diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 3 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/string.c | 47 | ||||
| -rw-r--r-- | lib/test_bitmap.c | 20 | ||||
| -rw-r--r-- | lib/test_printf.c | 17 | ||||
| -rw-r--r-- | lib/test_strscpy.c | 150 |
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"); |