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linux-kselftest-kunit-6.3-rc1

Browse Source 
This KUnit update for Linux 6.3-rc1 consists of cleanups, new features,
 and documentation updates:
 
 -- adds Function Redirection API to isolate the code being tested from
    other parts of the kernel. functionredirection.rst has the details.
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Merge tag 'linux-kselftest-kunit-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull KUnit update from Shuah Khan:

 - add Function Redirection API to isolate the code being tested from
   other parts of the kernel.

   Documentation/dev-tools/kunit/api/functionredirection.rst has the
   details.

* tag 'linux-kselftest-kunit-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: Add printf attribute to fail_current_test_impl
  lib/hashtable_test.c: add test for the hashtable structure
  Documentation: Add Function Redirection API docs
  kunit: Expose 'static stub' API to redirect functions
  kunit: Add "hooks" to call into KUnit when it's built as a module
  kunit: kunit.py extract handlers
  tools/testing/kunit/kunit.py: remove redundant double check
This commit is contained in:
Linus Torvalds 2023-02-23 09:40:14 -08:00
commit 89f1a2440a
15 changed files with 965 additions and 122 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

162
Documentation/dev-tools/kunit/api/functionredirection.rst Normal file
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@ -0,0 +1,162 @@
.. SPDX-License-Identifier: GPL-2.0
========================
Function Redirection API
========================
Overview
========
When writing unit tests, it's important to be able to isolate the code being
tested from other parts of the kernel. This ensures the reliability of the test
(it won't be affected by external factors), reduces dependencies on specific
hardware or config options (making the test easier to run), and protects the
stability of the rest of the system (making it less likely for test-specific
state to interfere with the rest of the system).
While for some code (typically generic data structures, helpers, and other
"pure functions") this is trivial, for others (like device drivers,
filesystems, core subsystems) the code is heavily coupled with other parts of
the kernel.
This coupling is often due to global state in some way: be it a global list of
devices, the filesystem, or some hardware state. Tests need to either carefully
manage, isolate, and restore state, or they can avoid it altogether by
replacing access to and mutation of this state with a "fake" or "mock" variant.
By refactoring access to such state, such as by introducing a layer of
indirection which can use or emulate a separate set of test state. However,
such refactoring comes with its own costs (and undertaking significant
refactoring before being able to write tests is suboptimal).
A simpler way to intercept and replace some of the function calls is to use
function redirection via static stubs.
Static Stubs
============
Static stubs are a way of redirecting calls to one function (the "real"
function) to another function (the "replacement" function).
It works by adding a macro to the "real" function which checks to see if a test
is running, and if a replacement function is available. If so, that function is
called in place of the original.
Using static stubs is pretty straightforward:
1. Add the KUNIT_STATIC_STUB_REDIRECT() macro to the start of the "real"
function.
This should be the first statement in the function, after any variable
declarations. KUNIT_STATIC_STUB_REDIRECT() takes the name of the
function, followed by all of the arguments passed to the real function.
For example:
.. code-block:: c
void send_data_to_hardware(const char *str)
{
KUNIT_STATIC_STUB_REDIRECT(send_data_to_hardware, str);
/* real implementation */
}
2. Write one or more replacement functions.
These functions should have the same function signature as the real function.
In the event they need to access or modify test-specific state, they can use
kunit_get_current_test() to get a struct kunit pointer. This can then
be passed to the expectation/assertion macros, or used to look up KUnit
resources.
For example:
.. code-block:: c
void fake_send_data_to_hardware(const char *str)
{
struct kunit *test = kunit_get_current_test();
KUNIT_EXPECT_STREQ(test, str, "Hello World!");
}
3. Activate the static stub from your test.
From within a test, the redirection can be enabled with
kunit_activate_static_stub(), which accepts a struct kunit pointer,
the real function, and the replacement function. You can call this several
times with different replacement functions to swap out implementations of the
function.
In our example, this would be
.. code-block:: c
kunit_activate_static_stub(test,
send_data_to_hardware,
fake_send_data_to_hardware);
4. Call (perhaps indirectly) the real function.
Once the redirection is activated, any call to the real function will call
the replacement function instead. Such calls may be buried deep in the
implementation of another function, but must occur from the test's kthread.
For example:
.. code-block:: c
send_data_to_hardware("Hello World!"); /* Succeeds */
send_data_to_hardware("Something else"); /* Fails the test. */
5. (Optionally) disable the stub.
When you no longer need it, disable the redirection (and hence resume the
original behaviour of the 'real' function) using
kunit_deactivate_static_stub(). Otherwise, it will be automatically disabled
when the test exits.
For example:
.. code-block:: c
kunit_deactivate_static_stub(test, send_data_to_hardware);
It's also possible to use these replacement functions to test to see if a
function is called at all, for example:
.. code-block:: c
void send_data_to_hardware(const char *str)
{
KUNIT_STATIC_STUB_REDIRECT(send_data_to_hardware, str);
/* real implementation */
}
/* In test file */
int times_called = 0;
void fake_send_data_to_hardware(const char *str)
{
times_called++;
}
...
/* In the test case, redirect calls for the duration of the test */
kunit_activate_static_stub(test, send_data_to_hardware, fake_send_data_to_hardware);
send_data_to_hardware("hello");
KUNIT_EXPECT_EQ(test, times_called, 1);
/* Can also deactivate the stub early, if wanted */
kunit_deactivate_static_stub(test, send_data_to_hardware);
send_data_to_hardware("hello again");
KUNIT_EXPECT_EQ(test, times_called, 1);
API Reference
=============
.. kernel-doc:: include/kunit/static_stub.h
:internal:

