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1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2021 Facebook */3 4#define _GNU_SOURCE /* See feature_test_macros(7) */5#include <unistd.h>6#include <sched.h>7#include <pthread.h>8#include <sys/syscall.h> /* For SYS_xxx definitions */9#include <sys/types.h>10#include <test_progs.h>11#include "task_local_storage_helpers.h"12#include "task_local_storage.skel.h"13#include "task_local_storage_exit_creds.skel.h"14#include "task_ls_recursion.skel.h"15#include "task_storage_nodeadlock.skel.h"16 17static void test_sys_enter_exit(void)18{19 struct task_local_storage *skel;20 int err;21 22 skel = task_local_storage__open_and_load();23 if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))24 return;25 26 skel->bss->target_pid = syscall(SYS_gettid);27 28 err = task_local_storage__attach(skel);29 if (!ASSERT_OK(err, "skel_attach"))30 goto out;31 32 syscall(SYS_gettid);33 syscall(SYS_gettid);34 35 /* 3x syscalls: 1x attach and 2x gettid */36 ASSERT_EQ(skel->bss->enter_cnt, 3, "enter_cnt");37 ASSERT_EQ(skel->bss->exit_cnt, 3, "exit_cnt");38 ASSERT_EQ(skel->bss->mismatch_cnt, 0, "mismatch_cnt");39out:40 task_local_storage__destroy(skel);41}42 43static void test_exit_creds(void)44{45 struct task_local_storage_exit_creds *skel;46 int err, run_count, sync_rcu_calls = 0;47 const int MAX_SYNC_RCU_CALLS = 1000;48 49 skel = task_local_storage_exit_creds__open_and_load();50 if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))51 return;52 53 err = task_local_storage_exit_creds__attach(skel);54 if (!ASSERT_OK(err, "skel_attach"))55 goto out;56 57 /* trigger at least one exit_creds() */58 if (CHECK_FAIL(system("ls > /dev/null")))59 goto out;60 61 /* kern_sync_rcu is not enough on its own as the read section we want62 * to wait for may start after we enter synchronize_rcu, so our call63 * won't wait for the section to finish. Loop on the run counter64 * as well to ensure the program has run.65 */66 do {67 kern_sync_rcu();68 run_count = __atomic_load_n(&skel->bss->run_count, __ATOMIC_SEQ_CST);69 } while (run_count == 0 && ++sync_rcu_calls < MAX_SYNC_RCU_CALLS);70 71 ASSERT_NEQ(sync_rcu_calls, MAX_SYNC_RCU_CALLS,72 "sync_rcu count too high");73 ASSERT_NEQ(run_count, 0, "run_count");74 ASSERT_EQ(skel->bss->valid_ptr_count, 0, "valid_ptr_count");75 ASSERT_NEQ(skel->bss->null_ptr_count, 0, "null_ptr_count");76out:77 task_local_storage_exit_creds__destroy(skel);78}79 80static void test_recursion(void)81{82 int err, map_fd, prog_fd, task_fd;83 struct task_ls_recursion *skel;84 struct bpf_prog_info info;85 __u32 info_len = sizeof(info);86 long value;87 88 task_fd = sys_pidfd_open(getpid(), 0);89 if (!ASSERT_NEQ(task_fd, -1, "sys_pidfd_open"))90 return;91 92 skel = task_ls_recursion__open_and_load();93 if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))94 goto out;95 96 err = task_ls_recursion__attach(skel);97 if (!ASSERT_OK(err, "skel_attach"))98 goto out;99 100 /* trigger sys_enter, make sure it does not cause deadlock */101 skel->bss->test_pid = getpid();102 syscall(SYS_gettid);103 skel->bss->test_pid = 0;104 task_ls_recursion__detach(skel);105 106 /* Refer to the comment in BPF_PROG(on_update) for107 * the explanation on the value 201 and 100.108 */109 map_fd = bpf_map__fd(skel->maps.map_a);110 err = bpf_map_lookup_elem(map_fd, &task_fd, &value);111 ASSERT_OK(err, "lookup map_a");112 ASSERT_EQ(value, 201, "map_a value");113 ASSERT_EQ(skel->bss->nr_del_errs, 1, "bpf_task_storage_delete