1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
7 char _license[] SEC("license") = "GPL";
10 int num_unknown_tid = 0;
11 int num_known_tid = 0;
14 int dump_task(struct bpf_iter__task *ctx)
16 struct seq_file *seq = ctx->meta->seq;
17 struct task_struct *task = ctx->task;
18 static char info[] = " === END ===";
20 if (task == (void *)0) {
21 BPF_SEQ_PRINTF(seq, "%s\n", info);
30 if (ctx->meta->seq_num == 0)
31 BPF_SEQ_PRINTF(seq, " tgid gid\n");
33 BPF_SEQ_PRINTF(seq, "%8d %8d\n", task->tgid, task->pid);
37 int num_expected_failure_copy_from_user_task = 0;
38 int num_success_copy_from_user_task = 0;
41 int dump_task_sleepable(struct bpf_iter__task *ctx)
43 struct seq_file *seq = ctx->meta->seq;
44 struct task_struct *task = ctx->task;
45 static const char info[] = " === END ===";
48 uint32_t user_data = 0;
51 if (task == (void *)0) {
52 BPF_SEQ_PRINTF(seq, "%s\n", info);
56 /* Read an invalid pointer and ensure we get an error */
58 ret = bpf_copy_from_user_task(&user_data, sizeof(uint32_t), ptr, task, 0);
60 ++num_expected_failure_copy_from_user_task;
62 BPF_SEQ_PRINTF(seq, "%s\n", info);
66 /* Try to read the contents of the task's instruction pointer from the
67 * remote task's address space.
69 regs = (struct pt_regs *)bpf_task_pt_regs(task);
70 if (regs == (void *)0) {
71 BPF_SEQ_PRINTF(seq, "%s\n", info);
74 ptr = (void *)PT_REGS_IP(regs);
76 ret = bpf_copy_from_user_task(&user_data, sizeof(uint32_t), ptr, task, 0);
78 BPF_SEQ_PRINTF(seq, "%s\n", info);
81 ++num_success_copy_from_user_task;
83 if (ctx->meta->seq_num == 0)
84 BPF_SEQ_PRINTF(seq, " tgid gid data\n");
86 BPF_SEQ_PRINTF(seq, "%8d %8d %8d\n", task->tgid, task->pid, user_data);