From fe977716b40cb98cf9c91a66454adf3dc2f8c59a Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 11 Nov 2023 09:00:29 +0000 Subject: [PATCH 1/6] bpf: Add a new kfunc for cgroup1 hierarchy A new kfunc is added to acquire cgroup1 of a task: - bpf_task_get_cgroup1 Acquires the associated cgroup of a task whithin a specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its hierarchy ID. This new kfunc enables the tracing of tasks within a designated container or cgroup directory in BPF programs. Suggested-by: Tejun Heo Signed-off-by: Yafang Shao Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20231111090034.4248-2-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/helpers.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 03517db5cfb36..b45a8381f9bda 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2228,6 +2228,25 @@ __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task, rcu_read_unlock(); return ret; } + +/** + * bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a + * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its + * hierarchy ID. + * @task: The target task + * @hierarchy_id: The ID of a cgroup1 hierarchy + * + * On success, the cgroup is returen. On failure, NULL is returned. + */ +__bpf_kfunc struct cgroup * +bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) +{ + struct cgroup *cgrp = task_get_cgroup1(task, hierarchy_id); + + if (IS_ERR(cgrp)) + return NULL; + return cgrp; +} #endif /* CONFIG_CGROUPS */ /** @@ -2534,6 +2553,7 @@ BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE) BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU) +BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL) #endif BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_throw) From 4849775587844e44d215289c425bcd70f315efe7 Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 11 Nov 2023 09:00:30 +0000 Subject: [PATCH 2/6] selftests/bpf: Fix issues in setup_classid_environment() If the net_cls subsystem is already mounted, attempting to mount it again in setup_classid_environment() will result in a failure with the error code EBUSY. Despite this, tmpfs will have been successfully mounted at /sys/fs/cgroup/net_cls. Consequently, the /sys/fs/cgroup/net_cls directory will be empty, causing subsequent setup operations to fail. Here's an error log excerpt illustrating the issue when net_cls has already been mounted at /sys/fs/cgroup/net_cls prior to running setup_classid_environment(): - Before that change $ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2 test_cgroup_v1v2:PASS:server_fd 0 nsec test_cgroup_v1v2:PASS:client_fd 0 nsec test_cgroup_v1v2:PASS:cgroup_fd 0 nsec test_cgroup_v1v2:PASS:server_fd 0 nsec run_test:PASS:skel_open 0 nsec run_test:PASS:prog_attach 0 nsec test_cgroup_v1v2:PASS:cgroup-v2-only 0 nsec (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs (cgroup_helpers.c:540: errno: No such file or directory) Opening cgroup classid: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/net_cls.classid run_test:PASS:skel_open 0 nsec run_test:PASS:prog_attach 0 nsec (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/cgroup.procs run_test:FAIL:join_classid unexpected error: 1 (errno 2) test_cgroup_v1v2:FAIL:cgroup-v1v2 unexpected error: -1 (errno 2) (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs #44 cgroup_v1v2:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED - After that change $ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2 #44 cgroup_v1v2:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Yafang Shao Link: https://lore.kernel.org/r/20231111090034.4248-3-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/cgroup_helpers.