Linux kernel -stable discussions
 help / color / mirror / Atom feed
* FAILED: patch "[PATCH] net: skmsg: preserve sg.copy across SG transforms" failed to apply to 5.10-stable tree
@ 2026-07-02  8:27 gregkh
  2026-07-02 15:26 ` [PATCH 5.10.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin
  0 siblings, 1 reply; 4+ messages in thread
From: gregkh @ 2026-07-02  8:27 UTC (permalink / raw)
  To: yimingqian591, keenanat2000, kuba; +Cc: stable


The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 406e8a651a7b854c41fecd5117bb282b3a6c2c6b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026070246-backer-dating-7275@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 406e8a651a7b854c41fecd5117bb282b3a6c2c6b Mon Sep 17 00:00:00 2001
From: Yiming Qian <yimingqian591@gmail.com>
Date: Wed, 10 Jun 2026 06:21:36 +0000
Subject: [PATCH] net: skmsg: preserve sg.copy across SG transforms

The sk_msg sg.copy bitmap is part of the scatterlist entry ownership
state. A set bit tells sk_msg_compute_data_pointers() not to expose the
entry through writable BPF ctx->data. This protects entries backed by
pages that are not private to the sk_msg, such as splice-backed file
page-cache pages.

Several sk_msg transform paths move, copy, split, or compact
msg->sg.data[] entries without moving the matching sg.copy bit. This can
make an externally backed entry arrive at a new slot with a clear copy
bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable
ctx->data and BPF stores can modify the original page cache.

Keep sg.copy synchronized with sg.data[] whenever entries are
transferred, shifted, split, or copied into a new sk_msg. Clear the bit
when an entry is replaced by a newly allocated private page or freed.
This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(),
sk_msg_xfer(), and tls_split_open_record(), including the partial tail
entry created during TLS open-record splitting.

Fixes: d3b18ad31f93 ("tls: add bpf support to sk_msg handling")
Cc: stable@vger.kernel.org
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Yiming Qian <yimingqian591@gmail.com>
Link: https://patch.msgid.link/20260610062137.49075-1-yimingqian591@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 19f4f253b4f9..937823856de5 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h
@@ -4,6 +4,7 @@
 #ifndef _LINUX_SKMSG_H
 #define _LINUX_SKMSG_H
 
+#include <linux/bitops.h>
 #include <linux/bpf.h>
 #include <linux/filter.h>
 #include <linux/scatterlist.h>
@@ -199,11 +200,14 @@ static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
 			       int which, u32 size)
 {
 	dst->sg.data[which] = src->sg.data[which];
+	__assign_bit(which, dst->sg.copy, test_bit(which, src->sg.copy));
 	dst->sg.data[which].length  = size;
 	dst->sg.size		   += size;
 	src->sg.size		   -= size;
 	src->sg.data[which].length -= size;
 	src->sg.data[which].offset += size;
+	if (!src->sg.data[which].length)
+		__clear_bit(which, src->sg.copy);
 }
 
 static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
@@ -273,16 +277,19 @@ static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
 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);
-		else
-			__clear_bit(i, msg->sg.copy);
+		__assign_bit(i, msg->sg.copy, copy_state);
 		sk_msg_iter_var_next(i);
 		if (i == msg->sg.end)
 			break;
 	} while (1);
 }
 
+static inline void sk_msg_sg_copy_assign(struct sk_msg *dst, u32 dst_i,
+					 const struct sk_msg *src, u32 src_i)
+{
+	__assign_bit(dst_i, dst->sg.copy, test_bit(src_i, src->sg.copy));
+}
+
 static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
 {
 	sk_msg_sg_copy(msg, start, true);
diff --git a/net/core/filter.c b/net/core/filter.c
index 80439767e0ee..40037413dd4e 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2733,11 +2733,13 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 		poffset += len;
 		sge->length = 0;
 		put_page(sg_page(sge));
+		__clear_bit(i, msg->sg.copy);
 
 		sk_msg_iter_var_next(i);
 	} while (i != last_sge);
 
 	sg_set_page(&msg->sg.data[first_sge], page, copy, 0);
+	__clear_bit(first_sge, msg->sg.copy);
 
