Commit 9d4502fe authored by Tzung-Bi Shih's avatar Tzung-Bi Shih Committed by Greg Kroah-Hartman
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selftests: revocable: Add kselftest cases 



Add kselftest cases for the revocable API.

The test consists of three parts:
- A kernel module (revocable_test.ko) that creates a debugfs interface
  with `/provider` and `/consumer` files.
- A user-space C program (revocable_test) that uses the kselftest
  harness to interact with the debugfs files.
- An orchestrating shell script (test-revocable.sh) that loads the
  module, runs the C program, and unloads the module.

The test cases cover the following scenarios:
- Basic: Verifies that a consumer can successfully access the resource
  provided via the provider.
- Revocation: Verifies that after the provider revokes the resource,
  the consumer correctly receives a NULL pointer on a subsequent access.
- Try Access Macro: Same as "Revocation" but uses the
  REVOCABLE_TRY_ACCESS_WITH() and REVOCABLE_TRY_ACCESS_SCOPED().

Signed-off-by: default avatarTzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260116080235.350305-4-tzungbi@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cd769341

MAINTAINERS

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@@ -22375,6 +22375,7 @@ S: Maintained 
F:	drivers/base/revocable.c

F:	drivers/base/revocable_test.c

F:	include/linux/revocable.h

F:	tools/testing/selftests/drivers/base/revocable/









RFKILL









M:	Johannes Berg <johannes@sipsolutions.net>

























tools/testing/selftests/Makefile



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@@ -17,6 +17,7 @@ TARGETS += damon







TARGETS += devices/error_logs









TARGETS += devices/probe









TARGETS += dmabuf-heaps









TARGETS += drivers/base/revocable









TARGETS += drivers/dma-buf









TARGETS += drivers/ntsync









TARGETS += drivers/s390x/uvdevice
































tools/testing/selftests/drivers/base/revocable/Makefile
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# SPDX-License-Identifier: GPL-2.0



















TEST_GEN_MODS_DIR := test_modules









TEST_GEN_PROGS_EXTENDED := revocable_test









TEST_PROGS := test-revocable.sh



















include ../../../lib.mk
























tools/testing/selftests/drivers/base/revocable/revocable_test.c
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// SPDX-License-Identifier: GPL-2.0









/*









 * Copyright 2026 Google LLC









 *









 * A selftest for the revocable API.









 *









 * The test cases cover the following scenarios:









 *









 * - Basic: Verifies that a consumer can successfully access the resource









 *   provided via the provider.









 *









 * - Revocation: Verifies that after the provider revokes the resource,









 *   the consumer correctly receives a NULL pointer on a subsequent access.









 *









 * - Try Access Macro: Same as "Revocation" but uses the









 *   REVOCABLE_TRY_ACCESS_WITH() and REVOCABLE_TRY_ACCESS_SCOPED().









 */



















#include <fcntl.h>









#include <unistd.h>



















#include "../../../kselftest_harness.h"



















#define DEBUGFS_PATH "/sys/kernel/debug/revocable_test"









#define TEST_CMD_RESOURCE_GONE "resource_gone"









#define TEST_DATA "12345678"









#define TEST_MAGIC_OFFSET 0x1234









#define TEST_MAGIC_OFFSET2 0x5678



















FIXTURE(revocable_fixture) {









	int pfd;









	int cfd;









};



















FIXTURE_SETUP(revocable_fixture) {









	int ret;



















	self->pfd = open(DEBUGFS_PATH "/provider", O_WRONLY);









	ASSERT_NE(-1, self->pfd)









		TH_LOG("failed to open provider fd");



















	ret = write(self->pfd, TEST_DATA, strlen(TEST_DATA));









	ASSERT_NE(-1, ret) {









		close(self->pfd);









		TH_LOG("failed to write test data");









	}



















	self->cfd = open(DEBUGFS_PATH "/consumer", O_RDONLY);









	ASSERT_NE(-1, self->cfd)









		TH_LOG("failed to open consumer fd");









}



















FIXTURE_TEARDOWN(revocable_fixture) {









	close(self->cfd);









	close(self->pfd);









}



















/*









 * ASSERT_* is only available in TEST or TEST_F block.  Use









 * macro for the helper.