13
Documentation/dev-tools/kunit/api/index.rst
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@ -4,17 +4,24 @@
API Reference
=============
.. toctree::
:hidden:
test
resource
functionredirection
This section documents the KUnit kernel testing API. It is divided into the
This page documents the KUnit kernel testing API. It is divided into the
following sections:
Documentation/dev-tools/kunit/api/test.rst
- documents all of the standard testing API
- Documents all of the standard testing API
Documentation/dev-tools/kunit/api/resource.rst
- documents the KUnit resource API
- Documents the KUnit resource API
Documentation/dev-tools/kunit/api/functionredirection.rst
- Documents the KUnit Function Redirection API

15
Documentation/dev-tools/kunit/usage.rst
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@ -648,10 +648,9 @@ We can do this via the ``kunit_test`` field in ``task_struct``, which we can
access using the ``kunit_get_current_test()`` function in ``kunit/test-bug.h``.
``kunit_get_current_test()`` is safe to call even if KUnit is not enabled. If
KUnit is not enabled, was built as a module (``CONFIG_KUNIT=m``), or no test is
running in the current task, it will return ``NULL``. This compiles down to
either a no-op or a static key check, so will have a negligible performance
impact when no test is running.
KUnit is not enabled, or if no test is running in the current task, it will
return ``NULL``. This compiles down to either a no-op or a static key check,
so will have a negligible performance impact when no test is running.
The example below uses this to implement a "mock" implementation of a function, ``foo``:
@ -726,8 +725,6 @@ structures as shown below:
#endif
``kunit_fail_current_test()`` is safe to call even if KUnit is not enabled. If
KUnit is not enabled, was built as a module (``CONFIG_KUNIT=m``), or no test is
running in the current task, it will do nothing. This compiles down to either a
no-op or a static key check, so will have a negligible performance impact when
no test is running.
KUnit is not enabled, or if no test is running in the current task, it will do
nothing. This compiles down to either a no-op or a static key check, so will
have a negligible performance impact when no test is running.

113
include/kunit/static_stub.h Normal file
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@ -0,0 +1,113 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* KUnit function redirection (static stubbing) API.
*
* Copyright (C) 2022, Google LLC.
* Author: David Gow <davidgow@google.com>
*/
#ifndef _KUNIT_STATIC_STUB_H
#define _KUNIT_STATIC_STUB_H
#if !IS_ENABLED(CONFIG_KUNIT)
/* If CONFIG_KUNIT is not enabled, these stubs quietly disappear. */
#define KUNIT_TRIGGER_STATIC_STUB(real_fn_name, args...) do {} while (0)
#else
#include <kunit/test.h>
#include <kunit/test-bug.h>
#include <linux/compiler.h> /* for {un,}likely() */
#include <linux/sched.h> /* for task_struct */
/**
* KUNIT_STATIC_STUB_REDIRECT() - call a replacement 'static stub' if one exists
* @real_fn_name: The name of this function (as an identifier, not a string)
* @args: All of the arguments passed to this function
*
* This is a function prologue which is used to allow calls to the current
* function to be redirected by a KUnit test. KUnit tests can call
* kunit_activate_static_stub() to pass a replacement function in. The
* replacement function will be called by KUNIT_TRIGGER_STATIC_STUB(), which
* will then return from the function. If the caller is not in a KUnit context,
* the function will continue execution as normal.
*
* Example:
*
* .. code-block:: c
*
* int real_func(int n)
* {
* KUNIT_STATIC_STUB_REDIRECT(real_func, n);
* return 0;
* }
*
* int replacement_func(int n)
* {
* return 42;
* }
*
* void example_test(struct kunit *test)
* {
* kunit_activate_static_stub(test, real_func, replacement_func);
* KUNIT_EXPECT_EQ(test, real_func(1), 42);
* }
*
*/
#define KUNIT_STATIC_STUB_REDIRECT(real_fn_name, args...) \
do { \
typeof(&real_fn_name) replacement; \
struct kunit *current_test = kunit_get_current_test(); \
\
if (likely(!current_test)) \
break; \
\
replacement = kunit_hooks.get_static_stub_address(current_test, \
&real_fn_name); \
\
if (unlikely(replacement)) \
return replacement(args); \
} while (0)
/* Helper function for kunit_activate_static_stub(). The macro does
* typechecking, so use it instead.
*/
void __kunit_activate_static_stub(struct kunit *test,
void *real_fn_addr,
void *replacement_addr);
/**
* kunit_activate_static_stub() - replace a function using static stubs.
* @test: A pointer to the 'struct kunit' test context for the current test.
* @real_fn_addr: The address of the function to replace.
* @replacement_addr: The address of the function to replace it with.
*
* When activated, calls to real_fn_addr from within this test (even if called
* indirectly) will instead call replacement_addr. The function pointed to by
* real_fn_addr must begin with the static stub prologue in
* KUNIT_TRIGGER_STATIC_STUB() for this to work. real_fn_addr and
* replacement_addr must have the same type.
*
* The redirection can be disabled again with kunit_deactivate_static_stub().
*/
#define kunit_activate_static_stub(test, real_fn_addr, replacement_addr) do { \
typecheck_fn(typeof(&real_fn_addr), replacement_addr); \
__kunit_activate_static_stub(test, real_fn_addr, replacement_addr); \
} while (0)
/**
* kunit_deactivate_static_stub() - disable a function redirection
* @test: A pointer to the 'struct kunit' test context for the current test.
* @real_fn_addr: The address of the function to no-longer redirect
*
* Deactivates a redirection configured with kunit_activate_static_stub(). After
* this function returns, calls to real_fn_addr() will execute the original
* real_fn, not any previously-configured replacement.
*/
void kunit_deactivate_static_stub(struct kunit *test, void *real_fn_addr);
#endif
#endif

