89 lines
2.0 KiB
C
89 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2020 Facebook */
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#include "bpf_iter.h"
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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char _license[] SEC("license") = "GPL";
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uint32_t tid = 0;
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int num_unknown_tid = 0;
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int num_known_tid = 0;
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SEC("iter/task")
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int dump_task(struct bpf_iter__task *ctx)
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{
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struct seq_file *seq = ctx->meta->seq;
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struct task_struct *task = ctx->task;
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static char info[] = " === END ===";
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if (task == (void *)0) {
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BPF_SEQ_PRINTF(seq, "%s\n", info);
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return 0;
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}
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if (task->pid != tid)
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num_unknown_tid++;
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else
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num_known_tid++;
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if (ctx->meta->seq_num == 0)
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BPF_SEQ_PRINTF(seq, " tgid gid\n");
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BPF_SEQ_PRINTF(seq, "%8d %8d\n", task->tgid, task->pid);
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return 0;
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}
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int num_expected_failure_copy_from_user_task = 0;
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int num_success_copy_from_user_task = 0;
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SEC("iter.s/task")
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int dump_task_sleepable(struct bpf_iter__task *ctx)
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{
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struct seq_file *seq = ctx->meta->seq;
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struct task_struct *task = ctx->task;
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static const char info[] = " === END ===";
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struct pt_regs *regs;
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void *ptr;
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uint32_t user_data = 0;
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int ret;
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if (task == (void *)0) {
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BPF_SEQ_PRINTF(seq, "%s\n", info);
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return 0;
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}
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/* Read an invalid pointer and ensure we get an error */
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ptr = NULL;
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ret = bpf_copy_from_user_task(&user_data, sizeof(uint32_t), ptr, task, 0);
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if (ret) {
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++num_expected_failure_copy_from_user_task;
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} else {
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BPF_SEQ_PRINTF(seq, "%s\n", info);
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return 0;
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}
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/* Try to read the contents of the task's instruction pointer from the
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* remote task's address space.
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*/
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regs = (struct pt_regs *)bpf_task_pt_regs(task);
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if (regs == (void *)0) {
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BPF_SEQ_PRINTF(seq, "%s\n", info);
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return 0;
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}
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ptr = (void *)PT_REGS_IP(regs);
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ret = bpf_copy_from_user_task(&user_data, sizeof(uint32_t), ptr, task, 0);
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if (ret) {
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BPF_SEQ_PRINTF(seq, "%s\n", info);
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return 0;
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}
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++num_success_copy_from_user_task;
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if (ctx->meta->seq_num == 0)
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BPF_SEQ_PRINTF(seq, " tgid gid data\n");
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BPF_SEQ_PRINTF(seq, "%8d %8d %8d\n", task->tgid, task->pid, user_data);
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return 0;
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}
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