 */









#define READ_TEST_DATA(_fd, _offset, _data, _msg)			\









	do {								\









		int ret;						\









									\









		ret = lseek(_fd, _offset, SEEK_SET);			\









		ASSERT_NE(-1, ret)					\









			TH_LOG("failed to lseek");			\









									\









		ret = read(_fd, _data, sizeof(_data) - 1);		\









		ASSERT_NE(-1, ret)					\









			TH_LOG(_msg);					\









		data[ret] = '\0';					\









	} while (0)



















TEST_F(revocable_fixture, basic) {









	char data[16];



















	READ_TEST_DATA(self->cfd, 0, data, "failed to read test data");









	EXPECT_STREQ(TEST_DATA, data);









}



















TEST_F(revocable_fixture, revocation) {









	char data[16];









	int ret;



















	READ_TEST_DATA(self->cfd, 0, data, "failed to read test data");









	EXPECT_STREQ(TEST_DATA, data);



















	ret = write(self->pfd, TEST_CMD_RESOURCE_GONE,









		    strlen(TEST_CMD_RESOURCE_GONE));









	ASSERT_NE(-1, ret)









		TH_LOG("failed to write resource gone cmd");



















	READ_TEST_DATA(self->cfd, 0, data,









		       "failed to read test data after resource gone");









	EXPECT_STREQ("(null)", data);









}



















TEST_F(revocable_fixture, try_access_macro) {









	char data[16];









	int ret;



















	READ_TEST_DATA(self->cfd, TEST_MAGIC_OFFSET, data,









		       "failed to read test data");









	EXPECT_STREQ(TEST_DATA, data);



















	ret = write(self->pfd, TEST_CMD_RESOURCE_GONE,









		    strlen(TEST_CMD_RESOURCE_GONE));









	ASSERT_NE(-1, ret)









		TH_LOG("failed to write resource gone cmd");



















	READ_TEST_DATA(self->cfd, TEST_MAGIC_OFFSET, data,









		       "failed to read test data after resource gone");









	EXPECT_STREQ("(null)", data);









}



















TEST_F(revocable_fixture, try_access_macro2) {









	char data[16];









	int ret;



















	READ_TEST_DATA(self->cfd, TEST_MAGIC_OFFSET2, data,









		       "failed to read test data");









	EXPECT_STREQ(TEST_DATA, data);



















	ret = write(self->pfd, TEST_CMD_RESOURCE_GONE,









		    strlen(TEST_CMD_RESOURCE_GONE));









	ASSERT_NE(-1, ret)









		TH_LOG("failed to write resource gone cmd");



















	READ_TEST_DATA(self->cfd, TEST_MAGIC_OFFSET2, data,









		       "failed to read test data after resource gone");









	EXPECT_STREQ("(null)", data);









}



















TEST_HARNESS_MAIN
























tools/testing/selftests/drivers/base/revocable/test-revocable.sh
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#!/bin/bash









# SPDX-License-Identifier: GPL-2.0



















mod_name="revocable_test"









ksft_fail=1









ksft_skip=4



















if [ "$(id -u)" -ne 0 ]; then









	echo "$0: Must be run as root"









	exit "$ksft_skip"









fi



















if ! which insmod > /dev/null 2>&1; then









	echo "$0: Need insmod"









	exit "$ksft_skip"









fi



















if ! which rmmod > /dev/null 2>&1; then









	echo "$0: Need rmmod"









	exit "$ksft_skip"









fi



















insmod test_modules/"${mod_name}".ko



















if [ ! -d /sys/kernel/debug/revocable_test/ ]; then









	mount -t debugfs none /sys/kernel/debug/



















	if [ ! -d /sys/kernel/debug/revocable_test/ ]; then









		echo "$0: Error mounting debugfs"









		exit "$ksft_fail"









	fi









fi



















./revocable_test









ret=$?



















rmmod "${mod_name}"



















exit "${ret}"