Commit fc078392 authored by Kees Cook's avatar Kees Cook
Browse files

seq_buf: Introduce KUnit tests 

Add KUnit tests for the seq_buf API to ensure its correctness and
prevent future regressions, covering the following functions:
- seq_buf_init()
- DECLARE_SEQ_BUF()
- seq_buf_clear()
- seq_buf_puts()
- seq_buf_putc()
- seq_buf_printf()
- seq_buf_get_buf()
- seq_buf_commit()

$ tools/testing/kunit/kunit.py run seq_buf
=================== seq_buf (9 subtests) ===================
[PASSED] seq_buf_init_test
[PASSED] seq_buf_declare_test
[PASSED] seq_buf_clear_test
[PASSED] seq_buf_puts_test
[PASSED] seq_buf_puts_overflow_test
[PASSED] seq_buf_putc_test
[PASSED] seq_buf_printf_test
[PASSED] seq_buf_printf_overflow_test
[PASSED] seq_buf_get_buf_commit_test
===================== [PASSED] seq_buf =====================

Link: https://lore.kernel.org/r/20250717085156.work.363-kees@kernel.org


Reviewed-by: default avatarDavid Gow <davidgow@google.com>
Signed-off-by: default avatarKees Cook <kees@kernel.org>
parent 2d8ae9a4

lib/Kconfig.debug

+9 −0
Original line number Diff line number Diff line
@@ -2460,6 +2460,15 @@ config SCANF_KUNIT_TEST 


	  If unsure, say N.



config SEQ_BUF_KUNIT_TEST

	tristate "KUnit test for seq_buf" if !KUNIT_ALL_TESTS

	depends on KUNIT

	default KUNIT_ALL_TESTS

	help

	  This builds unit tests for the seq_buf library.



	  If unsure, say N.



config STRING_KUNIT_TEST

	tristate "KUnit test string functions at runtime" if !KUNIT_ALL_TESTS

	depends on KUNIT

lib/tests/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow_kunit.o 
obj-$(CONFIG_PRINTF_KUNIT_TEST) += printf_kunit.o

obj-$(CONFIG_RANDSTRUCT_KUNIT_TEST) += randstruct_kunit.o

obj-$(CONFIG_SCANF_KUNIT_TEST) += scanf_kunit.o

obj-$(CONFIG_SEQ_BUF_KUNIT_TEST) += seq_buf_kunit.o

obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o

obj-$(CONFIG_SLUB_KUNIT_TEST) += slub_kunit.o

obj-$(CONFIG_TEST_SORT) += test_sort.o

lib/tests/seq_buf_kunit.c

0 → 100644
+208 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * KUnit tests for the seq_buf API

 *

 * Copyright (C) 2025, Google LLC.

 */



#include <kunit/test.h>

#include <linux/seq_buf.h>



static void seq_buf_init_test(struct kunit *test)

{

	char buf[32];

	struct seq_buf s;



	seq_buf_init(&s, buf, sizeof(buf));



	KUNIT_EXPECT_EQ(test, s.size, 32);

	KUNIT_EXPECT_EQ(test, s.len, 0);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_EQ(test, seq_buf_buffer_left(&s), 32);

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 0);

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "");

}



static void seq_buf_declare_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 24);



	KUNIT_EXPECT_EQ(test, s.size, 24);

	KUNIT_EXPECT_EQ(test, s.len, 0);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_EQ(test, seq_buf_buffer_left(&s), 24);

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 0);

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "");

}



static void seq_buf_clear_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 128);



	seq_buf_puts(&s, "hello");

	KUNIT_EXPECT_EQ(test, s.len, 5);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello");



	seq_buf_clear(&s);



	KUNIT_EXPECT_EQ(test, s.len, 0);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "");

}



static void seq_buf_puts_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 16);



	seq_buf_puts(&s, "hello");

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 5);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello");



	seq_buf_puts(&s, " world");

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 11);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello world");

}



static void seq_buf_puts_overflow_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 10);



	seq_buf_puts(&s, "123456789");

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 9);



	seq_buf_puts(&s, "0");

	KUNIT_EXPECT_TRUE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 10);

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "123456789");



	seq_buf_clear(&s);

	KUNIT_EXPECT_EQ(test, s.len, 0);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "");

}



static void seq_buf_putc_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 4);



	seq_buf_putc(&s, 'a');

	seq_buf_putc(&s, 'b');

	seq_buf_putc(&s, 'c');



	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 3);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "abc");



	seq_buf_putc(&s, 'd');

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 4);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "abc");



	seq_buf_putc(&s, 'e');

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 4);

	KUNIT_EXPECT_TRUE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "abc");



	seq_buf_clear(&s);

	KUNIT_EXPECT_EQ(test, s.len, 0);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "");

}



static void seq_buf_printf_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 32);



	seq_buf_printf(&s, "hello %s", "world");

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 11);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello world");



	seq_buf_printf(&s, " %d", 123);

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 15);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello world 123");

}



static void seq_buf_printf_overflow_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 16);



	seq_buf_printf(&s, "%lu", 1234567890UL);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 10);

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "1234567890");



	seq_buf_printf(&s, "%s", "abcdefghij");

	KUNIT_EXPECT_TRUE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 16);

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "1234567890abcde");



	seq_buf_clear(&s);

	KUNIT_EXPECT_EQ(test, s.len, 0);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "");

}



static void seq_buf_get_buf_commit_test(struct kunit *test)

{

	DECLARE_SEQ_BUF(s, 16);

	char *buf;

	size_t len;



	len = seq_buf_get_buf(&s, &buf);

	KUNIT_EXPECT_EQ(test, len, 16);

	KUNIT_EXPECT_PTR_NE(test, buf, NULL);



	memcpy(buf, "hello", 5);

	seq_buf_commit(&s, 5);



	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 5);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello");



	len = seq_buf_get_buf(&s, &buf);

	KUNIT_EXPECT_EQ(test, len, 11);

	KUNIT_EXPECT_PTR_NE(test, buf, NULL);



	memcpy(buf, " worlds!", 8);

	seq_buf_commit(&s, 6);



	KUNIT_EXPECT_EQ(test, seq_buf_used(&s), 11);

	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(&s));

	KUNIT_EXPECT_STREQ(test, seq_buf_str(&s), "hello world");



	len = seq_buf_get_buf(&s, &buf);

	KUNIT_EXPECT_EQ(test, len, 5);

	KUNIT_EXPECT_PTR_NE(test, buf, NULL);



	seq_buf_commit(&s, -1);

	KUNIT_EXPECT_TRUE(test, seq_buf_has_overflowed(&s));

}



static struct kunit_case seq_buf_test_cases[] = {

	KUNIT_CASE(seq_buf_init_test),

	KUNIT_CASE(seq_buf_declare_test),

	KUNIT_CASE(seq_buf_clear_test),

	KUNIT_CASE(seq_buf_puts_test),

	KUNIT_CASE(seq_buf_puts_overflow_test),

	KUNIT_CASE(seq_buf_putc_test),

	KUNIT_CASE(seq_buf_printf_test),

	KUNIT_CASE(seq_buf_printf_overflow_test),

	KUNIT_CASE(seq_buf_get_buf_commit_test),

	{}

};



static struct kunit_suite seq_buf_test_suite = {

	.name = "seq_buf",

	.test_cases = seq_buf_test_cases,

};



kunit_test_suite(seq_buf_test_suite);



MODULE_DESCRIPTION("Runtime test cases for seq_buf string API");

MODULE_LICENSE("GPL");