| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (c) 2019 Facebook |
| |
| #include <linux/bpf.h> |
| #include <stdint.h> |
| #include <stdbool.h> |
| #include <bpf/bpf_helpers.h> |
| #include <bpf/bpf_core_read.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| struct { |
| char in[256]; |
| char out[256]; |
| bool skip; |
| uint64_t my_pid_tgid; |
| } data = {}; |
| |
| struct core_reloc_kernel_output { |
| int valid[10]; |
| /* we have test_progs[-flavor], so cut flavor part */ |
| char comm[sizeof("test_progs")]; |
| int comm_len; |
| }; |
| |
| struct task_struct { |
| int pid; |
| int tgid; |
| char comm[16]; |
| struct task_struct *group_leader; |
| }; |
| |
| #define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*(dst)), src) |
| |
| SEC("raw_tracepoint/sys_enter") |
| int test_core_kernel(void *ctx) |
| { |
| struct task_struct *task = (void *)bpf_get_current_task(); |
| struct core_reloc_kernel_output *out = (void *)&data.out; |
| uint64_t pid_tgid = bpf_get_current_pid_tgid(); |
| uint32_t real_tgid = (uint32_t)pid_tgid; |
| int pid, tgid; |
| |
| if (data.my_pid_tgid != pid_tgid) |
| return 0; |
| |
| if (CORE_READ(&pid, &task->pid) || |
| CORE_READ(&tgid, &task->tgid)) |
| return 1; |
| |
| /* validate pid + tgid matches */ |
| out->valid[0] = (((uint64_t)pid << 32) | tgid) == pid_tgid; |
| |
| /* test variadic BPF_CORE_READ macros */ |
| out->valid[1] = BPF_CORE_READ(task, |
| tgid) == real_tgid; |
| out->valid[2] = BPF_CORE_READ(task, |
| group_leader, |
| tgid) == real_tgid; |
| out->valid[3] = BPF_CORE_READ(task, |
| group_leader, group_leader, |
| tgid) == real_tgid; |
| out->valid[4] = BPF_CORE_READ(task, |
| group_leader, group_leader, group_leader, |
| tgid) == real_tgid; |
| out->valid[5] = BPF_CORE_READ(task, |
| group_leader, group_leader, group_leader, |
| group_leader, |
| tgid) == real_tgid; |
| out->valid[6] = BPF_CORE_READ(task, |
| group_leader, group_leader, group_leader, |
| group_leader, group_leader, |
| tgid) == real_tgid; |
| out->valid[7] = BPF_CORE_READ(task, |
| group_leader, group_leader, group_leader, |
| group_leader, group_leader, group_leader, |
| tgid) == real_tgid; |
| out->valid[8] = BPF_CORE_READ(task, |
| group_leader, group_leader, group_leader, |
| group_leader, group_leader, group_leader, |
| group_leader, |
| tgid) == real_tgid; |
| out->valid[9] = BPF_CORE_READ(task, |
| group_leader, group_leader, group_leader, |
| group_leader, group_leader, group_leader, |
| group_leader, group_leader, |
| tgid) == real_tgid; |
| |
| /* test BPF_CORE_READ_STR_INTO() returns correct code and contents */ |
| out->comm_len = BPF_CORE_READ_STR_INTO( |
| &out->comm, task, |
| group_leader, group_leader, group_leader, group_leader, |
| group_leader, group_leader, group_leader, group_leader, |
| comm); |
| |
| return 0; |
| } |
| |