Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'hardening-v6.14-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook:
"This is a fix for the soon to be released GCC 15 which has regressed
its initialization of unions when performing explicit initialization
(i.e. a general problem, not specifically a hardening problem; we're
just carrying the fix).
Details in the final patch, Acked by Masahiro, with updated selftests
to validate the fix"
* tag 'hardening-v6.14-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: Use -fzero-init-padding-bits=all
stackinit: Add union initialization to selftests
stackinit: Add old-style zero-init syntax to struct tests
+109
+106
lib/stackinit_kunit.c
+106
lib/stackinit_kunit.c
···
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#define DO_NOTHING_TYPE_SCALAR(var_type) var_type
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#define DO_NOTHING_TYPE_STRING(var_type) void
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#define DO_NOTHING_TYPE_STRUCT(var_type) void
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+
#define DO_NOTHING_TYPE_UNION(var_type) void
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#define DO_NOTHING_RETURN_SCALAR(ptr) *(ptr)
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#define DO_NOTHING_RETURN_STRING(ptr) /**/
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#define DO_NOTHING_RETURN_STRUCT(ptr) /**/
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#define DO_NOTHING_RETURN_UNION(ptr) /**/
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#define DO_NOTHING_CALL_SCALAR(var, name) \
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(var) = do_nothing_ ## name(&(var))
···
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do_nothing_ ## name(var)
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#define DO_NOTHING_CALL_STRUCT(var, name) \
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do_nothing_ ## name(&(var))
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#define DO_NOTHING_CALL_UNION(var, name) \
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do_nothing_ ## name(&(var))
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#define FETCH_ARG_SCALAR(var) &var
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#define FETCH_ARG_STRING(var) var
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#define FETCH_ARG_STRUCT(var) &var
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#define FETCH_ARG_UNION(var) &var
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/*
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* On m68k, if the leaf function test variable is longer than 8 bytes,
···
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#define INIT_CLONE_SCALAR /**/
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#define INIT_CLONE_STRING [FILL_SIZE_STRING]
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#define INIT_CLONE_STRUCT /**/
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#define INIT_CLONE_UNION /**/
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#define ZERO_CLONE_SCALAR(zero) memset(&(zero), 0x00, sizeof(zero))
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#define ZERO_CLONE_STRING(zero) memset(&(zero), 0x00, sizeof(zero))
···
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zero.three = 0; \
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zero.four = 0; \
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} while (0)
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#define ZERO_CLONE_UNION(zero) ZERO_CLONE_STRUCT(zero)
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#define INIT_SCALAR_none(var_type) /**/
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#define INIT_SCALAR_zero(var_type) = 0
···
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#define INIT_STRUCT_none(var_type) /**/
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#define INIT_STRUCT_zero(var_type) = { }
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#define INIT_STRUCT_old_zero(var_type) = { 0 }
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#define __static_partial { .two = 0, }
···
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#define INIT_STRUCT_assigned_copy(var_type) \
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; var = *(arg)
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/* Union initialization is the same as structs. */
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#define INIT_UNION_none(var_type) INIT_STRUCT_none(var_type)
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#define INIT_UNION_zero(var_type) INIT_STRUCT_zero(var_type)
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#define INIT_UNION_old_zero(var_type) INIT_STRUCT_old_zero(var_type)
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#define INIT_UNION_static_partial(var_type) \
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INIT_STRUCT_static_partial(var_type)
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#define INIT_UNION_static_all(var_type) \
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INIT_STRUCT_static_all(var_type)
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#define INIT_UNION_dynamic_partial(var_type) \
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INIT_STRUCT_dynamic_partial(var_type)
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#define INIT_UNION_dynamic_all(var_type) \
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INIT_STRUCT_dynamic_all(var_type)
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#define INIT_UNION_runtime_partial(var_type) \
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INIT_STRUCT_runtime_partial(var_type)
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#define INIT_UNION_runtime_all(var_type) \
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INIT_STRUCT_runtime_all(var_type)
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#define INIT_UNION_assigned_static_partial(var_type) \
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INIT_STRUCT_assigned_static_partial(var_type)
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#define INIT_UNION_assigned_static_all(var_type) \
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INIT_STRUCT_assigned_static_all(var_type)
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#define INIT_UNION_assigned_dynamic_partial(var_type) \
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INIT_STRUCT_assigned_dynamic_partial(var_type)
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#define INIT_UNION_assigned_dynamic_all(var_type) \
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INIT_STRUCT_assigned_dynamic_all(var_type)
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#define INIT_UNION_assigned_copy(var_type) \
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INIT_STRUCT_assigned_copy(var_type)
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/*
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* @name: unique string name for the test
···
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unsigned long four;
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};
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/* No padding: all members are the same size. */
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union test_same_sizes {
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unsigned long one;
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unsigned long two;
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unsigned long three;
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unsigned long four;
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};
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/* Mismatched sizes, with one and two being small */
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union test_small_start {
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char one:1;
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char two;
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short three;
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unsigned long four;
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struct big_struct {
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unsigned long array[8];
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} big;
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};
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/* Mismatched sizes, with one and two being small */
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union test_small_end {
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short one;
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unsigned long two;
