Re: [PATCH v4 13/14] selftests/digest_cache: Add selftests for digest_cache LSM

Jarkko Sakkinen
2024-04-15T19:47:41Z

On Mon Apr 15, 2024 at 5:24 PM EEST, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
>
> Add tests to verify the correctness of the digest_cache LSM, in all_test.c.
>
> Add the kernel module digest_cache_kern.ko, to let all_test call the API
> of the digest_cache LSM through the newly introduced digest_cache_test file
> in securityfs.
>
> Test coverage information:
>
> File 'security/digest_cache/notifier.c'
> Lines executed:100.00% of 31
> File 'security/digest_cache/reset.c'
> Lines executed:98.36% of 61
> File 'security/digest_cache/main.c'
> Lines executed:90.29% of 206
> File 'security/digest_cache/modsig.c'
> Lines executed:42.86% of 21
> File 'security/digest_cache/htable.c'
> Lines executed:93.02% of 86
> File 'security/digest_cache/populate.c'
> Lines executed:92.86% of 56
> File 'security/digest_cache/verif.c'
> Lines executed:89.74% of 39
> File 'security/digest_cache/dir.c'
> Lines executed:90.62% of 96
> File 'security/digest_cache/secfs.c'
> Lines executed:57.14% of 21
> File 'security/digest_cache/parsers/tlv.c'
> Lines executed:79.75% of 79
> File 'security/digest_cache/parsers/rpm.c'
> Lines executed:88.46% of 78
>
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> ---
> MAINTAINERS | 1 +
> tools/testing/selftests/Makefile | 1 +
> .../testing/selftests/digest_cache/.gitignore | 3 +
> tools/testing/selftests/digest_cache/Makefile | 24 +
> .../testing/selftests/digest_cache/all_test.c | 815 ++++++++++++++++++
> tools/testing/selftests/digest_cache/common.c | 78 ++
> tools/testing/selftests/digest_cache/common.h | 135 +++
> .../selftests/digest_cache/common_user.c | 47 +
> .../selftests/digest_cache/common_user.h | 17 +
> tools/testing/selftests/digest_cache/config | 1 +
> .../selftests/digest_cache/generators.c | 248 ++++++
> .../selftests/digest_cache/generators.h | 19 +
> .../selftests/digest_cache/testmod/Makefile | 16 +
> .../selftests/digest_cache/testmod/kern.c | 564 ++++++++++++
> 14 files changed, 1969 insertions(+)
> create mode 100644 tools/testing/selftests/digest_cache/.gitignore
> create mode 100644 tools/testing/selftests/digest_cache/Makefile
> create mode 100644 tools/testing/selftests/digest_cache/all_test.c
> create mode 100644 tools/testing/selftests/digest_cache/common.c
> create mode 100644 tools/testing/selftests/digest_cache/common.h
> create mode 100644 tools/testing/selftests/digest_cache/common_user.c
> create mode 100644 tools/testing/selftests/digest_cache/common_user.h
> create mode 100644 tools/testing/selftests/digest_cache/config
> create mode 100644 tools/testing/selftests/digest_cache/generators.c
> create mode 100644 tools/testing/selftests/digest_cache/generators.h
> create mode 100644 tools/testing/selftests/digest_cache/testmod/Makefile
> create mode 100644 tools/testing/selftests/digest_cache/testmod/kern.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 72801a88449c..d7f700da009e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6198,6 +6198,7 @@ M: Roberto Sassu <roberto.sassu@huawei.com>
> L: linux-security-module@vger.kernel.org
> S: Maintained
> F: security/digest_cache/
> +F: tools/testing/selftests/digest_cache/
>
A common convetion is to have one patch with MAINTAINERS update in the
tail. This is now sprinkled to multiple patches which is not good.

> DIGITEQ AUTOMOTIVE MGB4 V4L2 DRIVER
> M: Martin Tuma <martin.tuma@digiteqautomotive.com>
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 15b6a111c3be..3c5965a62d28 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -13,6 +13,7 @@ TARGETS += core
> TARGETS += cpufreq
> TARGETS += cpu-hotplug
> TARGETS += damon
> +TARGETS += digest_cache
> TARGETS += dmabuf-heaps
> TARGETS += drivers/dma-buf
> TARGETS += drivers/s390x/uvdevice
> diff --git a/tools/testing/selftests/digest_cache/.gitignore b/tools/testing/selftests/digest_cache/.gitignore
> new file mode 100644
> index 000000000000..392096e18f4e
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/.gitignore
> @@ -0,0 +1,3 @@
> +/*.mod
> +/*_test
> +/*.ko
> diff --git a/tools/testing/selftests/digest_cache/Makefile b/tools/testing/selftests/digest_cache/Makefile
> new file mode 100644
> index 000000000000..6b1e0d3c08cf
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/Makefile
> @@ -0,0 +1,24 @@
> +# SPDX-License-Identifier: GPL-2.0
> +TEST_GEN_PROGS_EXTENDED = digest_cache_kern.ko
> +TEST_GEN_PROGS := all_test
> +
> +$(OUTPUT)/%.ko: $(wildcard common.[ch]) testmod/Makefile testmod/kern.c
> + $(call msg,MOD,,$@)
> + $(Q)$(MAKE) -C testmod
> + $(Q)cp testmod/digest_cache_kern.ko $@
> +
> +LOCAL_HDRS += common.h common_user.h generators.h
> +CFLAGS += -ggdb -Wall -Wextra $(KHDR_INCLUDES)
> +
> +OVERRIDE_TARGETS := 1
> +override define CLEAN
> + $(call msg,CLEAN)
> + $(Q)$(MAKE) -C testmod clean
> + rm -Rf $(TEST_GEN_PROGS)
> + rm -Rf $(OUTPUT)/common.o $(OUTPUT)/common_user.o $(OUTPUT)/generators.o
> + rm -Rf $(OUTPUT)/common.mod
> +endef
> +
> +include ../lib.mk
> +
> +$(OUTPUT)/all_test: common.c common.h common_user.c common_user.h generators.c
> diff --git a/tools/testing/selftests/digest_cache/all_test.c b/tools/testing/selftests/digest_cache/all_test.c
> new file mode 100644
> index 000000000000..9f45e522c43c
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/all_test.c
> @@ -0,0 +1,815 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Implement the tests of the digest_cache LSM.
> + */
> +
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <string.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <limits.h>
> +#include <fts.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/xattr.h>
> +#include <sys/syscall.h>
> +#include <linux/module.h>
> +
> +#include "generators.h"
> +
> +#include "../kselftest_harness.h"
> +#include "../../../../include/uapi/linux/xattr.h"
> +
> +#define BASE_DIR_TEMPLATE "/tmp/digest_cache_test_dirXXXXXX"
> +#define DIGEST_LISTS_SUBDIR "digest_lists"
> +#define NUM_DIGEST_LISTS_PREFETCH MAX_WORKS
> +
> +FIXTURE(shared_data) {
> + char base_dir[sizeof(BASE_DIR_TEMPLATE)];
> + char digest_lists_dir[sizeof(BASE_DIR_TEMPLATE) +
> + sizeof(DIGEST_LISTS_SUBDIR)];
> + int base_dirfd, digest_lists_dirfd, kernfd, pathfd, cmd_len;
> + int notify_inodesfd;
> +};
> +
> +FIXTURE_SETUP(shared_data)
> +{
> + char cmd[1024];
> + int fd, i, cmd_len;
> +
> + /* Create the base directory. */
> + snprintf(self->base_dir, sizeof(self->base_dir), BASE_DIR_TEMPLATE);
> + ASSERT_NE(NULL, mkdtemp(self->base_dir));
> +
> + /* Open base directory. */
> + self->base_dirfd = open(self->base_dir, O_RDONLY | O_DIRECTORY);
> + ASSERT_NE(-1, self->base_dirfd);
> +
> + /* Create the digest_lists subdirectory. */
> + snprintf(self->digest_lists_dir, sizeof(self->digest_lists_dir),
> + "%s/%s", self->base_dir, DIGEST_LISTS_SUBDIR);
> + ASSERT_EQ(0, mkdirat(self->base_dirfd, DIGEST_LISTS_SUBDIR, 0600));
> + self->digest_lists_dirfd = openat(self->base_dirfd, DIGEST_LISTS_SUBDIR,
> + O_RDONLY | O_DIRECTORY);
> + ASSERT_NE(-1, self->digest_lists_dirfd);
> +
> + fd = open("digest_cache_kern.ko", O_RDONLY);
> + ASSERT_LT(0, fd);
> +
> + ASSERT_EQ(0, syscall(SYS_finit_module, fd, "", 0));
> + close(fd);
> +
> + /* Open kernel test interface. */
