| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (c) 2020 Facebook */ |
| #include "bpf_iter.h" |
| #include <bpf/bpf_helpers.h> |
| #include <bpf/bpf_tracing.h> |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| #define MAX_STACK_TRACE_DEPTH 64 |
| unsigned long entries[MAX_STACK_TRACE_DEPTH] = {}; |
| #define SIZE_OF_ULONG (sizeof(unsigned long)) |
| |
| SEC("iter/task") |
| int dump_task_stack(struct bpf_iter__task *ctx) |
| { |
| struct seq_file *seq = ctx->meta->seq; |
| struct task_struct *task = ctx->task; |
| long i, retlen; |
| |
| if (task == (void *)0) |
| return 0; |
| |
| retlen = bpf_get_task_stack(task, entries, |
| MAX_STACK_TRACE_DEPTH * SIZE_OF_ULONG, 0); |
| if (retlen < 0) |
| return 0; |
| |
| BPF_SEQ_PRINTF(seq, "pid: %8u num_entries: %8u\n", task->pid, |
| retlen / SIZE_OF_ULONG); |
| for (i = 0; i < MAX_STACK_TRACE_DEPTH; i++) { |
| if (retlen > i * SIZE_OF_ULONG) |
| BPF_SEQ_PRINTF(seq, "[<0>] %pB\n", (void *)entries[i]); |
| } |
| BPF_SEQ_PRINTF(seq, "\n"); |
| |
| return 0; |
| } |