Currently if we wish to use kselftest to run tests within a kernel module we write a small script to load/unload and do error reporting. There are a bunch of these under tools/testing/selftests/lib/ that are all identical except for the test name. We can reduce code duplication and improve maintainability if we have one version of this. However kselftest requires an executable for each test. We can move all the script logic to a central script then have each individual test script call the main script.

Oneliner to call kselftest_module.sh courtesy of Kees, thanks!

Add test runner creation script. Convert tools/testing/selftests/lib/*.sh to use new test creation script.

Testing -------

Configure kselftests for lib/ then build and boot kernel. Then run kselftests as follows:

$ cd /path/to/kernel/tree $ sudo make O=$output_path -C tools/testing/selftests TARGETS="lib" run_tests

and also

$ cd /path/to/kernel/tree $ cd tools/testing/selftests $ sudo make O=$output_path TARGETS="lib" run_tests

and also

$ cd /path/to/kernel/tree $ cd tools/testing/selftests $ sudo make TARGETS="lib" run_tests

Acked-by: Kees Cook keescook@chromium.org Signed-off-by: Tobin C. Harding tobin@kernel.org --- tools/testing/selftests/kselftest_module.sh | 84 ++++++++++++++++++++ tools/testing/selftests/lib/bitmap.sh | 18 +---- tools/testing/selftests/lib/prime_numbers.sh | 17 +--- tools/testing/selftests/lib/printf.sh | 19 +---- 4 files changed, 88 insertions(+), 50 deletions(-) create mode 100755 tools/testing/selftests/kselftest_module.sh

diff --git a/tools/testing/selftests/kselftest_module.sh b/tools/testing/selftests/kselftest_module.sh new file mode 100755 index 000000000000..18e1c7992d30 --- /dev/null +++ b/tools/testing/selftests/kselftest_module.sh @@ -0,0 +1,84 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ + +# +# Runs an individual test module. +# +# kselftest expects a separate executable for each test, this can be +# created by adding a script like this: +# +# #!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ +# $(dirname $0)/../kselftest_module.sh "description" module_name +# +# Example: tools/testing/selftests/lib/printf.sh + +desc="" # Output prefix. +module="" # Filename (without the .ko). +args="" # modprobe arguments. + +modprobe="/sbin/modprobe" + +main() { + parse_args "$@" + assert_root + assert_have_module + run_module +} + +parse_args() { + script=${0##*/} + + if [ $# -lt 2 ]; then + echo "Usage: $script <description> <module_name> [FAIL]" + exit 1 + fi + + desc="$1" + shift || true + module="$1" + shift || true + args="$@" +} + +assert_root() { + if [ ! -w /dev ]; then + skip "please run as root" + fi +} + +assert_have_module() { + if ! $modprobe -q -n $module; then + skip "module $module is not found" + fi +} + +run_module() { + if $modprobe -q $module $args; then + $modprobe -q -r $module + say "ok" + else + fail "" + fi +} + +say() { + echo "$desc: $1" +} + + +fail() { + say "$1 [FAIL]" >&2 + exit 1 +} + +skip() { + say "$1 [SKIP]" >&2 + # Kselftest framework requirement - SKIP code is 4. + exit 4 +} + +# +# Main script +# +main "$@" diff --git a/tools/testing/selftests/lib/bitmap.sh b/tools/testing/selftests/lib/bitmap.sh index 5a90006d1aea..5511dddc5c2d 100755 --- a/tools/testing/selftests/lib/bitmap.sh +++ b/tools/testing/selftests/lib/bitmap.sh @@ -1,19 +1,3 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 - -# Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 - -# Runs bitmap infrastructure tests using test_bitmap kernel module -if ! /sbin/modprobe -q -n test_bitmap; then - echo "bitmap: module test_bitmap is not found [SKIP]" - exit $ksft_skip -fi - -if /sbin/modprobe -q test_bitmap; then - /sbin/modprobe -q -r test_bitmap - echo "bitmap: ok" -else - echo "bitmap: [FAIL]" - exit 1 -fi +$(dirname $0)/../kselftest_module.sh "bitmap" test_bitmap diff --git a/tools/testing/selftests/lib/prime_numbers.sh b/tools/testing/selftests/lib/prime_numbers.sh index 78e7483c8d60..43b28f24e453 100755 --- a/tools/testing/selftests/lib/prime_numbers.sh +++ b/tools/testing/selftests/lib/prime_numbers.sh @@ -1,19 +1,4 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 # Checks fast/slow prime_number generation for inconsistencies - -# Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 - -if ! /sbin/modprobe -q -n prime_numbers; then - echo "prime_numbers: module prime_numbers is not found [SKIP]" - exit $ksft_skip -fi - -if /sbin/modprobe -q prime_numbers selftest=65536; then - /sbin/modprobe -q -r prime_numbers - echo "prime_numbers: ok" -else - echo "prime_numbers: [FAIL]" - exit 1 -fi +$(dirname $0)/../kselftest_module.sh "prime numbers" prime_numbers selftest=65536 diff --git a/tools/testing/selftests/lib/printf.sh b/tools/testing/selftests/lib/printf.sh index 45a23e2d64ad..2ffa61da0296 100755 --- a/tools/testing/selftests/lib/printf.sh +++ b/tools/testing/selftests/lib/printf.sh @@ -1,19 +1,4 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 -# Runs printf infrastructure using test_printf kernel module - -# Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 - -if ! /sbin/modprobe -q -n test_printf; then - echo "printf: module test_printf is not found [SKIP]" - exit $ksft_skip -fi - -if /sbin/modprobe -q test_printf; then - /sbin/modprobe -q -r test_printf - echo "printf: ok" -else - echo "printf: [FAIL]" - exit 1 -fi +# Tests the printf infrastructure using test_printf kernel module. +$(dirname $0)/../kselftest_module.sh "printf" test_printf