> + self->kernfd = open(DIGEST_CACHE_TEST_INTERFACE, O_RDWR, 0600);
> + ASSERT_NE(-1, self->kernfd);
> +
> + /* Open kernel notify inodes interface. */
> + self->notify_inodesfd = open(DIGEST_CACHE_NOTIFY_INODES_INTERFACE,
> + O_RDWR, 0600);
> + ASSERT_NE(-1, self->notify_inodesfd);
> +
> + /* Open kernel digest list path interface. */
> + self->pathfd = open(DIGEST_CACHE_PATH_INTERFACE, O_RDWR, 0600);
> + ASSERT_NE(-1, self->pathfd);
> +
> + /* Write the path of the digest lists directory. */
> + ASSERT_LT(0, write(self->pathfd, self->digest_lists_dir,
> + strlen(self->digest_lists_dir)));
> +
> + /* Ensure that no verifier is enabled at the beginning of a test. */
> + for (i = 0; i < VERIF__LAST; i++) {
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_DISABLE_VERIF],
> + verifs_str[i]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> + }
> +}
> +
> +FIXTURE_TEARDOWN(shared_data)
> +{
> + FTS *fts = NULL;
> + FTSENT *ftsent;
> + int fts_flags = (FTS_PHYSICAL | FTS_COMFOLLOW | FTS_NOCHDIR | FTS_XDEV);
> + char *paths[2] = { self->base_dir, NULL };
> + char cmd[1024];
> + int cmd_len;
> +
> + /* Close digest_lists subdirectory. */
> + close(self->digest_lists_dirfd);
> +
> + /* Close base directory. */
> + close(self->base_dirfd);
> +
> + /* Delete files and directories. */
> + fts = fts_open(paths, fts_flags, NULL);
> + if (fts) {
> + while ((ftsent = fts_read(fts)) != NULL) {
> + switch (ftsent->fts_info) {
> + case FTS_DP:
> + rmdir(ftsent->fts_accpath);
> + break;
> + case FTS_F:
> + case FTS_SL:
> + case FTS_SLNONE:
> + case FTS_DEFAULT:
> + unlink(ftsent->fts_accpath);
> + break;
> + default:
> + break;
> + }
> + }
> + }
> +
> + /* Release digest cache reference, if the test was interrupted. */
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s",
> + commands_str[DIGEST_CACHE_PUT]);
> + write(self->kernfd, cmd, cmd_len);
> +
> + /* Close kernel notify inodes interface. */
> + close(self->notify_inodesfd);
> +
> + /* Close kernel test interface. */
> + close(self->kernfd);
> +
> + /* Close kernel digest list path interface. */
> + close(self->pathfd);
> +
> + syscall(SYS_delete_module, "digest_cache_kern", 0);
> +}
> +
> +static int query_test(int kernfd, char *base_dir, char *filename,
> + enum hash_algo algo, int start_number, int num_digests)
> +{
> + u8 digest[MAX_DIGEST_SIZE] = { 0 };
> + char digest_str[MAX_DIGEST_SIZE * 2 + 1] = { 0 };
> + int digest_len = hash_digest_size[algo];
> + char cmd[1024];
> + int ret, i, cmd_len;
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/%s",
> + commands_str[DIGEST_CACHE_GET], base_dir, filename);
> + ret = write(kernfd, cmd, cmd_len);
> + if (ret != cmd_len)
> + return -errno;
> +
> + ret = 0;
> +
> + *(u32 *)digest = start_number;
> +
> + for (i = 0; i < num_digests; i++) {
> + bin2hex(digest_str, digest, digest_len);
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/%s|%s:%s",
> + commands_str[DIGEST_CACHE_LOOKUP], base_dir,
> + filename, hash_algo_name[algo], digest_str);
> + ret = write(kernfd, cmd, cmd_len);
> + if (ret != cmd_len) {
> + ret = -errno;
> + goto out;
> + } else {
> + ret = 0;
> + }
> +
> + (*(u32 *)digest)++;
> + }
> +out:
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s",
> + commands_str[DIGEST_CACHE_PUT]);
> + write(kernfd, cmd, cmd_len);
> + return ret;
> +}
> +
> +static enum pgp_algos get_pgp_algo(enum hash_algo algo)
> +{
> + unsigned long i;
> +
> + for (i = DIGEST_ALGO_MD5; i < ARRAY_SIZE(pgp_algo_mapping); i++)
> + if (pgp_algo_mapping[i] == algo)
> + return i;
> +
> + return DIGEST_ALGO_SHA224 + 1;
> +}
> +
> +static void test_parser(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata,
> + char *digest_list_filename, char *filename,
> + enum hash_algo algo, int start_number, int num_digests,
> + unsigned int failure)
> +{
> + int expected_ret = (failure) ? -ENOENT : 0;
> +
> + if (!strncmp(digest_list_filename, "tlv-", 4)) {
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd,
> + digest_list_filename, algo,
> + start_number, num_digests,
> + (enum tlv_failures)failure));
> + } else if (!strncmp(digest_list_filename, "rpm-", 4)) {
> + enum pgp_algos pgp_algo = get_pgp_algo(algo);
> +
> + if (pgp_algo == DIGEST_ALGO_SHA224 + 1)
> + return;
> +
> + ASSERT_EQ(0, gen_rpm_list(self->digest_lists_dirfd,
> + digest_list_filename, algo, pgp_algo,
> + start_number, num_digests,
> + (enum rpm_failures)failure));
> + }
> +
> + ASSERT_EQ(0, create_file(self->base_dirfd, filename,
> + digest_list_filename));
> + ASSERT_EQ(expected_ret, query_test(self->kernfd, self->base_dir,
> + filename, algo, start_number,
> + num_digests));
> +
> + unlinkat(self->digest_lists_dirfd, digest_list_filename, 0);
> + unlinkat(self->base_dirfd, filename, 0);
> +}
> +
> +/*
> + * Verify that the tlv digest list parser returns success on well-formatted
> + * digest lists, for each defined hash algorithm.
> + */
> +TEST_F(shared_data, tlv_parser_ok)
> +{
> + enum hash_algo algo;
> +
> + /* Test every known algorithm. */
> + for (algo = 0; algo < HASH_ALGO__LAST; algo++)
> + test_parser(self, _metadata, "tlv-digest_list", "file", algo,
> + 0, 5, TLV_NO_FAILURE);
> +}
> +
> +/*
> + * Verify that the tlv digest list parser returns failure on invalid digest
> + * lists.
> + */
> +TEST_F(shared_data, tlv_parser_error)
> +{
> + enum tlv_failures failure;
> +
> + /* Test every failure. */
> + for (failure = 0; failure < TLV_FAILURE__LAST; failure++)
> + test_parser(self, _metadata, "tlv-digest_list", "file",
> + HASH_ALGO_SHA224, 0, 1, failure);
> +}
> +
> +/*
> + * Verify that the rpm digest list parser returns success on well-formatted
> + * digest lists, for each defined hash algorithm.
> + */
> +TEST_F(shared_data, rpm_parser_ok)
> +{
> + enum hash_algo algo;
> +
> + /* Test every known algorithm. */
> + for (algo = 0; algo < HASH_ALGO__LAST; algo++)
> + test_parser(self, _metadata, "rpm-digest_list", "file", algo,
> + 0, 5, RPM_NO_FAILURE);
> +}
> +
> +/*
> + * Verify that the rpm digest list parser returns failure on invalid digest
> + * lists.
> + */
> +TEST_F(shared_data, rpm_parser_error)
> +{
> + enum rpm_failures failure;
> +
> + /* Test every failure. */
> + for (failure = 0; failure < RPM_FAILURE__LAST; failure++)
> + test_parser(self, _metadata, "rpm-digest_list", "file",
> + HASH_ALGO_SHA224, 0, 1, failure);
> +}
> +
> +static void test_default_path(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata, bool file)
> +{
> + char path[PATH_MAX];
> + size_t path_len;
> +
> + if (file) {
> + path_len = snprintf(path, sizeof(path),
> + "%s/%s/tlv-digest_list", self->base_dir,
> + DIGEST_LISTS_SUBDIR);
> + ASSERT_LT(0, write(self->pathfd, path, path_len));
> + }
> +
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, "tlv-digest_list",
> + HASH_ALGO_SHA1, 0, 1, TLV_NO_FAILURE));
> +
> + ASSERT_EQ(0, create_file(self->base_dirfd, "file", NULL));
> +
> + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file",
> + HASH_ALGO_SHA1, 0, 1));
> +}
> +
> +/*
> + * Verify that the digest cache created from the default path (regular file)
> + * can be retrieved and used for lookup.
> + */
> +TEST_F(shared_data, default_path_file)
> +{
> + test_default_path(self, _metadata, true);
> +}
> +
> +/*
> + * Verify that the digest cache created from the default path (directory)
> + * can be retrieved and used for lookup.
