From 2c4fe44fb020f3cce904da2ba9e42bb1c118e8a3 Mon Sep 17 00:00:00 2001 From: Kui-Feng Lee Date: Mon, 26 Sep 2022 11:49:55 -0700 Subject: [PATCH] bpf: Handle show_fdinfo for the parameterized task BPF iterators Show information of iterators in the respective files under /proc//fdinfo/. For example, for a task file iterator with 1723 as the value of tid parameter, its fdinfo would look like the following lines. pos: 0 flags: 02000000 mnt_id: 14 ino: 38 link_type: iter link_id: 51 prog_tag: a590ac96db22b825 prog_id: 299 target_name: task_file task_type: TID tid: 1723 This patch add the last three fields. task_type is the type of the task parameter. TID means the iterator visit only the thread specified by tid. The value of tid in the above example is 1723. For the case of PID task_type, it means the iterator visits only threads of a process and will show the pid value of the process instead of a tid. Signed-off-by: Kui-Feng Lee Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20220926184957.208194-4-kuifeng@fb.com --- kernel/bpf/task_iter.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index 46f836be22e26..67e03e1833bae 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -10,6 +10,12 @@ #include #include "mmap_unlock_work.h" +static const char * const iter_task_type_names[] = { + "ALL", + "TID", + "PID", +}; + struct bpf_iter_seq_task_common { struct pid_namespace *ns; enum bpf_iter_task_type type; @@ -687,6 +693,15 @@ static int bpf_iter_fill_link_info(const struct bpf_iter_aux_info *aux, struct b return 0; } +static void bpf_iter_task_show_fdinfo(const struct bpf_iter_aux_info *aux, struct seq_file *seq) +{ + seq_printf(seq, "task_type:\t%s\n", iter_task_type_names[aux->task.type]); + if (aux->task.type == BPF_TASK_ITER_TID) + seq_printf(seq, "tid:\t%u\n", aux->task.pid); + else if (aux->task.type == BPF_TASK_ITER_TGID) + seq_printf(seq, "pid:\t%u\n", aux->task.pid); +} + static struct bpf_iter_reg task_reg_info = { .target = "task", .attach_target = bpf_iter_attach_task, @@ -698,6 +713,7 @@ static struct bpf_iter_reg task_reg_info = { }, .seq_info = &task_seq_info, .fill_link_info = bpf_iter_fill_link_info, + .show_fdinfo = bpf_iter_task_show_fdinfo, }; static const struct bpf_iter_seq_info task_file_seq_info = { @@ -720,6 +736,7 @@ static struct bpf_iter_reg task_file_reg_info = { }, .seq_info = &task_file_seq_info, .fill_link_info = bpf_iter_fill_link_info, + .show_fdinfo = bpf_iter_task_show_fdinfo, }; static const struct bpf_iter_seq_info task_vma_seq_info = { @@ -742,6 +759,7 @@ static struct bpf_iter_reg task_vma_reg_info = { }, .seq_info = &task_vma_seq_info, .fill_link_info = bpf_iter_fill_link_info, + .show_fdinfo = bpf_iter_task_show_fdinfo, }; BPF_CALL_5(bpf_find_vma, struct task_struct *, task, u64, start, -- 2.30.2