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 5b1da2a32ea72..10b5f42e65e78 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -523,10 +523,20 @@ int setup_classid_environment(void) return 1; } - if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls") && - errno != EBUSY) { - log_err("mount cgroup net_cls"); - return 1; + if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls")) { + if (errno != EBUSY) { + log_err("mount cgroup net_cls"); + return 1; + } + + if (rmdir(NETCLS_MOUNT_PATH)) { + log_err("rmdir cgroup net_cls"); + return 1; + } + if (umount(CGROUP_MOUNT_DFLT)) { + log_err("umount cgroup base"); + return 1; + } } cleanup_classid_environment(); From f744d35ecf46f111bf9b54bfdbc89a28ee8b928a Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 11 Nov 2023 09:00:31 +0000 Subject: [PATCH 3/6] selftests/bpf: Add parallel support for classid Include the current pid in the classid cgroup path. This way, different testers relying on classid-based configurations will have distinct classid cgroup directories, enabling them to run concurrently. Additionally, we leverage the current pid as the classid, ensuring unique identification. Signed-off-by: Yafang Shao Link: https://lore.kernel.org/r/20231111090034.4248-4-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/cgroup_helpers.c | 18 +++++++++++------- tools/testing/selftests/bpf/cgroup_helpers.h | 2 +- .../selftests/bpf/prog_tests/cgroup_v1v2.c | 2 +- 3 files changed, 13 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 10b5f42e65e78..f18649a79d646 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -45,9 +45,12 @@ #define format_parent_cgroup_path(buf, path) \ format_cgroup_path_pid(buf, path, getppid()) -#define format_classid_path(buf) \ - snprintf(buf, sizeof(buf), "%s%s", NETCLS_MOUNT_PATH, \ - CGROUP_WORK_DIR) +#define format_classid_path_pid(buf, pid) \ + snprintf(buf, sizeof(buf), "%s%s%d", NETCLS_MOUNT_PATH, \ + CGROUP_WORK_DIR, pid) + +#define format_classid_path(buf) \ + format_classid_path_pid(buf, getpid()) static __thread bool cgroup_workdir_mounted; @@ -551,15 +554,16 @@ int setup_classid_environment(void) /** * set_classid() - Set a cgroupv1 net_cls classid - * @id: the numeric classid * - * Writes the passed classid into the cgroup work dir's net_cls.classid + * Writes the classid into the cgroup work dir's net_cls.classid * file in order to later on trigger socket tagging. * + * We leverage the current pid as the classid, ensuring unique identification. + * * On success, it returns 0, otherwise on failure it returns 1. If there * is a failure, it prints the error to stderr. */ -int set_classid(unsigned int id) +int set_classid(void) { char cgroup_workdir[PATH_MAX - 42]; char cgroup_classid_path[PATH_MAX + 1]; @@ -575,7 +579,7 @@ int set_classid(unsigned int id) return 1; } - if (dprintf(fd, "%u\n", id) < 0) { + if (dprintf(fd, "%u\n", getpid()) < 0) { log_err("Setting cgroup classid"); rc = 1; } diff --git a/tools/testing/selftests/bpf/cgroup_helpers.h b/tools/testing/selftests/bpf/cgroup_helpers.h index 5c2cb9c8b5463..92fc41daf4a4f 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.h +++ b/tools/testing/selftests/bpf/cgroup_helpers.h @@ -29,7 +29,7 @@ int setup_cgroup_environment(void); void cleanup_cgroup_environment(void); /* cgroupv1 related */ -int set_classid(unsigned int id); +int set_classid(void); int join_classid(void); int setup_classid_environment(void); diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_v1v2.c b/tools/testing/selftests/bpf/prog_tests/cgroup_v1v2.c index 9026b42914d31..addf720428f7d 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_v1v2.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_v1v2.c @@ -71,7 +71,7 @@ void test_cgroup_v1v2(void) } ASSERT_OK(run_test(cgroup_fd, server_fd, false), "cgroup-v2-only"); setup_classid_environment(); - set_classid(42); + set_classid(); ASSERT_OK(run_test(cgroup_fd, server_fd, true), "cgroup-v1v2"); cleanup_classid_environment(); close(server_fd); From c1dcc050aa648bb3b831030d547c3fcc1c68140c Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 11 Nov 2023 09:00:32 +0000 Subject: [PATCH 4/6] selftests/bpf: Add a new cgroup helper get_classid_cgroup_id() Introduce a new helper function to retrieve the cgroup ID from a net_cls cgroup directory. Signed-off-by: Yafang Shao Link: https://lore.kernel.org/r/20231111090034.4248-5-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/cgroup_helpers.c | 28 +++++++++++++++----- tools/testing/selftests/bpf/cgroup_helpers.h | 1 + 2 files changed, 23 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index f18649a79d646..63bfa72185be2 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -422,26 +422,23 @@ int create_and_get_cgroup(const char *relative_path) } /** - * get_cgroup_id() - Get cgroup id for a particular cgroup path - * @relative_path: The cgroup