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-rw-r--r--lib/Kconfig.debug3
-rw-r--r--lib/Makefile1
-rw-r--r--lib/string.c47
-rw-r--r--lib/test_bitmap.c20
-rw-r--r--lib/test_printf.c17
-rw-r--r--lib/test_strscpy.c150
6 files changed, 203 insertions, 35 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d5a4a4036d2f..4c54a89f06ee 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1769,6 +1769,9 @@ config TEST_HEXDUMP
config TEST_STRING_HELPERS
tristate "Test functions located in the string_helpers module at runtime"
+config TEST_STRSCPY
+ tristate "Test strscpy*() family of functions at runtime"
+
config TEST_KSTRTOX
tristate "Test kstrto*() family of functions at runtime"
diff --git a/lib/Makefile b/lib/Makefile
index e16e7aadc41a..07506e3891a0 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
obj-$(CONFIG_TEST_PRINTF) += test_printf.o
obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
+obj-$(CONFIG_TEST_STRSCPY) += test_strscpy.o
obj-$(CONFIG_TEST_BITFIELD) += test_bitfield.o
obj-$(CONFIG_TEST_UUID) += test_uuid.o
obj-$(CONFIG_TEST_XARRAY) += test_xarray.o
diff --git a/lib/string.c b/lib/string.c
index 3ab861c1a857..6016eb3ac73d 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -159,11 +159,9 @@ EXPORT_SYMBOL(strlcpy);
* @src: Where to copy the string from
* @count: Size of destination buffer
*
- * Copy the string, or as much of it as fits, into the dest buffer.
- * The routine returns the number of characters copied (not including
- * the trailing NUL) or -E2BIG if the destination buffer wasn't big enough.
- * The behavior is undefined if the string buffers overlap.
- * The destination buffer is always NUL terminated, unless it's zero-sized.
+ * Copy the string, or as much of it as fits, into the dest buffer. The
+ * behavior is undefined if the string buffers overlap. The destination
+ * buffer is always NUL terminated, unless it's zero-sized.
*
* Preferred to strlcpy() since the API doesn't require reading memory
* from the src string beyond the specified "count" bytes, and since
@@ -173,8 +171,10 @@ EXPORT_SYMBOL(strlcpy);
*
* Preferred to strncpy() since it always returns a valid string, and
* doesn't unnecessarily force the tail of the destination buffer to be
- * zeroed. If the zeroing is desired, it's likely cleaner to use strscpy()
- * with an overflow test, then just memset() the tail of the dest buffer.
+ * zeroed. If zeroing is desired please use strscpy_pad().
+ *
+ * Return: The number of characters copied (not including the trailing
+ * %NUL) or -E2BIG if the destination buffer wasn't big enough.
*/
ssize_t strscpy(char *dest, const char *src, size_t count)
{
@@ -237,6 +237,39 @@ ssize_t strscpy(char *dest, const char *src, size_t count)
EXPORT_SYMBOL(strscpy);
#endif
+/**
+ * strscpy_pad() - Copy a C-string into a sized buffer
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @count: Size of destination buffer
+ *
+ * Copy the string, or as much of it as fits, into the dest buffer. The
+ * behavior is undefined if the string buffers overlap. The destination
+ * buffer is always %NUL terminated, unless it's zero-sized.
+ *
+ * If the source string is shorter than the destination buffer, zeros
+ * the tail of the destination buffer.
+ *
+ * For full explanation of why you may want to consider using the
+ * 'strscpy' functions please see the function docstring for strscpy().
+ *
+ * Return: The number of characters copied (not including the trailing
+ * %NUL) or -E2BIG if the destination buffer wasn't big enough.
