linux/lib/fortify_kunit.c
Kees Cook 5e2956ee46 Revert "fortify: Allow KUnit test to build without FORTIFY"
This reverts commit a9dc8d0442.

The standard for KUnit is to not build tests at all when required
functionality is missing, rather than doing test "skip". Restore this
for the fortify tests, so that architectures without
CONFIG_ARCH_HAS_FORTIFY_SOURCE do not emit unsolvable warnings.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/all/CAMuHMdUrxOEroHVUt7-mAnKSBjY=a-D3jr+XiAifuwv06Ob9Pw@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2023-07-03 12:50:26 -07:00

331 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Runtime test cases for CONFIG_FORTIFY_SOURCE that aren't expected to
* Oops the kernel on success. (For those, see drivers/misc/lkdtm/fortify.c)
*
* For corner cases with UBSAN, try testing with:
*
* ./tools/testing/kunit/kunit.py run --arch=x86_64 \
* --kconfig_add CONFIG_FORTIFY_SOURCE=y \
* --kconfig_add CONFIG_UBSAN=y \
* --kconfig_add CONFIG_UBSAN_TRAP=y \
* --kconfig_add CONFIG_UBSAN_BOUNDS=y \
* --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \
* --make_options LLVM=1 fortify
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <kunit/test.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
static const char array_of_10[] = "this is 10";
static const char *ptr_of_11 = "this is 11!";
static char array_unknown[] = "compiler thinks I might change";
static void known_sizes_test(struct kunit *test)
{
KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11);
KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX);
/* Externally defined and dynamically sized string pointer: */
KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX);
}
/* This is volatile so the optimizer can't perform DCE below. */
static volatile int pick;
/* Not inline to keep optimizer from figuring out which string we want. */
static noinline size_t want_minus_one(int pick)
{
const char *str;
switch (pick) {
case 1:
str = "4444";
break;
case 2:
str = "333";
break;
default:
str = "1";
break;
}
return __compiletime_strlen(str);
}
static void control_flow_split_test(struct kunit *test)
{
KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
}
#define KUNIT_EXPECT_BOS(test, p, expected, name) \
KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \
expected, \
"__alloc_size() not working with __bos on " name "\n")
#if !__has_builtin(__builtin_dynamic_object_size)
#define KUNIT_EXPECT_BDOS(test, p, expected, name) \
/* Silence "unused variable 'expected'" warning. */ \
KUNIT_EXPECT_EQ(test, expected, expected)
#else
#define KUNIT_EXPECT_BDOS(test, p, expected, name) \
KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \
expected, \
"__alloc_size() not working with __bdos on " name "\n")
#endif
/* If the execpted size is a constant value, __bos can see it. */
#define check_const(_expected, alloc, free) do { \
size_t expected = (_expected); \
void *p = alloc; \
KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \
KUNIT_EXPECT_BOS(test, p, expected, #alloc); \
KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \
free; \
} while (0)
/* If the execpted size is NOT a constant value, __bos CANNOT see it. */
#define check_dynamic(_expected, alloc, free) do { \
size_t expected = (_expected); \
void *p = alloc; \
KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \
KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \
KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \
free; \
} while (0)
/* Assortment of constant-value kinda-edge cases. */
#define CONST_TEST_BODY(TEST_alloc) do { \
/* Special-case vmalloc()-family to skip 0-sized allocs. */ \
if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \
TEST_alloc(check_const, 0, 0); \
TEST_alloc(check_const, 1, 1); \
TEST_alloc(check_const, 128, 128); \
TEST_alloc(check_const, 1023, 1023); \
TEST_alloc(check_const, 1025, 1025); \
TEST_alloc(check_const, 4096, 4096); \
TEST_alloc(check_const, 4097, 4097); \
} while (0)
static volatile size_t zero_size;
static volatile size_t unknown_size = 50;
#if !__has_builtin(__builtin_dynamic_object_size)
#define DYNAMIC_TEST_BODY(TEST_alloc) \
kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n")
#else
#define DYNAMIC_TEST_BODY(TEST_alloc) do { \
size_t size = unknown_size; \
\
/* \
* Expected size is "size" in each test, before it is then \
* internally incremented in each test. Requires we disable \
* -Wunsequenced. \
*/ \
TEST_alloc(check_dynamic, size, size++); \
/* Make sure incrementing actually happened. */ \
KUNIT_EXPECT_NE(test, size, unknown_size); \
} while (0)
#endif
#define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \
static void alloc_size_##allocator##_const_test(struct kunit *test) \
{ \