29
include/kunit/test-bug.h
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@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* KUnit API allowing dynamic analysis tools to interact with KUnit tests
* KUnit API providing hooks for non-test code to interact with tests.
*
* Copyright (C) 2020, Google LLC.
* Author: Uriel Guajardo <urielguajardo@google.com>
@ -9,7 +9,7 @@
#ifndef _KUNIT_TEST_BUG_H
#define _KUNIT_TEST_BUG_H
#if IS_BUILTIN(CONFIG_KUNIT)
#if IS_ENABLED(CONFIG_KUNIT)
#include <linux/jump_label.h> /* For static branch */
#include <linux/sched.h>
@ -17,6 +17,12 @@
/* Static key if KUnit is running any tests. */
DECLARE_STATIC_KEY_FALSE(kunit_running);
/* Hooks table: a table of function pointers filled in when kunit loads */
extern struct kunit_hooks_table {
__printf(3, 4) void (*fail_current_test)(const char*, int, const char*, ...);
void *(*get_static_stub_address)(struct kunit *test, void *real_fn_addr);
} kunit_hooks;
/**
* kunit_get_current_test() - Return a pointer to the currently running
* KUnit test.
@ -43,33 +49,20 @@ static inline struct kunit *kunit_get_current_test(void)
* kunit_fail_current_test() - If a KUnit test is running, fail it.
*
* If a KUnit test is running in the current task, mark that test as failed.
*
* This macro will only work if KUnit is built-in (though the tests
* themselves can be modules). Otherwise, it compiles down to nothing.
*/
#define kunit_fail_current_test(fmt, ...) do { \
if (static_branch_unlikely(&kunit_running)) { \
__kunit_fail_current_test(__FILE__, __LINE__, \
/* Guaranteed to be non-NULL when kunit_running true*/ \
kunit_hooks.fail_current_test(__FILE__, __LINE__, \
fmt, ##__VA_ARGS__); \
} \
} while (0)
extern __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,
const char *fmt, ...);
#else
static inline struct kunit *kunit_get_current_test(void) { return NULL; }
/* We define this with an empty helper function so format string warnings work */
#define kunit_fail_current_test(fmt, ...) \
__kunit_fail_current_test(__FILE__, __LINE__, fmt, ##__VA_ARGS__)
static inline __printf(3, 4) void __kunit_fail_current_test(const char *file, int line,
const char *fmt, ...)
{
}
#define kunit_fail_current_test(fmt, ...) do {} while (0)
#endif

13
lib/Kconfig.debug
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@ -2517,6 +2517,19 @@ config LIST_KUNIT_TEST
If unsure, say N.
config HASHTABLE_KUNIT_TEST
tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
depends on KUNIT
default KUNIT_ALL_TESTS
help
This builds the hashtable KUnit test suite.
It tests the basic functionality of the API defined in
include/linux/hashtable.h. For more information on KUnit and
unit tests in general please refer to the KUnit documentation
in Documentation/dev-tools/kunit/.
If unsure, say N.
config LINEAR_RANGES_TEST
tristate "KUnit test for linear_ranges"
depends on KUNIT

9
lib/Makefile
View File

@ -126,6 +126,14 @@ CFLAGS_test_fpu.o += $(FPU_CFLAGS)
obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/
obj-$(CONFIG_KUNIT) += kunit/
# Include the KUnit hooks unconditionally. They'll compile to nothing if
# CONFIG_KUNIT=n, otherwise will be a small table of static data (static key,
# function pointers) which need to be built-in even when KUnit is a module.
ifeq ($(CONFIG_KUNIT), m)
obj-y += kunit/hooks.o
else
obj-$(CONFIG_KUNIT) += kunit/hooks.o
endif
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
@ -369,6 +377,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/
CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN)
obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o
obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o
obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
obj-$(CONFIG_BITS_TEST) += test_bits.o
obj-$(CONFIG_CMDLINE_KUNIT_TEST) += cmdline_kunit.o

