bpf: add BTF ids in procfs for file descriptors to BTF objects (3481e64b) · Commits · 戴 / test

Implement the show_fdinfo hook for BTF FDs file operations, and make it print the id of the BTF object. This allows for a quick retrieval of the BTF id from its FD; or it can help understanding what type of object (BTF) the file descriptor points to. v2: - Do not expose data_size, only btf_id, in FD info. Signed-off-by:

Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by:

Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:

Daniel Borkmann <daniel@iogearbox.net>

kernel/bpf/btf.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -3376,6 +3376,15 @@ void btf_type_seq_show(const struct btf btf, u32 type_id, void obj,
		btf_type_ops(t)->seq_show(btf, t, type_id, obj, 0, m);
		}

		#ifdef CONFIG_PROC_FS
		static void bpf_btf_show_fdinfo(struct seq_file m, struct file filp)
		{
		const struct btf *btf = filp->private_data;

		seq_printf(m, "btf_id:\t%u\n", btf->id);
		}
		#endif

		static int btf_release(struct inode inode, struct file filp)
		{
		btf_put(filp->private_data);
		@@ -3383,6 +3392,9 @@ static int btf_release(struct inode inode, struct file filp)
		}

		const struct file_operations btf_fops = {
		#ifdef CONFIG_PROC_FS
		.show_fdinfo = bpf_btf_show_fdinfo,
		#endif
		.release = btf_release,
		};

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