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 2025-09-23

We've added 9 non-merge commits during the last 33 day(s) which contain
a total of 10 files changed, 480 insertions(+), 53 deletions(-).

The main changes are:

1) A new bpf_xdp_pull_data kfunc that supports pulling data from
   a frag into the linear area of a xdp_buff, from Amery Hung.

   This includes changes in the xdp_native.bpf.c selftest, which
   Nimrod's future work depends on.

   It is a merge from a stable branch 'xdp_pull_data' which has
   also been merged to bpf-next.

   There is a conflict with recent changes in 'include/net/xdp.h'
   in the net-next tree that will need to be resolved.

2) A compiler warning fix when CONFIG_NET=n in the recent dynptr
   skb_meta support, from Jakub Sitnicki.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests: drv-net: Pull data before parsing headers
  selftests/bpf: Test bpf_xdp_pull_data
  bpf: Support specifying linear xdp packet data size for BPF_PROG_TEST_RUN
  bpf: Make variables in bpf_prog_test_run_xdp less confusing
  bpf: Clear packet pointers after changing packet data in kfuncs
  bpf: Support pulling non-linear xdp data
  bpf: Allow bpf_xdp_shrink_data to shrink a frag from head and tail
  bpf: Clear pfmemalloc flag when freeing all fragments
  bpf: Return an error pointer for skb metadata when CONFIG_NET=n
====================

Link: https://patch.msgid.link/20250924050303.2466356-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 24 insertions, 4 deletions

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 9ed21b65e2e9..af6d9354662c 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1822,7 +1822,7 @@ static inline void bpf_xdp_copy_buf(struct xdp_buff *xdp, unsigned long off, voi
 
 static inline void *bpf_skb_meta_pointer(struct sk_buff *skb, u32 offset)
 {
-	return NULL;
+	return ERR_PTR(-EOPNOTSUPP);
 }
 #endif /* CONFIG_NET */
 
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 6fd294fa6841..aa742f413c35 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -136,6 +136,11 @@ static __always_inline u32 xdp_buff_get_skb_flags(const struct xdp_buff *xdp)
 	return xdp->flags;
 }
 
+static __always_inline void xdp_buff_clear_frag_pfmemalloc(struct xdp_buff *xdp)
+{
+	xdp->flags &= ~XDP_FLAGS_FRAGS_PF_MEMALLOC;
+}
+
 static __always_inline void
 xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
 {
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 513c8e9704f6..4f2d3268a676 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h
@@ -160,13 +160,23 @@ static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first)
 	return ret;
 }
 
-static inline void xsk_buff_del_tail(struct xdp_buff *tail)
+static inline void xsk_buff_del_frag(struct xdp_buff *xdp)
 {
-	struct xdp_buff_xsk *xskb = container_of(tail, struct xdp_buff_xsk, xdp);
+	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
 
 	list_del(&xskb->list_node);
 }
 
+static inline struct xdp_buff *xsk_buff_get_head(struct xdp_buff *first)
+{
+	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
+	struct xdp_buff_xsk *frag;
+
+	frag = list_first_entry(&xskb->pool->xskb_list, struct xdp_buff_xsk,
+				list_node);
+	return &frag->xdp;
+}
+
 static inline struct xdp_buff *xsk_buff_get_tail(struct xdp_buff *first)
 {
 	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
@@ -389,8 +399,13 @@ static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first)
 	return NULL;
 }
 
-static inline void xsk_buff_del_tail(struct xdp_buff *tail)
+static inline void xsk_buff_del_frag(struct xdp_buff *xdp)
+{
+}
+
+static inline struct xdp_buff *xsk_buff_get_head(struct xdp_buff *first)
 {
+	return NULL;
 }
 
 static inline struct xdp_buff *xsk_buff_get_tail(struct xdp_buff *first)