 	/* To repair sg ring we need to shift entries. If we only
 	 * had a single entry though we can just replace it and
@@ -2763,9 +2765,11 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 			break;
 
 		msg->sg.data[i] = msg->sg.data[move_from];
+		sk_msg_sg_copy_assign(msg, i, msg, move_from);
 		msg->sg.data[move_from].length = 0;
 		msg->sg.data[move_from].page_link = 0;
 		msg->sg.data[move_from].offset = 0;
+		__clear_bit(move_from, msg->sg.copy);
 		sk_msg_iter_var_next(i);
 	} while (1);
 
@@ -2794,6 +2798,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 {
 	struct scatterlist sge, nsge, nnsge, rsge = {0}, *psge;
 	u32 new, i = 0, l = 0, space, copy = 0, offset = 0;
+	bool sge_copy, nsge_copy, nnsge_copy, rsge_copy = false;
 	u8 *raw, *to, *from;
 	struct page *page;
 
@@ -2866,6 +2871,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 			sk_msg_iter_var_prev(i);
 		psge = sk_msg_elem(msg, i);
 		rsge = sk_msg_elem_cpy(msg, i);
+		rsge_copy = test_bit(i, msg->sg.copy);
 
 		psge->length = start - offset;
 		rsge.length -= psge->length;
@@ -2890,24 +2896,32 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 
 	/* Shift one or two slots as needed */
 	sge = sk_msg_elem_cpy(msg, new);
+	sge_copy = test_bit(new, msg->sg.copy);
 	sg_unmark_end(&sge);
 
 	nsge = sk_msg_elem_cpy(msg, i);
+	nsge_copy = test_bit(i, msg->sg.copy);
 	if (rsge.length) {
 		sk_msg_iter_var_next(i);
 		nnsge = sk_msg_elem_cpy(msg, i);
+		nnsge_copy = test_bit(i, msg->sg.copy);
 		sk_msg_iter_next(msg, end);
 	}
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		__assign_bit(i, msg->sg.copy, sge_copy);
 		sge = nsge;
+		sge_copy = nsge_copy;
 		sk_msg_iter_var_next(i);
 		if (rsge.length) {
 			nsge = nnsge;
+			nsge_copy = nnsge_copy;
 			nnsge = sk_msg_elem_cpy(msg, i);
+			nnsge_copy = test_bit(i, msg->sg.copy);
 		} else {
 			nsge = sk_msg_elem_cpy(msg, i);
+			nsge_copy = test_bit(i, msg->sg.copy);
 		}
 	}
 
@@ -2921,6 +2935,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 		get_page(sg_page(&rsge));
 		sk_msg_iter_var_next(new);
 		msg->sg.data[new] = rsge;
+		__assign_bit(new, msg->sg.copy, rsge_copy);
 	}
 
 	sk_msg_reset_curr(msg);
@@ -2948,25 +2963,33 @@ static void sk_msg_shift_left(struct sk_msg *msg, int i)
 		prev = i;
 		sk_msg_iter_var_next(i);
 		msg->sg.data[prev] = msg->sg.data[i];
+		sk_msg_sg_copy_assign(msg, prev, msg, i);
 	} while (i != msg->sg.end);
 
 	sk_msg_iter_prev(msg, end);
+	__clear_bit(msg->sg.end, msg->sg.copy);
 }
 
 static void sk_msg_shift_right(struct sk_msg *msg, int i)
 {
 	struct scatterlist tmp, sge;
+	bool tmp_copy, sge_copy;
 
 	sk_msg_iter_next(msg, end);
 	sge = sk_msg_elem_cpy(msg, i);
+	sge_copy = test_bit(i, msg->sg.copy);
 	sk_msg_iter_var_next(i);
 	tmp = sk_msg_elem_cpy(msg, i);
+	tmp_copy = test_bit(i, msg->sg.copy);
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		__assign_bit(i, msg->sg.copy, sge_copy);
 		sk_msg_iter_var_next(i);
 		sge = tmp;
+		sge_copy = tmp_copy;
 		tmp = sk_msg_elem_cpy(msg, i);
+		tmp_copy = test_bit(i, msg->sg.copy);
 	}
 }
 