path, relative to the workdir, to join + * get_cgroup_id_from_path - Get cgroup id for a particular cgroup path + * @cgroup_workdir: The absolute cgroup path * * On success, it returns the cgroup id. On failure it returns 0, * which is an invalid cgroup id. * If there is a failure, it prints the error to stderr. */ -unsigned long long get_cgroup_id(const char *relative_path) +unsigned long long get_cgroup_id_from_path(const char *cgroup_workdir) { int dirfd, err, flags, mount_id, fhsize; union { unsigned long long cgid; unsigned char raw_bytes[8]; } id; - char cgroup_workdir[PATH_MAX + 1]; struct file_handle *fhp, *fhp2; unsigned long long ret = 0; - format_cgroup_path(cgroup_workdir, relative_path); - dirfd = AT_FDCWD; flags = 0; fhsize = sizeof(*fhp); @@ -477,6 +474,14 @@ unsigned long long get_cgroup_id(const char *relative_path) return ret; } +unsigned long long get_cgroup_id(const char *relative_path) +{ + char cgroup_workdir[PATH_MAX + 1]; + + format_cgroup_path(cgroup_workdir, relative_path); + return get_cgroup_id_from_path(cgroup_workdir); +} + int cgroup_setup_and_join(const char *path) { int cg_fd; @@ -621,3 +626,14 @@ void cleanup_classid_environment(void) join_cgroup_from_top(NETCLS_MOUNT_PATH); nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT); } + +/** + * get_classid_cgroup_id - Get the cgroup id of a net_cls cgroup + */ +unsigned long long get_classid_cgroup_id(void) +{ + char cgroup_workdir[PATH_MAX + 1]; + + format_classid_path(cgroup_workdir); + return get_cgroup_id_from_path(cgroup_workdir); +} diff --git a/tools/testing/selftests/bpf/cgroup_helpers.h b/tools/testing/selftests/bpf/cgroup_helpers.h index 92fc41daf4a4f..e71da4ef031be 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.h +++ b/tools/testing/selftests/bpf/cgroup_helpers.h @@ -31,6 +31,7 @@ void cleanup_cgroup_environment(void); /* cgroupv1 related */ int set_classid(void); int join_classid(void); +unsigned long long get_classid_cgroup_id(void); int setup_classid_environment(void); void cleanup_classid_environment(void); From bf47300b186facc8ae66a0e2aa89073565f82bb3 Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 11 Nov 2023 09:00:33 +0000 Subject: [PATCH 5/6] selftests/bpf: Add a new cgroup helper get_cgroup_hierarchy_id() A new cgroup helper function, get_cgroup1_hierarchy_id(), has been introduced to obtain the ID of a cgroup1 hierarchy based on the provided cgroup name. This cgroup name can be obtained from the /proc/self/cgroup file. Signed-off-by: Yafang Shao Link: https://lore.kernel.org/r/20231111090034.4248-6-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/cgroup_helpers.c | 52 ++++++++++++++++++++ tools/testing/selftests/bpf/cgroup_helpers.h | 1 + 2 files changed, 53 insertions(+) diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 63bfa72185be2..5aa133bf36880 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -637,3 +637,55 @@ unsigned long long get_classid_cgroup_id(void) format_classid_path(cgroup_workdir); return get_cgroup_id_from_path(cgroup_workdir); } + +/** + * get_cgroup1_hierarchy_id - Retrieves the ID of a cgroup1 hierarchy from the cgroup1 subsys name. + * @subsys_name: The cgroup1 subsys name, which can be retrieved from /proc/self/cgroup. It can be + * a named cgroup like "name=systemd", a controller name like "net_cls", or multi-contollers like + * "net_cls,net_prio". + */ +int get_cgroup1_hierarchy_id(const char *subsys_name) +{ + char *c, *c2, *c3, *c4; + bool found = false; + char line[1024]; + FILE *file; + int i, id; + + if (!subsys_name) + return -1; + + file = fopen("/proc/self/cgroup", "r"); + if (!file) { + log_err("fopen /proc/self/cgroup"); + return -1; + } + + while (fgets(line, 1024, file)) { + i = 0; + for (c = strtok_r(line, ":", &c2); c && i < 2; c = strtok_r(NULL, ":", &c2)) { + if (i == 0) { + id = strtol(c, NULL, 10); + } else if (i == 1) { + if (!strcmp(c, subsys_name)) { + found = true; + break; + } + + /* Multiple subsystems may share one single mount point */ + for (c3 = strtok_r(c, ",", &c4); c3; + c3 = strtok_r(NULL, ",", &c4)) { + if (!strcmp(c, subsys_name)) { + found = true; + break; + } + } + } + i++; + } + if (found) + break; + } + fclose(file); + return found ? id : -1; +} diff --git a/tools/testing/selftests/bpf/cgroup_helpers.h