diff options
author | Kees Cook <kees@kernel.org> | 2024-12-02 15:55:40 +0800 |
---|---|---|
committer | Kees Cook <kees@kernel.org> | 2025-02-10 18:25:39 -0800 |
commit | db6fe4d61ece24193eb4d94a82d967501d53358c (patch) | |
tree | 6c4cd0e856fb6249cfb0cb6a45b87f5dfafbb6f8 /lib/stackinit_kunit.c | |
parent | 84ec093f55f58f5a4a66eb98bd6b6af413190bde (diff) |
lib: Move KUnit tests into tests/ subdirectory
Following from the recent KUnit file naming discussion[1], move all
KUnit tests in lib/ into lib/tests/.
Link: https://lore.kernel.org/lkml/20240720165441.it.320-kees@kernel.org/ [1]
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Rae Moar <rmoar@google.com>
Link: https://lore.kernel.org/r/20241202075545.3648096-4-davidgow@google.com
Signed-off-by: Kees Cook <kees@kernel.org>
Diffstat (limited to 'lib/stackinit_kunit.c')
-rw-r--r-- | lib/stackinit_kunit.c | 584 |
1 files changed, 0 insertions, 584 deletions
diff --git a/lib/stackinit_kunit.c b/lib/stackinit_kunit.c deleted file mode 100644 index 135322592faf..000000000000 --- a/lib/stackinit_kunit.c +++ /dev/null @@ -1,584 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Test cases for compiler-based stack variable zeroing via - * -ftrivial-auto-var-init={zero,pattern} or CONFIG_GCC_PLUGIN_STRUCTLEAK*. - * For example, see: - * "Running tests with kunit_tool" at Documentation/dev-tools/kunit/start.rst - * ./tools/testing/kunit/kunit.py run stackinit [--raw_output] \ - * --make_option LLVM=1 \ - * --kconfig_add CONFIG_INIT_STACK_ALL_ZERO=y - * - */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <kunit/test.h> -#include <linux/init.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/string.h> - -/* Exfiltration buffer. */ -#define MAX_VAR_SIZE 128 -static u8 check_buf[MAX_VAR_SIZE]; - -/* Character array to trigger stack protector in all functions. */ -#define VAR_BUFFER 32 - -/* Volatile mask to convince compiler to copy memory with 0xff. */ -static volatile u8 forced_mask = 0xff; - -/* Location and size tracking to validate fill and test are colocated. */ -static void *fill_start, *target_start; -static size_t fill_size, target_size; - -static bool stackinit_range_contains(char *haystack_start, size_t haystack_size, - char *needle_start, size_t needle_size) -{ - if (needle_start >= haystack_start && - needle_start + needle_size <= haystack_start + haystack_size) - return true; - return false; -} - -/* Whether the test is expected to fail. */ -#define WANT_SUCCESS 0 -#define XFAIL 1 - -#define DO_NOTHING_TYPE_SCALAR(var_type) var_type -#define DO_NOTHING_TYPE_STRING(var_type) void -#define DO_NOTHING_TYPE_STRUCT(var_type) void -#define DO_NOTHING_TYPE_UNION(var_type) void - -#define DO_NOTHING_RETURN_SCALAR(ptr) *(ptr) -#define DO_NOTHING_RETURN_STRING(ptr) /**/ -#define DO_NOTHING_RETURN_STRUCT(ptr) /**/ -#define DO_NOTHING_RETURN_UNION(ptr) /**/ - -#define DO_NOTHING_CALL_SCALAR(var, name) \ - (var) = do_nothing_ ## name(&(var)) -#define DO_NOTHING_CALL_STRING(var, name) \ - do_nothing_ ## name(var) -#define DO_NOTHING_CALL_STRUCT(var, name) \ - do_nothing_ ## name(&(var)) -#define DO_NOTHING_CALL_UNION(var, name) \ - do_nothing_ ## name(&(var)) - -#define FETCH_ARG_SCALAR(var) &var -#define FETCH_ARG_STRING(var) var -#define FETCH_ARG_STRUCT(var) &var -#define FETCH_ARG_UNION(var) &var - -/* - * On m68k, if the leaf function test variable is longer than 8 bytes, - * the start of the stack frame moves. 