From e6a4750ffe9d701c4d55212b14b615e63571d235 Mon Sep 17 00:00:00 2001
From: Björn Töpel <bjorn.topel@intel.com>
Date: Mon, 8 Mar 2021 12:29:06 +0100
Subject: bpf, xdp: Make bpf_redirect_map() a map operation
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Currently the bpf_redirect_map() implementation dispatches to the
correct map-lookup function via a switch-statement. To avoid the
dispatching, this change adds bpf_redirect_map() as a map
operation. Each map provides its bpf_redirect_map() version, and
correct function is automatically selected by the BPF verifier.

A nice side-effect of the code movement is that the map lookup
functions are now local to the map implementation files, which removes
one additional function call.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210308112907.559576-2-bjorn.topel@gmail.com
---
 include/linux/filter.h | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'include/linux/filter.h')

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 3b00fc906ccd..008691fd3b58 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1472,4 +1472,31 @@ static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol,
 }
 #endif /* IS_ENABLED(CONFIG_IPV6) */
 
+static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifindex, u64 flags,
+						  void *lookup_elem(struct bpf_map *map, u32 key))
+{
+	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
+
+	/* Lower bits of the flags are used as return code on lookup failure */
+	if (unlikely(flags > XDP_TX))
+		return XDP_ABORTED;
+
+	ri->tgt_value = lookup_elem(map, ifindex);
+	if (unlikely(!ri->tgt_value)) {
+		/* If the lookup fails we want to clear out the state in the
+		 * redirect_info struct completely, so that if an eBPF program
+		 * performs multiple lookups, the last one always takes
+		 * precedence.
+		 */
+		WRITE_ONCE(ri->map, NULL);
+		return flags;
+	}
+
+	ri->flags = flags;
+	ri->tgt_index = ifindex;
+	WRITE_ONCE(ri->map, map);
+
+	return XDP_REDIRECT;
+}
+
 #endif /* __LINUX_FILTER_H__ */
-- 
cgit v1.3-18-gd494


From ee75aef23afe6e88497151c127c13ed69f41aaa2 Mon Sep 17 00:00:00 2001
From: Björn Töpel <bjorn.topel@intel.com>
Date: Mon, 8 Mar 2021 12:29:07 +0100
Subject: bpf, xdp: Restructure redirect actions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The XDP_REDIRECT implementations for maps and non-maps are fairly
similar, but obviously need to take different code paths depending on
if the target is using a map or not. Today, the redirect targets for
XDP either uses a map, or is based on ifindex.

Here, the map type and id are added to bpf_redirect_info, instead of
the actual map. Map type, map item/ifindex, and the map_id (if any) is
passed to xdp_do_redirect().

For ifindex-based redirect, used by the bpf_redirect() XDP BFP helper,
a special map type/id are used. Map type of UNSPEC together with map id
equal to INT_MAX has the special meaning of an ifindex based
redirect. Note that valid map ids are 1 inclusive, INT_MAX exclusive
([1,INT_MAX[).

In addition to making the code easier to follow, using explicit type
and id in bpf_redirect_info has a slight positive performance impact
by avoiding a pointer indirection for the map type lookup, and instead
use the cacheline for bpf_redirect_info.

Since the actual map is not passed via bpf_redirect_info anymore, the
map lookup is only done in the BPF helper. This means that the
bpf_clear_redirect_map() function can be removed. The actual map item
is RCU protected.

The bpf_redirect_info flags member is not used by XDP, and not
read/written any more. The map member is only written to when
required/used, and not unconditionally.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210308112907.559576-3-bjorn.topel@gmail.com
---
 include/linux/filter.h     |  10 +--
 include/trace/events/xdp.h |  62 ++++++++++-------
 kernel/bpf/cpumap.c        |   1 -
 kernel/bpf/devmap.c        |   1 -
 net/core/filter.c          | 170 ++++++++++++++++++++-------------------------
 net/xdp/xskmap.c           |   1 -
 6 files changed, 116 insertions(+), 129 deletions(-)

(limited to 'include/linux/filter.h')

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 008691fd3b58..b2b85b2cad8e 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -646,7 +646,8 @@ struct bpf_redirect_info {
 	u32 flags;
 	u32 tgt_index;
 	void *tgt_value;
-	struct bpf_map *map;
+	u32 map_id;
+	enum bpf_map_type map_type;
 	u32 kern_flags;
 	struct bpf_nh_params nh;
 };
@@ -1488,13 +1489,14 @@ static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifind
 		 * performs multiple lookups, the last one always takes
 		 * precedence.
 		 */
-		WRITE_ONCE(ri->map, NULL);
+		ri->map_id = INT_MAX; /* Valid map id idr range: [1,INT_MAX[ */
+		ri->map_type = BPF_MAP_TYPE_UNSPEC;
 		return flags;
 	}
 
-	ri->flags = flags;
 	ri->tgt_index = ifindex;
-	WRITE_ONCE(ri->map, map);
+	ri->map_id = map->id;
+	ri->map_type = map->map_type;
 
 	return XDP_REDIRECT;
 }
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 76a97176ab81..fcad3645a70b 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -86,19 +86,15 @@ struct _bpf_dtab_netdev {
 };
 #endif /* __DEVMAP_OBJ_TYPE */
 
