diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 6cb077b646a5..ef7031f8a304 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -14,6 +14,7 @@ #include #define MAX_MSG_FRAGS MAX_SKB_FRAGS +#define NR_MSG_FRAG_IDS (MAX_MSG_FRAGS + 1) enum __sk_action { __SK_DROP = 0, @@ -29,13 +30,15 @@ struct sk_msg_sg { u32 size; u32 copybreak; unsigned long copy; - /* The extra element is used for chaining the front and sections when - * the list becomes partitioned (e.g. end < start). The crypto APIs - * require the chaining. + /* The extra two elements: + * 1) used for chaining the front and sections when the list becomes + * partitioned (e.g. end < start). The crypto APIs require the + * chaining; + * 2) to chain tailer SG entries after the message. */ - struct scatterlist data[MAX_MSG_FRAGS + 1]; + struct scatterlist data[MAX_MSG_FRAGS + 2]; }; -static_assert(BITS_PER_LONG >= MAX_MSG_FRAGS); +static_assert(BITS_PER_LONG >= NR_MSG_FRAG_IDS); /* UAPI in filter.c depends on struct sk_msg_sg being first element. */ struct sk_msg { @@ -142,13 +145,13 @@ static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes) static inline u32 sk_msg_iter_dist(u32 start, u32 end) { - return end >= start ? end - start : end + (MAX_MSG_FRAGS - start); + return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start); } #define sk_msg_iter_var_prev(var) \ do { \ if (var == 0) \ - var = MAX_MSG_FRAGS - 1; \ + var = NR_MSG_FRAG_IDS - 1; \ else \ var--; \ } while (0) @@ -156,7 +159,7 @@ static inline u32 sk_msg_iter_dist(u32 start, u32 end) #define sk_msg_iter_var_next(var) \ do { \ var++; \ - if (var == MAX_MSG_FRAGS) \ + if (var == NR_MSG_FRAG_IDS) \ var = 0; \ } while (0) @@ -173,9 +176,9 @@ static inline void sk_msg_clear_meta(struct sk_msg *msg) static inline void sk_msg_init(struct sk_msg *msg) { - BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != MAX_MSG_FRAGS); + BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != NR_MSG_FRAG_IDS); memset(msg, 0, sizeof(*msg)); - sg_init_marker(msg->sg.data, MAX_MSG_FRAGS); + sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS); } static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src, @@ -196,14 +199,11 @@ static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src) static inline bool sk_msg_full(const struct sk_msg *msg) { - return (msg->sg.end == msg->sg.start) && msg->sg.size; + return sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS; } static inline u32 sk_msg_elem_used(const struct sk_msg *msg) { - if (sk_msg_full(msg)) - return MAX_MSG_FRAGS; - return sk_msg_iter_dist(msg->sg.start, msg->sg.end); } diff --git a/net/core/filter.c b/net/core/filter.c index b0ed048585ba..f1e703eed3d2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2299,7 +2299,7 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start, WARN_ON_ONCE(last_sge == first_sge); shift = last_sge > first_sge ? last_sge - first_sge - 1 : - MAX_SKB_FRAGS - first_sge + last_sge - 1; + NR_MSG_FRAG_IDS - first_sge + last_sge - 1; if (!shift) goto out; @@ -2308,8 +2308,8 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start, do { u32 move_from; - if (i + shift >= MAX_MSG_FRAGS) - move_from = i + shift - MAX_MSG_FRAGS; + if (i + shift >= NR_MSG_FRAG_IDS) + move_from = i + shift - NR_MSG_FRAG_IDS; else move_from = i + shift; if (move_from == msg->sg.end) @@ -2323,7 +2323,7 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start, } while (1); msg->sg.end = msg->sg.end - shift > msg->sg.end ? - msg->sg.end - shift + MAX_MSG_FRAGS : + msg->sg.end - shift + NR_MSG_FRAG_IDS : msg->sg.end - shift; out: msg->data = sg_virt(&msg->sg.data[first_sge]) + start - offset; diff --git a/net/core/skmsg.c b/net/core/skmsg.c index a469d2124f3f..ded2d5227678 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -421,7 +421,7 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) copied = skb->len; msg->sg.start = 0; msg->sg.size = copied; - msg->sg.end = num_sge == MAX_MSG_FRAGS ? 0 : num_sge; + msg->sg.end = num_sge; msg->skb = skb; sk_psock_queue_msg(psock, msg); diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 8a56e09cfb0e..e38705165ac9 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -301,7 +301,7 @@ EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir); static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, struct sk_msg *msg, int *copied, int flags) { - bool cork = false, enospc = msg->sg.start == msg->sg.end; + bool cork = false, enospc = sk_msg_full(msg); struct sock *sk_redir; u32 tosend, delta = 0; int ret;