@@ -3026,6 +3049,8 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 		struct scatterlist *nsge, *sge = sk_msg_elem(msg, i);
 		int a = start - offset;
 		int b = sge->length - pop - a;
+		u32 sge_i = i;
+		bool sge_copy = test_bit(i, msg->sg.copy);
 
 		sk_msg_iter_var_next(i);
 
@@ -3038,6 +3063,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				sg_set_page(nsge,
 					    sg_page(sge),
 					    b, sge->offset + pop + a);
+				__assign_bit(i, msg->sg.copy, sge_copy);
 			} else {
 				struct page *page, *orig;
 				u8 *to, *from;
@@ -3054,6 +3080,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				memcpy(to, from, a);
 				memcpy(to + a, from + a + pop, b);
 				sg_set_page(sge, page, a + b, 0);
+				__clear_bit(sge_i, msg->sg.copy);
 				put_page(orig);
 			}
 			pop = 0;
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index e1850caf1a71..30c3b9a2681c 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -66,6 +66,7 @@ int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
 			sge = &msg->sg.data[msg->sg.end];
 			sg_unmark_end(sge);
 			sg_set_page(sge, pfrag->page, use, orig_offset);
+			__clear_bit(msg->sg.end, msg->sg.copy);
 			get_page(pfrag->page);
 			sk_msg_iter_next(msg, end);
 		}
@@ -186,6 +187,7 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
 			sk_mem_uncharge(sk, len);
 		put_page(sg_page(sge));
 	}
+	__clear_bit(i, msg->sg.copy);
 	memset(sge, 0, sizeof(*sge));
 	return len;
 }
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 964ebc268ee4..a47f6a1e2c77 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -623,6 +623,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	struct scatterlist *sge, *osge, *nsge;
 	u32 orig_size = msg_opl->sg.size;
 	struct scatterlist tmp = { };
+	u32 tmp_i = 0;
 	struct sk_msg *msg_npl;
 	struct tls_rec *new;
 	int ret;
@@ -644,6 +645,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 		if (sge->length > apply) {
 			u32 len = sge->length - apply;
 
+			tmp_i = i;
 			get_page(sg_page(sge));
 			sg_set_page(&tmp, sg_page(sge), len,
 				    sge->offset + apply);
@@ -675,6 +677,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	nsge = sk_msg_elem(msg_npl, j);
 	if (tmp.length) {
 		memcpy(nsge, &tmp, sizeof(*nsge));
+		sk_msg_sg_copy_assign(msg_npl, j, msg_opl, tmp_i);
 		sk_msg_iter_var_next(j);
 		nsge = sk_msg_elem(msg_npl, j);
 	}
@@ -682,6 +685,7 @@ static int tls_split_open_record(struct sock *sk, struct tls_rec *from,
 	osge = sk_msg_elem(msg_opl, i);
 	while (osge->length) {
 		memcpy(nsge, osge, sizeof(*nsge));
+		sk_msg_sg_copy_assign(msg_npl, j, msg_opl, i);
 		sg_unmark_end(nsge);
 		sk_msg_iter_var_next(i);
 		sk_msg_iter_var_next(j);


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* FAILED: patch "[PATCH] bpf, sockmap: keep sk_msg copy state in sync" failed to apply to 5.10-stable tree
@ 2026-07-14 15:54 gregkh
  2026-07-18 15:20 ` [PATCH 5.10.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin
  0 siblings, 1 reply; 4+ messages in thread
From: gregkh @ 2026-07-14 15:54 UTC (permalink / raw)
  To: rollkingzzc, 2045gemini, ast, emil, jiayuan.chen, john.fastabend,
	kuniyu
  Cc: stable