8 is sufficiently large to - * test m68k char arrays, but leave it at 16 for other architectures. - */ -#ifdef CONFIG_M68K -#define FILL_SIZE_STRING 8 -#define FILL_SIZE_ARRAY 2 -#else -#define FILL_SIZE_STRING 16 -#define FILL_SIZE_ARRAY 8 -#endif - -#define INIT_CLONE_SCALAR /**/ -#define INIT_CLONE_STRING [FILL_SIZE_STRING] -#define INIT_CLONE_STRUCT /**/ -#define INIT_CLONE_UNION /**/ - -#define ZERO_CLONE_SCALAR(zero) memset(&(zero), 0x00, sizeof(zero)) -#define ZERO_CLONE_STRING(zero) memset(&(zero), 0x00, sizeof(zero)) -/* - * For the struct, intentionally poison padding to see if it gets - * copied out in direct assignments. - * */ -#define ZERO_CLONE_STRUCT(zero) \ - do { \ - memset(&(zero), 0xFF, sizeof(zero)); \ - zero.one = 0; \ - zero.two = 0; \ - zero.three = 0; \ - zero.four = 0; \ - } while (0) -#define ZERO_CLONE_UNION(zero) ZERO_CLONE_STRUCT(zero) - -#define INIT_SCALAR_none(var_type) /**/ -#define INIT_SCALAR_zero(var_type) = 0 - -#define INIT_STRING_none(var_type) [FILL_SIZE_STRING] /**/ -#define INIT_STRING_zero(var_type) [FILL_SIZE_STRING] = { } - -#define INIT_STRUCT_none(var_type) /**/ -#define INIT_STRUCT_zero(var_type) = { } -#define INIT_STRUCT_old_zero(var_type) = { 0 } - - -#define __static_partial { .two = 0, } -#define __static_all { .one = 0, \ - .two = 0, \ - .three = 0, \ - .four = 0, \ - } -#define __dynamic_partial { .two = arg->two, } -#define __dynamic_all { .one = arg->one, \ - .two = arg->two, \ - .three = arg->three, \ - .four = arg->four, \ - } -#define __runtime_partial var.two = 0 -#define __runtime_all var.one = 0; \ - var.two = 0; \ - var.three = 0; \ - var.four = 0 - -#define INIT_STRUCT_static_partial(var_type) \ - = __static_partial -#define INIT_STRUCT_static_all(var_type) \ - = __static_all -#define INIT_STRUCT_dynamic_partial(var_type) \ - = __dynamic_partial -#define INIT_STRUCT_dynamic_all(var_type) \ - = __dynamic_all -#define INIT_STRUCT_runtime_partial(var_type) \ - ; __runtime_partial -#define INIT_STRUCT_runtime_all(var_type) \ - ; __runtime_all - -#define INIT_STRUCT_assigned_static_partial(var_type) \ - ; var = (var_type)__static_partial -#define INIT_STRUCT_assigned_static_all(var_type) \ - ; var = (var_type)__static_all -#define INIT_STRUCT_assigned_dynamic_partial(var_type) \ - ; var = (var_type)__dynamic_partial -#define INIT_STRUCT_assigned_dynamic_all(var_type) \ - ; var = (var_type)__dynamic_all - -#define INIT_STRUCT_assigned_copy(var_type) \ - ; var = *(arg) - -/* Union initialization is the same as structs. */ -#define INIT_UNION_none(var_type) INIT_STRUCT_none(var_type) -#define INIT_UNION_zero(var_type) INIT_STRUCT_zero(var_type) -#define INIT_UNION_old_zero(var_type) INIT_STRUCT_old_zero(var_type) - -#define INIT_UNION_static_partial(var_type) \ - INIT_STRUCT_static_partial(var_type) -#define INIT_UNION_static_all(var_type) \ - INIT_STRUCT_static_all(var_type) -#define INIT_UNION_dynamic_partial(var_type) \ - INIT_STRUCT_dynamic_partial(var_type) -#define INIT_UNION_dynamic_all(var_type) \ - INIT_STRUCT_dynamic_all(var_type) -#define