317
lib/hashtable_test.c Normal file
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@ -0,0 +1,317 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KUnit test for the Kernel Hashtable structures.
*
* Copyright (C) 2022, Google LLC.
* Author: Rae Moar <rmoar@google.com>
*/
#include <kunit/test.h>
#include <linux/hashtable.h>
struct hashtable_test_entry {
int key;
int data;
struct hlist_node node;
int visited;
};
static void hashtable_test_hash_init(struct kunit *test)
{
/* Test the different ways of initialising a hashtable. */
DEFINE_HASHTABLE(hash1, 2);
DECLARE_HASHTABLE(hash2, 3);
/* When using DECLARE_HASHTABLE, must use hash_init to
* initialize the hashtable.
*/
hash_init(hash2);
KUNIT_EXPECT_TRUE(test, hash_empty(hash1));
KUNIT_EXPECT_TRUE(test, hash_empty(hash2));
}
static void hashtable_test_hash_empty(struct kunit *test)
{
struct hashtable_test_entry a;
DEFINE_HASHTABLE(hash, 1);
KUNIT_EXPECT_TRUE(test, hash_empty(hash));
a.key = 1;
a.data = 13;
hash_add(hash, &a.node, a.key);
/* Hashtable should no longer be empty. */
KUNIT_EXPECT_FALSE(test, hash_empty(hash));
}
static void hashtable_test_hash_hashed(struct kunit *test)
{
struct hashtable_test_entry a, b;
DEFINE_HASHTABLE(hash, 4);
a.key = 1;
a.data = 13;
hash_add(hash, &a.node, a.key);
b.key = 1;
b.data = 2;
hash_add(hash, &b.node, b.key);
KUNIT_EXPECT_TRUE(test, hash_hashed(&a.node));
KUNIT_EXPECT_TRUE(test, hash_hashed(&b.node));
}
static void hashtable_test_hash_add(struct kunit *test)
{
struct hashtable_test_entry a, b, *x;
int bkt;
DEFINE_HASHTABLE(hash, 3);
a.key = 1;
a.data = 13;
a.visited = 0;
hash_add(hash, &a.node, a.key);
b.key = 2;
b.data = 10;
b.visited = 0;
hash_add(hash, &b.node, b.key);
hash_for_each(hash, bkt, x, node) {
x->visited++;
if (x->key == a.key)
KUNIT_EXPECT_EQ(test, x->data, 13);
else if (x->key == b.key)
KUNIT_EXPECT_EQ(test, x->data, 10);
else
KUNIT_FAIL(test, "Unexpected key in hashtable.");
}
/* Both entries should have been visited exactly once. */
KUNIT_EXPECT_EQ(test, a.visited, 1);
KUNIT_EXPECT_EQ(test, b.visited, 1);
}
static void hashtable_test_hash_del(struct kunit *test)
{
struct hashtable_test_entry a, b, *x;
DEFINE_HASHTABLE(hash, 6);
a.key = 1;
a.data = 13;
hash_add(hash, &a.node, a.key);
b.key = 2;
b.data = 10;
b.visited = 0;
hash_add(hash, &b.node, b.key);
hash_del(&b.node);
hash_for_each_possible(hash, x, node, b.key) {
x->visited++;
KUNIT_EXPECT_NE(test, x->key, b.key);
}
/* The deleted entry should not have been visited. */
KUNIT_EXPECT_EQ(test, b.visited, 0);
hash_del(&a.node);
/* The hashtable should be empty. */
KUNIT_EXPECT_TRUE(test, hash_empty(hash));
}
static void hashtable_test_hash_for_each(struct kunit *test)
{
struct hashtable_test_entry entries[3];
struct hashtable_test_entry *x;
int bkt, i, j, count;
DEFINE_HASHTABLE(hash, 3);
/* Add three entries to the hashtable. */
for (i = 0; i < 3; i++) {
entries[i].key = i;
entries[i].data = i + 10;
entries[i].visited = 0;
hash_add(hash, &entries[i].node, entries[i].key);
}
count = 0;
hash_for_each(hash, bkt, x, node) {
x->visited += 1;
KUNIT_ASSERT_GE_MSG(test, x->key, 0, "Unexpected key in hashtable.");
KUNIT_ASSERT_LT_MSG(test, x->key, 3, "Unexpected key in hashtable.");
count++;
}
/* Should have visited each entry exactly once. */
KUNIT_EXPECT_EQ(test, count, 3);
for (j = 0; j < 3; j++)
KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
}
static void hashtable_test_hash_for_each_safe(struct kunit *test)
{
struct hashtable_test_entry entries[3];
struct hashtable_test_entry *x;
struct hlist_node *tmp;
int bkt, i, j, count;
DEFINE_HASHTABLE(hash, 3);
/* Add three entries to the hashtable. */
for (i = 0; i < 3; i++) {
entries[i].key = i;
entries[i].data = i + 10;
entries[i].visited = 0;
hash_add(hash, &entries[i].node, entries[i].key);
}
count = 0;
hash_for_each_safe(hash, bkt, tmp, x, node) {
x->visited += 1;
KUNIT_ASSERT_GE_MSG(test, x->key, 0, "Unexpected key in hashtable.");
KUNIT_ASSERT_LT_MSG(test, x->key, 3, "Unexpected key in hashtable.");
count++;