We just added a new C header file for use with test modules that are intended to be run with kselftest. We can reduce code duplication by using this header.

Use new kselftest header to reduce code duplication in test_printf and test_bitmap test modules.

Acked-by: Kees Cook keescook@chromium.org Signed-off-by: Tobin C. Harding tobin@kernel.org --- lib/test_bitmap.c | 20 ++++---------------- lib/test_printf.c | 23 +++++------------------ 2 files changed, 9 insertions(+), 34 deletions(-)

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 601e8519319a..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(); @@ -604,22 +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); - -static void __exit test_printf_exit(void) -{ -} - -module_exit(test_printf_exit); - +KSTM_MODULE_LOADERS(test_printf); MODULE_AUTHOR("Rasmus Villemoes linux@rasmusvillemoes.dk"); MODULE_LICENSE("GPL");

Add a test module for the new strscpy_pad() function. Tie it into the kselftest infrastructure for lib/ tests.

Acked-by: Kees Cook keescook@chromium.org Signed-off-by: Tobin C. Harding tobin@kernel.org --- lib/Kconfig.debug | 3 + lib/Makefile | 1 + lib/test_strscpy.c | 150 +++++++++++++++++++++++++ tools/testing/selftests/lib/Makefile | 2 +- tools/testing/selftests/lib/config | 1 + tools/testing/selftests/lib/strscpy.sh | 3 + 6 files changed, 159 insertions(+), 1 deletion(-) create mode 100644 lib/test_strscpy.c create mode 100755 tools/testing/selftests/lib/strscpy.sh

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0d9e81779e37..4b644ad399dd 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 3b08673e8881..b4e08d6234ba 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -70,6 +70,7 @@ 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/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"); diff --git a/tools/testing/selftests/lib/Makefile b/tools/testing/selftests/lib/Makefile index 70d5711e3ac8..9f26635f3e57 100644 --- a/tools/testing/selftests/lib/Makefile +++ b/tools/testing/selftests/lib/Makefile @@ -3,6 +3,6 @@ # No binaries, but make sure arg-less "make" doesn't trigger "run_tests" all:

-TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh +TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh strscpy.sh

include ../lib.mk diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config index 126933bcc950..14a77ea4a8da 100644 --- a/tools/testing/selftests/lib/config +++ b/tools/testing/selftests/lib/config @@ -1,3 +1,4 @@ CONFIG_TEST_PRINTF=m CONFIG_TEST_BITMAP=m CONFIG_PRIME_NUMBERS=m +CONFIG_TEST_STRSCPY=m diff --git a/tools/testing/selftests/lib/strscpy.sh b/tools/testing/selftests/lib/strscpy.sh new file mode 100755 index 000000000000..71f2be6afba6 --- /dev/null +++ b/tools/testing/selftests/lib/strscpy.sh @@ -0,0 +1,3 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ +$(dirname $0)/../kselftest_module.sh "strscpy*" test_strscpy