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char three:1;
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char four;
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};
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#define ALWAYS_PASS WANT_SUCCESS
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#define ALWAYS_FAIL XFAIL
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···
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struct test_ ## name, STRUCT, init, \
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xfail)
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#define DEFINE_UNION_TEST(name, init, xfail) \
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DEFINE_TEST(name ## _ ## init, \
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union test_ ## name, STRUCT, init, \
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xfail)
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#define DEFINE_STRUCT_TESTS(init, xfail) \
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DEFINE_STRUCT_TEST(small_hole, init, xfail); \
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DEFINE_STRUCT_TEST(big_hole, init, xfail); \
···
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xfail); \
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DEFINE_STRUCT_TESTS(base ## _ ## all, xfail)
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#define DEFINE_UNION_INITIALIZER_TESTS(base, xfail) \
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DEFINE_UNION_TESTS(base ## _ ## partial, \
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xfail); \
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DEFINE_UNION_TESTS(base ## _ ## all, xfail)
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#define DEFINE_UNION_TESTS(init, xfail) \
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DEFINE_UNION_TEST(same_sizes, init, xfail); \
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DEFINE_UNION_TEST(small_start, init, xfail); \
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DEFINE_UNION_TEST(small_end, init, xfail);
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+
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/* These should be fully initialized all the time! */
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DEFINE_SCALAR_TESTS(zero, ALWAYS_PASS);
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DEFINE_STRUCT_TESTS(zero, ALWAYS_PASS);
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DEFINE_STRUCT_TESTS(old_zero, ALWAYS_PASS);
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DEFINE_UNION_TESTS(zero, ALWAYS_PASS);
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DEFINE_UNION_TESTS(old_zero, ALWAYS_PASS);
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/* Struct initializers: padding may be left uninitialized. */
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DEFINE_STRUCT_INITIALIZER_TESTS(static, STRONG_PASS);
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DEFINE_STRUCT_INITIALIZER_TESTS(dynamic, STRONG_PASS);
···
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DEFINE_STRUCT_INITIALIZER_TESTS(assigned_static, STRONG_PASS);
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DEFINE_STRUCT_INITIALIZER_TESTS(assigned_dynamic, STRONG_PASS);
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DEFINE_STRUCT_TESTS(assigned_copy, ALWAYS_FAIL);
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DEFINE_UNION_INITIALIZER_TESTS(static, STRONG_PASS);
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DEFINE_UNION_INITIALIZER_TESTS(dynamic, STRONG_PASS);
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DEFINE_UNION_INITIALIZER_TESTS(runtime, STRONG_PASS);
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DEFINE_UNION_INITIALIZER_TESTS(assigned_static, STRONG_PASS);
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DEFINE_UNION_INITIALIZER_TESTS(assigned_dynamic, STRONG_PASS);
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DEFINE_UNION_TESTS(assigned_copy, ALWAYS_FAIL);
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/* No initialization without compiler instrumentation. */
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DEFINE_SCALAR_TESTS(none, STRONG_PASS);
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DEFINE_STRUCT_TESTS(none, BYREF_PASS);
···
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KUNIT_CASE(test_trailing_hole_ ## init),\
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KUNIT_CASE(test_packed_ ## init) \
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#define KUNIT_test_unions(init) \
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KUNIT_CASE(test_same_sizes_ ## init), \
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KUNIT_CASE(test_small_start_ ## init), \
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KUNIT_CASE(test_small_end_ ## init) \
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+
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static struct kunit_case stackinit_test_cases[] = {
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/* These are explicitly initialized and should always pass. */
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KUNIT_test_scalars(zero),
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KUNIT_test_structs(zero),
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+
KUNIT_test_structs(old_zero),
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KUNIT_test_unions(zero),
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KUNIT_test_unions(old_zero),
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/* Padding here appears to be accidentally always initialized? */
531
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KUNIT_test_structs(dynamic_partial),
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KUNIT_test_structs(assigned_dynamic_partial),
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KUNIT_test_unions(dynamic_partial),
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KUNIT_test_unions(assigned_dynamic_partial),
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/* Padding initialization depends on compiler behaviors. */
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KUNIT_test_structs(static_partial),
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KUNIT_test_structs(static_all),
···
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452
KUNIT_test_structs(assigned_static_partial),
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KUNIT_test_structs(assigned_static_all),
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KUNIT_test_structs(assigned_dynamic_all),
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+
KUNIT_test_unions(static_partial),
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+
KUNIT_test_unions(static_all),
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KUNIT_test_unions(dynamic_all),
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+
KUNIT_test_unions(runtime_partial),
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KUNIT_test_unions(runtime_all),
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KUNIT_test_unions(assigned_static_partial),
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KUNIT_test_unions(assigned_static_all),
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KUNIT_test_unions(assigned_dynamic_all),
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/* Everything fails this since it effectively performs a memcpy(). */
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KUNIT_test_structs(assigned_copy),
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KUNIT_test_unions(assigned_copy),
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/* STRUCTLEAK_BYREF_ALL should cover everything from here down. */
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KUNIT_test_scalars(none),
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KUNIT_CASE(test_switch_1_none),
+3
scripts/Makefile.extrawarn
+3
scripts/Makefile.extrawarn
···
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# Warn if there is an enum types mismatch
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KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion)
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# Explicitly clear padding bits during variable initialization
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KBUILD_CFLAGS += $(call cc-option,-fzero-init-padding-bits=all)
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KBUILD_CFLAGS += -Wextra
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KBUILD_CFLAGS += -Wunused
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