/* Delete entry during loop. */
hash_del(&x->node);
}
/* Should have visited each entry exactly once. */
KUNIT_EXPECT_EQ(test, count, 3);
for (j = 0; j < 3; j++)
KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
}
static void hashtable_test_hash_for_each_possible(struct kunit *test)
{
struct hashtable_test_entry entries[4];
struct hashtable_test_entry *x, *y;
int buckets[2];
int bkt, i, j, count;
DEFINE_HASHTABLE(hash, 5);
/* Add three entries with key = 0 to the hashtable. */
for (i = 0; i < 3; i++) {
entries[i].key = 0;
entries[i].data = i;
entries[i].visited = 0;
hash_add(hash, &entries[i].node, entries[i].key);
}
/* Add an entry with key = 1. */
entries[3].key = 1;
entries[3].data = 3;
entries[3].visited = 0;
hash_add(hash, &entries[3].node, entries[3].key);
count = 0;
hash_for_each_possible(hash, x, node, 0) {
x->visited += 1;
KUNIT_ASSERT_GE_MSG(test, x->data, 0, "Unexpected data in hashtable.");
KUNIT_ASSERT_LT_MSG(test, x->data, 4, "Unexpected data in hashtable.");
count++;
}
/* Should have visited each entry with key = 0 exactly once. */
for (j = 0; j < 3; j++)
KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
/* Save the buckets for the different keys. */
hash_for_each(hash, bkt, y, node) {
KUNIT_ASSERT_GE_MSG(test, y->key, 0, "Unexpected key in hashtable.");
KUNIT_ASSERT_LE_MSG(test, y->key, 1, "Unexpected key in hashtable.");
buckets[y->key] = bkt;
}
/* If entry with key = 1 is in the same bucket as the entries with
* key = 0, check it was visited. Otherwise ensure that only three
* entries were visited.
*/
if (buckets[0] == buckets[1]) {
KUNIT_EXPECT_EQ(test, count, 4);
KUNIT_EXPECT_EQ(test, entries[3].visited, 1);
} else {
KUNIT_EXPECT_EQ(test, count, 3);
KUNIT_EXPECT_EQ(test, entries[3].visited, 0);
}
}
static void hashtable_test_hash_for_each_possible_safe(struct kunit *test)
{
struct hashtable_test_entry entries[4];
struct hashtable_test_entry *x, *y;
struct hlist_node *tmp;
int buckets[2];
int bkt, i, j, count;
DEFINE_HASHTABLE(hash, 5);
/* Add three entries with key = 0 to the hashtable. */
for (i = 0; i < 3; i++) {
entries[i].key = 0;
entries[i].data = i;
entries[i].visited = 0;
hash_add(hash, &entries[i].node, entries[i].key);
}
/* Add an entry with key = 1. */
entries[3].key = 1;
entries[3].data = 3;
entries[3].visited = 0;
hash_add(hash, &entries[3].node, entries[3].key);
count = 0;
hash_for_each_possible_safe(hash, x, tmp, node, 0) {
x->visited += 1;
KUNIT_ASSERT_GE_MSG(test, x->data, 0, "Unexpected data in hashtable.");
KUNIT_ASSERT_LT_MSG(test, x->data, 4, "Unexpected data in hashtable.");
count++;
/* Delete entry during loop. */
hash_del(&x->node);
}
/* Should have visited each entry with key = 0 exactly once. */
for (j = 0; j < 3; j++)
KUNIT_EXPECT_EQ(test, entries[j].visited, 1);
/* Save the buckets for the different keys. */
hash_for_each(hash, bkt, y, node) {
KUNIT_ASSERT_GE_MSG(test, y->key, 0, "Unexpected key in hashtable.");
KUNIT_ASSERT_LE_MSG(test, y->key, 1, "Unexpected key in hashtable.");
buckets[y->key] = bkt;
}
/* If entry with key = 1 is in the same bucket as the entries with
* key = 0, check it was visited. Otherwise ensure that only three
* entries were visited.
*/
if (buckets[0] == buckets[1]) {
KUNIT_EXPECT_EQ(test, count, 4);
KUNIT_EXPECT_EQ(test, entries[3].visited, 1);
} else {
KUNIT_EXPECT_EQ(test, count, 3);
KUNIT_EXPECT_EQ(test, entries[3].visited, 0);
}
}
static struct kunit_case hashtable_test_cases[] = {
KUNIT_CASE(hashtable_test_hash_init),
KUNIT_CASE(hashtable_test_hash_empty),
KUNIT_CASE(hashtable_test_hash_hashed),
KUNIT_CASE(hashtable_test_hash_add),
KUNIT_CASE(hashtable_test_hash_del),
KUNIT_CASE(hashtable_test_hash_for_each),
KUNIT_CASE(hashtable_test_hash_for_each_safe),
KUNIT_CASE(hashtable_test_hash_for_each_possible),
KUNIT_CASE(hashtable_test_hash_for_each_possible_safe),
{},
};
static struct kunit_suite hashtable_test_module = {
.name = "hashtable",
.test_cases = hashtable_test_cases,
};
kunit_test_suites(&hashtable_test_module);
MODULE_LICENSE("GPL");

