Re: [PATCH v3] kunit: Cover 'assert.c' with tests

Ivan Orlov <ivan.orlov0322@xxxxxxxxx> · Tue, 14 May 2024 15:31:33 +0100

On 5/14/24 01:17, Rae Moar wrote:
On Thu, May 9, 2024 at 5:05 AM Ivan Orlov <ivan.orlov0322@xxxxxxxxx> wrote:

There are multiple assertion formatting functions in the `assert.c`
file, which are not covered with tests yet. Implement the KUnit test
for these functions.

The test consists of 11 test cases for the following functions:

1) 'is_literal'
2) 'is_str_literal'
3) 'kunit_assert_prologue', test case for multiple assert types
4) 'kunit_assert_print_msg'
5) 'kunit_unary_assert_format'
6) 'kunit_ptr_not_err_assert_format'
7) 'kunit_binary_assert_format'
8) 'kunit_binary_ptr_assert_format'
9) 'kunit_binary_str_assert_format'
10) 'kunit_assert_hexdump'
11) 'kunit_mem_assert_format'

The test aims at maximizing the branch coverage for the assertion
formatting functions.

As you can see, it covers some of the static helper functions as
well, so mark the static functions in `assert.c` as 'VISIBLE_IF_KUNIT'
and conditionally export them with EXPORT_SYMBOL_IF_KUNIT. Add the
corresponding definitions to `assert.h`.

Build the assert test when CONFIG_KUNIT_TEST is enabled, similar to
how it is done for the string stream test.

Hello!

This looks great to me! Thanks for all your work on this! There is
just one comment I have below. Once that is fixed up, I am happy to
add a reviewed-by.

Thanks!
-Rae


Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
---
V1 -> V2:
- Check the output from the string stream for containing the key parts
instead of comparing the results with expected strings char by char, as
it was suggested by Rae Moar <rmoar@xxxxxxxxxx>. Define two macros to
make it possible (ASSERT_TEST_EXPECT_CONTAIN and
ASSERT_TEST_EXPECT_NCONTAIN).
- Mark the static functions in `assert.c` as VISIBLE_IF_KUNIT and export
them conditionally if kunit is enabled instead of including the
`assert_test.c` file in the end of `assert.c`. This way we will decouple
the test from the implementation (SUT).
- Update the kunit_assert_hexdump test: now it checks for presense of
the brackets '<>' around the non-matching bytes, instead of comparing
the kunit_assert_hexdump output char by char.
V2 -> V3:
- Make test case array and test suite definitions static
- Change the condition in `assert.h`: we should declare VISIBLE_IF_KUNIT
functions in the header file when CONFIG_KUNIT is enabled, not
CONFIG_KUNIT_TEST. Otherwise, if CONFIG_KUNIT_TEST is disabled,
VISIBLE_IF_KUNIT functions in the `assert.c` are not static, and
prototypes for them can't be found.
- Add MODULE_LICENSE and MODULE_DESCRIPTION macros

  include/kunit/assert.h  |  11 ++
  lib/kunit/Makefile      |   1 +
  lib/kunit/assert.c      |  24 ++-
  lib/kunit/assert_test.c | 391 ++++++++++++++++++++++++++++++++++++++++
  4 files changed, 419 insertions(+), 8 deletions(-)
  create mode 100644 lib/kunit/assert_test.c

diff --git a/include/kunit/assert.h b/include/kunit/assert.h
index 24c2b9fa61e8..7e7490a74b13 100644
--- a/include/kunit/assert.h
+++ b/include/kunit/assert.h
@@ -218,4 +218,15 @@ void kunit_mem_assert_format(const struct kunit_assert *assert,
                              const struct va_format *message,
                              struct string_stream *stream);

