skmsg: convert struct sk_msg_sg::copy to a bitmap

We have plans for increasing MAX_SKB_FRAGS, but sk_msg_sg::copy
is currently an unsigned long, limiting MAX_SKB_FRAGS to 30 on 32bit arches.

Convert it to a bitmap, as Jakub suggested.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 18a717f..1ff68a8 100644 (file)
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -29,7 +29,7 @@ struct sk_msg_sg {
        u32                             end;
        u32                             size;
        u32                             copybreak;
-       unsigned long                   copy;
+       DECLARE_BITMAP(copy, MAX_MSG_FRAGS + 2);
        /* 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
@@ -38,7 +38,6 @@ struct sk_msg_sg {
         */
        struct scatterlist              data[MAX_MSG_FRAGS + 2];
 };
-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 {
@@ -234,7 +233,7 @@ static inline void sk_msg_compute_data_pointers(struct sk_msg *msg)
 {
        struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start);
 
-       if (test_bit(msg->sg.start, &msg->sg.copy)) {
+       if (test_bit(msg->sg.start, msg->sg.copy)) {
                msg->data = NULL;
                msg->data_end = NULL;
        } else {
@@ -253,7 +252,7 @@ static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
        sg_set_page(sge, page, len, offset);
        sg_unmark_end(sge);
 
-       __set_bit(msg->sg.end, &msg->sg.copy);
+       __set_bit(msg->sg.end, msg->sg.copy);
        msg->sg.size += len;
        sk_msg_iter_next(msg, end);
 }
@@ -262,9 +261,9 @@ static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state)
 {
        do {
                if (copy_state)
-                       __set_bit(i, &msg->sg.copy);
+                       __set_bit(i, msg->sg.copy);
                else
-                       __clear_bit(i, &msg->sg.copy);
+                       __clear_bit(i, msg->sg.copy);
                sk_msg_iter_var_next(i);
                if (i == msg->sg.end)
                        break;

diff --git a/net/core/filter.c b/net/core/filter.c
index 9615ae1..f497ca7 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2603,7 +2603,7 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
         * account for the headroom.
         */
        bytes_sg_total = start - offset + bytes;
-       if (!test_bit(i, &msg->sg.copy) && bytes_sg_total <= len)
+       if (!test_bit(i, msg->sg.copy) && bytes_sg_total <= len)
                goto out;
 
        /* At this point we need to linearize multiple scatterlist
@@ -2809,7 +2809,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
        /* Place newly allocated data buffer */
        sk_mem_charge(msg->sk, len);
        msg->sg.size += len;
-       __clear_bit(new, &msg->sg.copy);
+       __clear_bit(new, msg->sg.copy);
        sg_set_page(&msg->sg.data[new], page, len + copy, 0);
        if (rsge.length) {
                get_page(sg_page(&rsge));