4
lib/kunit/Makefile
View File

@ -2,6 +2,7 @@ obj-$(CONFIG_KUNIT) += kunit.o
kunit-objs += test.o \
resource.o \
static_stub.o \
string-stream.o \
assert.o \
try-catch.o \
@ -11,6 +12,9 @@ ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
kunit-objs += debugfs.o
endif
# KUnit 'hooks' are built-in even when KUnit is built as a module.
lib-y += hooks.o
obj-$(CONFIG_KUNIT_TEST) += kunit-test.o
# string-stream-test compiles built-in only.

31
lib/kunit/hooks-impl.h Normal file
View File

@ -0,0 +1,31 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Declarations for hook implementations.
*
* These will be set as the function pointers in struct kunit_hook_table,
* found in include/kunit/test-bug.h.
*
* Copyright (C) 2023, Google LLC.
* Author: David Gow <davidgow@google.com>
*/
#ifndef _KUNIT_HOOKS_IMPL_H
#define _KUNIT_HOOKS_IMPL_H
#include <kunit/test-bug.h>
/* List of declarations. */
void __printf(3, 4) __kunit_fail_current_test_impl(const char *file,
int line,
const char *fmt, ...);
void *__kunit_get_static_stub_address_impl(struct kunit *test, void *real_fn_addr);
/* Code to set all of the function pointers. */
static inline void kunit_install_hooks(void)
{
/* Install the KUnit hook functions. */
kunit_hooks.fail_current_test = __kunit_fail_current_test_impl;
kunit_hooks.get_static_stub_address = __kunit_get_static_stub_address_impl;
}
#endif /* _KUNIT_HOOKS_IMPL_H */

21
lib/kunit/hooks.c Normal file
View File

@ -0,0 +1,21 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KUnit 'Hooks' implementation.
*
* This file contains code / structures which should be built-in even when
* KUnit itself is built as a module.
*
* Copyright (C) 2022, Google LLC.
* Author: David Gow <davidgow@google.com>
*/
#include <kunit/test-bug.h>
DEFINE_STATIC_KEY_FALSE(kunit_running);
EXPORT_SYMBOL(kunit_running);
/* Function pointers for hooks. */
struct kunit_hooks_table kunit_hooks;
EXPORT_SYMBOL(kunit_hooks);

38
lib/kunit/kunit-example-test.c
View File

@ -7,6 +7,7 @@
*/
#include <kunit/test.h>
#include <kunit/static_stub.h>
/*
* This is the most fundamental element of KUnit, the test case. A test case
@ -130,6 +131,42 @@ static void example_all_expect_macros_test(struct kunit *test)
KUNIT_ASSERT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!");
}
/* This is a function we'll replace with static stubs. */
static int add_one(int i)
{
/* This will trigger the stub if active. */
KUNIT_STATIC_STUB_REDIRECT(add_one, i);
return i + 1;
}
/* This is used as a replacement for the above function. */
static int subtract_one(int i)
{
/* We don't need to trigger the stub from the replacement. */
return i - 1;
}
/*
* This test shows the use of static stubs.
*/
static void example_static_stub_test(struct kunit *test)
{
/* By default, function is not stubbed. */
KUNIT_EXPECT_EQ(test, add_one(1), 2);
/* Replace add_one() with subtract_one(). */
kunit_activate_static_stub(test, add_one, subtract_one);
/* add_one() is now replaced. */
KUNIT_EXPECT_EQ(test, add_one(1), 0);
/* Return add_one() to normal. */
kunit_deactivate_static_stub(test, add_one);
KUNIT_EXPECT_EQ(test, add_one(1), 2);
}
/*
* Here we make a list of all the test cases we want to add to the test suite
* below.
@ -145,6 +182,7 @@ static struct kunit_case example_test_cases[] = {
KUNIT_CASE(example_skip_test),
KUNIT_CASE(example_mark_skipped_test),
KUNIT_CASE(example_all_expect_macros_test),
KUNIT_CASE(example_static_stub_test),
{}
};

123
lib/kunit/static_stub.c Normal file
View File

@ -0,0 +1,123 @@
// SPDX-License-Identifier: GPL-2.0
/*
* KUnit function redirection (static stubbing) API.
*
* Copyright (C) 2022, Google LLC.
* Author: David Gow <davidgow@google.com>
*/
#include <kunit/test.h>
#include <kunit/static_stub.h>
#include "hooks-impl.h"
/* Context for a static stub. This is stored in the resource data. */
struct kunit_static_stub_ctx {
void *real_fn_addr;
void *replacement_addr;
};
static void __kunit_static_stub_resource_free(struct kunit_resource *res)
{
kfree(res->data);
}
/* Matching function for kunit_find_resource(). match_data is real_fn_addr. */
static bool __kunit_static_stub_resource_match(struct kunit *test,
struct kunit_resource *res,
void *match_real_fn_addr)
{
/* This pointer is only valid if res is a static stub resource. */
struct kunit_static_stub_ctx *ctx = res->data;
/* Make sure the resource is a static stub resource. */
if (res->free != &__kunit_static_stub_resource_free)
return false;
return ctx->real_fn_addr == match_real_fn_addr;
}
/* Hook to return the address of the replacement function. */
void *__kunit_get_static_stub_address_impl(struct kunit *test, void *real_fn_addr)
{
struct kunit_resource *res;
struct kunit_static_stub_ctx *ctx;
void *replacement_addr;
res = kunit_find_resource(test,
__kunit_static_stub_resource_match,
real_fn_addr);
if (!res)
return NULL;
ctx = res->data;
replacement_addr = ctx->replacement_addr;
kunit_put_resource(res);
return replacement_addr;
}
void kunit_deactivate_static_stub(struct kunit *test, void *real_fn_addr)
{
struct kunit_resource *res;
KUNIT_ASSERT_PTR_NE_MSG(test, real_fn_addr, NULL,
"Tried to deactivate a NULL stub.");
/* Look up the existing stub for this function. */
res = kunit_find_resource(test,
__kunit_static_stub_resource_match,
real_fn_addr);
/* Error out if the stub doesn't exist. */
KUNIT_ASSERT_PTR_NE_MSG(test, res, NULL,
"Tried to deactivate a nonexistent stub.");
/* Free the stub. We 'put' twice, as we got a reference
* from kunit_find_resource()
*/
kunit_remove_resource(test, res);
kunit_put_resource(res);
}
EXPORT_SYMBOL_GPL(kunit_deactivate_static_stub);
/* Helper function for kunit_activate_static_stub(). The macro does
* typechecking, so use it instead.
*/
void __kunit_activate_static_stub(struct kunit *test,
void *real_fn_addr,
void *replacement_addr)
{
struct kunit_static_stub_ctx *ctx;
struct kunit_resource *res;
KUNIT_ASSERT_PTR_NE_MSG(test, real_fn_addr, NULL,
"Tried to activate a stub for function NULL");
/* If the replacement address is NULL, deactivate the stub. */
if (!replacement_addr) {
kunit_deactivate_static_stub(test, replacement_addr);
return;
}
/* Look up any existing stubs for this function, and replace them. */
res = kunit_find_resource(test,
__kunit_static_stub_resource_match,
real_fn_addr);
if (res) {
ctx = res->data;
ctx->replacement_addr = replacement_addr;
/* We got an extra reference from find_resource(), so put it. */
kunit_put_resource(res);
} else {
ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
ctx->real_fn_addr = real_fn_addr;
ctx->replacement_addr = replacement_addr;
res = kunit_alloc_resource(test, NULL,
&__kunit_static_stub_resource_free,
GFP_KERNEL, ctx);
}
}
EXPORT_SYMBOL_GPL(__kunit_activate_static_stub);

