(kunittest, try_cc, ARRAY_SIZE(try_cc), "%p4cc");
+	fourcc_pointer_test(kunittest, try_ch, ARRAY_SIZE(try_ch), "%p4ch");
+	fourcc_pointer_test(kunittest, try_chR, ARRAY_SIZE(try_chR), "%p4chR");
+	fourcc_pointer_test(kunittest, try_cl, ARRAY_SIZE(try_cl), "%p4cl");
+	fourcc_pointer_test(kunittest, try_cb, ARRAY_SIZE(try_cb), "%p4cb");
+}
+
+static 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(kunittest, "%pe", PTR);
+
+#ifdef CONFIG_SYMBOLIC_ERRNAME
+	test("(-ENOTSOCK)", "(%pe)", ERR_PTR(-ENOTSOCK));
+	test("(-EAGAIN)", "(%pe)", ERR_PTR(-EAGAIN));
+	BUILD_BUG_ON(EAGAIN != EWOULDBLOCK);
+	test("(-EAGAIN)", "(%pe)", ERR_PTR(-EWOULDBLOCK));
+	test("[-EIO    ]", "[%-8pe]", ERR_PTR(-EIO));
+	test("[    -EIO]", "[%8pe]", ERR_PTR(-EIO));
+	test("-EPROBE_DEFER", "%pe", ERR_PTR(-EPROBE_DEFER));
+#endif
+}
+
+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 -ENOMEM;
+	test_buffer = alloced_buffer + PAD_SIZE;
+
+	return 0;
+}
+
+static void printf_suite_exit(struct kunit_suite *suite)
+{
+	kfree(alloced_buffer);
+
+	kunit_info(suite, "ran %u tests\n", total_tests);
+}
+
+static struct kunit_case printf_test_cases[] = {
+	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),
+	{}
+};
+
+static struct kunit_suite printf_test_suite = {
+	.name = "printf",
+	.suite_init = printf_suite_init,
+	.suite_exit = printf_suite_exit,
+	.test_cases = printf_test_cases,
+};
+
+kunit_test_suite(printf_test_suite);
+
+MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
+MODULE_DESCRIPTION("Test cases for printf facility");
+MODULE_LICENSE("GPL");