> + */
> +TEST_F(shared_data, default_path_dir)
> +{
> + test_default_path(self, _metadata, false);
> +}
> +
> +static void notify_inode_init(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata)
> +{
> + /* Clear buffer. */
> + ASSERT_EQ(1, write(self->notify_inodesfd, "1", 1));
> +}
> +
> +static void notify_inodes_check(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata,
> + char *filenames)
> +{
> + char notify_inodes_buf[1024] = { 0 };
> + char notify_inodes_buf_kernel[1024] = { 0 };
> + char *filename, *filenames_copy, *buf_ptr = notify_inodes_buf;
> + struct stat st;
> + int fd;
> +
> + ASSERT_LT(0, read(self->notify_inodesfd, notify_inodes_buf_kernel,
> + sizeof(notify_inodes_buf_kernel)));
> +
> + filenames_copy = strdup(filenames);
> + ASSERT_NE(NULL, filenames_copy);
> +
> + while ((filename = strsep(&filenames_copy, ","))) {
> + fd = openat(self->base_dirfd, filename, O_RDONLY);
> + ASSERT_NE(-1, fd);
> + ASSERT_EQ(0, fstat(fd, &st));
> + close(fd);
> +
> + buf_ptr += snprintf(buf_ptr,
> + sizeof(notify_inodes_buf) -
> + (buf_ptr - notify_inodes_buf), "%s%lu",
> + notify_inodes_buf[0] ? "," : "", st.st_ino);
> + }
> +
> + free(filenames_copy);
> +
> + ASSERT_EQ(0, strcmp(notify_inodes_buf, notify_inodes_buf_kernel));
> +}
> +
> +static void test_file_changes(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata,
> + enum file_changes change)
> +{
> + char digest_list_filename[] = "tlv-digest_list";
> + char digest_list_filename_new[] = "tlv-digest_list6";
> + char digest_list_filename_xattr[] = "tlv-digest_list7";
> + char digest_list_path[sizeof(self->digest_lists_dir) +
> + sizeof(digest_list_filename)];
> + int fd;
> +
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd,
> + digest_list_filename, HASH_ALGO_SHA1, 0, 1,
> + TLV_NO_FAILURE));
> +
> + ASSERT_EQ(0, create_file(self->base_dirfd, "file",
> + digest_list_filename));
> +
> + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file",
> + HASH_ALGO_SHA1, 0, 1));
> +
> + notify_inode_init(self, _metadata);
> +
> + switch (change) {
> + case FILE_WRITE:
> + fd = openat(self->digest_lists_dirfd, digest_list_filename,
> + O_WRONLY);
> + ASSERT_NE(-1, fd);
> +
> + ASSERT_EQ(4, write(fd, "1234", 4));
> + close(fd);
> + break;
> + case FILE_TRUNCATE:
> + snprintf(digest_list_path, sizeof(digest_list_path),
> + "%s/%s", self->digest_lists_dir, digest_list_filename);
> + ASSERT_EQ(0, truncate(digest_list_path, 4));
> + break;
> + case FILE_FTRUNCATE:
> + fd = openat(self->digest_lists_dirfd, digest_list_filename,
> + O_WRONLY);
> + ASSERT_NE(-1, fd);
> + ASSERT_EQ(0, ftruncate(fd, 4));
> + close(fd);
> + break;
> + case FILE_UNLINK:
> + ASSERT_EQ(0, unlinkat(self->digest_lists_dirfd,
> + digest_list_filename, 0));
> + break;
> + case FILE_RENAME:
> + ASSERT_EQ(0, renameat(self->digest_lists_dirfd,
> + digest_list_filename,
> + self->digest_lists_dirfd,
> + digest_list_filename_new));
> + break;
> + case FILE_SETXATTR:
> + fd = openat(self->base_dirfd, "file", O_WRONLY);
> + ASSERT_NE(-1, fd);
> +
> + ASSERT_EQ(0, fsetxattr(fd, XATTR_NAME_DIGEST_LIST,
> + digest_list_filename_xattr,
> + strlen(digest_list_filename_xattr) + 1,
> + 0));
> + close(fd);
> + break;
> + case FILE_REMOVEXATTR:
> + fd = openat(self->base_dirfd, "file", O_WRONLY);
> + ASSERT_NE(-1, fd);
> +
> + ASSERT_EQ(0, fremovexattr(fd, XATTR_NAME_DIGEST_LIST));
> + close(fd);
> +
> + /*
> + * Removing security.digest_list does not cause a failure,
> + * the digest can be still retrieved via directory lookup.
> + */
> + ASSERT_EQ(0, query_test(self->kernfd, self->base_dir, "file",
> + HASH_ALGO_SHA1, 0, 1));
> +
> + notify_inodes_check(self, _metadata, "file");
> + return;
> + default:
> + break;
> + }
> +
> + ASSERT_NE(0, query_test(self->kernfd, self->base_dir, "file",
> + HASH_ALGO_SHA1, 0, 1));
> +
> + notify_inodes_check(self, _metadata, "file");
> +}
> +
> +/*
> + * Verify that operations on a digest list cause a reset of the digest cache,
> + * and that the digest is not found in the invalid/missing digest list.
> + */
> +TEST_F(shared_data, file_reset)
> +{
> + enum file_changes change;
> +
> + /* Test for every file change. */
> + for (change = 0; change < FILE_CHANGE__LAST; change++)
> + test_file_changes(self, _metadata, change);
> +}
> +
> +static void query_test_with_failures(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata,
> + int start_number, int num_digests,
> + int *removed, int num_removed)
> +{
> + int i, j, expected_ret;
> +
> + for (i = start_number; i < start_number + num_digests; i++) {
> + expected_ret = 0;
> +
> + for (j = 0; j < num_removed; j++) {
> + if (removed[j] == i) {
> + expected_ret = -ENOENT;
> + break;
> + }
> + }
> +
> + ASSERT_EQ(expected_ret, query_test(self->kernfd, self->base_dir,
> + "file", HASH_ALGO_SHA1, i,
> + 1));
> + }
> +}
> +
> +/*
> + * Verify that changes in the digest list directory are monitored and that
> + * a digest cannot be found if the respective digest list file has been moved
> + * away from the directory, and that a digest can be found if the respective
> + * digest list has been moved/created in the directory.
> + */
> +TEST_F(shared_data, dir_reset)
> +{
> + char digest_list_filename[NAME_MAX + 1];
> + int i, removed[10];
> +
> + for (i = 0; i < 10; i++) {
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "tlv-digest_list%d", i);
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd,
> + digest_list_filename, HASH_ALGO_SHA1,
> + i, 1, TLV_NO_FAILURE));
> + }
> +
> + ASSERT_EQ(0, create_file(self->base_dirfd, "file", NULL));
> + /* The second file is to have duplicate notifications (file and dir). */
> + ASSERT_EQ(0, create_file(self->base_dirfd, "file2",
> + "tlv-digest_list7"));
> + /* The query adds file2 inode to the file digest cache notif. list. */
> + ASSERT_NE(0, query_test(self->kernfd, self->base_dir, "file2",
> + HASH_ALGO_SHA1, 0, 1));
> +
> + query_test_with_failures(self, _metadata, 0, 10, removed, 0);
> +
> + notify_inode_init(self, _metadata);
> + ASSERT_EQ(0, unlinkat(self->digest_lists_dirfd, "tlv-digest_list7", 0));
> + /* File notification comes before directory notification. */
> + notify_inodes_check(self, _metadata, "file2,file");
> +
> + removed[0] = 7;
> +
> + query_test_with_failures(self, _metadata, 0, 10, removed, 1);
> +
> + notify_inode_init(self, _metadata);
> + ASSERT_EQ(0, renameat(self->digest_lists_dirfd, "tlv-digest_list6",
> + self->base_dirfd, "tlv-digest_list6"));
> + notify_inodes_check(self, _metadata, "file");
> +
> + removed[1] = 6;
> +
> + query_test_with_failures(self, _metadata, 0, 10, removed, 2);
> +
> + notify_inode_init(self, _metadata);
> + ASSERT_EQ(0, renameat(self->base_dirfd, "tlv-digest_list6",
> + self->digest_lists_dirfd, "tlv-digest_list6"));
> + notify_inodes_check(self, _metadata, "file");
> +
> + query_test_with_failures(self, _metadata, 0, 10, removed, 1);
> +
> + notify_inode_init(self, _metadata);
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd, "tlv-digest_list10",
> + HASH_ALGO_SHA1, 10, 1, TLV_NO_FAILURE));
> + notify_inodes_check(self, _metadata, "file");
> +
> + query_test_with_failures(self, _metadata, 0, 11, removed, 1);
> +}
> +
> +static void _check_verif_data(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata,
> + char *digest_list_filename, int num,
> + enum hash_algo algo, bool check_dir)
> +{
> + char digest_list_filename_kernel[NAME_MAX + 1];
> + char cmd[1024], number[20];
> + u8 digest[MAX_DIGEST_SIZE] = { 0 };
> + char digest_str[MAX_DIGEST_SIZE * 2 + 1] = { 0 };
> + int len, cmd_len;
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/file",
> + commands_str[DIGEST_CACHE_GET], self->base_dir);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + /*
> + * If a directory digest cache was requested, we need to do a lookup,
> + * to make the kernel module retrieve verification data from the digest
> + * cache of the directory entry.
> + */
> + if (check_dir) {
> + *(u32 *)digest = num;
> +
> + bin2hex(digest_str, digest, hash_digest_size[algo]);
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/file|%s:%s",
> + commands_str[DIGEST_CACHE_LOOKUP],
> + self->base_dir, hash_algo_name[algo],
> + digest_str);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> + }
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_SET_VERIF],
> + verifs_str[VERIF_FILENAMES]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + ASSERT_LT(0, read(self->kernfd, digest_list_filename_kernel,
> + sizeof(digest_list_filename_kernel)));
> + ASSERT_EQ(0, strcmp(digest_list_filename, digest_list_filename_kernel));
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_SET_VERIF],
> + verifs_str[VERIF_NUMBER]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + len = read(self->kernfd, number, sizeof(number) - 1);
> + ASSERT_LT(0, len);
> + number[len] = '\0';
> + ASSERT_EQ(num, atoi(number));
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s",
> + commands_str[DIGEST_CACHE_PUT]);
> + write(self->kernfd, cmd, cmd_len);
> +}
> +
> +static void check_verif_data(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata)
> +{
> + char digest_list_filename[NAME_MAX + 1];
> + char cmd[1024];
> + int i, cmd_len;
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_ENABLE_VERIF],
> + verifs_str[VERIF_FILENAMES]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_ENABLE_VERIF],
> + verifs_str[VERIF_NUMBER]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + /*
> + * Reverse order is intentional, so that directory entries are created
> + * in the opposite order as when they are searched (when prefetching is
> + * requested).