+#if IS_ENABLED(CONFIG_KUNIT)
+void kunit_assert_print_msg(const struct va_format *message,
+                           struct string_stream *stream);
+bool is_literal(const char *text, long long value);
+bool is_str_literal(const char *text, const char *value);
+void kunit_assert_hexdump(struct string_stream *stream,
+                         const void *buf,
+                         const void *compared_buf,
+                         const size_t len);
+#endif
+
  #endif /*  _KUNIT_ASSERT_H */
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index 309659a32a78..be7c9903936f 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -18,6 +18,7 @@ endif
  obj-y +=                               hooks.o

  obj-$(CONFIG_KUNIT_TEST) +=            kunit-test.o
+obj-$(CONFIG_KUNIT_TEST) +=            assert_test.o

  # string-stream-test compiles built-in only.
  ifeq ($(CONFIG_KUNIT_TEST),y)
diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c
index dd1d633d0fe2..382eb409d34b 100644
--- a/lib/kunit/assert.c
+++ b/lib/kunit/assert.c
@@ -7,6 +7,7 @@
   */
  #include <kunit/assert.h>
  #include <kunit/test.h>
+#include <kunit/visibility.h>

  #include "string-stream.h"

@@ -30,12 +31,14 @@ void kunit_assert_prologue(const struct kunit_loc *loc,
  }
  EXPORT_SYMBOL_GPL(kunit_assert_prologue);

-static void kunit_assert_print_msg(const struct va_format *message,
-                                  struct string_stream *stream)
+VISIBLE_IF_KUNIT
+void kunit_assert_print_msg(const struct va_format *message,
+                           struct string_stream *stream)
  {
         if (message->fmt)
                 string_stream_add(stream, "\n%pV", message);
  }
+EXPORT_SYMBOL_IF_KUNIT(kunit_assert_print_msg);

  void kunit_fail_assert_format(const struct kunit_assert *assert,
                               const struct va_format *message,
@@ -89,7 +92,7 @@ void kunit_ptr_not_err_assert_format(const struct kunit_assert *assert,
  EXPORT_SYMBOL_GPL(kunit_ptr_not_err_assert_format);

  /* Checks if `text` is a literal representing `value`, e.g. "5" and 5 */
-static bool is_literal(const char *text, long long value)
+VISIBLE_IF_KUNIT bool is_literal(const char *text, long long value)
  {
         char *buffer;
         int len;
@@ -110,6 +113,7 @@ static bool is_literal(const char *text, long long value)

         return ret;
  }
+EXPORT_SYMBOL_IF_KUNIT(is_literal);

  void kunit_binary_assert_format(const struct kunit_assert *assert,
                                 const struct va_format *message,
@@ -166,7 +170,7 @@ EXPORT_SYMBOL_GPL(kunit_binary_ptr_assert_format);
  /* Checks if KUNIT_EXPECT_STREQ() args were string literals.
   * Note: `text` will have ""s where as `value` will not.
   */
-static bool is_str_literal(const char *text, const char *value)
+VISIBLE_IF_KUNIT bool is_str_literal(const char *text, const char *value)
  {
         int len;

@@ -178,6 +182,7 @@ static bool is_str_literal(const char *text, const char *value)

         return strncmp(text + 1, value, len - 2) == 0;
  }
+EXPORT_SYMBOL_IF_KUNIT(is_str_literal);

  void kunit_binary_str_assert_format(const struct kunit_assert *assert,
                                     const struct va_format *message,
@@ -208,10 +213,11 @@ EXPORT_SYMBOL_GPL(kunit_binary_str_assert_format);
  /* Adds a hexdump of a buffer to a string_stream comparing it with
   * a second buffer. The different bytes are marked with <>.
   */
-static void kunit_assert_hexdump(struct string_stream *stream,
-                                const void *buf,
-                                const void *compared_buf,
-                                const size_t len)
+VISIBLE_IF_KUNIT
+void kunit_assert_hexdump(struct string_stream *stream,
+                         const void *buf,
+                         const void *compared_buf,
+                         const size_t len)
  {
         size_t i;
         const u8 *buf1 = buf;
@@ -229,6 +235,7 @@ static void kunit_assert_hexdump(struct string_stream *stream,
                         string_stream_add(stream, " %02x ", buf1[i]);
         }
  }
+EXPORT_SYMBOL_IF_KUNIT(kunit_assert_hexdump);

