[PATCH net-next 1/4] bpf: minor cleanups in helpers

[Daniel Borkmann]

Some minor misc cleanups, f.e. use sizeof(__u32) instead of hardcoding
and in __bpf_skb_max_len(), I missed that we always have skb->dev valid
anyway, so we can drop the unneeded test for dev; also few more other
misc bits addressed here.

Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
Acked-by: Alexei Starovoitov <a...@kernel.org>
---
 kernel/bpf/helpers.c | 6 +++---
 net/core/filter.c    | 7 +++----
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 1ea3afb..6df73bd 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -126,7 +126,7 @@ static u64 bpf_get_current_pid_tgid(u64 r1, u64 r2, u64 r3, 
u64 r4, u64 r5)
 {
        struct task_struct *task = current;
 
-       if (!task)
+       if (unlikely(!task))
                return -EINVAL;
 
        return (u64) task->tgid << 32 | task->pid;
@@ -144,12 +144,12 @@ static u64 bpf_get_current_uid_gid(u64 r1, u64 r2, u64 
r3, u64 r4, u64 r5)
        kuid_t uid;
        kgid_t gid;
 
-       if (!task)
+       if (unlikely(!task))
                return -EINVAL;
 
        current_uid_gid(&uid, &gid);
        return (u64) from_kgid(&init_user_ns, gid) << 32 |
-               from_kuid(&init_user_ns, uid);
+                    from_kuid(&init_user_ns, uid);
 }
 
 const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
diff --git a/net/core/filter.c b/net/core/filter.c
index a83766b..628ed8c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2010,8 +2010,7 @@ static u32 __bpf_skb_min_len(const struct sk_buff *skb)
 
 static u32 __bpf_skb_max_len(const struct sk_buff *skb)
 {
-       return skb->dev ? skb->dev->mtu + skb->dev->hard_header_len :
-              65536;
+       return skb->dev->mtu + skb->dev->hard_header_len;
 }
 
 static int bpf_skb_grow_rcsum(struct sk_buff *skb, unsigned int new_len)
@@ -2605,7 +2604,7 @@ static bool __is_valid_xdp_access(int off, int size,
                return false;
        if (off % size != 0)
                return false;
-       if (size != 4)
+       if (size != sizeof(__u32))
                return false;
 
        return true;
@@ -2727,7 +2726,7 @@ static u32 bpf_net_convert_ctx_access(enum 
bpf_access_type type, int dst_reg,
                                          dst_reg, src_reg, insn);
 
        case offsetof(struct __sk_buff, cb[0]) ...
-               offsetof(struct __sk_buff, cb[4]):
+            offsetof(struct __sk_buff, cb[4]):
                BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20);
 
                prog->cb_access = 1;
-- 
1.9.3