+ */
+ssize_t strscpy_pad(char *dest, const char *src, size_t count)
+{
+ ssize_t written;
+
+ written = strscpy(dest, src, count);
+ if (written < 0 || written == count - 1)
+ return written;
+
+ memset(dest + written + 1, 0, count - written - 1);
+
+ return written;
+}
+EXPORT_SYMBOL(strscpy_pad);
+
#ifndef __HAVE_ARCH_STRCAT
/**
* strcat - Append one %NUL-terminated string to another
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 6cd7d0740005..792d90608052 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -12,6 +12,8 @@
#include <linux/slab.h>
#include <linux/string.h>
+#include "../tools/testing/selftests/kselftest_module.h"
+
static unsigned total_tests __initdata;
static unsigned failed_tests __initdata;
@@ -361,7 +363,7 @@ static void noinline __init test_mem_optimisations(void)
}
}
-static int __init test_bitmap_init(void)
+static void __init selftest(void)
{
test_zero_clear();
test_fill_set();
@@ -369,22 +371,8 @@ static int __init test_bitmap_init(void)
test_bitmap_arr32();
test_bitmap_parselist();
test_mem_optimisations();
-
- if (failed_tests == 0)
- pr_info("all %u tests passed\n", total_tests);
- else
- pr_warn("failed %u out of %u tests\n",
- failed_tests, total_tests);
-
- return failed_tests ? -EINVAL : 0;
}
-static void __exit test_bitmap_cleanup(void)
-{
-}
-
-module_init(test_bitmap_init);
-module_exit(test_bitmap_cleanup);
-
+KSTM_MODULE_LOADERS(test_bitmap);
MODULE_AUTHOR("david decotigny <david.decotigny@googlers.com>");
MODULE_LICENSE("GPL");
diff --git a/lib/test_printf.c b/lib/test_printf.c
index 659b6cc0d483..f4fcc1c43739 100644
--- a/lib/test_printf.c
+++ b/lib/test_printf.c
@@ -21,6 +21,8 @@
#include <linux/gfp.h>
#include <linux/mm.h>
+#include "../tools/testing/selftests/kselftest_module.h"
+
#define BUF_SIZE 256
#define PAD_SIZE 16
#define FILL_CHAR '$'
@@ -590,12 +592,11 @@ test_pointer(void)
flags();
}
-static int __init
-test_printf_init(void)
+static void __init selftest(void)
{
alloced_buffer = kmalloc(BUF_SIZE + 2*PAD_SIZE, GFP_KERNEL);
if (!alloced_buffer)
- return -ENOMEM;
+ return;
test_buffer = alloced_buffer + PAD_SIZE;
test_basic();
@@ -604,16 +605,8 @@ test_printf_init(void)
test_pointer();
kfree(alloced_buffer);
-
- if (failed_tests == 0)
- pr_info("all %u tests passed\n", total_tests);
- else
- pr_warn("failed %u out of %u tests\n", failed_tests, total_tests);
-
- return failed_tests ? -EINVAL : 0;
}
-module_init(test_printf_init);
-
+KSTM_MODULE_LOADERS(test_printf);
MODULE_AUTHOR("Rasmus Villemoes <linux@rasmusvillemoes.dk>");
MODULE_LICENSE("GPL");
diff --git a/lib/test_strscpy.c b/lib/test_strscpy.c
new file mode 100644
index 000000000000..a827f94601f5
--- /dev/null
+++ b/lib/test_strscpy.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/string.h>
+
+#include "../tools/testing/selftests/kselftest_module.h"
+
+/*
+ * Kernel module for testing 'strscpy' family of functions.
+ */
+
+KSTM_MODULE_GLOBALS();
+
+/*
+ * tc() - Run a specific test case.
+ * @src: Source string, argument to strscpy_pad()
+ * @count: Size of destination buffer, argument to strscpy_pad()
+ * @expected: Expected return value from call to strscpy_pad()
+ * @terminator: 1 if there should be a terminating null byte 0 otherwise.
+ * @chars: Number of characters from the src string expected to be
+ * written to the dst buffer.
+ * @pad: Number of pad characters expected (in the tail of dst buffer).
+ * (@pad does not include the null terminator byte.)
+ *
+ * Calls strscpy_pad() and verifies the return value and state of the
+ * destination buffer after the call returns.