> + */
> + for (i = 10; i >= 0; i--) {
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", i, i);
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd,
> + digest_list_filename, HASH_ALGO_SHA1,
> + i, 1, TLV_NO_FAILURE));
> +
> + ASSERT_EQ(0, create_file(self->base_dirfd, "file",
> + digest_list_filename));
> +
> + _check_verif_data(self, _metadata, digest_list_filename, i,
> + HASH_ALGO_SHA1, false);
> +
> + ASSERT_EQ(0, unlinkat(self->base_dirfd, "file", 0));
> + }
> +
> + ASSERT_EQ(0, create_file(self->base_dirfd, "file", NULL));
> +
> + for (i = 0; i < 11; i++) {
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", i, i);
> + _check_verif_data(self, _metadata, digest_list_filename, i,
> + HASH_ALGO_SHA1, true);
> + }
> +
> + ASSERT_EQ(0, unlinkat(self->base_dirfd, "file", 0));
> +}
> +
> +/*
> + * Verify that the correct verification data can be retrieved from the digest
> + * caches (without digest list prefetching).
> + */
> +TEST_F(shared_data, verif_data_no_prefetch)
> +{
> + check_verif_data(self, _metadata);
> +}
> +
> +/*
> + * Verify that the correct verification data can be retrieved from the digest
> + * caches (with digest list prefetching).
> + */
> +TEST_F(shared_data, verif_data_prefetch)
> +{
> + ASSERT_EQ(0, lsetxattr(self->base_dir, XATTR_NAME_DIG_PREFETCH,
> + "1", 1, 0));
> +
> + check_verif_data(self, _metadata);
> +}
> +
> +static void check_prefetch_list(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata,
> + int start_number, int end_number)
> +{
> + char digest_list_filename[NAME_MAX + 1], filename[NAME_MAX + 1];
> + char digest_lists[1024], digest_lists_kernel[1024] = { 0 };
> + char cmd[1024];
> + int i, cmd_len;
> +
> + snprintf(filename, sizeof(filename), "file%d", end_number);
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", end_number, end_number);
> + ASSERT_EQ(0, create_file(self->base_dirfd, filename,
> + digest_list_filename));
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/%s",
> + commands_str[DIGEST_CACHE_GET], self->base_dir,
> + filename);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + ASSERT_LT(0, read(self->kernfd, digest_lists, sizeof(digest_lists)));
> +
> + for (i = start_number; i <= end_number; i++) {
> + if (digest_lists_kernel[0])
> + strcat(digest_lists_kernel, ",");
> +
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", i, i);
> + strcat(digest_lists_kernel, digest_list_filename);
> + }
> +
> + ASSERT_EQ(0, strcmp(digest_lists, digest_lists_kernel));
> +
> + ASSERT_EQ(0, unlinkat(self->base_dirfd, filename, 0));
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s",
> + commands_str[DIGEST_CACHE_PUT]);
> + write(self->kernfd, cmd, cmd_len);
> +}
> +
> +static void check_prefetch_list_async(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata)
> +{
> + char digest_list_filename[NAME_MAX + 1], filename[NAME_MAX + 1];
> + char digest_lists[1024], digest_lists_kernel[1024] = { 0 };
> + char cmd[1024];
> + int i, cmd_len;
> +
> + for (i = 0; i < NUM_DIGEST_LISTS_PREFETCH; i++) {
> + snprintf(filename, sizeof(filename), "file%d",
> + NUM_DIGEST_LISTS_PREFETCH - 1 - i);
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", i, i);
> + ASSERT_EQ(0, create_file(self->base_dirfd, filename,
> + digest_list_filename));
> + }
> +
> + /* Do batch of get/put to test the kernel for concurrent requests. */
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s/file|%d|%d",
> + commands_str[DIGEST_CACHE_GET_PUT_ASYNC],
> + self->base_dir, 0, NUM_DIGEST_LISTS_PREFETCH - 1);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + ASSERT_LT(0, read(self->kernfd, digest_lists, sizeof(digest_lists)));
> +
> + for (i = 0; i < NUM_DIGEST_LISTS_PREFETCH; i++) {
> + if (digest_lists_kernel[0])
> + strcat(digest_lists_kernel, ",");
> +
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", i, i);
> + strcat(digest_lists_kernel, digest_list_filename);
> + }
> +
> + ASSERT_EQ(0, strcmp(digest_lists, digest_lists_kernel));
> +}
> +
> +static void prepare_prefetch(struct _test_data_shared_data *self,
> + struct __test_metadata *_metadata)
> +{
> + char digest_list_filename[NAME_MAX + 1];
> + char cmd[1024];
> + int i, cmd_len;
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_ENABLE_VERIF],
> + verifs_str[VERIF_PREFETCH]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + cmd_len = snprintf(cmd, sizeof(cmd), "%s|%s",
> + commands_str[DIGEST_CACHE_SET_VERIF],
> + verifs_str[VERIF_PREFETCH]);
> + ASSERT_EQ(cmd_len, write(self->kernfd, cmd, cmd_len));
> +
> + for (i = NUM_DIGEST_LISTS_PREFETCH - 1; i >= 0; i--) {
> + snprintf(digest_list_filename, sizeof(digest_list_filename),
> + "%d-tlv-digest_list%d", i, i);
> + ASSERT_EQ(0, gen_tlv_list(self->digest_lists_dirfd,
> + digest_list_filename, HASH_ALGO_SHA1,
> + i, 1, TLV_NO_FAILURE));
> + }
> +
> + ASSERT_EQ(0, fsetxattr(self->digest_lists_dirfd,
> + XATTR_NAME_DIG_PREFETCH, "1", 1, 0));
> +}
> +
> +/*
> + * Verify that digest lists are prefetched when requested, in the correct order
> + * (synchronous version).
> + */
> +TEST_F(shared_data, prefetch_sync)
> +{
> + int i;
> +
> + prepare_prefetch(self, _metadata);
> +
> + for (i = 2; i < NUM_DIGEST_LISTS_PREFETCH; i += 3)
> + check_prefetch_list(self, _metadata, i - 2, i);
> +}
> +
> +/*
> + * Verify that digest lists are prefetched when requested, in the correct order
> + * (asynchronous version).
> + */
> +TEST_F(shared_data, prefetch_async)
> +{
> + prepare_prefetch(self, _metadata);
> +
> + check_prefetch_list_async(self, _metadata);
> +}
> +
> +TEST_HARNESS_MAIN
> diff --git a/tools/testing/selftests/digest_cache/common.c b/tools/testing/selftests/digest_cache/common.c
> new file mode 100644
> index 000000000000..2123f7d937ce
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/common.c
> @@ -0,0 +1,78 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Add common code for testing the digest_cache LSM.
> + */
> +
> +#include "common.h"
> +
> +const char *commands_str[DIGEST_CACHE__LAST] = {
> + [DIGEST_CACHE_GET] = "get",
> + [DIGEST_CACHE_LOOKUP] = "lookup",
> + [DIGEST_CACHE_PUT] = "put",
> + [DIGEST_CACHE_ENABLE_VERIF] = "enable_verif",
> + [DIGEST_CACHE_DISABLE_VERIF] = "disable_verif",
> + [DIGEST_CACHE_SET_VERIF] = "set_verif",
> + [DIGEST_CACHE_GET_PUT_ASYNC] = "get_put_async",
> +};
> +
> +const char *const hash_algo_name[HASH_ALGO__LAST] = {
> + [HASH_ALGO_MD4] = "md4",
> + [HASH_ALGO_MD5] = "md5",
> + [HASH_ALGO_SHA1] = "sha1",
> + [HASH_ALGO_RIPE_MD_160] = "rmd160",
> + [HASH_ALGO_SHA256] = "sha256",
> + [HASH_ALGO_SHA384] = "sha384",
> + [HASH_ALGO_SHA512] = "sha512",
> + [HASH_ALGO_SHA224] = "sha224",
> + [HASH_ALGO_RIPE_MD_128] = "rmd128",
> + [HASH_ALGO_RIPE_MD_256] = "rmd256",
> + [HASH_ALGO_RIPE_MD_320] = "rmd320",
> + [HASH_ALGO_WP_256] = "wp256",
> + [HASH_ALGO_WP_384] = "wp384",
> + [HASH_ALGO_WP_512] = "wp512",
> + [HASH_ALGO_TGR_128] = "tgr128",
> + [HASH_ALGO_TGR_160] = "tgr160",
> + [HASH_ALGO_TGR_192] = "tgr192",
> + [HASH_ALGO_SM3_256] = "sm3",
> + [HASH_ALGO_STREEBOG_256] = "streebog256",
> + [HASH_ALGO_STREEBOG_512] = "streebog512",
> + [HASH_ALGO_SHA3_256] = "sha3-256",
> + [HASH_ALGO_SHA3_384] = "sha3-384",
> + [HASH_ALGO_SHA3_512] = "sha3-512",
> +};
> +
> +const int hash_digest_size[HASH_ALGO__LAST] = {
> + [HASH_ALGO_MD4] = MD5_DIGEST_SIZE,
> + [HASH_ALGO_MD5] = MD5_DIGEST_SIZE,
> + [HASH_ALGO_SHA1] = SHA1_DIGEST_SIZE,
> + [HASH_ALGO_RIPE_MD_160] = RMD160_DIGEST_SIZE,
> + [HASH_ALGO_SHA256] = SHA256_DIGEST_SIZE,
> + [HASH_ALGO_SHA384] = SHA384_DIGEST_SIZE,
> + [HASH_ALGO_SHA512] = SHA512_DIGEST_SIZE,
> + [HASH_ALGO_SHA224] = SHA224_DIGEST_SIZE,
> + [HASH_ALGO_RIPE_MD_128] = RMD128_DIGEST_SIZE,
> + [HASH_ALGO_RIPE_MD_256] = RMD256_DIGEST_SIZE,
> + [HASH_ALGO_RIPE_MD_320] = RMD320_DIGEST_SIZE,
> + [HASH_ALGO_WP_256] = WP256_DIGEST_SIZE,
> + [HASH_ALGO_WP_384] = WP384_DIGEST_SIZE,
> + [HASH_ALGO_WP_512] = WP512_DIGEST_SIZE,
> + [HASH_ALGO_TGR_128] = TGR128_DIGEST_SIZE,
> + [HASH_ALGO_TGR_160] = TGR160_DIGEST_SIZE,
> + [HASH_ALGO_TGR_192] = TGR192_DIGEST_SIZE,
> + [HASH_ALGO_SM3_256] = SM3256_DIGEST_SIZE,
> + [HASH_ALGO_STREEBOG_256] = STREEBOG256_DIGEST_SIZE,
> + [HASH_ALGO_STREEBOG_512] = STREEBOG512_DIGEST_SIZE,
> + [HASH_ALGO_SHA3_256] = SHA3_256_DIGEST_SIZE,
> + [HASH_ALGO_SHA3_384] = SHA3_384_DIGEST_SIZE,
> + [HASH_ALGO_SHA3_512] = SHA3_512_DIGEST_SIZE,
> +};
> +
> +const char *verifs_str[] = {
> + [VERIF_FILENAMES] = "filenames",
> + [VERIF_NUMBER] = "number",
> + [VERIF_PREFETCH] = "prefetch",
> +};
> diff --git a/tools/testing/selftests/digest_cache/common.h b/tools/testing/selftests/digest_cache/common.h
> new file mode 100644
> index 000000000000..e52e4b137807
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/common.h
> @@ -0,0 +1,135 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Header of common.c.