The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 2ccbc9a3874620c9623419034f572e4507c33e4f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071405-duo-banknote-b789@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2ccbc9a3874620c9623419034f572e4507c33e4f Mon Sep 17 00:00:00 2001
From: Zhang Cen <rollkingzzc@gmail.com>
Date: Mon, 15 Jun 2026 10:19:56 +0800
Subject: [PATCH] bpf, sockmap: keep sk_msg copy state in sync

SK_MSG uses msg->sg.copy as per-scatterlist-entry provenance. Entries
with this bit set are copied before data/data_end are exposed to SK_MSG
BPF programs for direct packet access.

bpf_msg_pull_data(), bpf_msg_push_data(), and bpf_msg_pop_data()
rewrite the sk_msg scatterlist ring by collapsing, splitting, and
shifting entries. These operations move msg->sg.data[] entries, but the
parallel copy bitmap can be left behind on the old slot. A copied entry
can then return to msg->sg.start with its copy bit clear and be exposed
as directly writable packet data.

This corruption path requires an attached SK_MSG BPF program that calls
the mutating helpers; ordinary sockmap/TLS traffic that never runs
push/pop/pull helper sequences is not affected.

Keep msg->sg.copy synchronized with scatterlist entry moves, preserve
the copy bit when an entry is split, clear it when a helper replaces an
entry with a private page, and clear slots vacated by pull-data
compaction.

Fixes: 015632bb30da ("bpf: sk_msg program helper bpf_sk_msg_pull_data")
Fixes: 6fff607e2f14 ("bpf: sk_msg program helper bpf_msg_push_data")
Fixes: 7246d8ed4dcc ("bpf: helper to pop data from messages")
Cc: stable@vger.kernel.org
Co-developed-by: Han Guidong <2045gemini@gmail.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Han Guidong <2045gemini@gmail.com>
Signed-off-by: Zhang Cen <rollkingzzc@gmail.com>
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260615021959.140010-4-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/net/core/filter.c b/net/core/filter.c
index 978e740792be..3ecac0eb7da1 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2654,6 +2654,38 @@ static void sk_msg_reset_curr(struct sk_msg *msg)
 	}
 }
 
+static bool sk_msg_elem_is_copy(const struct sk_msg *msg, u32 i)
+{
+	return test_bit(i, msg->sg.copy);
+}
+
+static void sk_msg_clear_elem_copy(struct sk_msg *msg, u32 i)
+{
+	__clear_bit(i, msg->sg.copy);
+}
+
+static void sk_msg_set_elem_copy(struct sk_msg *msg, u32 i)
+{
+	__set_bit(i, msg->sg.copy);
+}
+
+static void sk_msg_clear_copy_range(struct sk_msg *msg, u32 start, u32 end)
+{
+	while (start != end) {
+		sk_msg_clear_elem_copy(msg, start);
+		sk_msg_iter_var_next(start);
+	}
+}
+
+static void sk_msg_sg_move(struct sk_msg *msg, u32 dst, u32 src)
+{
+	msg->sg.data[dst] = msg->sg.data[src];
+	if (sk_msg_elem_is_copy(msg, src))
+		sk_msg_set_elem_copy(msg, dst);
+	else
+		sk_msg_clear_elem_copy(msg, dst);
+}
+
 static const struct bpf_func_proto bpf_msg_cork_bytes_proto = {
 	.func           = bpf_msg_cork_bytes,
 	.gpl_only       = false,
@@ -2692,7 +2724,7 @@ 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 (!sk_msg_elem_is_copy(msg, i) && bytes_sg_total <= len)
 		goto out;
 
 	/* At this point we need to linearize multiple scatterlist
@@ -2738,6 +2770,7 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 	} while (i != last_sge);
 
 	sg_set_page(&msg->sg.data[first_sge], page, copy, 0);
+	sk_msg_clear_elem_copy(msg, first_sge);
 
