From 965de87e54b803223bff703ea6b2a76c056695ae Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 11 Dec 2017 11:36:49 -0500 Subject: samples/bpf: add a test for bpf_override_return This adds a basic test for bpf_override_return to verify it works. We override the main function for mounting a btrfs fs so it'll return -ENOMEM and then make sure that trying to mount a btrfs fs will fail. Acked-by: Alexei Starovoitov Acked-by: Ingo Molnar Signed-off-by: Josef Bacik Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/bpf.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'tools/include') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4c223ab..cf446c2 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -677,6 +677,10 @@ union bpf_attr { * @buf: buf to fill * @buf_size: size of the buf * Return : 0 on success or negative error code + * + * int bpf_override_return(pt_regs, rc) + * @pt_regs: pointer to struct pt_regs + * @rc: the return value to set */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -736,7 +740,8 @@ union bpf_attr { FN(xdp_adjust_meta), \ FN(perf_event_read_value), \ FN(perf_prog_read_value), \ - FN(getsockopt), + FN(getsockopt), \ + FN(override_return), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call -- cgit v1.1