From 341f06fdddf72cd60a10945152f69f0f1d614519 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 29 Nov 2023 15:44:16 -0800 Subject: selftests/bpf: Add tests for filesystem kfuncs Add selftests for two new filesystem kfuncs: 1. bpf_get_file_xattr 2. bpf_get_fsverity_digest These tests simply make sure the two kfuncs work. Another selftest will be added to demonstrate how to use these kfuncs to verify file signature. CONFIG_FS_VERITY is added to selftests config. However, this is not sufficient to guarantee bpf_get_fsverity_digest works. This is because fsverity need to be enabled at file system level (for example, with tune2fs on ext4). If local file system doesn't have this feature enabled, just skip the test. Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20231129234417.856536-6-song@kernel.org Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c | 134 +++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c (limited to 'tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c') diff --git a/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c b/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c new file mode 100644 index 000000000000..d3196a4b089f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include +#include +#include +#include "test_get_xattr.skel.h" +#include "test_fsverity.skel.h" + +static const char testfile[] = "/tmp/test_progs_fs_kfuncs"; + +static void test_xattr(void) +{ + struct test_get_xattr *skel = NULL; + int fd = -1, err; + + fd = open(testfile, O_CREAT | O_RDONLY, 0644); + if (!ASSERT_GE(fd, 0, "create_file")) + return; + + close(fd); + fd = -1; + + err = setxattr(testfile, "user.kfuncs", "hello", sizeof("hello"), 0); + if (!ASSERT_OK(err, "setxattr")) + goto out; + + skel = test_get_xattr__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_get_xattr__open_and_load")) + goto out; + + skel->bss->monitored_pid = getpid(); + err = test_get_xattr__attach(skel); + + if (!ASSERT_OK(err, "test_get_xattr__attach")) + goto out; + + fd = open(testfile, O_RDONLY, 0644); + if (!ASSERT_GE(fd, 0, "open_file")) + goto out; + + ASSERT_EQ(skel->bss->found_xattr, 1, "found_xattr"); + +out: + close(fd); + test_get_xattr__destroy(skel); + remove(testfile); +} + +#ifndef SHA256_DIGEST_SIZE +#define SHA256_DIGEST_SIZE 32 +#endif + +static void test_fsverity(void) +{ + struct fsverity_enable_arg arg = {0}; + struct test_fsverity *skel = NULL; + struct fsverity_digest *d; + int fd, err; + char buffer[4096]; + + fd = open(testfile, O_CREAT | O_RDWR, 0644); + if (!ASSERT_GE(fd, 0, "create_file")) + return; + + /* Write random buffer, so the file is not empty */ + err = write(fd, buffer, 4096); + if (!ASSERT_EQ(err, 4096, "write_file")) + goto out; + close(fd); + + /* Reopen read-only, otherwise FS_IOC_ENABLE_VERITY will fail */ + fd = open(testfile, O_RDONLY, 0644); + if (!ASSERT_GE(fd, 0, "open_file1")) + return; + + /* Enable fsverity for the file. + * If the file system doesn't support verity, this will fail. Skip + * the test in such case. + */ + arg.version = 1; + arg.hash_algorithm = FS_VERITY_HASH_ALG_SHA256; + arg.block_size = 4096; + err = ioctl(fd, FS_IOC_ENABLE_VERITY, &arg); + if (err) { + printf("%s:SKIP:local fs doesn't support fsverity (%d)\n" + "To run this test, try enable CONFIG_FS_VERITY and enable FSVerity for the filesystem.\n", + __func__, errno); + test__skip(); + goto out; + } + + skel = test_fsverity__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_fsverity__open_and_load")) + goto out; + + /* Get fsverity_digest from ioctl */ + d = (struct fsverity_digest *)skel->bss->expected_digest; + d->digest_algorithm = FS_VERITY_HASH_ALG_SHA256; + d->digest_size = SHA256_DIGEST_SIZE; + err = ioctl(fd, FS_IOC_MEASURE_VERITY, skel->bss->expected_digest); + if (!ASSERT_OK(err, "ioctl_FS_IOC_MEASURE_VERITY")) + goto out; + + skel->bss->monitored_pid = getpid(); + err = test_fsverity__attach(skel); + if (!ASSERT_OK(err, "test_fsverity__attach")) + goto out; + + /* Reopen the file to trigger the program */ + close(fd); + fd = open(testfile, O_RDONLY); + if (!ASSERT_GE(fd, 0, "open_file2")) + goto out; + + ASSERT_EQ(skel->bss->got_fsverity, 1, "got_fsverity"); + ASSERT_EQ(skel->bss->digest_matches, 1, "digest_matches"); +out: + close(fd); + test_fsverity__destroy(skel); + remove(testfile); +} + +void test_fs_kfuncs(void) +{ + if (test__start_subtest("xattr")) + test_xattr(); + + if (test__start_subtest("fsverity")) + test_fsverity(); +} -- cgit From f77d795618b92ac6fdb43de0d4036c6ce49f0b82 Mon Sep 17 00:00:00 2001 From: Manu Bretelle Date: Mon, 11 Dec 2023 10:07:33 -0800 Subject: selftests/bpf: Fixes tests for filesystem kfuncs `fs_kfuncs.c`'s `test_xattr` would fail the test even when the filesystem did not support xattr, for instance when /tmp is mounted as tmpfs. This change checks errno when setxattr fail. If the failure is due to the operation being unsupported, we will skip the test (just like we would if verity was not enabled on the FS. Before the change, fs_kfuncs test would fail in test_axattr: $ vmtest -k $(make -s image_name) './tools/testing/selftests/bpf/test_progs -a fs_kfuncs' => bzImage ===> Booting [ 0.000000] rcu: RCU restricting CPUs from NR_CPUS=128 to nr_cpu_ ===> Setting up VM ===> Running command [ 4.157491] bpf_testmod: loading out-of-tree module taints kernel. [ 4.161515] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel test_xattr:PASS:create_file 0 nsec test_xattr:FAIL:setxattr unexpected error: -1 (errno 95) #90/1 fs_kfuncs/xattr:FAIL #90/2 fs_kfuncs/fsverity:SKIP #90 fs_kfuncs:FAIL All error logs: test_xattr:PASS:create_file 0 nsec test_xattr:FAIL:setxattr unexpected error: -1 (errno 95) #90/1 fs_kfuncs/xattr:FAIL #90 fs_kfuncs:FAIL Summary: 0/0 PASSED, 1 SKIPPED, 1 FAILED Test plan: $ touch tmpfs_file && truncate -s 1G tmpfs_file && mkfs.ext4 tmpfs_file # /tmp mounted as tmpfs $ vmtest -k $(make -s image_name) './tools/testing/selftests/bpf/test_progs -a fs_kfuncs' => bzImage ===> Booting ===> Setting up VM ===> Running command WARNING! Selftests relying on bpf_testmod.ko will be skipped. Can't find bpf_testmod.ko kernel module: -2 #90/1 fs_kfuncs/xattr:SKIP #90/2 fs_kfuncs/fsverity:SKIP #90 fs_kfuncs:SKIP Summary: 1/0 PASSED, 2 SKIPPED, 0 FAILED # /tmp mounted as ext4 with xattr enabled but not verity $ vmtest -k $(make -s image_name) 'mount -o loop tmpfs_file /tmp && \ /tools/testing/selftests/bpf/test_progs -a fs_kfuncs' => bzImage ===> Booting ===> Setting up VM ===> Running command [ 4.067071] loop0: detected capacity change from 0 to 2097152 [ 4.191882] EXT4-fs (loop0): mounted filesystem 407ffa36-4553-4c8c-8c78-134443630f69 r/w with ordered data mode. Quota mode: none. WARNING! Selftests relying on bpf_testmod.ko will be skipped. Can't find bpf_testmod.ko kernel module: -2 #90/1 fs_kfuncs/xattr:OK #90/2 fs_kfuncs/fsverity:SKIP #90 fs_kfuncs:OK (SKIP: 1/2) Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED $ tune2fs -O verity tmpfs_file # /tmp as ext4 with both xattr and verity enabled $ vmtest -k $(make -s image_name) 'mount -o loop tmpfs_file /tmp && \ ./tools/testing/selftests/bpf/test_progs -a fs_kfuncs' => bzImage ===> Booting ===> Setting up VM ===> Running command [ 4.291434] loop0: detected capacity change from 0 to 2097152 [ 4.460828] EXT4-fs (loop0): recovery complete [ 4.468631] EXT4-fs (loop0): mounted filesystem 7b4a7b7f-c442-4b06-9ede-254e63cceb52 r/w with ordered data mode. Quota mode: none. [ 4.988074] fs-verity: sha256 using implementation "sha256-generic" WARNING! Selftests relying on bpf_testmod.ko will be skipped. Can't find bpf_testmod.ko kernel module: -2 #90/1 fs_kfuncs/xattr:OK #90/2 fs_kfuncs/fsverity:OK #90 fs_kfuncs:OK Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED Fixes: 341f06fdddf7 ("selftests/bpf: Add tests for filesystem kfuncs") Signed-off-by: Manu Bretelle Signed-off-by: Andrii Nakryiko Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20231211180733.763025-1-chantr4@gmail.com --- tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c') diff --git a/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c b/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c index d3196a4b089f..37056ba73847 100644 --- a/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c +++ b/tools/testing/selftests/bpf/prog_tests/fs_kfuncs.c @@ -25,6 +25,14 @@ static void test_xattr(void) fd = -1; err = setxattr(testfile, "user.kfuncs", "hello", sizeof("hello"), 0); + if (err && errno == EOPNOTSUPP) { + printf("%s:SKIP:local fs doesn't support xattr (%d)\n" + "To run this test, make sure /tmp filesystem supports xattr.\n", + __func__, errno); + test__skip(); + goto out; + } + if (!ASSERT_OK(err, "setxattr")) goto out; -- cgit