15
lib/kunit/test.c
View File

@ -17,17 +17,14 @@
#include <linux/sched.h>
#include "debugfs.h"
#include "hooks-impl.h"
#include "string-stream.h"
#include "try-catch-impl.h"
DEFINE_STATIC_KEY_FALSE(kunit_running);
EXPORT_SYMBOL_GPL(kunit_running);
#if IS_BUILTIN(CONFIG_KUNIT)
/*
* Fail the current test and print an error message to the log.
* Hook to fail the current test and print an error message to the log.
*/
void __kunit_fail_current_test(const char *file, int line, const char *fmt, ...)
void __printf(3, 4) __kunit_fail_current_test_impl(const char *file, int line, const char *fmt, ...)
{
va_list args;
int len;
@ -54,8 +51,6 @@ void __kunit_fail_current_test(const char *file, int line, const char *fmt, ...)
kunit_err(current->kunit_test, "%s:%d: %s", file, line, buffer);
kunit_kfree(current->kunit_test, buffer);
}
EXPORT_SYMBOL_GPL(__kunit_fail_current_test);
#endif
/*
* Enable KUnit tests to run.
@ -778,6 +773,9 @@ EXPORT_SYMBOL_GPL(kunit_cleanup);
static int __init kunit_init(void)
{
/* Install the KUnit hook functions. */
kunit_install_hooks();
kunit_debugfs_init();
#ifdef CONFIG_MODULES
return register_module_notifier(&kunit_mod_nb);
@ -789,6 +787,7 @@ late_initcall(kunit_init);
static void __exit kunit_exit(void)
{
memset(&kunit_hooks, 0, sizeof(kunit_hooks));
#ifdef CONFIG_MODULES
unregister_module_notifier(&kunit_mod_nb);
#endif