busy");114 115 map_fd = bpf_map__fd(skel->maps.map_b);116 err = bpf_map_lookup_elem(map_fd, &task_fd, &value);117 ASSERT_OK(err, "lookup map_b");118 ASSERT_EQ(value, 100, "map_b value");119 120 prog_fd = bpf_program__fd(skel->progs.on_update);121 memset(&info, 0, sizeof(info));122 err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);123 ASSERT_OK(err, "get prog info");124 ASSERT_EQ(info.recursion_misses, 0, "on_update prog recursion");125 126 prog_fd = bpf_program__fd(skel->progs.on_enter);127 memset(&info, 0, sizeof(info));128 err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);129 ASSERT_OK(err, "get prog info");130 ASSERT_EQ(info.recursion_misses, 0, "on_enter prog recursion");131 132out:133 close(task_fd);134 task_ls_recursion__destroy(skel);135}136 137static bool stop;138 139static void waitall(const pthread_t *tids, int nr)140{141 int i;142 143 stop = true;144 for (i = 0; i < nr; i++)145 pthread_join(tids[i], NULL);146}147 148static void *sock_create_loop(void *arg)149{150 struct task_storage_nodeadlock *skel = arg;151 int fd;152 153 while (!stop) {154 fd = socket(AF_INET, SOCK_STREAM, 0);155 close(fd);156 if (skel->bss->nr_get_errs || skel->bss->nr_del_errs)157 stop = true;158 }159 160 return NULL;161}162 163static void test_nodeadlock(void)164{165 struct task_storage_nodeadlock *skel;166 struct bpf_prog_info info = {};167 __u32 info_len = sizeof(info);168 const int nr_threads = 32;169 pthread_t tids[nr_threads];170 int i, prog_fd, err;171 cpu_set_t old, new;172 173 /* Pin all threads to one cpu to increase the chance of preemption174 * in a sleepable bpf prog.175 */176 CPU_ZERO(&new);177 CPU_SET(0, &new);178 err = sched_getaffinity(getpid(), sizeof(old), &old);179 if (!ASSERT_OK(err, "getaffinity"))180 return;181 err = sched_setaffinity(getpid(), sizeof(new), &new);182 if (!ASSERT_OK(err, "setaffinity"))183 return;184 185 skel = task_storage_nodeadlock__open_and_load();186 if (!ASSERT_OK_PTR(skel, "open_and_load"))187 goto done;188 189 /* Unnecessary recursion and deadlock detection are reproducible190 * in the preemptible kernel.191 */192 if (!skel->kconfig->CONFIG_PREEMPT) {193 test__skip();194 goto done;195 }196 197 err = task_storage_nodeadlock__attach(skel);198 ASSERT_OK(err, "attach prog");199 200 for (i = 0; i < nr_threads; i++) {201 err = pthread_create(&tids[i], NULL, sock_create_loop, skel);202 if (err) {203 /* Only assert once here to avoid excessive204 * PASS printing during test failure.205 */206 ASSERT_OK(err, "pthread_create");207 waitall(tids, i);208 goto done;209 }210 }211 212 /* With 32 threads, 1s is enough to reproduce the issue */213 sleep(1);214 waitall(tids, nr_threads);215 216 info_len = sizeof(info);217 prog_fd = bpf_program__fd(skel->progs.socket_post_create);218 err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);219 ASSERT_OK(err, "get prog info");220 ASSERT_EQ(info.recursion_misses, 0, "prog recursion");221 222 ASSERT_EQ(skel->bss->nr_get_errs, 0, "bpf_task_storage_get busy");223 ASSERT_EQ(skel->bss->nr_del_errs, 0, "bpf_task_storage_delete busy");224 225done:226 task_storage_nodeadlock__destroy(skel);227 sched_setaffinity(getpid(), sizeof(old), &old);228}229 230void test_task_local_storage(void)231{232 if (test__start_subtest("sys_enter_exit"))233 test_sys_enter_exit();234 if (test__start_subtest("exit_creds"))235 test_exit_creds();236 if (test__start_subtest("recursion"))237 test_recursion();238 if (test__start_subtest("nodeadlock"))239 test_nodeadlock();240}241