  void kunit_mem_assert_format(const struct kunit_assert *assert,
                              const struct va_format *message,
@@ -269,4 +276,5 @@ void kunit_mem_assert_format(const struct kunit_assert *assert,
                 kunit_assert_print_msg(message, stream);
         }
  }
+
  EXPORT_SYMBOL_GPL(kunit_mem_assert_format);
diff --git a/lib/kunit/assert_test.c b/lib/kunit/assert_test.c
new file mode 100644
index 000000000000..1347a964204b
--- /dev/null
+++ b/lib/kunit/assert_test.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * KUnit test for the assertion formatting functions.
+ * Author: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
+ */
+#include <kunit/test.h>
+#include "string-stream.h"
+
+#define TEST_PTR_EXPECTED_BUF_SIZE 32
+#define HEXDUMP_TEST_BUF_LEN 5
+#define ASSERT_TEST_EXPECT_CONTAIN(test, str, substr) KUNIT_EXPECT_TRUE(test, strstr(str, substr))
+#define ASSERT_TEST_EXPECT_NCONTAIN(test, str, substr) KUNIT_EXPECT_FALSE(test, strstr(str, substr))
+
+static void kunit_test_is_literal(struct kunit *test)
+{
+       KUNIT_EXPECT_TRUE(test, is_literal("5", 5));
+       KUNIT_EXPECT_TRUE(test, is_literal("0", 0));
+       KUNIT_EXPECT_TRUE(test, is_literal("1234567890", 1234567890));
+       KUNIT_EXPECT_TRUE(test, is_literal("-1234567890", -1234567890));
+       KUNIT_EXPECT_FALSE(test, is_literal("05", 5));
+       KUNIT_EXPECT_FALSE(test, is_literal("", 0));
+       KUNIT_EXPECT_FALSE(test, is_literal("-0", 0));
+       KUNIT_EXPECT_FALSE(test, is_literal("12#45", 1245));
+}
+
+static void kunit_test_is_str_literal(struct kunit *test)
+{
+       KUNIT_EXPECT_TRUE(test, is_str_literal("\"Hello, World!\"", "Hello, World!"));
+       KUNIT_EXPECT_TRUE(test, is_str_literal("\"\"", ""));
+       KUNIT_EXPECT_TRUE(test, is_str_literal("\"\"\"", "\""));
+       KUNIT_EXPECT_FALSE(test, is_str_literal("", ""));
+       KUNIT_EXPECT_FALSE(test, is_str_literal("\"", "\""));
+       KUNIT_EXPECT_FALSE(test, is_str_literal("\"Abacaba", "Abacaba"));
+       KUNIT_EXPECT_FALSE(test, is_str_literal("Abacaba\"", "Abacaba"));
+       KUNIT_EXPECT_FALSE(test, is_str_literal("\"Abacaba\"", "\"Abacaba\""));
+}
+
+KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *);
+
+/* this function is used to get a "char *" string from the string stream and defer its cleanup  */
+static char *get_str_from_stream(struct kunit *test, struct string_stream *stream)
+{
+       char *str = string_stream_get_string(stream);
+

When trying to make the kernel with this test loaded in, I am getting
an error that string_stream_get_string, string_stream_clear, and
kunit_alloc_string_stream are undefined.

So either these three methods will have to be exported using
EXPORT_SYMBOL_KUNIT or this test cannot be loaded and run as a module.

But once this is fixed up this should be good to go.

Hi Rae,

Thank you so much for the review.

At the moment, I believe the best approach would be to make this test 
depend on CONFIG_KUNIT_TEST=y (as it is done for string-stream-test).

However, I assume that every (standalone) test should be able to run as 
a module, and I'd like to add EXPORT_SYMBOL_IF_KUNIT to all of the 
non-static string-stream functions in a separate patch series. It will 
require updating string-stream-test.c as well (adding MODULE_IMPORT_NS). 
What do you think?

Thank you once again,
--
Kind regards,
Ivan Orlov








