sparse complains about wrong data types within the BPF callbacks. Functions like bpf_l3_csum_replace() are invoked with a specific set of arguments and its further usage is based on a flag. So it can not be set right upfront. There is also access to variables in struct bpf_nh_params and struct bpf_xfrm_state which should be __be32. The content comes directly from the BPF program so conversion is already right. Add __force casts for the right data type and update the members in struct bpf_xfrm_state and bpf_nh_params in order to keep sparse happy. Reported-by: kernel test robot <lkp@xxxxxxxxx> Closes: https://lore.kernel.org/oe-kbuild-all/202406261217.A4hdCnYa-lkp@xxxxxxxxx Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- include/linux/filter.h | 2 +- include/uapi/linux/bpf.h | 6 +++--- net/core/filter.c | 18 ++++++++++-------- 3 files changed, 14 insertions(+), 12 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index c0349522de8fb..9a96019376b67 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -728,7 +728,7 @@ struct bpf_skb_data_end { struct bpf_nh_params { u32 nh_family; union { - u32 ipv4_nh; + __be32 ipv4_nh; struct in6_addr ipv6_nh; }; }; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 25ea393cf084b..f45b03706e4e9 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6290,12 +6290,12 @@ struct bpf_tunnel_key { */ struct bpf_xfrm_state { __u32 reqid; - __u32 spi; /* Stored in network byte order */ + __be32 spi; /* Stored in network byte order */ __u16 family; __u16 ext; /* Padding, future use. */ union { - __u32 remote_ipv4; /* Stored in network byte order */ - __u32 remote_ipv6[4]; /* Stored in network byte order */ + __be32 remote_ipv4; /* Stored in network byte order */ + __be32 remote_ipv6[4]; /* Stored in network byte order */ }; }; diff --git a/net/core/filter.c b/net/core/filter.c index eb1c4425c06f3..11939971f3c6a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1939,13 +1939,13 @@ BPF_CALL_5(bpf_l3_csum_replace, struct sk_buff *, skb, u32, offset, if (unlikely(from != 0)) return -EINVAL; - csum_replace_by_diff(ptr, to); + csum_replace_by_diff(ptr, (__force __wsum)to); break; case 2: - csum_replace2(ptr, from, to); + csum_replace2(ptr, (__force __be16)from, (__force __be16)to); break; case 4: - csum_replace4(ptr, from, to); + csum_replace4(ptr, (__force __be32)from, (__force __be32)to); break; default: return -EINVAL; @@ -1990,13 +1990,15 @@ BPF_CALL_5(bpf_l4_csum_replace, struct sk_buff *, skb, u32, offset, if (unlikely(from != 0)) return -EINVAL; - inet_proto_csum_replace_by_diff(ptr, skb, to, is_pseudo); + inet_proto_csum_replace_by_diff(ptr, skb, (__force __wsum)to, is_pseudo); break; case 2: - inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo); + inet_proto_csum_replace2(ptr, skb, (__force __be16)from, (__force __be16)to, + is_pseudo); break; case 4: - inet_proto_csum_replace4(ptr, skb, from, to, is_pseudo); + inet_proto_csum_replace4(ptr, skb, (__force __be32)from, (__force __be32)to, + is_pseudo); break; default: return -EINVAL; @@ -2046,7 +2048,7 @@ BPF_CALL_5(bpf_csum_diff, __be32 *, from, u32, from_size, ret = csum_partial(sp->diff, diff_size, seed); local_unlock_nested_bh(&bpf_sp.bh_lock); - return ret; + return (__force __u32)ret; } static const struct bpf_func_proto bpf_csum_diff_proto = { @@ -2068,7 +2070,7 @@ BPF_CALL_2(bpf_csum_update, struct sk_buff *, skb, __wsum, csum) * as emulating csum_sub() can be done from the eBPF program. */ if (skb->ip_summed == CHECKSUM_COMPLETE) - return (skb->csum = csum_add(skb->csum, csum)); + return (__force __u32)(skb->csum = csum_add(skb->csum, csum)); return -ENOTSUPP; } -- 2.45.2