INIT_UNION_runtime_partial(var_type) \ - INIT_STRUCT_runtime_partial(var_type) -#define INIT_UNION_runtime_all(var_type) \ - INIT_STRUCT_runtime_all(var_type) -#define INIT_UNION_assigned_static_partial(var_type) \ - INIT_STRUCT_assigned_static_partial(var_type) -#define INIT_UNION_assigned_static_all(var_type) \ - INIT_STRUCT_assigned_static_all(var_type) -#define INIT_UNION_assigned_dynamic_partial(var_type) \ - INIT_STRUCT_assigned_dynamic_partial(var_type) -#define INIT_UNION_assigned_dynamic_all(var_type) \ - INIT_STRUCT_assigned_dynamic_all(var_type) -#define INIT_UNION_assigned_copy(var_type) \ - INIT_STRUCT_assigned_copy(var_type) - -/* - * @name: unique string name for the test - * @var_type: type to be tested for zeroing initialization - * @which: is this a SCALAR, STRING, or STRUCT type? - * @init_level: what kind of initialization is performed - * @xfail: is this test expected to fail? - */ -#define DEFINE_TEST_DRIVER(name, var_type, which, xfail) \ -/* Returns 0 on success, 1 on failure. */ \ -static noinline void test_ ## name (struct kunit *test) \ -{ \ - var_type zero INIT_CLONE_ ## which; \ - int ignored; \ - u8 sum = 0, i; \ - \ - /* Notice when a new test is larger than expected. */ \ - BUILD_BUG_ON(sizeof(zero) > MAX_VAR_SIZE); \ - \ - /* Fill clone type with zero for per-field init. */ \ - ZERO_CLONE_ ## which(zero); \ - /* Clear entire check buffer for 0xFF overlap test. */ \ - memset(check_buf, 0x00, sizeof(check_buf)); \ - /* Fill stack with 0xFF. */ \ - ignored = leaf_ ##name((unsigned long)&ignored, 1, \ - FETCH_ARG_ ## which(zero)); \ - /* Verify all bytes overwritten with 0xFF. */ \ - for (sum = 0, i = 0; i < target_size; i++) \ - sum += (check_buf[i] != 0xFF); \ - /* Clear entire check buffer for later bit tests. */ \ - memset(check_buf, 0x00, sizeof(check_buf)); \ - /* Extract stack-defined variable contents. */ \ - ignored = leaf_ ##name((unsigned long)&ignored, 0, \ - FETCH_ARG_ ## which(zero)); \ - /* \ - * Delay the sum test to here to do as little as \ - * possible between the two leaf function calls. \ - */ \ - KUNIT_ASSERT_EQ_MSG(test, sum, 0, \ - "leaf fill was not 0xFF!?\n"); \ - \ - /* Validate that compiler lined up fill and target. */ \ - KUNIT_ASSERT_TRUE_MSG(test, \ - stackinit_range_contains(fill_start, fill_size, \ - target_start, target_size), \ - "stackframe was not the same between calls!? " \ - "(fill %zu wide, target offset by %d)\n", \ - fill_size, \ - (int)((ssize_t)(uintptr_t)fill_start - \ - (ssize_t)(uintptr_t)target_start)); \ - \ - /* Look for any bytes still 0xFF in check region. */ \ - for (sum = 0, i = 0; i < target_size; i++) \ - sum += (check_buf[i] == 0xFF); \ - \ - if (sum != 0 && xfail) \ - kunit_skip(test, \ - "XFAIL uninit bytes: %d\n", \ - sum); \ - KUNIT_ASSERT_EQ_MSG(test, sum, 0, \ - "uninit bytes: %d\n", sum); \ -} -#define DEFINE_TEST(name, var_type, which, init_level, xfail) \ -/* no-op to force compiler into ignoring "uninitialized" vars */\ -static noinline DO_NOTHING_TYPE_ ## which(var_type) \ -do_nothing_ ## name(var_type *ptr) \ -{ \ - OPTIMIZER_HIDE_VAR(ptr); \ - /* Will always be true, but compiler doesn't know. */ \ - if ((unsigned long)ptr > 0x2) \ - return DO_NOTHING_RETURN_ ## which(ptr); \ - else \ - return DO_NOTHING_RETURN_ ## which(ptr + 1); \ -} \ -static noinline int leaf_ ## name(unsigned long sp, bool fill, \ - var_type *arg) \ -{ \ - char buf[VAR_BUFFER]; \ - var_type var \ - INIT_ ## which ## _ ## init_level(var_type); \ - \ - target_start = &var; \ - target_size = sizeof(var); \ - /* \ - * Keep this buffer around to make sure we've got a \ - * stack frame of SOME kind... \ - */ \ - memset(buf, (char)(sp & 0xff), sizeof(buf)); \ - /* Fill variable with 0xFF. */ \ - if (fill) { \ - fill_start = &var; \ - fill_size = sizeof(var); \ - memset(fill_start, \ - (char)((sp & 0xff) | forced_mask), \ - fill_size); \ - } \ - \ - /* Silence "never initialized" warnings. */ \ - DO_NOTHING_CALL_ ## which(var, name); \ - \ - /* Exfiltrate "var". */ \ - memcpy(check_buf, target_start, target_size); \ - \ - return (int)buf[0] | (int)buf[sizeof(buf) - 1]; \ -} \ -DEFINE_TEST_DRIVER(name, var_type, which, xfail) - -/* Structure with no padding. */ -struct test_packed { - unsigned long one; - unsigned long two; - unsigned long three; - unsigned long four; -}; - -/* Simple structure with padding likely to be covered by compiler. */ -struct test_small_hole { - size_t one; - char two; - /* 3 byte padding hole here. */ - int three; - unsigned long four; -}; - -/* Trigger unhandled padding in a structure. */ -struct test_big_hole { - u8 one; - u8 two; - u8 three; - /* 61 byte padding hole here. */ - u8 four __aligned(64); -} __aligned(64); - -struct test_trailing_hole { - char *one; - char *two; - char *three; - char four; - /* "sizeof(unsigned long) - 1" byte padding hole here. */ -}; - -/* Test if STRUCTLEAK is clearing structs with __user fields. */ -struct test_user { - u8 one; - unsigned long two; - char __user *three; - unsigned long four; -}; - -/* No padding: all members are the same size. */ -union test_same_sizes { - unsigned long one; - unsigned long two; - unsigned long three; - unsigned long four; -}; - -/* Mismatched sizes, with one and two being small */ -union test_small_start { - char one:1; - char two; - short three; - unsigned long four; - struct big_struct { - unsigned long array[FILL_SIZE_ARRAY]; - } big; -}; - -/* Mismatched sizes, with three and four being small */ -union test_small_end { - short one; - unsigned long two; - char three:1; - char four; -}; - -#define ALWAYS_PASS WANT_SUCCESS -#define ALWAYS_FAIL XFAIL - -#ifdef CONFIG_INIT_STACK_NONE -# define USER_PASS XFAIL -# define BYREF_PASS XFAIL -# define STRONG_PASS XFAIL -#elif defined(CONFIG_GCC_PLUGIN_STRUCTLEAK_USER) -# define USER_PASS WANT_SUCCESS -# define BYREF_PASS XFAIL -# define STRONG_PASS XFAIL -#elif defined(CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF) -# define USER_PASS WANT_SUCCESS -# define BYREF_PASS WANT_SUCCESS -# define STRONG_PASS XFAIL -#else -# define USER_PASS WANT_SUCCESS -# define BYREF_PASS WANT_SUCCESS -# define STRONG_PASS WANT_SUCCESS -#endif - -#define DEFINE_SCALAR_TEST(name, init, xfail) \ - DEFINE_TEST(name ## _ ## init, name, SCALAR, \ - init, xfail) - -#define DEFINE_SCALAR_TESTS(init, xfail) \ - DEFINE_SCALAR_TEST(u8, init, xfail); \ - DEFINE_SCALAR_TEST(u16, init, xfail); \ - DEFINE_SCALAR_TEST(u32, init, xfail); \ - DEFINE_SCALAR_TEST(u64, init, xfail); \ - DEFINE_TEST(char_array_ ## init, unsigned char, \ - STRING, init, xfail) - -#define DEFINE_STRUCT_TEST(name, init, xfail) \ - DEFINE_TEST(name ## _ ## init, \ - struct test_ ## name, STRUCT, init, \ - xfail) - -#define DEFINE_UNION_TEST(name, init, xfail) \ - DEFINE_TEST(name ## _ ## init, \ - union test_ ## name, STRUCT, init, \ - xfail) - -#define DEFINE_STRUCT_TESTS(init, xfail) \ - DEFINE_STRUCT_TEST(small_hole, init, xfail); \ - DEFINE_STRUCT_TEST(big_hole, init, xfail); \ - DEFINE_STRUCT_TEST(trailing_hole, init, xfail); \ - DEFINE_STRUCT_TEST(packed, init, xfail) - -#define DEFINE_STRUCT_INITIALIZER_TESTS(base, xfail) \ - DEFINE_STRUCT_TESTS(base ## _ ## partial, \ - xfail); \ - DEFINE_STRUCT_TESTS(base ## _ ## all, xfail) - -#define DEFINE_UNION_INITIALIZER_TESTS(base, xfail) \ - DEFINE_UNION_TESTS(base ## _ ## partial, \ - xfail); \ - DEFINE_UNION_TESTS(base ## _ ## all, xfail) - -#define DEFINE_UNION_TESTS(init, xfail) \ - DEFINE_UNION_TEST(same_sizes, init, xfail); \ - DEFINE_UNION_TEST(small_start, init, xfail); \ - DEFINE_UNION_TEST(small_end, init, xfail); - -/* These should be fully initialized all the time! */ -DEFINE_SCALAR_TESTS(zero, ALWAYS_PASS); -DEFINE_STRUCT_TESTS(zero, ALWAYS_PASS); -DEFINE_STRUCT_TESTS(old_zero, ALWAYS_PASS); -DEFINE_UNION_TESTS(zero, ALWAYS_PASS); -DEFINE_UNION_TESTS(old_zero, ALWAYS_PASS); -/* Struct initializers: padding may be left uninitialized. */ -DEFINE_STRUCT_INITIALIZER_TESTS(static, STRONG_PASS); -DEFINE_STRUCT_INITIALIZER_TESTS(dynamic, STRONG_PASS); -DEFINE_STRUCT_INITIALIZER_TESTS(runtime, STRONG_PASS); -DEFINE_STRUCT_INITIALIZER_TESTS(assigned_static, STRONG_PASS); -DEFINE_STRUCT_INITIALIZER_TESTS(assigned_dynamic, STRONG_PASS); -DEFINE_STRUCT_TESTS(assigned_copy, ALWAYS_FAIL); -DEFINE_UNION_INITIALIZER_TESTS(static, STRONG_PASS); -DEFINE_UNION_INITIALIZER_TESTS(dynamic, STRONG_PASS); -DEFINE_UNION_INITIALIZER_TESTS(runtime, STRONG_PASS); -DEFINE_UNION_INITIALIZER_TESTS(assigned_static, STRONG_PASS); -DEFINE_UNION_INITIALIZER_TESTS(assigned_dynamic, STRONG_PASS); -DEFINE_UNION_TESTS(assigned_copy, ALWAYS_FAIL); -/* No initialization without compiler instrumentation. */ -DEFINE_SCALAR_TESTS(none, STRONG_PASS); -DEFINE_STRUCT_TESTS(none, BYREF_PASS); -/* Initialization of members with __user attribute. */ -DEFINE_TEST(user, struct test_user, STRUCT, none, USER_PASS); - -/* - * Check two uses through a variable declaration outside either path, - * which was noticed as a special case in porting earlier stack init - * compiler logic. - */ -static int noinline __leaf_switch_none(int path, bool fill) -{ - switch (path) { - /* - * This is intentionally unreachable. To silence the - * warning, build with -Wno-switch-unreachable - */ - uint64_t var[10]; - - case 1: - target_start = &var; - target_size = sizeof(var); - if (fill) { - fill_start = &var; - fill_size = sizeof(var); - - memset(fill_start, forced_mask | 0x55, fill_size); - } - memcpy(check_buf, target_start, target_size); - break; - case 2: - target_start = &var; - target_size = sizeof(var); - if (fill) { - fill_start = &var; - fill_size = sizeof(var); - - memset(fill_start, forced_mask | 0xaa, fill_size); - } - memcpy(check_buf, target_start, target_size); - break; - default: - var[1] = 5; - return var[1] & forced_mask; - } - return 0; -} - -static noinline int leaf_switch_1_none(unsigned long sp, bool fill, - uint64_t *arg) -{ - return __leaf_switch_none(1, fill); -} - -static noinline int leaf_switch_2_none(unsigned long sp, bool fill, - uint64_t *arg) -{ - return __leaf_switch_none(2, fill); -} - -/* - * These are expected to fail for most configurations because neither - * GCC nor Clang have a way to perform initialization of variables in - * non-code areas (i.e. in a switch statement before the first "case"). - * https://llvm.org/pr44916 - */ -DEFINE_TEST_DRIVER(switch_1_none, uint64_t, SCALAR, ALWAYS_FAIL); -DEFINE_TEST_DRIVER(switch_2_none, uint64_t, SCALAR, ALWAYS_FAIL); - -#define KUNIT_test_scalars(init) \ - KUNIT_CASE(test_u8_ ## init), \ - KUNIT_CASE(test_u16_ ## init), \ - KUNIT_CASE(test_u32_ ## init), \ - KUNIT_CASE(test_u64_ ## init), \ - KUNIT_CASE(test_char_array_ ## init) - -#define KUNIT_test_structs(init) \ - KUNIT_CASE(test_small_hole_ ## init), \ - KUNIT_CASE(test_big_hole_ ## init), \ - KUNIT_CASE(test_trailing_hole_ ## init),\ - KUNIT_CASE(test_packed_ ## init) \ - -#define KUNIT_test_unions(init) \ - KUNIT_CASE(test_same_sizes_ ## init), \ - KUNIT_CASE(test_small_start_ ## init), \ - KUNIT_CASE(test_small_end_ ## init) \ - -static struct kunit_case stackinit_test_cases[] = { - /* These are explicitly initialized and should always pass. */ - KUNIT_test_scalars(zero), - KUNIT_test_structs(zero), - KUNIT_test_structs(old_zero), - KUNIT_test_unions(zero), - KUNIT_test_unions(old_zero), - /* Padding here appears to be accidentally always initialized? */ - KUNIT_test_structs(dynamic_partial), - KUNIT_test_structs(assigned_dynamic_partial), - KUNIT_test_unions(dynamic_partial), - KUNIT_test_unions(assigned_dynamic_partial), - /* Padding initialization depends on compiler behaviors. */ - KUNIT_test_structs(static_partial), - KUNIT_test_structs(static_all), - KUNIT_test_structs(dynamic_all), - KUNIT_test_structs(runtime_partial), - KUNIT_test_structs(runtime_all), - KUNIT_test_structs(assigned_static_partial), - KUNIT_test_structs(assigned_static_all), - KUNIT_test_structs(assigned_dynamic_all), - KUNIT_test_unions(static_partial), - KUNIT_test_unions(static_all), - KUNIT_test_unions(dynamic_all), - KUNIT_test_unions(runtime_partial), - KUNIT_test_unions(runtime_all), - KUNIT_test_unions(assigned_static_partial), - KUNIT_test_unions(assigned_static_all), - KUNIT_test_unions(assigned_dynamic_all), - /* Everything fails this since it effectively performs a memcpy(). */ - KUNIT_test_structs(assigned_copy), - KUNIT_test_unions(assigned_copy), - /* STRUCTLEAK_BYREF_ALL should cover everything from here down. */ - KUNIT_test_scalars(none), - KUNIT_CASE(test_switch_1_none), - KUNIT_CASE(test_switch_2_none), - /* STRUCTLEAK_BYREF should cover from here down. */ - KUNIT_test_structs(none), - /* STRUCTLEAK will only cover this. */ - KUNIT_CASE(test_user), - {} -}; - -static struct kunit_suite stackinit_test_suite = { - .name = "stackinit", - .test_cases = stackinit_test_cases, -}; - -kunit_test_suites(&stackinit_test_suite); - -MODULE_DESCRIPTION("Test cases for compiler-based stack variable zeroing"); -MODULE_LICENSE("GPL"); |