 	/* To repair sg ring we need to shift entries. If we only
 	 * had a single entry though we can just replace it and
@@ -2747,8 +2780,14 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 	shift = last_sge > first_sge ?
 		last_sge - first_sge - 1 :
 		NR_MSG_FRAG_IDS - first_sge + last_sge - 1;
-	if (!shift)
+	if (!shift) {
+		sk_msg_clear_elem_copy(msg, msg->sg.end);
 		goto out;
+	}
+
+	i = first_sge;
+	sk_msg_iter_var_next(i);
+	sk_msg_clear_copy_range(msg, i, last_sge);
 
 	i = first_sge;
 	sk_msg_iter_var_next(i);
@@ -2762,16 +2801,18 @@ BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
 		if (move_from == msg->sg.end)
 			break;
 
-		msg->sg.data[i] = msg->sg.data[move_from];
+		sk_msg_sg_move(msg, i, move_from);
 		msg->sg.data[move_from].length = 0;
 		msg->sg.data[move_from].page_link = 0;
 		msg->sg.data[move_from].offset = 0;
+		sk_msg_clear_elem_copy(msg, move_from);
 		sk_msg_iter_var_next(i);
 	} while (1);
 
 	msg->sg.end = msg->sg.end - shift > msg->sg.end ?
 		      msg->sg.end - shift + NR_MSG_FRAG_IDS :
 		      msg->sg.end - shift;
+	sk_msg_clear_elem_copy(msg, msg->sg.end);
 out:
 	sk_msg_reset_curr(msg);
 	msg->data = sg_virt(&msg->sg.data[first_sge]) + start - offset;
@@ -2792,8 +2833,10 @@ static const struct bpf_func_proto bpf_msg_pull_data_proto = {
 BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 	   u32, len, u64, flags)
 {
+	bool sge_copy = false, nsge_copy = false, nnsge_copy = false;
 	struct scatterlist sge, nsge, nnsge, rsge = {0}, *psge;
 	u32 new, i = 0, l = 0, space, copy = 0, offset = 0;
+	bool rsge_copy = false;
 	u8 *raw, *to, *from;
 	struct page *page;
 
@@ -2869,6 +2912,7 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 			sk_msg_iter_var_prev(i);
 		psge = sk_msg_elem(msg, i);
 		rsge = sk_msg_elem_cpy(msg, i);
+		rsge_copy = sk_msg_elem_is_copy(msg, i);
 
 		psge->length = start - offset;
 		rsge.length -= psge->length;
@@ -2894,23 +2938,34 @@ BPF_CALL_4(bpf_msg_push_data, struct sk_msg *, msg, u32, start,
 	/* Shift one or two slots as needed */
 	sge = sk_msg_elem_cpy(msg, new);
 	sg_unmark_end(&sge);
+	sge_copy = sk_msg_elem_is_copy(msg, new);
 
 	nsge = sk_msg_elem_cpy(msg, i);
+	nsge_copy = sk_msg_elem_is_copy(msg, i);
 	if (rsge.length) {
 		sk_msg_iter_var_next(i);
 		nnsge = sk_msg_elem_cpy(msg, i);
+		nnsge_copy = sk_msg_elem_is_copy(msg, i);
 		sk_msg_iter_next(msg, end);
 	}
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		if (sge_copy)
+			sk_msg_set_elem_copy(msg, i);
+		else
+			sk_msg_clear_elem_copy(msg, i);
 		sge = nsge;
+		sge_copy = nsge_copy;
 		sk_msg_iter_var_next(i);
 		if (rsge.length) {
 			nsge = nnsge;
+			nsge_copy = nnsge_copy;
 			nnsge = sk_msg_elem_cpy(msg, i);
+			nnsge_copy = sk_msg_elem_is_copy(msg, i);
 		} else {
 			nsge = sk_msg_elem_cpy(msg, i);
+			nsge_copy = sk_msg_elem_is_copy(msg, i);
 		}
 	}
 