b/tools/testing/selftests/bpf/cgroup_helpers.h index e71da4ef031be..ee053641c0267 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.h +++ b/tools/testing/selftests/bpf/cgroup_helpers.h @@ -20,6 +20,7 @@ int get_root_cgroup(void); int create_and_get_cgroup(const char *relative_path); void remove_cgroup(const char *relative_path); unsigned long long get_cgroup_id(const char *relative_path); +int get_cgroup1_hierarchy_id(const char *subsys_name); int join_cgroup(const char *relative_path); int join_root_cgroup(void); From 360769233cc9c921e90ae387d167ea3cd3cbb04c Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sat, 11 Nov 2023 09:00:34 +0000 Subject: [PATCH 6/6] selftests/bpf: Add selftests for cgroup1 hierarchy Add selftests for cgroup1 hierarchy. The result as follows, $ tools/testing/selftests/bpf/test_progs --name=cgroup1_hierarchy #36/1 cgroup1_hierarchy/test_cgroup1_hierarchy:OK #36/2 cgroup1_hierarchy/test_root_cgid:OK #36/3 cgroup1_hierarchy/test_invalid_level:OK #36/4 cgroup1_hierarchy/test_invalid_cgid:OK #36/5 cgroup1_hierarchy/test_invalid_hid:OK #36/6 cgroup1_hierarchy/test_invalid_cgrp_name:OK #36/7 cgroup1_hierarchy/test_invalid_cgrp_name2:OK #36/8 cgroup1_hierarchy/test_sleepable_prog:OK #36 cgroup1_hierarchy:OK Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED Besides, I also did some stress test similar to the patch #2 in this series, as follows (with CONFIG_PROVE_RCU_LIST enabled): - Continuously mounting and unmounting named cgroups in some tasks, for example: cgrp_name=$1 while true do mount -t cgroup -o none,name=$cgrp_name none /$cgrp_name umount /$cgrp_name done - Continuously run this selftest concurrently, while true; do ./test_progs --name=cgroup1_hierarchy; done They can ran successfully without any RCU warnings in dmesg. Signed-off-by: Yafang Shao Link: https://lore.kernel.org/r/20231111090034.4248-7-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- .../bpf/prog_tests/cgroup1_hierarchy.c | 158 ++++++++++++++++++ .../bpf/progs/test_cgroup1_hierarchy.c | 71 ++++++++ 2 files changed, 229 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c create mode 100644 tools/testing/selftests/bpf/progs/test_cgroup1_hierarchy.c diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c b/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c new file mode 100644 index 0000000000000..74d6d7546f40f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/cgroup1_hierarchy.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 Yafang Shao */ + +#include +#include +#include +#include "cgroup_helpers.h" +#include "test_cgroup1_hierarchy.skel.h" + +static void bpf_cgroup1(struct test_cgroup1_hierarchy *skel) +{ + struct bpf_link *lsm_link, *fentry_link; + int err; + + /* Attach LSM prog first */ + lsm_link = bpf_program__attach_lsm(skel->progs.lsm_run); + if (!ASSERT_OK_PTR(lsm_link, "lsm_attach")) + return; + + /* LSM prog will be triggered when attaching fentry */ + fentry_link = bpf_program__attach_trace(skel->progs.fentry_run); + ASSERT_NULL(fentry_link, "fentry_attach_fail"); + + err = bpf_link__destroy(lsm_link); + ASSERT_OK(err, "destroy_lsm"); +} + +static void bpf_cgroup1_sleepable(struct test_cgroup1_hierarchy *skel) +{ + struct bpf_link *lsm_link, *fentry_link; + int err; + + /* Attach LSM prog first */ + lsm_link = bpf_program__attach_lsm(skel->progs.lsm_s_run); + if (!ASSERT_OK_PTR(lsm_link, "lsm_attach")) + return; + + /* LSM prog will be triggered when attaching fentry */ + fentry_link = bpf_program__attach_trace(skel->progs.fentry_run); + ASSERT_NULL(fentry_link, "fentry_attach_fail"); + + err = bpf_link__destroy(lsm_link); + ASSERT_OK(err, "destroy_lsm"); +} + +static void bpf_cgroup1_invalid_id(struct test_cgroup1_hierarchy *skel) +{ + struct bpf_link *lsm_link, *fentry_link; + int err; + + /* Attach LSM prog first */ + lsm_link = bpf_program__attach_lsm(skel->progs.lsm_run); + if (!ASSERT_OK_PTR(lsm_link, "lsm_attach")) + return; + + /* LSM prog will be triggered when attaching fentry */ + fentry_link = bpf_program__attach_trace(skel->progs.fentry_run); + if (!ASSERT_OK_PTR(fentry_link, "fentry_attach_success")) + goto cleanup; + + err = bpf_link__destroy(fentry_link); + ASSERT_OK(err, "destroy_lsm"); + +cleanup: + err = bpf_link__destroy(lsm_link); + ASSERT_OK(err, "destroy_fentry"); +} + +void test_cgroup1_hierarchy(void) +{ + struct test_cgroup1_hierarchy *skel; + __u64 current_cgid; + int hid, err; + + skel = test_cgroup1_hierarchy__open(); + if (!ASSERT_OK_PTR(skel, "open")) + return; + + skel->bss->target_pid = getpid(); + + err = bpf_program__set_attach_target(skel->progs.fentry_run, 0, "bpf_fentry_test1"); + if (!ASSERT_OK(err, "fentry_set_target")) + goto destroy; + + err = test_cgroup1_hierarchy__load(skel); + if (!ASSERT_OK(err, "load")) + goto destroy; + + /* Setup cgroup1 hierarchy */ + err = setup_classid_environment(); + if (!ASSERT_OK(err, "setup_classid_environment")) + goto destroy; + + err = join_classid(); + if (!ASSERT_OK(err, "join_cgroup1")) + goto cleanup; + + current_cgid = get_classid_cgroup_id(); + if (!ASSERT_GE(current_cgid, 0, "cgroup1 id")) + goto cleanup; + + hid = get_cgroup1_hierarchy_id("net_cls"); + if (!ASSERT_GE(hid, 0, "cgroup1 id")) + goto cleanup; + skel->bss->target_hid = hid; + + if (test__start_subtest("test_cgroup1_hierarchy")) { + skel->bss->target_ancestor_cgid = current_cgid; + bpf_cgroup1(skel); + } + + if (test__start_subtest("test_root_cgid")) { + skel->bss->target_ancestor_cgid = 1; + skel->bss->target_ancestor_level = 0; + bpf_cgroup1(skel); + } + + if (test__start_subtest("test_invalid_level")) { + skel->bss->target_ancestor_cgid = 1; + skel->bss->target_ancestor_level = 1; + bpf_cgroup1_invalid_id(skel); + } + + if (test__start_subtest("test_invalid_cgid")) { + skel->bss->target_ancestor_cgid = 0; + bpf_cgroup1_invalid_id(skel); + } + + if (test__start_subtest("test_invalid_hid")) { + skel->bss->target_ancestor_cgid = 1; + skel->bss->target_ancestor_level = 0; + skel->bss->target_hid = -1; + bpf_cgroup1_invalid_id(skel); + } + + if (test__start_subtest("test_invalid_cgrp_name")) { + skel->bss->target_hid = get_cgroup1_hierarchy_id("net_cl"); + skel->bss->target_ancestor_cgid = current_cgid; + bpf_cgroup1_invalid_id(skel); + } + + if (test__start_subtest("test_invalid_cgrp_name2")) { + skel->bss->target_hid = get_cgroup1_hierarchy_id("net_cls,"); + skel->bss->target_ancestor_cgid = current_cgid; + bpf_cgroup1_invalid_id(skel); + } + + if (test__start_subtest("test_sleepable_prog")) { + skel->bss->target_hid = hid; + skel->bss->target_ancestor_cgid = current_cgid; + bpf_cgroup1_sleepable(skel); + } + +cleanup: + cleanup_classid_environment(); +destroy: + test_cgroup1_hierarchy__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_cgroup1_hierarchy.c b/tools/testing/selftests/bpf/progs/test_cgroup1_hierarchy.c new file mode 100644 index 0000000000000..44628865fe1d4 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_cgroup1_hierarchy.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023 Yafang Shao */ + +#include "vmlinux.h" +#include +#include +#include + +__u32 target_ancestor_level; +__u64 target_ancestor_cgid; +int target_pid, target_hid; + +struct cgroup *bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id) __ksym; +struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level) __ksym; +void bpf_cgroup_release(struct cgroup *cgrp) __ksym; + +static int bpf_link_create_verify(int cmd) +{ + struct cgroup *cgrp, *ancestor; + struct task_struct *task; + int ret = 0; + + if (cmd != BPF_LINK_CREATE) + return 0; + + task = bpf_get_current_task_btf(); + + /* Then it can run in parallel with others */ + if (task->pid != target_pid) + return 0; + + cgrp = bpf_task_get_cgroup1(task, target_hid); + if (!cgrp) + return 0; + + /* Refuse it if its cgid or its ancestor's cgid is the target cgid */ + if (cgrp->kn->id == target_ancestor_cgid) + ret = -1; + + ancestor = bpf_cgroup_ancestor(cgrp, target_ancestor_level); + if (!ancestor) + goto out; + + if (ancestor->kn->id == target_ancestor_cgid) + ret = -1; + bpf_cgroup_release(ancestor); + +out: + bpf_cgroup_release(cgrp); + return ret; +} + +SEC("lsm/bpf") +int BPF_PROG(lsm_run, int cmd, union bpf_attr *attr, unsigned int size) +{ + return bpf_link_create_verify(cmd); +} + +SEC("lsm.s/bpf") +int BPF_PROG(lsm_s_run, int cmd, union bpf_attr *attr, unsigned int size) +{ + return bpf_link_create_verify(cmd); +} + +SEC("fentry") +int BPF_PROG(fentry_run) +{ + return 0; +} + +char _license[] SEC("license") = "GPL";