From: Song Liu Date: Fri, 27 Jun 2025 19:12:21 +0000 (-0700) Subject: selftests/bpf: Fix cgroup_xattr/read_cgroupfs_xattr X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bacdf5a0e69d343e2a380be768c1f277088e35d8;p=thirdparty%2Flinux.git selftests/bpf: Fix cgroup_xattr/read_cgroupfs_xattr cgroup_xattr/read_cgroupfs_xattr has two issues: 1. cgroup_xattr/read_cgroupfs_xattr messes up lo without creating a netns first. This causes issue with other tests. Fix this by using a different hook (lsm.s/file_open) and not messing with lo. 2. cgroup_xattr/read_cgroupfs_xattr sets up cgroups without proper mount namespaces. Fix this by using the existing cgroup helpers. A new helper set_cgroup_xattr() is added to set xattr on cgroup files. Fixes: f4fba2d6d282 ("selftests/bpf: Add tests for bpf_cgroup_read_xattr") Reported-by: Alexei Starovoitov Closes: https://lore.kernel.org/bpf/CAADnVQ+iqMi2HEj_iH7hsx+XJAsqaMWqSDe4tzcGAnehFWA9Sw@mail.gmail.com/ Signed-off-by: Song Liu Tested-by: Eduard Zingerman Tested-by: Ihor Solodrai Link: https://lore.kernel.org/r/20250627191221.765921-1-song@kernel.org Signed-off-by: Alexei Starovoitov --- diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index e4535451322ef..15f6260148728 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -318,6 +319,26 @@ int join_parent_cgroup(const char *relative_path) return join_cgroup_from_top(cgroup_path); } +/** + * set_cgroup_xattr() - Set xattr on a cgroup dir + * @relative_path: The cgroup path, relative to the workdir, to set xattr + * @name: xattr name + * @value: xattr value + * + * This function set xattr on cgroup dir. + * + * On success, it returns 0, otherwise on failure it returns -1. + */ +int set_cgroup_xattr(const char *relative_path, + const char *name, + const char *value) +{ + char cgroup_path[PATH_MAX + 1]; + + format_cgroup_path(cgroup_path, relative_path); + return setxattr(cgroup_path, name, value, strlen(value) + 1, 0); +} + /** * __cleanup_cgroup_environment() - Delete temporary cgroups * diff --git a/tools/testing/selftests/bpf/cgroup_helpers.h b/tools/testing/selftests/bpf/cgroup_helpers.h index 502845160d886..182e1ac36c95d 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.h +++ b/tools/testing/selftests/bpf/cgroup_helpers.h @@ -26,6 +26,10 @@ int join_cgroup(const char *relative_path); int join_root_cgroup(void); int join_parent_cgroup(const char *relative_path); +int set_cgroup_xattr(const char *relative_path, + const char *name, + const char *value); + int setup_cgroup_environment(void); void cleanup_cgroup_environment(void); diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_xattr.c b/tools/testing/selftests/bpf/prog_tests/cgroup_xattr.c index 87978a0f7eb7c..e0dd966e4a3ef 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_xattr.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_xattr.c @@ -7,133 +7,60 @@ #include #include #include -#include - #include +#include "cgroup_helpers.h" #include "read_cgroupfs_xattr.skel.h" #include "cgroup_read_xattr.skel.h" -#define CGROUP_FS_ROOT "/sys/fs/cgroup/" -#define CGROUP_FS_PARENT CGROUP_FS_ROOT "foo/" +#define CGROUP_FS_PARENT "foo/" #define CGROUP_FS_CHILD CGROUP_FS_PARENT "bar/" - -static int move_pid_to_cgroup(const char *cgroup_folder, pid_t pid) -{ - char filename[128]; - char pid_str[64]; - int procs_fd; - int ret; - - snprintf(filename, sizeof(filename), "%scgroup.procs", cgroup_folder); - snprintf(pid_str, sizeof(pid_str), "%d", pid); - - procs_fd = open(filename, O_WRONLY | O_APPEND); - if (!ASSERT_OK_FD(procs_fd, "open")) - return -1; - - ret = write(procs_fd, pid_str, strlen(pid_str)); - close(procs_fd); - if (!ASSERT_GT(ret, 0, "write cgroup.procs")) - return -1; - return 0; -} - -static void reset_cgroups_and_lo(void) -{ - rmdir(CGROUP_FS_CHILD); - rmdir(CGROUP_FS_PARENT); - system("ip