> + */
> +
> +#ifndef _COMMON_H
> +#define _COMMON_H
> +#include <linux/types.h>
> +
> +#include "../../../../include/uapi/linux/hash_info.h"
> +
> +#define MD5_DIGEST_SIZE 16
> +#define SHA1_DIGEST_SIZE 20
> +#define RMD160_DIGEST_SIZE 20
> +#define SHA256_DIGEST_SIZE 32
> +#define SHA384_DIGEST_SIZE 48
> +#define SHA512_DIGEST_SIZE 64
> +#define SHA224_DIGEST_SIZE 28
> +#define RMD128_DIGEST_SIZE 16
> +#define RMD256_DIGEST_SIZE 32
> +#define RMD320_DIGEST_SIZE 40
> +#define WP256_DIGEST_SIZE 32
> +#define WP384_DIGEST_SIZE 48
> +#define WP512_DIGEST_SIZE 64
> +#define TGR128_DIGEST_SIZE 16
> +#define TGR160_DIGEST_SIZE 20
> +#define TGR192_DIGEST_SIZE 24
> +#define SM3256_DIGEST_SIZE 32
> +#define STREEBOG256_DIGEST_SIZE 32
> +#define STREEBOG512_DIGEST_SIZE 64
> +#define SHA3_224_DIGEST_SIZE (224 / 8)
> +#define SHA3_256_DIGEST_SIZE (256 / 8)
> +#define SHA3_384_DIGEST_SIZE (384 / 8)
> +#define SHA3_512_DIGEST_SIZE (512 / 8)
> +
> +#define DIGEST_CACHE_TEST_INTERFACE "/sys/kernel/security/digest_cache_test"
> +#define DIGEST_CACHE_PATH_INTERFACE "/sys/kernel/security/digest_cache_path"
> +#define DIGEST_CACHE_NOTIFY_INODES_INTERFACE \
> + "/sys/kernel/security/digest_cache_notify_inodes"
> +#define MAX_DIGEST_SIZE 64
> +
> +#define RPMTAG_FILEDIGESTS 1035
> +#define RPMTAG_FILEDIGESTALGO 5011
> +
> +#define RPM_INT32_TYPE 4
> +#define RPM_STRING_ARRAY_TYPE 8
> +
> +#define MAX_WORKS 21
> +
> +typedef __u8 u8;
> +typedef __u16 u16;
> +typedef __u32 u32;
> +typedef __s32 s32;
> +typedef __u64 u64;
> +
> +enum commands {
> + DIGEST_CACHE_GET, // args: <path>
> + DIGEST_CACHE_LOOKUP, // args: <algo>|<digest>
> + DIGEST_CACHE_PUT, // args:
> + DIGEST_CACHE_ENABLE_VERIF, // args: <verif name>
> + DIGEST_CACHE_DISABLE_VERIF, // args: <verif name>
> + DIGEST_CACHE_SET_VERIF, // args: <verif name>
> + DIGEST_CACHE_GET_PUT_ASYNC, // args: <path>|<start#>|<end#>
> + DIGEST_CACHE__LAST,
> +};
> +
> +enum tlv_failures { TLV_NO_FAILURE,
> + TLV_FAILURE_ALGO_LEN,
> + TLV_FAILURE_HDR_LEN,
> + TLV_FAILURE_ALGO_MISMATCH,
> + TLV_FAILURE_NUM_DIGESTS,
> + TLV_FAILURE__LAST
> +};
> +
> +enum rpm_failures { RPM_NO_FAILURE,
> + RPM_FAILURE_WRONG_MAGIC,
> + RPM_FAILURE_BAD_DATA_OFFSET,
> + RPM_FAILURE_WRONG_TAGS,
> + RPM_FAILURE_WRONG_DIGEST_COUNT,
> + RPM_FAILURE_DIGEST_WRONG_TYPE,
> + RPM_FAILURE__LAST
> +};
> +
> +enum file_changes { FILE_WRITE,
> + FILE_TRUNCATE,
> + FILE_FTRUNCATE,
> + FILE_UNLINK,
> + FILE_RENAME,
> + FILE_SETXATTR,
> + FILE_REMOVEXATTR,
> + FILE_CHANGE__LAST
> +};
> +
> +enum VERIFS {
> + VERIF_FILENAMES,
> + VERIF_NUMBER,
> + VERIF_PREFETCH,
> + VERIF__LAST
> +};
> +
> +enum pgp_algos {
> + DIGEST_ALGO_MD5 = 1,
> + DIGEST_ALGO_SHA1 = 2,
> + DIGEST_ALGO_RMD160 = 3,
> + /* 4, 5, 6, and 7 are reserved. */
> + DIGEST_ALGO_SHA256 = 8,
> + DIGEST_ALGO_SHA384 = 9,
> + DIGEST_ALGO_SHA512 = 10,
> + DIGEST_ALGO_SHA224 = 11,
> +};
> +
> +struct rpm_hdr {
> + u32 magic;
> + u32 reserved;
> + u32 tags;
> + u32 datasize;
> +} __attribute__ ((__packed__));
> +
> +struct rpm_entryinfo {
> + s32 tag;
> + u32 type;
> + s32 offset;
> + u32 count;
> +} __attribute__ ((__packed__));
> +
> +extern const char *commands_str[DIGEST_CACHE__LAST];
> +extern const char *const hash_algo_name[HASH_ALGO__LAST];
> +extern const int hash_digest_size[HASH_ALGO__LAST];
> +extern const char *verifs_str[VERIF__LAST];
> +
> +#endif /* _COMMON_H */
> diff --git a/tools/testing/selftests/digest_cache/common_user.c b/tools/testing/selftests/digest_cache/common_user.c
> new file mode 100644
> index 000000000000..1bacadad6b6a
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/common_user.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Add common code in user space for testing the digest_cache LSM.
> + */
> +
> +#include <stddef.h>
> +
> +#include "common_user.h"
> +
> +static const char hex_asc[] = "0123456789abcdef";
> +
> +#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
> +#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
> +
> +const enum hash_algo pgp_algo_mapping[DIGEST_ALGO_SHA224 + 1] = {
> + [DIGEST_ALGO_MD5] = HASH_ALGO_MD5,
> + [DIGEST_ALGO_SHA1] = HASH_ALGO_SHA1,
> + [DIGEST_ALGO_RMD160] = HASH_ALGO_RIPE_MD_160,
> + [4] = HASH_ALGO__LAST,
> + [5] = HASH_ALGO__LAST,
> + [6] = HASH_ALGO__LAST,
> + [7] = HASH_ALGO__LAST,
> + [DIGEST_ALGO_SHA256] = HASH_ALGO_SHA256,
> + [DIGEST_ALGO_SHA384] = HASH_ALGO_SHA384,
> + [DIGEST_ALGO_SHA512] = HASH_ALGO_SHA512,
> + [DIGEST_ALGO_SHA224] = HASH_ALGO_SHA224,
> +};
> +
> +static inline char *hex_byte_pack(char *buf, unsigned char byte)
> +{
> + *buf++ = hex_asc_hi(byte);
> + *buf++ = hex_asc_lo(byte);
> + return buf;
> +}
> +
> +char *bin2hex(char *dst, const void *src, size_t count)
> +{
> + const unsigned char *_src = src;
> +
> + while (count--)
> + dst = hex_byte_pack(dst, *_src++);
> + return dst;
> +}
> diff --git a/tools/testing/selftests/digest_cache/common_user.h b/tools/testing/selftests/digest_cache/common_user.h
> new file mode 100644
> index 000000000000..4eef52cc5c27
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/common_user.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Header of common_user.c.