184
tools/testing/kunit/kunit.py
View File

@ -77,11 +77,8 @@ def config_tests(linux: kunit_kernel.LinuxSourceTree,
config_start = time.time()
success = linux.build_reconfig(request.build_dir, request.make_options)
config_end = time.time()
if not success:
return KunitResult(KunitStatus.CONFIG_FAILURE,
config_end - config_start)
return KunitResult(KunitStatus.SUCCESS,
config_end - config_start)
status = KunitStatus.SUCCESS if success else KunitStatus.CONFIG_FAILURE
return KunitResult(status, config_end - config_start)
def build_tests(linux: kunit_kernel.LinuxSourceTree,
request: KunitBuildRequest) -> KunitResult:
@ -92,14 +89,8 @@ def build_tests(linux: kunit_kernel.LinuxSourceTree,
request.build_dir,
request.make_options)
build_end = time.time()
if not success:
return KunitResult(KunitStatus.BUILD_FAILURE,
build_end - build_start)
if not success:
return KunitResult(KunitStatus.BUILD_FAILURE,
build_end - build_start)
return KunitResult(KunitStatus.SUCCESS,
build_end - build_start)
status = KunitStatus.SUCCESS if success else KunitStatus.BUILD_FAILURE
return KunitResult(status, build_end - build_start)
def config_and_build_tests(linux: kunit_kernel.LinuxSourceTree,
request: KunitBuildRequest) -> KunitResult:
@ -145,7 +136,7 @@ def exec_tests(linux: kunit_kernel.LinuxSourceTree, request: KunitExecRequest) -
tests = _list_tests(linux, request)
if request.run_isolated == 'test':
filter_globs = tests
if request.run_isolated == 'suite':
elif request.run_isolated == 'suite':
filter_globs = _suites_from_test_list(tests)
# Apply the test-part of the user's glob, if present.
if '.' in request.filter_glob:
@ -395,6 +386,95 @@ def tree_from_args(cli_args: argparse.Namespace) -> kunit_kernel.LinuxSourceTree
extra_qemu_args=qemu_args)
def run_handler(cli_args):
if not os.path.exists(cli_args.build_dir):
os.mkdir(cli_args.build_dir)
linux = tree_from_args(cli_args)
request = KunitRequest(build_dir=cli_args.build_dir,
make_options=cli_args.make_options,
jobs=cli_args.jobs,
raw_output=cli_args.raw_output,
json=cli_args.json,
timeout=cli_args.timeout,
filter_glob=cli_args.filter_glob,
kernel_args=cli_args.kernel_args,
run_isolated=cli_args.run_isolated)
result = run_tests(linux, request)
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
def config_handler(cli_args):
if cli_args.build_dir and (
not os.path.exists(cli_args.build_dir)):
os.mkdir(cli_args.build_dir)
linux = tree_from_args(cli_args)
request = KunitConfigRequest(build_dir=cli_args.build_dir,
make_options=cli_args.make_options)
result = config_tests(linux, request)
stdout.print_with_timestamp((
'Elapsed time: %.3fs\n') % (
result.elapsed_time))
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
def build_handler(cli_args):
linux = tree_from_args(cli_args)
request = KunitBuildRequest(build_dir=cli_args.build_dir,
make_options=cli_args.make_options,
jobs=cli_args.jobs)
result = config_and_build_tests(linux, request)
stdout.print_with_timestamp((
'Elapsed time: %.3fs\n') % (
result.elapsed_time))
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
def exec_handler(cli_args):
linux = tree_from_args(cli_args)
exec_request = KunitExecRequest(raw_output=cli_args.raw_output,
build_dir=cli_args.build_dir,
json=cli_args.json,
timeout=cli_args.timeout,
filter_glob=cli_args.filter_glob,
kernel_args=cli_args.kernel_args,
run_isolated=cli_args.run_isolated)
result = exec_tests(linux, exec_request)
stdout.print_with_timestamp((
'Elapsed time: %.3fs\n') % (result.elapsed_time))
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
def parse_handler(cli_args):
if cli_args.file is None:
sys.stdin.reconfigure(errors='backslashreplace') # pytype: disable=attribute-error
kunit_output = sys.stdin
else:
with open(cli_args.file, 'r', errors='backslashreplace') as f:
kunit_output = f.read().splitlines()
# We know nothing about how the result was created!
metadata = kunit_json.Metadata()
request = KunitParseRequest(raw_output=cli_args.raw_output,
json=cli_args.json)
result, _ = parse_tests(request, metadata, kunit_output)
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
subcommand_handlers_map = {
'run': run_handler,
'config': config_handler,
'build': build_handler,
'exec': exec_handler,
'parse': parse_handler
}
def main(argv):
parser = argparse.ArgumentParser(
description='Helps writing and running KUnit tests.')
@ -438,78 +518,14 @@ def main(argv):
if get_kernel_root_path():
os.chdir(get_kernel_root_path())
if cli_args.subcommand == 'run':
if not os.path.exists(cli_args.build_dir):
os.mkdir(cli_args.build_dir)
subcomand_handler = subcommand_handlers_map.get(cli_args.subcommand, None)
linux = tree_from_args(cli_args)
request = KunitRequest(build_dir=cli_args.build_dir,
make_options=cli_args.make_options,
jobs=cli_args.jobs,
raw_output=cli_args.raw_output,
json=cli_args.json,
timeout=cli_args.timeout,
filter_glob=cli_args.filter_glob,
kernel_args=cli_args.kernel_args,
run_isolated=cli_args.run_isolated)
result = run_tests(linux, request)
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
elif cli_args.subcommand == 'config':
if cli_args.build_dir and (
not os.path.exists(cli_args.build_dir)):
os.mkdir(cli_args.build_dir)
linux = tree_from_args(cli_args)
request = KunitConfigRequest(build_dir=cli_args.build_dir,
make_options=cli_args.make_options)
result = config_tests(linux, request)
stdout.print_with_timestamp((
'Elapsed time: %.3fs\n') % (
result.elapsed_time))
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
elif cli_args.subcommand == 'build':
linux = tree_from_args(cli_args)
request = KunitBuildRequest(build_dir=cli_args.build_dir,
make_options=cli_args.make_options,
jobs=cli_args.jobs)
result = config_and_build_tests(linux, request)
stdout.print_with_timestamp((
'Elapsed time: %.3fs\n') % (
result.elapsed_time))
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
elif cli_args.subcommand == 'exec':
linux = tree_from_args(cli_args)
exec_request = KunitExecRequest(raw_output=cli_args.raw_output,
build_dir=cli_args.build_dir,
json=cli_args.json,
timeout=cli_args.timeout,
filter_glob=cli_args.filter_glob,
kernel_args=cli_args.kernel_args,
run_isolated=cli_args.run_isolated)
result = exec_tests(linux, exec_request)
stdout.print_with_timestamp((
'Elapsed time: %.3fs\n') % (result.elapsed_time))
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
elif cli_args.subcommand == 'parse':
if cli_args.file is None:
sys.stdin.reconfigure(errors='backslashreplace') # pytype: disable=attribute-error
kunit_output = sys.stdin
else:
with open(cli_args.file, 'r', errors='backslashreplace') as f:
kunit_output = f.read().splitlines()
# We know nothing about how the result was created!
metadata = kunit_json.Metadata()
request = KunitParseRequest(raw_output=cli_args.raw_output,
json=cli_args.json)
result, _ = parse_tests(request, metadata, kunit_output)
if result.status != KunitStatus.SUCCESS:
sys.exit(1)
else:
if subcomand_handler is None:
parser.print_help()
return
subcomand_handler(cli_args)
if __name__ == '__main__':
main(sys.argv[1:])