From c872bdb38febb4c31ece3599c52cf1f833b89f4e Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 12 Dec 2018 09:37:46 -0800 Subject: bpf: include sub program tags in bpf_prog_info Changes v2 -> v3: 1. remove check for bpf_dump_raw_ok(). Changes v1 -> v2: 1. Fix error path as Martin suggested. This patch adds nr_prog_tags and prog_tags to bpf_prog_info. This is a reliable way for user space to get tags of all sub programs. Before this patch, user space need to find sub program tags via kallsyms. This feature will be used in BPF introspection, where user space queries information about BPF programs via sys_bpf. Signed-off-by: Song Liu Acked-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- kernel/bpf/syscall.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b7c585838c72..7f1410d6fbe9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2315,6 +2315,28 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, } } + ulen = info.nr_prog_tags; + info.nr_prog_tags = prog->aux->func_cnt ? : 1; + if (ulen) { + __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; + u32 i; + + user_prog_tags = u64_to_user_ptr(info.prog_tags); + ulen = min_t(u32, info.nr_prog_tags, ulen); + if (prog->aux->func_cnt) { + for (i = 0; i < ulen; i++) { + if (copy_to_user(user_prog_tags[i], + prog->aux->func[i]->tag, + BPF_TAG_SIZE)) + return -EFAULT; + } + } else { + if (copy_to_user(user_prog_tags[0], + prog->tag, BPF_TAG_SIZE)) + return -EFAULT; + } + } + done: if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) -- cgit v1.2.3