> + */
> +
> +#include <linux/types.h>
> +#include <stddef.h>
> +
> +#include "common.h"
> +
> +extern const enum hash_algo pgp_algo_mapping[DIGEST_ALGO_SHA224 + 1];
> +
> +char *bin2hex(char *dst, const void *src, size_t count);
> diff --git a/tools/testing/selftests/digest_cache/config b/tools/testing/selftests/digest_cache/config
> new file mode 100644
> index 000000000000..075a06cc4f8e
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/config
> @@ -0,0 +1 @@
> +CONFIG_SECURITY_DIGEST_CACHE=y
> diff --git a/tools/testing/selftests/digest_cache/generators.c b/tools/testing/selftests/digest_cache/generators.c
> new file mode 100644
> index 000000000000..c7791a3589f2
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/generators.c
> @@ -0,0 +1,248 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Generate digest lists for testing.
> + */
> +
> +#include <stddef.h>
> +#include <fcntl.h>
> +#include <errno.h>
> +#include <limits.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/xattr.h>
> +#include <asm/byteorder.h>
> +
> +#include "generators.h"
> +#include "../../../../include/uapi/linux/hash_info.h"
> +#include "../../../../include/uapi/linux/xattr.h"
> +#include "../../../../include/uapi/linux/tlv_digest_list.h"
> +#include "../../../../include/uapi/linux/tlv_parser.h"
> +
> +int gen_tlv_list(int temp_dirfd, char *digest_list_filename,
> + enum hash_algo algo, int start_number, int num_digests,
> + enum tlv_failures failure)
> +{
> + u64 _algo = __cpu_to_be64(algo);
> + u8 digest[MAX_DIGEST_SIZE] = { 0 };
> + int digest_len = hash_digest_size[algo];
> + int digest_len_to_copy = digest_len;
> + int ret, fd, i;
> +
> + struct tlv_data_entry algo_entry = {
> + .field = __cpu_to_be64(DIGEST_LIST_ALGO),
> + .length = __cpu_to_be64(sizeof(_algo)),
> + };
> +
> + struct tlv_data_entry entry_digest = {
> + .field = __cpu_to_be64(DIGEST_LIST_ENTRY_DIGEST),
> + .length = __cpu_to_be64(digest_len),
> + };
> +
> + struct tlv_hdr entry_hdr = {
> + .data_type = __cpu_to_be64(DIGEST_LIST_ENTRY_DATA),
> + ._reserved = 0,
> + .num_entries = __cpu_to_be64(1),
> + .total_len = __cpu_to_be64(sizeof(entry_digest) + digest_len),
> + };
> +
> + struct tlv_data_entry entry_entry = {
> + .field = __cpu_to_be64(DIGEST_LIST_ENTRY),
> + .length = __cpu_to_be64(sizeof(entry_hdr) +
> + __be64_to_cpu(entry_hdr.total_len)),
> + };
> +
> + struct tlv_hdr hdr = {
> + .data_type = __cpu_to_be64(DIGEST_LIST_FILE),
> + ._reserved = 0,
> + .num_entries = __cpu_to_be64(1 + num_digests),
> + .total_len = __cpu_to_be64(sizeof(algo_entry) +
> + __be64_to_cpu(algo_entry.length) +
> + num_digests * (sizeof(entry_entry) +
> + __be64_to_cpu(entry_entry.length)))
> + };
> +
> + switch (failure) {
> + case TLV_FAILURE_ALGO_LEN:
> + algo_entry.length = algo_entry.length / 2;
> + break;
> + case TLV_FAILURE_HDR_LEN:
> + hdr.total_len--;
> + break;
> + case TLV_FAILURE_ALGO_MISMATCH:
> + _algo = __cpu_to_be64(algo - 1);
> + break;
> + case TLV_FAILURE_NUM_DIGESTS:
> + num_digests = 0;
> + break;
> + default:
> + break;
> + }
> +
> + fd = openat(temp_dirfd, digest_list_filename,
> + O_WRONLY | O_CREAT | O_TRUNC, 0600);
> + if (fd == -1)
> + return -errno;
> +
> + ret = write(fd, (u8 *)&hdr, sizeof(hdr));
> + if (ret != sizeof(hdr))
> + return -errno;
> +
> + ret = write(fd, (u8 *)&algo_entry, sizeof(algo_entry));
> + if (ret != sizeof(algo_entry))
> + return -errno;
> +
> + ret = write(fd, (u8 *)&_algo, sizeof(_algo));
> + if (ret != sizeof(_algo))
> + return -errno;
> +
> + *(u32 *)digest = start_number;
> +
> + for (i = 0; i < num_digests; i++) {
> + ret = write(fd, (u8 *)&entry_entry, sizeof(entry_entry));
> + if (ret != sizeof(entry_entry))
> + return -errno;
> +
> + ret = write(fd, (u8 *)&entry_hdr, sizeof(entry_hdr));
> + if (ret != sizeof(entry_hdr))
> + return -errno;
> +
> + ret = write(fd, (u8 *)&entry_digest, sizeof(entry_digest));
> + if (ret != sizeof(entry_digest))
> + return -errno;
> +
> + ret = write(fd, digest, digest_len_to_copy);
> + if (ret != digest_len_to_copy)
> + return -errno;
> +
> + (*(u32 *)digest)++;
> + }
> +
> + close(fd);
> + return 0;
> +}
> +
> +int gen_rpm_list(int temp_dirfd, char *digest_list_filename,
> + enum hash_algo algo, enum pgp_algos pgp_algo, int start_number,
> + int num_digests, enum rpm_failures failure)
> +{
> + u32 _pgp_algo = __cpu_to_be32(pgp_algo);
> + u8 digest[MAX_DIGEST_SIZE] = { 0 };
> + char digest_str[MAX_DIGEST_SIZE * 2 + 1];
> + struct rpm_hdr hdr;
> + struct rpm_entryinfo algo_entry, digest_entry;
> + int digest_len = hash_digest_size[algo];
> + int ret, fd, d_len, i;
> +
> + d_len = hash_digest_size[algo] * 2 + 1;
> +
> + hdr.magic = __cpu_to_be32(0x8eade801);
> + hdr.reserved = 0;
> + hdr.tags = __cpu_to_be32(1);
> +
> + /*
> + * Skip the algo section, to ensure that the parser recognizes MD5 as
> + * the default hash algorithm.
> + */
> + if (algo != HASH_ALGO_MD5)
> + hdr.tags = __cpu_to_be32(2);
> +
> + hdr.datasize = __cpu_to_be32(d_len * num_digests);
> +
> + if (algo != HASH_ALGO_MD5)
> + hdr.datasize = __cpu_to_be32(sizeof(u32) + d_len * num_digests);
> +
> + digest_entry.tag = __cpu_to_be32(RPMTAG_FILEDIGESTS);
> + digest_entry.type = __cpu_to_be32(RPM_STRING_ARRAY_TYPE);
> + digest_entry.offset = 0;
> + digest_entry.count = __cpu_to_be32(num_digests);
> +
> + algo_entry.tag = __cpu_to_be32(RPMTAG_FILEDIGESTALGO);
> + algo_entry.type = __cpu_to_be32(RPM_INT32_TYPE);
> + algo_entry.offset = __cpu_to_be32(d_len * num_digests);
> + algo_entry.count = __cpu_to_be32(1);
> +
> + switch (failure) {
> + case RPM_FAILURE_WRONG_MAGIC:
> + hdr.magic++;
> + break;
> + case RPM_FAILURE_BAD_DATA_OFFSET:
> + algo_entry.offset = __cpu_to_be32(UINT_MAX);
> + break;
> + case RPM_FAILURE_WRONG_TAGS:
> + hdr.tags = __cpu_to_be32(2 + 10);
> + break;
> + case RPM_FAILURE_WRONG_DIGEST_COUNT:
> + /* We need to go beyond the algorithm, to fail. */
> + digest_entry.count = __cpu_to_be32(num_digests + 5);
> + break;
> + case RPM_FAILURE_DIGEST_WRONG_TYPE:
> + digest_entry.type = __cpu_to_be32(RPM_INT32_TYPE);
> + break;
> + default:
> + break;
> + }
> +
> + fd = openat(temp_dirfd, digest_list_filename,
> + O_WRONLY | O_CREAT | O_TRUNC, 0600);
> + if (fd == -1)
> + return -errno;
> +
> + ret = write(fd, (u8 *)&hdr, sizeof(hdr));
> + if (ret != sizeof(hdr))
> + return -errno;
> +
> + if (algo != HASH_ALGO_MD5) {
> + ret = write(fd, (u8 *)&algo_entry, sizeof(algo_entry));
> + if (ret != sizeof(algo_entry))
> + return -errno;
> + }
> +
> + ret = write(fd, (u8 *)&digest_entry, sizeof(digest_entry));
> + if (ret != sizeof(digest_entry))
> + return -errno;
> +
> + *(u32 *)digest = start_number;
> +
> + for (i = 0; i < num_digests; i++) {
> + bin2hex(digest_str, digest, digest_len);
> +
> + ret = write(fd, (u8 *)digest_str, d_len);
> + if (ret != d_len)
> + return -errno;
> +
> + (*(u32 *)digest)++;
> + }
> +
> + if (algo != HASH_ALGO_MD5) {
> + ret = write(fd, (u8 *)&_pgp_algo, sizeof(_pgp_algo));
> + if (ret != sizeof(_pgp_algo))
> + return -errno;
> + }
> +
> + close(fd);
> + return 0;
> +}
> +
> +int create_file(int temp_dirfd, char *filename, char *digest_list_filename)
> +{
> + int ret = 0, fd;
> +
> + fd = openat(temp_dirfd, filename, O_WRONLY | O_CREAT | O_TRUNC, 0600);
> + if (fd == -1)
> + return -errno;
> +
> + if (!digest_list_filename)
> + goto out;
> +
> + ret = fsetxattr(fd, XATTR_NAME_DIGEST_LIST, digest_list_filename,
> + strlen(digest_list_filename) + 1, 0);
> + if (ret == -1)
> + ret = -errno;
> +out:
> + close(fd);
> + return ret;
> +}
> diff --git a/tools/testing/selftests/digest_cache/generators.h b/tools/testing/selftests/digest_cache/generators.h
> new file mode 100644
> index 000000000000..1c83e531b799
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/generators.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Header of generators.c.
