2018-04-03 12:12:19

by Anders Roxell

Subject: [PATCH] kernel/bpf/syscall: fix warning defined but not used

There will be a build warning -Wunused-function if CONFIG_CGROUP_BPF
isn't defined, since the only user is inside #ifdef CONFIG_CGROUP_BPF:
kernel/bpf/syscall.c:1229:12: warning: ‘bpf_prog_attach_check_attach_type’
defined but not used [-Wunused-function]
static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Current code moves function bpf_prog_attach_check_attach_type inside
ifdef CONFIG_CGROUP_BPF.

Fixes: 5e43f899b03a ("bpf: Check attach type at prog load time")
Signed-off-by: Anders Roxell <[email protected]>
---
kernel/bpf/syscall.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7457f2676c6d..56f49557adda 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1226,18 +1226,6 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
}
}

-static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
- enum bpf_attach_type attach_type)
-{
- switch (prog->type) {
- case BPF_PROG_TYPE_CGROUP_SOCK:
- case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
- return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
- default:
- return 0;
- }
-}
-
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD expected_attach_type

@@ -1465,6 +1453,18 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)

#ifdef CONFIG_CGROUP_BPF

+static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
+ enum bpf_attach_type attach_type)
+{
+ switch (prog->type) {
+ case BPF_PROG_TYPE_CGROUP_SOCK:
+ case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+ return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
+ default:
+ return 0;
+ }
+}
+
#define BPF_PROG_ATTACH_LAST_FIELD attach_flags

static int sockmap_get_from_fd(const union bpf_attr *attr,
--
2.16.2

2018-04-04 09:17:26

by Daniel Borkmann

Subject: Re: [PATCH] kernel/bpf/syscall: fix warning defined but not used

On 04/03/2018 02:09 PM, Anders Roxell wrote:
> There will be a build warning -Wunused-function if CONFIG_CGROUP_BPF
> isn't defined, since the only user is inside #ifdef CONFIG_CGROUP_BPF:
> kernel/bpf/syscall.c:1229:12: warning: ‘bpf_prog_attach_check_attach_type’
> defined but not used [-Wunused-function]
> static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Current code moves function bpf_prog_attach_check_attach_type inside
> ifdef CONFIG_CGROUP_BPF.
>
> Fixes: 5e43f899b03a ("bpf: Check attach type at prog load time")
> Signed-off-by: Anders Roxell <[email protected]>

Applied to bpf tree, thanks Anders!