addr del 1.1.1.1/32 dev lo"); - system("ip link set dev lo down"); -} +#define TMP_FILE "/tmp/selftests_cgroup_xattr" static const char xattr_value_a[] = "bpf_selftest_value_a"; static const char xattr_value_b[] = "bpf_selftest_value_b"; static const char xattr_name[] = "user.bpf_test"; -static int setup_cgroups_and_lo(void) -{ - int err; - - err = mkdir(CGROUP_FS_PARENT, 0755); - if (!ASSERT_OK(err, "mkdir 1")) - goto error; - err = mkdir(CGROUP_FS_CHILD, 0755); - if (!ASSERT_OK(err, "mkdir 2")) - goto error; - - err = setxattr(CGROUP_FS_PARENT, xattr_name, xattr_value_a, - strlen(xattr_value_a) + 1, 0); - if (!ASSERT_OK(err, "setxattr 1")) - goto error; - - err = setxattr(CGROUP_FS_CHILD, xattr_name, xattr_value_b, - strlen(xattr_value_b) + 1, 0); - if (!ASSERT_OK(err, "setxattr 2")) - goto error; - - err = system("ip link set dev lo up"); - if (!ASSERT_OK(err, "lo up")) - goto error; - - err = system("ip addr add 1.1.1.1 dev lo"); - if (!ASSERT_OK(err, "lo addr v4")) - goto error; - - err = write_sysctl("/proc/sys/net/ipv4/ping_group_range", "0 0"); - if (!ASSERT_OK(err, "write_sysctl")) - goto error; - - return 0; -error: - reset_cgroups_and_lo(); - return err; -} - static void test_read_cgroup_xattr(void) { - struct sockaddr_in sa4 = { - .sin_family = AF_INET, - .sin_addr.s_addr = htonl(INADDR_LOOPBACK), - }; + int tmp_fd, parent_cgroup_fd = -1, child_cgroup_fd = -1; struct read_cgroupfs_xattr *skel = NULL; - pid_t pid = gettid(); - int sock_fd = -1; - int connect_fd = -1; - if (!ASSERT_OK(setup_cgroups_and_lo(), "setup_cgroups_and_lo")) + parent_cgroup_fd = test__join_cgroup(CGROUP_FS_PARENT); + if (!ASSERT_OK_FD(parent_cgroup_fd, "create parent cgroup")) return; - if (!ASSERT_OK(move_pid_to_cgroup(CGROUP_FS_CHILD, pid), - "move_pid_to_cgroup")) + if (!ASSERT_OK(set_cgroup_xattr(CGROUP_FS_PARENT, xattr_name, xattr_value_a), + "set parent xattr")) + goto out; + + child_cgroup_fd = test__join_cgroup(CGROUP_FS_CHILD); + if (!ASSERT_OK_FD(child_cgroup_fd, "create child cgroup")) + goto out; + if (!ASSERT_OK(set_cgroup_xattr(CGROUP_FS_CHILD, xattr_name, xattr_value_b), + "set child xattr")) goto out; skel = read_cgroupfs_xattr__open_and_load(); if (!ASSERT_OK_PTR(skel, "read_cgroupfs_xattr__open_and_load")) goto out; - skel->bss->target_pid = pid; + skel->bss->target_pid = gettid(); if (!ASSERT_OK(read_cgroupfs_xattr__attach(skel), "read_cgroupfs_xattr__attach")) goto out; - sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP); - if (!ASSERT_OK_FD(sock_fd, "sock create")) - goto out; - - connect_fd = connect(sock_fd, &sa4, sizeof(sa4)); - if (!ASSERT_OK_FD(connect_fd, "connect 1")) - goto out; - close(connect_fd); + tmp_fd = open(TMP_FILE, O_RDONLY | O_CREAT); + ASSERT_OK_FD(tmp_fd, "open tmp file"); + close(tmp_fd); ASSERT_TRUE(skel->bss->found_value_a, "found_value_a"); ASSERT_TRUE(skel->bss->found_value_b, "found_value_b"); out: - close(connect_fd); - close(sock_fd); + close(child_cgroup_fd); + close(parent_cgroup_fd); read_cgroupfs_xattr__destroy(skel); - move_pid_to_cgroup(CGROUP_FS_ROOT, pid); - reset_cgroups_and_lo(); + unlink(TMP_FILE); } void test_cgroup_xattr(void) diff --git a/tools/testing/selftests/bpf/progs/read_cgroupfs_xattr.c b/tools/testing/selftests/bpf/progs/read_cgroupfs_xattr.c index 855f85fc5522b..405adbe5e8b03 100644 --- a/tools/testing/selftests/bpf/progs/read_cgroupfs_xattr.c +++ b/tools/testing/selftests/bpf/progs/read_cgroupfs_xattr.c @@ -17,8 +17,8 @@ static const char expected_value_b[] = "bpf_selftest_value_b"; bool found_value_a; bool found_value_b; -SEC("lsm.s/socket_connect") -int BPF_PROG(test_socket_connect) +SEC("lsm.s/file_open") +int BPF_PROG(test_file_open) { u64 cgrp_id = bpf_get_current_cgroup_id(); struct cgroup_subsys_state *css, *tmp;