> + */
> +
> +#include "common.h"
> +#include "common_user.h"
> +
> +int gen_tlv_list(int temp_dirfd, char *digest_list_filename,
> + enum hash_algo algo, int start_number, int num_digests,
> + enum tlv_failures failure);
> +int gen_rpm_list(int temp_dirfd, char *digest_list_filename,
> + enum hash_algo algo, enum pgp_algos pgp_algo, int start_number,
> + int num_digests, enum rpm_failures failure);
> +int create_file(int temp_dirfd, char *filename, char *digest_list_filename);
> diff --git a/tools/testing/selftests/digest_cache/testmod/Makefile b/tools/testing/selftests/digest_cache/testmod/Makefile
> new file mode 100644
> index 000000000000..1ba1c7f08658
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/testmod/Makefile
> @@ -0,0 +1,16 @@
> +KDIR ?= ../../../../..
> +
> +MODULES = digest_cache_kern.ko
> +
> +obj-m += digest_cache_kern.o
> +
> +digest_cache_kern-y := kern.o ../common.o
> +
> +all:
> + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD modules
> +
> +clean:
> + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD clean
> +
> +install: all
> + +$(Q)$(MAKE) -C $(KDIR) M=$$PWD modules_install
> diff --git a/tools/testing/selftests/digest_cache/testmod/kern.c b/tools/testing/selftests/digest_cache/testmod/kern.c
> new file mode 100644
> index 000000000000..7215ef638e66
> --- /dev/null
> +++ b/tools/testing/selftests/digest_cache/testmod/kern.c
> @@ -0,0 +1,564 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2024 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@huawei.com>
> + *
> + * Implement the kernel module to interact with the digest_cache LSM.
> + */
> +
> +#define pr_fmt(fmt) "DIGEST CACHE TEST: "fmt
> +#include <linux/module.h>
> +#include <linux/namei.h>
> +#include <linux/security.h>
> +#include <linux/dynamic_debug.h>
> +#include <linux/digest_cache.h>
> +#include <linux/kprobes.h>
> +#include <linux/cpu.h>
> +#include <linux/kernel_read_file.h>
> +#include <crypto/hash_info.h>
> +
> +#include "../common.h"
> +
> +struct verif {
> + int (*update)(struct file *file);
> + ssize_t (*read)(struct file *file, char __user *buf, size_t datalen,
> + loff_t *ppos);
> + bool enabled;
> +};
> +
> +struct read_work {
> + struct work_struct work;
> + char *path_str;
> + int ret;
> +};
> +
> +static struct dentry *test, *notify_inodes;
> +static struct digest_cache *digest_cache;
> +static digest_cache_found_t found;
> +static int cur_verif_index;
> +static u8 prefetch_buf[4096];
> +static u8 notify_inodes_buf[4096];
> +static struct read_work w[MAX_WORKS];
> +
> +static int filenames_update(struct file *file)
> +{
> + char *filename = (char *)file->f_path.dentry->d_name.name;
> +
> + return digest_cache_verif_set(file, "filenames", filename,
> + strlen(filename) + 1);
> +}
> +
> +static int number_update(struct file *file)
> +{
> + const char *filename = file_dentry(file)->d_name.name;
> + size_t filename_len = strlen(filename);
> + u64 number = U64_MAX;
> + int ret;
> +
> + while (filename_len) {
> + if (filename[filename_len - 1] < '0' ||
> + filename[filename_len - 1] > '9')
> + break;
> +
> + filename_len--;
> + }
> +
> + ret = kstrtoull(filename + filename_len, 10, &number);
> + if (ret < 0) {
> + pr_debug("Failed to convert filename %s into number\n",
> + file_dentry(file)->d_name.name);
> + return ret;
> + }
> +
> + return digest_cache_verif_set(file, "number", &number, sizeof(number));
> +}
> +
> +static ssize_t filenames_read(struct file *file, char __user *buf,
> + size_t datalen, loff_t *ppos)
> +{
> + loff_t _ppos = 0;
> + char *filenames_list;
> +
> + filenames_list = digest_cache_verif_get(found ?
> + digest_cache_from_found_t(found) : digest_cache,
> + verifs_str[VERIF_FILENAMES]);
> + if (!filenames_list)
> + return -ENOENT;
> +
> + return simple_read_from_buffer(buf, datalen, &_ppos, filenames_list,
> + strlen(filenames_list) + 1);
> +}
> +
> +static ssize_t number_read(struct file *file, char __user *buf, size_t datalen,
> + loff_t *ppos)
> +{
> + loff_t _ppos = 0;
> + u64 *number;
> + char temp[20];
> + ssize_t len;
> +
> + number = digest_cache_verif_get(found ?
> + digest_cache_from_found_t(found) :
> + digest_cache, verifs_str[VERIF_NUMBER]);
> + if (!number)
> + return -ENOENT;
> +
> + len = snprintf(temp, sizeof(temp), "%llu", *number);
> +
> + return simple_read_from_buffer(buf, datalen, &_ppos, temp, len);
> +}
> +
> +static int prefetch_update(struct file *file)
> +{
> + char *filename = (char *)file->f_path.dentry->d_name.name;
> + char *start_ptr = prefetch_buf, *end_ptr;
> + int ret;
> +
> + ret = digest_cache_verif_set(file, "probe_digest_cache", "1", 1);
> + if (!ret) {
> + /* Don't include duplicates of requested digest lists. */
> + while ((end_ptr = strchrnul(start_ptr, ','))) {
> + if (end_ptr > start_ptr &&
> + !strncmp(start_ptr, filename, end_ptr - start_ptr))
> + return 0;
> +
> + if (!*end_ptr)
> + break;
> +
> + start_ptr = end_ptr + 1;
> + }
> + }
> +
> + if (prefetch_buf[0])
> + strlcat(prefetch_buf, ",", sizeof(prefetch_buf));
> +
> + strlcat(prefetch_buf, filename, sizeof(prefetch_buf));
> + return 0;
> +}
> +
> +static ssize_t prefetch_read(struct file *file, char __user *buf,
> + size_t datalen, loff_t *ppos)
> +{
> + loff_t _ppos = 0;
> + ssize_t ret;
> +
> + ret = simple_read_from_buffer(buf, datalen, &_ppos, prefetch_buf,
> + strlen(prefetch_buf) + 1);
> + memset(prefetch_buf, 0, sizeof(prefetch_buf));
> + return ret;
> +}
> +
> +static int test_digest_cache_change(struct notifier_block *nb,
> + unsigned long event, void *data)
> +{
> + struct digest_cache_event_data *event_data = data;
> + char i_ino_str[10];
> +
> + if (event != DIGEST_CACHE_RESET)
> + return NOTIFY_DONE;
> +
> + if (notify_inodes_buf[0])
> + strlcat(notify_inodes_buf, ",", sizeof(notify_inodes_buf));
> +
> + snprintf(i_ino_str, sizeof(i_ino_str), "%lu", event_data->inode->i_ino);
> + strlcat(notify_inodes_buf, i_ino_str, sizeof(notify_inodes_buf));
> + return 0;
> +}
> +
> +static struct notifier_block digest_cache_notifier = {
> + .notifier_call = test_digest_cache_change,
> +};
> +
> +static ssize_t write_notify_inodes(struct file *file, const char __user *buf,
> + size_t datalen, loff_t *ppos)
> +{
> + memset(notify_inodes_buf, 0, sizeof(notify_inodes_buf));
> + return datalen;
> +}
> +
> +static ssize_t read_notify_inodes(struct file *file, char __user *buf,
> + size_t datalen, loff_t *ppos)
> +{
> + loff_t _ppos = 0;
> +
> + return simple_read_from_buffer(buf, datalen, &_ppos, notify_inodes_buf,
> + strlen(notify_inodes_buf) + 1);
> +}
> +
> +static struct verif verifs_methods[] = {
> + [VERIF_FILENAMES] = { .update = filenames_update,
> + .read = filenames_read },
> + [VERIF_NUMBER] = { .update = number_update, .read = number_read },
> + [VERIF_PREFETCH] = { .update = prefetch_update, .read = prefetch_read },
> +};
> +
> +static void digest_cache_get_put_work(struct work_struct *work)
> +{
> + struct read_work *w = container_of(work, struct read_work, work);
> + struct digest_cache *digest_cache;
> + struct path path;
> +
> + w->ret = kern_path(w->path_str, 0, &path);
> + if (w->ret < 0)
> + return;
> +
> + digest_cache = digest_cache_get(path.dentry);
> +
> + path_put(&path);
> +
> + if (!digest_cache) {
> + w->ret = -ENOENT;
> + return;
> + }
> +
> + digest_cache_put(digest_cache);
> + w->ret = 0;
> +}
> +
> +static int digest_cache_get_put_async(char *path_str, int start_number,
> + int end_number)
> +{
> + int ret = 0, i;
> +
> + cpus_read_lock();
> + for (i = start_number; i <= end_number; i++) {
> + w[i].path_str = kasprintf(GFP_KERNEL, "%s%u", path_str, i);
> + if (!w[i].path_str) {
> + ret = -ENOMEM;
> + break;
> + }
> +
> + INIT_WORK_ONSTACK(&w[i].work, digest_cache_get_put_work);
> + schedule_work_on(i % num_online_cpus(), &w[i].work);
> + }
> + cpus_read_unlock();
> +
> + for (i = start_number; i <= end_number; i++) {
> + if (!w[i].path_str)
> + continue;
> +
> + flush_work(&w[i].work);
> + destroy_work_on_stack(&w[i].work);
> + kfree(w[i].path_str);
> + w[i].path_str = NULL;
> + if (!ret)
> + ret = w[i].ret;
> + }
> +
> + return ret;
> +}
> +
> +static ssize_t write_request(struct file *file, const char __user *buf,
> + size_t datalen, loff_t *ppos)
> +{
> + char *data, *data_ptr, *cmd_str, *path_str, *algo_str, *digest_str;
> + char *verif_name_str, *start_number_str, *end_number_str;
> + u8 digest[64];
> + struct path path;
> + int ret, cmd, algo, verif_index, start_number, end_number;
> +
> + data = memdup_user_nul(buf, datalen);
> + if (IS_ERR(data))
> + return PTR_ERR(data);
> +
> + data_ptr = data;
> +
> + cmd_str = strsep(&data_ptr, "|");
> + if (!cmd_str) {
> + pr_debug("No command\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + cmd = match_string(commands_str, DIGEST_CACHE__LAST, cmd_str);
> + if (cmd < 0) {
> + pr_err("Unknown command %s\n", cmd_str);
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + switch (cmd) {
> + case DIGEST_CACHE_GET:
> + found = 0UL;
> +
> + path_str = strsep(&data_ptr, "|");
> + if (!path_str) {
> + pr_debug("No path\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = kern_path(path_str, 0, &path);
> + if (ret < 0) {
> + pr_debug("Cannot find file %s\n", path_str);
> + goto out;
> + }
> +
> + if (digest_cache) {
> + pr_debug("Digest cache exists, doing a put\n");
> + digest_cache_put(digest_cache);
> + }
> +
> + digest_cache = digest_cache_get(path.dentry);
> + ret = digest_cache ? 0 : -ENOENT;
> + pr_debug("digest cache get %s, ret: %d\n", path_str, ret);
> + path_put(&path);
> + break;
> + case DIGEST_CACHE_LOOKUP:
> + if (!digest_cache) {
> + pr_debug("No digest cache\n");
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + path_str = strsep(&data_ptr, "|");
> + if (!path_str) {
> + pr_debug("No path\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + algo_str = strsep(&data_ptr, ":");
> + digest_str = data_ptr;
> +
> + if (!algo_str || !digest_str) {
> + pr_debug("No algo or digest\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + algo = match_string(hash_algo_name, HASH_ALGO__LAST, algo_str);
> + if (algo < 0) {
> + pr_err("Unknown algorithm %s", algo_str);
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + ret = hex2bin(digest, digest_str, hash_digest_size[algo]);
> + if (ret < 0) {
> + pr_debug("Invalid digest %s\n", digest_str);
> + goto out;
> + }
> +
> + ret = kern_path(path_str, 0, &path);
> + if (ret < 0) {
> + pr_debug("Cannot find file %s\n", path_str);
> + goto out;
> + }
> +
> + ret = -ENOENT;
> +
> + found = digest_cache_lookup(path.dentry, digest_cache, digest,
> + algo);
> + path_put(&path);
> + if (found)
> + ret = 0;
> +
> + pr_debug("%s:%s lookup %s, ret: %d\n", algo_str, digest_str,
> + path_str, ret);
> + break;
> + case DIGEST_CACHE_PUT:
> + if (digest_cache) {
> + digest_cache_put(digest_cache);
> + digest_cache = NULL;
> + }
> + ret = 0;
> + pr_debug("digest cache put, ret: %d\n", ret);
> + break;
> + case DIGEST_CACHE_ENABLE_VERIF:
> + case DIGEST_CACHE_DISABLE_VERIF:
> + memset(prefetch_buf, 0, sizeof(prefetch_buf));
> + fallthrough;
> + case DIGEST_CACHE_SET_VERIF:
> + verif_name_str = strsep(&data_ptr, "|");
> + if (!verif_name_str) {
> + pr_debug("No verifier name\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + verif_index = match_string(verifs_str, ARRAY_SIZE(verifs_str),
> + verif_name_str);
> + if (verif_index < 0) {
> + pr_err("Unknown verifier name %s\n", verif_name_str);
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + if (cmd == DIGEST_CACHE_ENABLE_VERIF)
> + verifs_methods[verif_index].enabled = true;
> + else if (cmd == DIGEST_CACHE_DISABLE_VERIF)
> + verifs_methods[verif_index].enabled = false;
> + else
> + cur_verif_index = verif_index;
> +
> + ret = 0;
> + pr_debug("digest cache %s %s, ret: %d\n", cmd_str,
> + verif_name_str, ret);
> + break;
> + case DIGEST_CACHE_GET_PUT_ASYNC:
> + path_str = strsep(&data_ptr, "|");
> + if (!path_str) {
> + pr_debug("No path\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + start_number_str = strsep(&data_ptr, "|");
> + if (!start_number_str) {
> + pr_debug("No start number\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = kstrtoint(start_number_str, 10, &start_number);
> + if (ret < 0) {
> + pr_debug("Invalid start number %s\n", start_number_str);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + end_number_str = strsep(&data_ptr, "|");
> + if (!end_number_str) {
> + pr_debug("No end number\n");
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = kstrtoint(end_number_str, 10, &end_number);
> + if (ret < 0) {
> + pr_debug("Invalid end number %s\n", end_number_str);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + if (end_number - start_number >= MAX_WORKS) {
> + pr_debug("Too many works (%d), max %d\n",
> + end_number - start_number, MAX_WORKS - 1);
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = digest_cache_get_put_async(path_str, start_number,
> + end_number);
> + pr_debug("digest cache %s on %s, start: %d, end: %d, ret: %d\n",
> + cmd_str, path_str, start_number, end_number, ret);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +out:
> + kfree(data);
> + return ret ?: datalen;
> +}
> +
> +static ssize_t read_request(struct file *file, char __user *buf, size_t datalen,
> + loff_t *ppos)
> +{
> + return verifs_methods[cur_verif_index].read(file, buf, datalen, ppos);
> +}
> +
> +static const struct file_operations digest_cache_test_ops = {
> + .open = generic_file_open,
> + .write = write_request,
> + .read = read_request,
> + .llseek = generic_file_llseek,
> +};
> +
> +static const struct file_operations digest_cache_notify_inodes_ops = {
> + .open = generic_file_open,
> + .write = write_notify_inodes,
> + .read = read_notify_inodes,
> + .llseek = generic_file_llseek,
> +};
> +
> +static int __kprobes kernel_post_read_file_hook(struct kprobe *p,
> + struct pt_regs *regs)
> +{
> +#ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
> + struct file *file = (struct file *)regs_get_kernel_argument(regs, 0);
> + enum kernel_read_file_id id = regs_get_kernel_argument(regs, 3);
> +#else
> + struct file *file = NULL;
> + enum kernel_read_file_id id = READING_UNKNOWN;
> +#endif
> + int ret, i;
> +
> + if (id != READING_DIGEST_LIST)
> + return 0;
> +
> + for (i = 0; i < ARRAY_SIZE(verifs_methods); i++) {
> + if (!verifs_methods[i].enabled)
> + continue;
> +
> + ret = verifs_methods[i].update(file);
> + if (ret < 0)
> + return 0;
> + }
> +
> + return 0;
> +}
> +
> +static struct kprobe kp = {
> + .symbol_name = "security_kernel_post_read_file",
> +};
> +
> +static int __init digest_cache_test_init(void)
> +{
> + int ret;
> +
> + kp.pre_handler = kernel_post_read_file_hook;
> +
> + ret = register_kprobe(&kp);
> + if (ret < 0) {
> + pr_err("register_kprobe failed, returned %d\n", ret);
> + return ret;
> + }
> +
> + test = securityfs_create_file("digest_cache_test", 0660, NULL, NULL,
> + &digest_cache_test_ops);
> + if (IS_ERR(test)) {
> + ret = PTR_ERR(test);
> + goto out_kprobe;
> + }
> +
> + notify_inodes = securityfs_create_file("digest_cache_notify_inodes",
> + 0660, NULL, NULL,
> + &digest_cache_notify_inodes_ops);
> + if (IS_ERR(notify_inodes)) {
> + ret = PTR_ERR(notify_inodes);
> + goto out_test;
> + }
> +
> + ret = digest_cache_register_notifier(&digest_cache_notifier);
> + if (ret < 0)
> + goto out_notify_inodes;
> +
> + return 0;
> +
> +out_notify_inodes:
> + securityfs_remove(notify_inodes);
> +out_test:
> + securityfs_remove(test);
> +out_kprobe:
> + unregister_kprobe(&kp);
> + return ret;
> +}
> +
> +static void __exit digest_cache_test_fini(void)
> +{
> + if (digest_cache)
> + digest_cache_put(digest_cache);
> +
> + digest_cache_unregister_notifier(&digest_cache_notifier);
> + securityfs_remove(notify_inodes);
> + securityfs_remove(test);
> + unregister_kprobe(&kp);
> + pr_debug("kprobe at %p unregistered\n", kp.addr);
> +}
> +
> +module_init(digest_cache_test_init);
> +module_exit(digest_cache_test_fini);
> +MODULE_LICENSE("GPL");

BR, Jarkko