Commit b4dfe26f authored by Tao Chen's avatar Tao Chen Committed by Alexei Starovoitov
Browse files

bpf: Add show_fdinfo for uprobe_multi 



Show uprobe_multi link info with fdinfo, the info as follows:

link_type:	uprobe_multi
link_id:	9
prog_tag:	e729f789e34a8eca
prog_id:	39
uprobe_cnt:	3
pid:	0
path:	/home/dylane/bpf/tools/testing/selftests/bpf/test_progs
cookie	 offset	 ref_ctr_offset
3	 0xa69f13	 0x0
1	 0xa69f1e	 0x0
2	 0xa69f29	 0x0

Signed-off-by: default avatarTao Chen <chen.dylane@linux.dev>
Link: https://lore.kernel.org/r/20250702153958.639852-2-chen.dylane@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 803f0700

kernel/trace/bpf_trace.c

+44 −0
Original line number Diff line number Diff line
@@ -3152,10 +3152,54 @@ static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link, 
	return err;

}



#ifdef CONFIG_PROC_FS

static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link,

					 struct seq_file *seq)

{

	struct bpf_uprobe_multi_link *umulti_link;

	char *p, *buf;

	pid_t pid;



	umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);



	buf = kmalloc(PATH_MAX, GFP_KERNEL);

	if (!buf)

		return;



	p = d_path(&umulti_link->path, buf, PATH_MAX);

	if (IS_ERR(p)) {

		kfree(buf);

		return;

	}



	pid = umulti_link->task ?

	      task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;

	seq_printf(seq,

		   "uprobe_cnt:\t%u\n"

		   "pid:\t%u\n"

		   "path:\t%s\n",

		   umulti_link->cnt, pid, p);



	seq_printf(seq, "%s\t %s\t %s\n", "cookie", "offset", "ref_ctr_offset");

	for (int i = 0; i < umulti_link->cnt; i++) {

		seq_printf(seq,

			   "%llu\t %#llx\t %#lx\n",

			   umulti_link->uprobes[i].cookie,

			   umulti_link->uprobes[i].offset,

			   umulti_link->uprobes[i].ref_ctr_offset);

	}



	kfree(buf);

}

#endif



static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {

	.release = bpf_uprobe_multi_link_release,

	.dealloc_deferred = bpf_uprobe_multi_link_dealloc,

	.fill_link_info = bpf_uprobe_multi_link_fill_link_info,

#ifdef CONFIG_PROC_FS

	.show_fdinfo = bpf_uprobe_multi_show_fdinfo,

#endif

};



static int uprobe_prog_run(struct bpf_uprobe *uprobe,