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-rw-r--r--lib/strcat_kunit.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/lib/strcat_kunit.c b/lib/strcat_kunit.c
new file mode 100644
index 000000000000..e21be95514af
--- /dev/null
+++ b/lib/strcat_kunit.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kernel module for testing 'strcat' family of functions.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/string.h>
+
+static volatile int unconst;
+
+static void strcat_test(struct kunit *test)
+{
+ char dest[8];
+
+ /* Destination is terminated. */
+ memset(dest, 0, sizeof(dest));
+ KUNIT_EXPECT_EQ(test, strlen(dest), 0);
+ /* Empty copy does nothing. */
+ KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "");
+ /* 4 characters copied in, stops at %NUL. */
+ KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "four");
+ KUNIT_EXPECT_EQ(test, dest[5], '\0');
+ /* 2 more characters copied in okay. */
+ KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+}
+
+static void strncat_test(struct kunit *test)
+{
+ char dest[8];
+
+ /* Destination is terminated. */
+ memset(dest, 0, sizeof(dest));
+ KUNIT_EXPECT_EQ(test, strlen(dest), 0);
+ /* Empty copy of size 0 does nothing. */
+ KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "");
+ /* Empty copy of size 1 does nothing too. */
+ KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "");
+ /* Copy of max 0 characters should do nothing. */
+ KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "");
+
+ /* 4 characters copied in, even if max is 8. */
+ KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "four");
+ KUNIT_EXPECT_EQ(test, dest[5], '\0');
+ KUNIT_EXPECT_EQ(test, dest[6], '\0');
+ /* 2 characters copied in okay, 2 ignored. */
+ KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest);
+ KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+}
+
+static void strlcat_test(struct kunit *test)
+{
+ char dest[8] = "";
+ int len = sizeof(dest) + unconst;
+
+ /* Destination is terminated. */
+ KUNIT_EXPECT_EQ(test, strlen(dest), 0);
+ /* Empty copy is size 0. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0);
+ KUNIT_EXPECT_STREQ(test, dest, "");
+ /* Size 1 should keep buffer terminated, report size of source only. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4);
+ KUNIT_EXPECT_STREQ(test, dest, "");
+
+ /* 4 characters copied in. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4);
+ KUNIT_EXPECT_STREQ(test, dest, "four");
+ /* 2 characters copied in okay, gets to 6 total. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6);
+ KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+ /* 2 characters ignored if max size (7) reached. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8);
+ KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+ /* 1 of 2 characters skipped, now at true max size. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9);
+ KUNIT_EXPECT_STREQ(test, dest, "fourABE");
+ /* Everything else ignored, now at full size. */
+ KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11);
+ KUNIT_EXPECT_STREQ(test, dest, "fourABE");
+}
+
+static struct kunit_case strcat_test_cases[] = {
+ KUNIT_CASE(strcat_test),
+ KUNIT_CASE(strncat_test),
+ KUNIT_CASE(strlcat_test),
+ {}
+};
+
+static struct kunit_suite strcat_test_suite = {
+ .name = "strcat",
+ .test_cases = strcat_test_cases,
+};
+
+kunit_test_suite(strcat_test_suite);
+
+MODULE_LICENSE("GPL");