130e0f7af9
This patch adds 4 subtests to demonstrate these patterns and validating correctness. subtest1: 1) We use task_iter to iterate all process in the system and search for the current process with a given pid. 2) We create some threads in current process context, and use BPF_TASK_ITER_PROC_THREADS to iterate all threads of current process. As expected, we would find all the threads of current process. 3) We create some threads and use BPF_TASK_ITER_ALL_THREADS to iterate all threads in the system. As expected, we would find all the threads which was created. subtest2: We create a cgroup and add the current task to the cgroup. In the BPF program, we would use bpf_for_each(css_task, task, css) to iterate all tasks under the cgroup. As expected, we would find the current process. subtest3: 1) We create a cgroup tree. In the BPF program, we use bpf_for_each(css, pos, root, XXX) to iterate all descendant under the root with pre and post order. As expected, we would find all descendant and the last iterating cgroup in post-order is root cgroup, the first iterating cgroup in pre-order is root cgroup. 2) We wse BPF_CGROUP_ITER_ANCESTORS_UP to traverse the cgroup tree starting from leaf and root separately, and record the height. The diff of the hights would be the total tree-high - 1. subtest4: Add some failure testcase when using css_task, task and css iters, e.g, unlock when using task-iters to iterate tasks. Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com> Link: https://lore.kernel.org/r/20231018061746.111364-9-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
41 lines
1 KiB
C
41 lines
1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (C) 2023 Chuyi Zhou <zhouchuyi@bytedance.com> */
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#include "vmlinux.h"
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include "bpf_misc.h"
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#include "bpf_experimental.h"
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char _license[] SEC("license") = "GPL";
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pid_t target_pid;
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int procs_cnt, threads_cnt, proc_threads_cnt;
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void bpf_rcu_read_lock(void) __ksym;
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void bpf_rcu_read_unlock(void) __ksym;
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SEC("fentry.s/" SYS_PREFIX "sys_getpgid")
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int iter_task_for_each_sleep(void *ctx)
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{
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struct task_struct *cur_task = bpf_get_current_task_btf();
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struct task_struct *pos;
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if (cur_task->pid != target_pid)
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return 0;
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procs_cnt = threads_cnt = proc_threads_cnt = 0;
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bpf_rcu_read_lock();
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bpf_for_each(task, pos, NULL, BPF_TASK_ITER_ALL_PROCS)
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if (pos->pid == target_pid)
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procs_cnt++;
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bpf_for_each(task, pos, cur_task, BPF_TASK_ITER_PROC_THREADS)
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proc_threads_cnt++;
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bpf_for_each(task, pos, NULL, BPF_TASK_ITER_ALL_THREADS)
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if (pos->tgid == target_pid)
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threads_cnt++;
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bpf_rcu_read_unlock();
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return 0;
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}
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