CONST_TEST_BODY(TEST_##allocator); \
} \
static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \
{ \
DYNAMIC_TEST_BODY(TEST_##allocator); \
}
#define TEST_kmalloc(checker, expected_size, alloc_size) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
void *orig; \
size_t len; \
\
checker(expected_size, kmalloc(alloc_size, gfp), \
kfree(p)); \
checker(expected_size, \
kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, kzalloc(alloc_size, gfp), \
kfree(p)); \
checker(expected_size, \
kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, kcalloc(1, alloc_size, gfp), \
kfree(p)); \
checker(expected_size, kcalloc(alloc_size, 1, gfp), \
kfree(p)); \
checker(expected_size, \
kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, \
kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, kmalloc_array(1, alloc_size, gfp), \
kfree(p)); \
checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \
kfree(p)); \
checker(expected_size, \
kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, \
kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \
kfree(p)); \
checker(expected_size, __kmalloc(alloc_size, gfp), \
kfree(p)); \
checker(expected_size, \
__kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \
kfree(p)); \
\
orig = kmalloc(alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
krealloc(orig, (alloc_size) * 2, gfp), \
kfree(p)); \
orig = kmalloc(alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
krealloc_array(orig, 1, (alloc_size) * 2, gfp), \
kfree(p)); \
orig = kmalloc(alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
krealloc_array(orig, (alloc_size) * 2, 1, gfp), \
kfree(p)); \
\
len = 11; \
/* Using memdup() with fixed size, so force unknown length. */ \
if (!__builtin_constant_p(expected_size)) \
len += zero_size; \
checker(len, kmemdup("hello there", len, gfp), kfree(p)); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc)
/* Sizes are in pages, not bytes. */
#define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
checker((expected_pages) * PAGE_SIZE, \
vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
__vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc)
/* Sizes are in pages (and open-coded for side-effects), not bytes. */
#define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
size_t prev_size; \
void *orig; \
\
checker((expected_pages) * PAGE_SIZE, \
kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \
vfree(p)); \
checker((expected_pages) * PAGE_SIZE, \
kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \
vfree(p)); \
\
prev_size = (expected_pages) * PAGE_SIZE; \
orig = kvmalloc(prev_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker(((expected_pages) * PAGE_SIZE) * 2, \
kvrealloc(orig, prev_size, \
((alloc_pages) * PAGE_SIZE) * 2, gfp), \
kvfree(p)); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc)
#define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \
const char dev_name[] = "fortify-test"; \
struct device *dev; \
void *orig; \
size_t len; \
\
/* Create dummy device for devm_kmalloc()-family tests. */ \
dev = root_device_register(dev_name); \
KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \
"Cannot register test device\n"); \
\
checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kmalloc_array(dev, 1, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kmalloc_array(dev, alloc_size, 1, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kcalloc(dev, 1, alloc_size, gfp), \
devm_kfree(dev, p)); \
checker(expected_size, \
devm_kcalloc(dev, alloc_size, 1, gfp), \
devm_kfree(dev, p)); \
\
orig = devm_kmalloc(dev, alloc_size, gfp); \
KUNIT_EXPECT_TRUE(test, orig != NULL); \
checker((expected_size) * 2, \
devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \
devm_kfree(dev, p)); \
\
len = 4; \
/* Using memdup() with fixed size, so force unknown length. */ \
if (!__builtin_constant_p(expected_size)) \
len += zero_size; \
checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \
devm_kfree(dev, p)); \
\
device_unregister(dev); \
} while (0)
DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc)
static struct kunit_case fortify_test_cases[] = {
KUNIT_CASE(known_sizes_test),
KUNIT_CASE(control_flow_split_test),
KUNIT_CASE(alloc_size_kmalloc_const_test),
KUNIT_CASE(alloc_size_kmalloc_dynamic_test),
KUNIT_CASE(alloc_size_vmalloc_const_test),
KUNIT_CASE(alloc_size_vmalloc_dynamic_test),
KUNIT_CASE(alloc_size_kvmalloc_const_test),
KUNIT_CASE(alloc_size_kvmalloc_dynamic_test),
KUNIT_CASE(alloc_size_devm_kmalloc_const_test),
KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test),
{}
};
static struct kunit_suite fortify_test_suite = {
.name = "fortify",
.test_cases = fortify_test_cases,
};
kunit_test_suite(fortify_test_suite);
MODULE_LICENSE("GPL");