pkg/kfuzztest: add pkg/kfuzztest

Add a new package, pkg/kfuzztest, that implements dynamic discovery of
KFuzzTest targets by parsing a vmlinux kernel binary.

Signed-off-by: Ethan Graham <ethangraham@google.com>

2 files changed, 54 insertions, 0 deletions

diff --git a/pkg/kfuzztest/testdata/2/desc.txt b/pkg/kfuzztest/testdata/2/desc.txt
new file mode 100644
index 000000000..2705252dd
--- /dev/null
+++ b/pkg/kfuzztest/testdata/2/desc.txt
@@ -0,0 +1,15 @@
+# This description was automatically generated with tools/kfuzztest-gen
+bar {
+	a	int32
+	b	int32
+}
+
+foo {
+	b	ptr[in, bar]
+	str	ptr[in, string]
+	data	ptr[in, array[int8]]
+	datalen	len[data, int64]
+	numbers	ptr[in, array[int64]]
+}
+
+syz_kfuzztest_run$some_target(name ptr[in, string["some_target"]], data ptr[in, foo], len bytesize[data]) (kfuzz_test)
diff --git a/pkg/kfuzztest/testdata/2/prog.c b/pkg/kfuzztest/testdata/2/prog.c
new file mode 100644
index 000000000..908ccd271
--- /dev/null
+++ b/pkg/kfuzztest/testdata/2/prog.c
@@ -0,0 +1,39 @@
+// Copyright 2025 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+#include "../common.h"
+
+#include <stdlib.h>
+
+struct bar {
+	int a;
+	int b;
+};
+
+struct foo {
+	struct bar* b;
+	const char* str;
+	const char* data;
+	size_t datalen;
+	uint64_t* numbers;
+};
+
+DEFINE_FUZZ_TARGET(some_target, struct foo);
+/* Expect foo.bar != NULL. */
+DEFINE_CONSTRAINT(foo, bar, NULL, NULL, EXPECT_NE);
+/* Expect foo.str != NULL. */
+DEFINE_CONSTRAINT(foo, str, NULL, NULL, EXPECT_NE);
+/* Annotate foo.str as a string. */
+DEFINE_ANNOTATION(foo, str, , ATTRIBUTE_STRING);
+/* Expect foo.data != NULL. */
+DEFINE_CONSTRAINT(foo, data, NULL, NULL, EXPECT_NE);
+/* Annotate foo.data as an array. */
+DEFINE_ANNOTATION(foo, data, , ATTRIBUTE_ARRAY);
+/* Annotate foo.datalen == len(foo.data). */
+DEFINE_ANNOTATION(foo, datalen, data, ATTRIBUTE_LEN);
+/* Annotate foo.numbers as an array. */
+DEFINE_ANNOTATION(foo, numbers, , ATTRIBUTE_ARRAY);
+
+/* Define a main function, otherwise the compiler complains. */
+int main(void)
+{
+}