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Commit ff1889fc authored by Song Liu's avatar Song Liu Committed by Daniel Borkmann
Browse files

bpf: show main program address and length in bpf_prog_info 



Currently, when there is no subprog (prog->aux->func_cnt == 0),
bpf_prog_info does not return any jited_ksyms or jited_func_lens. This
patch adds main program address (prog->bpf_func) and main program
length (prog->jited_len) to bpf_prog_info.

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent de57e99c

kernel/bpf/syscall.c

+24 −9
Original line number Diff line number Diff line
@@ -2158,11 +2158,11 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
	}



	ulen = info.nr_jited_ksyms;

	info.nr_jited_ksyms = prog->aux->func_cnt;

	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;

	if (info.nr_jited_ksyms && ulen) {

		if (bpf_dump_raw_ok()) {

			unsigned long ksym_addr;

			u64 __user *user_ksyms;

			ulong ksym_addr;

			u32 i;



			/* copy the address of the kernel symbol
@@ -2170,9 +2170,17 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
			 */

			ulen = min_t(u32, info.nr_jited_ksyms, ulen);

			user_ksyms = u64_to_user_ptr(info.jited_ksyms);

			if (prog->aux->func_cnt) {

				for (i = 0; i < ulen; i++) {

				ksym_addr = (ulong) prog->aux->func[i]->bpf_func;

				if (put_user((u64) ksym_addr, &user_ksyms[i]))

					ksym_addr = (unsigned long)

						prog->aux->func[i]->bpf_func;

					if (put_user((u64) ksym_addr,

						     &user_ksyms[i]))

						return -EFAULT;

				}

			} else {

				ksym_addr = (unsigned long) prog->bpf_func;

				if (put_user((u64) ksym_addr, &user_ksyms[0]))

					return -EFAULT;

			}

		} else {
@@ -2181,7 +2189,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
	}



	ulen = info.nr_jited_func_lens;

	info.nr_jited_func_lens = prog->aux->func_cnt;

	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;

	if (info.nr_jited_func_lens && ulen) {

		if (bpf_dump_raw_ok()) {

			u32 __user *user_lens;
@@ -2190,11 +2198,18 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, 
			/* copy the JITed image lengths for each function */

			ulen = min_t(u32, info.nr_jited_func_lens, ulen);

			user_lens = u64_to_user_ptr(info.jited_func_lens);

			if (prog->aux->func_cnt) {

				for (i = 0; i < ulen; i++) {

				func_len = prog->aux->func[i]->jited_len;

					func_len =

						prog->aux->func[i]->jited_len;

					if (put_user(func_len, &user_lens[i]))

						return -EFAULT;

				}

			} else {

				func_len = prog->jited_len;

				if (put_user(func_len, &user_lens[0]))

					return -EFAULT;

			}

		} else {

			info.jited_func_lens = 0;

		}