diff options
| author |   Josef Bacik <jbacik@fb.com> | 2017-12-11 11:36:49 -0500 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2017-12-12 09:02:40 -0800 |
| commit | 965de87e54b803223bff703ea6b2a76c056695ae (patch) | |
| tree | 43f90acde38704b6831d3819ce0bffee092eade4 /tools | |
| parent | bpf: add a bpf_override_function helper (diff) | |
| download | linux-dev-965de87e54b803223bff703ea6b2a76c056695ae.tar.xz linux-dev-965de87e54b803223bff703ea6b2a76c056695ae.zip | |
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 <ast@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 7 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/bpf_helpers.h | 3 |
2 files changed, 8 insertions, 2 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4c223ab30293..cf446c25c0ec 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 diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index fd9a17fa8a8b..33cb00e46c49 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -82,7 +82,8 @@ static int (*bpf_perf_event_read_value)(void *map, unsigned long long flags, static int (*bpf_perf_prog_read_value)(void *ctx, void *buf, unsigned int buf_size) = (void *) BPF_FUNC_perf_prog_read_value; - +static int (*bpf_override_return)(void *ctx, unsigned long rc) = + (void *) BPF_FUNC_override_return; /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions |