[PATCH net-next V2] bpf: fix return in load_bpf_file

[PATCH net-next V2] bpf: fix return in load_bpf_file

[Lawrence Brakmo]

The function load_bpf_file ignores the return value of
load_and_attach(), so even if load_and_attach() returns an error,
load_bpf_file() will return 0.

Now, load_bpf_file() can call load_and_attach() multiple times and some
can succeed and some could fail. I think the correct behavor is to
return error on the first failed load_and_attach().

v2: Added missing SOB

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
---
 samples/bpf/bpf_load.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index a4be7cf..899f403 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -567,8 +567,12 @@ static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
 		    memcmp(shname, "perf_event", 10) == 0 ||
 		    memcmp(shname, "socket", 6) == 0 ||
 		    memcmp(shname, "cgroup/", 7) == 0 ||
-		    memcmp(shname, "sockops", 7) == 0)
-			load_and_attach(shname, data->d_buf, data->d_size);
+		    memcmp(shname, "sockops", 7) == 0) {
+			ret = load_and_attach(shname, data->d_buf,
+					      data->d_size);
+			if (ret != 0)
+				goto done;
+		}
 	}
 
 	ret = 0;
-- 
2.9.3

Re: [PATCH net-next V2] bpf: fix return in load_bpf_file

[David Miller]

From: Lawrence Brakmo <brakmo@fb.com>
Date: Tue, 4 Jul 2017 15:57:50 -0700

> The function load_bpf_file ignores the return value of
> load_and_attach(), so even if load_and_attach() returns an error,
> load_bpf_file() will return 0.
> 
> Now, load_bpf_file() can call load_and_attach() multiple times and some
> can succeed and some could fail. I think the correct behavor is to
> return error on the first failed load_and_attach().
> 
> v2: Added missing SOB
> 
> Signed-off-by: Lawrence Brakmo <brakmo@fb.com>

Applied.