@@ -2918,13 +2973,18 @@ 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);
+	sk_msg_clear_elem_copy(msg, new);
 	sg_set_page(&msg->sg.data[new], page, len + copy, 0);
 	if (rsge.length) {
 		get_page(sg_page(&rsge));
 		sk_msg_iter_var_next(new);
 		msg->sg.data[new] = rsge;
+		if (rsge_copy)
+			sk_msg_set_elem_copy(msg, new);
+		else
+			sk_msg_clear_elem_copy(msg, new);
 	}
+	sk_msg_clear_elem_copy(msg, msg->sg.end);
 
 	sk_msg_reset_curr(msg);
 	sk_msg_compute_data_pointers(msg);
@@ -2950,27 +3010,38 @@ static void sk_msg_shift_left(struct sk_msg *msg, int i)
 	do {
 		prev = i;
 		sk_msg_iter_var_next(i);
-		msg->sg.data[prev] = msg->sg.data[i];
+		sk_msg_sg_move(msg, prev, i);
 	} while (i != msg->sg.end);
 
 	sk_msg_iter_prev(msg, end);
+	sk_msg_clear_elem_copy(msg, msg->sg.end);
 }
 
 static void sk_msg_shift_right(struct sk_msg *msg, int i)
 {
 	struct scatterlist tmp, sge;
+	bool tmp_copy, sge_copy;
 
 	sk_msg_iter_next(msg, end);
 	sge = sk_msg_elem_cpy(msg, i);
+	sge_copy = sk_msg_elem_is_copy(msg, i);
 	sk_msg_iter_var_next(i);
 	tmp = sk_msg_elem_cpy(msg, i);
+	tmp_copy = sk_msg_elem_is_copy(msg, i);
 
 	while (i != msg->sg.end) {
 		msg->sg.data[i] = sge;
+		if (sge_copy)
+			sk_msg_set_elem_copy(msg, i);
+		else
+			sk_msg_clear_elem_copy(msg, i);
 		sk_msg_iter_var_next(i);
 		sge = tmp;
+		sge_copy = tmp_copy;
 		tmp = sk_msg_elem_cpy(msg, i);
+		tmp_copy = sk_msg_elem_is_copy(msg, i);
 	}
+	sk_msg_clear_elem_copy(msg, msg->sg.end);
 }
 
 BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
@@ -3027,8 +3098,10 @@ 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);
+		bool sge_copy = sk_msg_elem_is_copy(msg, i);
 		int a = start - offset;
 		int b = sge->length - pop - a;
+		u32 sge_idx = i;
 
 		sk_msg_iter_var_next(i);
 
@@ -3041,6 +3114,10 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				sg_set_page(nsge,
 					    sg_page(sge),
 					    b, sge->offset + pop + a);
+				if (sge_copy)
+					sk_msg_set_elem_copy(msg, i);
+				else
+					sk_msg_clear_elem_copy(msg, i);
 			} else {
 				struct page *page, *orig;
 				u8 *to, *from;
@@ -3057,6 +3134,7 @@ BPF_CALL_4(bpf_msg_pop_data, struct sk_msg *, msg, u32, start,
 				memcpy(to, from, a);
 				memcpy(to + a, from + a + pop, b);
 				sg_set_page(sge, page, a + b, 0);
+				sk_msg_clear_elem_copy(msg, sge_idx);
 				put_page(orig);
 			}
 			pop = 0;


^ permalink raw reply related	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-07-18 15:20 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-02  8:27 FAILED: patch "[PATCH] net: skmsg: preserve sg.copy across SG transforms" failed to apply to 5.10-stable tree gregkh
2026-07-02 15:26 ` [PATCH 5.10.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin
2026-07-02 15:26   ` [PATCH 5.10.y 2/2] net: skmsg: preserve sg.copy across SG transforms Sasha Levin
  -- strict thread matches above, loose matches on Subject: below --
2026-07-14 15:54 FAILED: patch "[PATCH] bpf, sockmap: keep sk_msg copy state in sync" failed to apply to 5.10-stable tree gregkh
2026-07-18 15:20 ` [PATCH 5.10.y 1/2] skmsg: convert struct sk_msg_sg::copy to a bitmap Sasha Levin

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox