Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Martin KaFai Lau says:

====================
pull-request: bpf-next 2024-11-14

We've added 9 non-merge commits during the last 4 day(s) which contain
a total of 3 files changed, 226 insertions(+), 84 deletions(-).

The main changes are:

1) Fixes to bpf_msg_push/pop_data and test_sockmap. The changes has
   dependency on the other changes in the bpf-next/net branch,
   from Zijian Zhang.

2) Drop netns codes from mptcp test. Reuse the common helpers in
   test_progs, from Geliang Tang.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  bpf, sockmap: Fix sk_msg_reset_curr
  bpf, sockmap: Several fixes to bpf_msg_pop_data
  bpf, sockmap: Several fixes to bpf_msg_push_data
  selftests/bpf: Add more tests for test_txmsg_push_pop in test_sockmap
  selftests/bpf: Add push/pop checking for msg_verify_data in test_sockmap
  selftests/bpf: Fix total_bytes in msg_loop_rx in test_sockmap
  selftests/bpf: Fix SENDPAGE data logic in test_sockmap
  selftests/bpf: Add txmsg_pass to pull/push/pop in test_sockmap
  selftests/bpf: Drop netns helpers in mptcp
====================

Link: https://patch.msgid.link/20241114202832.3187927-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 51 insertions, 37 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 4c396305cd4d..6625b3f563a4 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2604,18 +2604,16 @@ BPF_CALL_2(bpf_msg_cork_bytes, struct sk_msg *, msg, u32, bytes)
 
 static void sk_msg_reset_curr(struct sk_msg *msg)
 {
-	u32 i = msg->sg.start;
-	u32 len = 0;
-
-	do {
-		len += sk_msg_elem(msg, i)->length;
-		sk_msg_iter_var_next(i);
-		if (len >= msg->sg.size)
-			break;
-	} while (i != msg->sg.end);
+	if (!msg->sg.size) {
+		msg->sg.curr = msg->sg.start;
+		msg->sg.copybreak = 0;
+	} else {
+		u32 i = msg->sg.end;
 
-	msg->sg.curr = i;
-	msg->sg.copybreak = 0;
+		sk_msg_iter_var_prev(i);
+		msg->sg.curr = i;
+		msg->sg.copybreak = msg->sg.data[i].length;
+	}
 }
 
 static const struct bpf_func_proto bpf_msg_cork_bytes_proto = {
@@ -2778,7 +2776,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 		sk_msg_iter_var_next(i);
 	} while (i != msg->sg.end);
 
-	if (start >= offset + l)
+	if (start > offset + l)
 		return -EINVAL;
 
 	space = MAX_MSG_FRAGS - sk_msg_elem_used(msg);
@@ -2803,6 +2801,8 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 
 		raw = page_address(page);
 
+		if (i == msg->sg.end)
+			sk_msg_iter_var_prev(i);
 		psge = sk_msg_elem(msg, i);
 		front = start - offset;
 		back = psge->length - front;
@@ -2819,7 +2819,13 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 		}
 
 		put_page(sg_page(psge));
-	} else if (start - offset) {
+		new = i;
+		goto place_new;
+	}
+
+	if (start - offset) {
+		if (i == msg->sg.end)
+			sk_msg_iter_var_prev(i);
 		psge = sk_msg_elem(msg, i);
 		rsge = sk_msg_elem_cpy(msg, i);
 
@@ -2830,39 +2836,44 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 		sk_msg_iter_var_next(i);
 		sg_unmark_end(psge);
 		sg_unmark_end(&rsge);
-		sk_msg_iter_next(msg, end);
 	}
 
 	/* Slot(s) to place newly allocated data */
+	sk_msg_iter_next(msg, end);
 	new = i;
+	sk_msg_iter_var_next(i);
+
+	if (i == msg->sg.end) {
+		if (!rsge.length)
+			goto place_new;
+		sk_msg_iter_next(msg, end);
+		goto place_new;
+	}
 
 	/* Shift one or two slots as needed */
-	if (!copy) {
-		sge = sk_msg_elem_cpy(msg, i);
+	sge = sk_msg_elem_cpy(msg, new);
+	sg_unmark_end(&sge);
 
+	nsge = sk_msg_elem_cpy(msg, i);
+	if (rsge.length) {
 		sk_msg_iter_var_next(i);
-		sg_unmark_end(&sge);
+		nnsge = sk_msg_elem_cpy(msg, i);
 		sk_msg_iter_next(msg, end);
+	}
 
-		nsge = sk_msg_elem_cpy(msg, i);
+	while (i != msg->sg.end) {
+		msg->sg.data[i] = sge;
+		sge = nsge;
+		sk_msg_iter_var_next(i);
 		if (rsge.length) {
-			sk_msg_iter_var_next(i);
+			nsge = nnsge;
 			nnsge = sk_msg_elem_cpy(msg, i);
-		}
-
-		while (i != msg->sg.end) {
-			msg->sg.data[i] = sge;
-			sge = nsge;
-			sk_msg_iter_var_next(i);
-			if (rsge.length) {
-				nsge = nnsge;
-				nnsge = sk_msg_elem_cpy(msg, i);
-			} else {
-				nsge = sk_msg_elem_cpy(msg, i);
-			}
+		} else {
+			nsge = sk_msg_elem_cpy(msg, i);
 		}
 	}
 
+place_new:
 	/* Place newly allocated data buffer */
 	sk_mem_charge(msg->sk, len);
 	msg->sg.size += len;
@@ -2891,8 +2902,10 @@ static const struct bpf_func_proto bpf_msg_push_data_proto = {
 
 static void sk_msg_shift_left(struct sk_msg *msg, int i)
 {
+	struct scatterlist *sge = sk_msg_elem(msg, i);
 	int prev;
 
+	put_page(sg_page(sge));
 	do {
 		prev = i;
 		sk_msg_iter_var_next(i);
@@ -2929,6 +2942,9 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 	if (unlikely(flags))
 		return -EINVAL;
 
+	if (unlikely(len == 0))
+		return 0;
+
 	/* First find the starting scatterlist element */
 	i = msg->sg.start;
 	do {
@@ -2941,7 +2957,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 	} while (i != msg->sg.end);
 
 	/* Bounds checks: start and pop must be inside message */
-	if (start >= offset + l || last >= msg->sg.size)
+	if (start >= offset + l || last > msg->sg.size)
 		return -EINVAL;
 
 	space = MAX_MSG_FRAGS - sk_msg_elem_used(msg);
@@ -2970,12 +2986,12 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 	 */
 	if (start != offset) {
 		struct scatterlist *nsge, *sge = sk_msg_elem(msg, i);
-		int a = start;
+		int a = start - offset;
 		int b = sge->length - pop - a;
 
 		sk_msg_iter_var_next(i);
 
-		if (pop < sge->length - a) {
+		if (b > 0) {
 			if (space) {
 				sge->length = a;
 				sk_msg_shift_right(msg, i);
@@ -2994,7 +3010,6 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				if (unlikely(!page))
 					return -ENOMEM;
 
-				sge->length = a;
 				orig = sg_page(sge);
 				from = sg_virt(sge);
 				to = page_address(page);
@@ -3004,7 +3019,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				put_page(orig);
 			}
 			pop = 0;
-		} else if (pop >= sge->length - a) {
+		} else {
 			pop -= (sge->length - a);
 			sge->length = a;
 		}
@@ -3038,7 +3053,6 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 			pop -= sge->length;
 			sk_msg_shift_left(msg, i);
 		}
-		sk_msg_iter_var_next(i);
 	}
 
 	sk_mem_uncharge(msg->sk, len - pop);