lib/hashtable_test.c: add test for the hashtable structure

Add a KUnit test for the kernel hashtable implementation in
include/linux/hashtable.h.

Note that this version does not yet test each of the rcu
alternative versions of functions.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 02ee440f7be36cab2c0a28b64b3009e1320bdebc..6a7ce60c8412c9de2d309f9f02ebb4d19ad8f26f 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2497,6 +2497,19 @@ 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

diff --git a/lib/Makefile b/lib/Makefile
index 55fd04a7d0fb1b9df35435e9f7503e22aaf5a73b..b25a324fa326d3c5c6d1944363db5b23e31f3c2f 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -377,6 +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

diff --git a/lib/hashtable_test.c b/lib/hashtable_test.c
new file mode 100644 (file)
index 0000000..1d1b328
--- /dev/null
+++ b/lib/hashtable_test.c
@@ -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");