Commit 66bd8501 authored by Pasha Tatashin's avatar Pasha Tatashin Committed by Andrew Morton
Browse files

list: add kunit test for private list primitives 

Add a KUnit test suite for the new private list primitives.

The test defines a struct with a __private list_head and exercises every
macro defined in <linux/list_private.h>.

This ensures that the macros correctly handle the ACCESS_PRIVATE()
abstraction and compile without warnings when acting on private members,
verifying that qualifiers are stripped and offsets are calculated
correctly.

Link: https://lkml.kernel.org/r/20251218155752.3045808-3-pasha.tatashin@soleen.com


Signed-off-by: default avatarPasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: default avatarDavid Gow <davidgow@google.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: David Matlack <dmatlack@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <kees@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Samiullah Khawaja <skhawaja@google.com>
Cc: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 989b3c5a

lib/Kconfig.debug

+14 −0
Original line number Diff line number Diff line
@@ -2786,6 +2786,20 @@ config LIST_KUNIT_TEST 


	  If unsure, say N.



config LIST_PRIVATE_KUNIT_TEST

	tristate "KUnit Test for Kernel Private Linked-list structures" if !KUNIT_ALL_TESTS

	depends on KUNIT

	default KUNIT_ALL_TESTS

	help

	  This builds the KUnit test for the private linked-list primitives

	  defined in include/linux/list_private.h.



	  These primitives allow manipulation of list_head members that are

	  marked as private and require special accessors (ACCESS_PRIVATE)

	  to strip qualifiers or handle encapsulation.



	  If unsure, say N.



config HASHTABLE_KUNIT_TEST

	tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS

	depends on KUNIT

lib/tests/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ obj-$(CONFIG_TEST_IOV_ITER) += kunit_iov_iter.o 
obj-$(CONFIG_IS_SIGNED_TYPE_KUNIT_TEST) += is_signed_type_kunit.o

obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o

obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o

obj-$(CONFIG_LIST_PRIVATE_KUNIT_TEST) += list-private-test.o

obj-$(CONFIG_KFIFO_KUNIT_TEST) += kfifo_kunit.o

obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o

obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o

lib/tests/list-private-test.c

0 → 100644
+76 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * KUnit compilation/smoke test for Private list primitives.

 *

 * Copyright (c) 2025, Google LLC.

 * Pasha Tatashin <pasha.tatashin@soleen.com>

 */

#include <linux/list_private.h>

#include <kunit/test.h>



/*

 * This forces compiler to warn if you access it directly, because list

 * primitives expect (struct list_head *), not (volatile struct list_head *).

 */

#undef __private

#define __private volatile



/* Redefine ACCESS_PRIVATE for this test. */

#undef ACCESS_PRIVATE

#define ACCESS_PRIVATE(p, member) \

	(*((struct list_head *)((unsigned long)&((p)->member))))



struct list_test_struct {

	int data;

	struct list_head __private list;

};



static void list_private_compile_test(struct kunit *test)

{

	struct list_test_struct entry;

	struct list_test_struct *pos, *n;

	LIST_HEAD(head);



	INIT_LIST_HEAD(&ACCESS_PRIVATE(&entry, list));

	list_add(&ACCESS_PRIVATE(&entry, list), &head);

	pos = &entry;



	pos = list_private_entry(&ACCESS_PRIVATE(&entry, list), struct list_test_struct, list);

	pos = list_private_first_entry(&head, struct list_test_struct, list);

	pos = list_private_last_entry(&head, struct list_test_struct, list);

	pos = list_private_next_entry(pos, list);

	pos = list_private_prev_entry(pos, list);

	pos = list_private_next_entry_circular(pos, &head, list);

	pos = list_private_prev_entry_circular(pos, &head, list);



	if (list_private_entry_is_head(pos, &head, list))

		return;



	list_private_for_each_entry(pos, &head, list) { }

	list_private_for_each_entry_reverse(pos, &head, list) { }

	list_private_for_each_entry_continue(pos, &head, list) { }

	list_private_for_each_entry_continue_reverse(pos, &head, list) { }

	list_private_for_each_entry_from(pos, &head, list) { }

	list_private_for_each_entry_from_reverse(pos, &head, list) { }



	list_private_for_each_entry_safe(pos, n, &head, list)

		list_private_safe_reset_next(pos, n, list);

	list_private_for_each_entry_safe_continue(pos, n, &head, list) { }

	list_private_for_each_entry_safe_from(pos, n, &head, list) { }

	list_private_for_each_entry_safe_reverse(pos, n, &head, list) { }

}



static struct kunit_case list_private_test_cases[] = {

	KUNIT_CASE(list_private_compile_test),

	{},

};



static struct kunit_suite list_private_test_module = {

	.name = "list-private-kunit-test",

	.test_cases = list_private_test_cases,

};



kunit_test_suite(list_private_test_module);



MODULE_DESCRIPTION("KUnit compilation test for private list primitives");

MODULE_LICENSE("GPL");