+ */
+static int __init tc(char *src, int count, int expected,
+ int chars, int terminator, int pad)
+{
+ int nr_bytes_poison;
+ int max_expected;
+ int max_count;
+ int written;
+ char buf[6];
+ int index, i;
+ const char POISON = 'z';
+
+ total_tests++;
+
+ if (!src) {
+ pr_err("null source string not supported\n");
+ return -1;
+ }
+
+ memset(buf, POISON, sizeof(buf));
+ /* Future proofing test suite, validate args */
+ max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */
+ max_expected = count - 1; /* Space for the null */
+ if (count > max_count) {
+ pr_err("count (%d) is too big (%d) ... aborting", count, max_count);
+ return -1;
+ }
+ if (expected > max_expected) {
+ pr_warn("expected (%d) is bigger than can possibly be returned (%d)",
+ expected, max_expected);
+ }
+
+ written = strscpy_pad(buf, src, count);
+ if ((written) != (expected)) {
+ pr_err("%d != %d (written, expected)\n", written, expected);
+ goto fail;
+ }
+
+ if (count && written == -E2BIG) {
+ if (strncmp(buf, src, count - 1) != 0) {
+ pr_err("buffer state invalid for -E2BIG\n");
+ goto fail;
+ }
+ if (buf[count - 1] != '\0') {
+ pr_err("too big string is not null terminated correctly\n");
+ goto fail;
+ }
+ }
+
+ for (i = 0; i < chars; i++) {
+ if (buf[i] != src[i]) {
+ pr_err("buf[i]==%c != src[i]==%c\n", buf[i], src[i]);
+ goto fail;
+ }
+ }
+
+ if (terminator) {
+ if (buf[count - 1] != '\0') {
+ pr_err("string is not null terminated correctly\n");
+ goto fail;
+ }
+ }
+
+ for (i = 0; i < pad; i++) {
+ index = chars + terminator + i;
+ if (buf[index] != '\0') {
+ pr_err("padding missing at index: %d\n", i);
+ goto fail;
+ }
+ }
+
+ nr_bytes_poison = sizeof(buf) - chars - terminator - pad;
+ for (i = 0; i < nr_bytes_poison; i++) {
+ index = sizeof(buf) - 1 - i; /* Check from the end back */
+ if (buf[index] != POISON) {
+ pr_err("poison value missing at index: %d\n", i);
+ goto fail;
+ }
+ }
+
+ return 0;
+fail:
+ failed_tests++;
+ return -1;
+}
+
+static void __init selftest(void)
+{
+ /*
+ * tc() uses a destination buffer of size 6 and needs at
+ * least 2 characters spare (one for null and one to check for
+ * overflow). This means we should only call tc() with
+ * strings up to a maximum of 4 characters long and 'count'
+ * should not exceed 4. To test with longer strings increase
+ * the buffer size in tc().
+ */
+
+ /* tc(src, count, expected, chars, terminator, pad) */
+ KSTM_CHECK_ZERO(tc("a", 0, -E2BIG, 0, 0, 0));
+ KSTM_CHECK_ZERO(tc("", 0, -E2BIG, 0, 0, 0));
+
+ KSTM_CHECK_ZERO(tc("a", 1, -E2BIG, 0, 1, 0));
+ KSTM_CHECK_ZERO(tc("", 1, 0, 0, 1, 0));
+
+ KSTM_CHECK_ZERO(tc("ab", 2, -E2BIG, 1, 1, 0));
+ KSTM_CHECK_ZERO(tc("a", 2, 1, 1, 1, 0));
+ KSTM_CHECK_ZERO(tc("", 2, 0, 0, 1, 1));
+
+ KSTM_CHECK_ZERO(tc("abc", 3, -E2BIG, 2, 1, 0));
+ KSTM_CHECK_ZERO(tc("ab", 3, 2, 2, 1, 0));
+ KSTM_CHECK_ZERO(tc("a", 3, 1, 1, 1, 1));
+ KSTM_CHECK_ZERO(tc("", 3, 0, 0, 1, 2));
+
+ KSTM_CHECK_ZERO(tc("abcd", 4, -E2BIG, 3, 1, 0));
+ KSTM_CHECK_ZERO(tc("abc", 4, 3, 3, 1, 0));
+ KSTM_CHECK_ZERO(tc("ab", 4, 2, 2, 1, 1));
+ KSTM_CHECK_ZERO(tc("a", 4, 1, 1, 1, 2));
+ KSTM_CHECK_ZERO(tc("", 4, 0, 0, 1, 3));
+}
+
+KSTM_MODULE_LOADERS(test_strscpy);
+MODULE_AUTHOR("Tobin C. Harding <tobin@kernel.org>");
+MODULE_LICENSE("GPL");