-#define devmap_ifindex(tgt, map)				\
-	(((map->map_type == BPF_MAP_TYPE_DEVMAP ||	\
-		  map->map_type == BPF_MAP_TYPE_DEVMAP_HASH)) ? \
-	  ((struct _bpf_dtab_netdev *)tgt)->dev->ifindex : 0)
-
 DECLARE_EVENT_CLASS(xdp_redirect_template,
 
 	TP_PROTO(const struct net_device *dev,
 		 const struct bpf_prog *xdp,
 		 const void *tgt, int err,
-		 const struct bpf_map *map, u32 index),
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
 
-	TP_ARGS(dev, xdp, tgt, err, map, index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index),
 
 	TP_STRUCT__entry(
 		__field(int, prog_id)
@@ -111,14 +107,22 @@ DECLARE_EVENT_CLASS(xdp_redirect_template,
 	),
 
 	TP_fast_assign(
+		u32 ifindex = 0, map_index = index;
+
+		if (map_type == BPF_MAP_TYPE_DEVMAP || map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+			ifindex = ((struct _bpf_dtab_netdev *)tgt)->dev->ifindex;
+		} else if (map_type == BPF_MAP_TYPE_UNSPEC && map_id == INT_MAX) {
+			ifindex = index;
+			map_index = 0;
+		}
+
 		__entry->prog_id	= xdp->aux->id;
 		__entry->act		= XDP_REDIRECT;
 		__entry->ifindex	= dev->ifindex;
 		__entry->err		= err;
-		__entry->to_ifindex	= map ? devmap_ifindex(tgt, map) :
-						index;
-		__entry->map_id		= map ? map->id : 0;
-		__entry->map_index	= map ? index : 0;
+		__entry->to_ifindex	= ifindex;
+		__entry->map_id		= map_id;
+		__entry->map_index	= map_index;
 	),
 
 	TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
@@ -133,45 +137,49 @@ DEFINE_EVENT(xdp_redirect_template, xdp_redirect,
 	TP_PROTO(const struct net_device *dev,
 		 const struct bpf_prog *xdp,
 		 const void *tgt, int err,
-		 const struct bpf_map *map, u32 index),
-	TP_ARGS(dev, xdp, tgt, err, map, index)
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
 );
 
 DEFINE_EVENT(xdp_redirect_template, xdp_redirect_err,
 	TP_PROTO(const struct net_device *dev,
 		 const struct bpf_prog *xdp,
 		 const void *tgt, int err,
-		 const struct bpf_map *map, u32 index),
-	TP_ARGS(dev, xdp, tgt, err, map, index)
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
 );
 
-#define _trace_xdp_redirect(dev, xdp, to)				\
-	 trace_xdp_redirect(dev, xdp, NULL, 0, NULL, to)
+#define _trace_xdp_redirect(dev, xdp, to)						\
+	 trace_xdp_redirect(dev, xdp, NULL, 0, BPF_MAP_TYPE_UNSPEC, INT_MAX, to)
 
-#define _trace_xdp_redirect_err(dev, xdp, to, err)			\
-	 trace_xdp_redirect_err(dev, xdp, NULL, err, NULL, to)
+#define _trace_xdp_redirect_err(dev, xdp, to, err)					\
+	 trace_xdp_redirect_err(dev, xdp, NULL, err, BPF_MAP_TYPE_UNSPEC, INT_MAX, to)
 
-#define _trace_xdp_redirect_map(dev, xdp, to, map, index)		\
-	 trace_xdp_redirect(dev, xdp, to, 0, map, index)
+#define _trace_xdp_redirect_map(dev, xdp, to, map_type, map_id, index) \
+	 trace_xdp_redirect(dev, xdp, to, 0, map_type, map_id, index)
 
-#define _trace_xdp_redirect_map_err(dev, xdp, to, map, index, err)	\
-	 trace_xdp_redirect_err(dev, xdp, to, err, map, index)
+#define _trace_xdp_redirect_map_err(dev, xdp, to, map_type, map_id, index, err) \
+	 trace_xdp_redirect_err(dev, xdp, to, err, map_type, map_id, index)
 
 /* not used anymore, but kept around so as not to break old programs */
 DEFINE_EVENT(xdp_redirect_template, xdp_redirect_map,
 	TP_PROTO(const struct net_device *dev,
 		 const struct bpf_prog *xdp,
 		 const void *tgt, int err,
-		 const struct bpf_map *map, u32 index),
-	TP_ARGS(dev, xdp, tgt, err, map, index)
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
 );
 
 DEFINE_EVENT(xdp_redirect_template, xdp_redirect_map_err,
 	TP_PROTO(const struct net_device *dev,
 		 const struct bpf_prog *xdp,
 		 const void *tgt, int err,
-		 const struct bpf_map *map, u32 index),
-	TP_ARGS(dev, xdp, tgt, err, map, index)
+		 enum bpf_map_type map_type,
+		 u32 map_id, u32 index),
+	TP_ARGS(dev, xdp, tgt, err, map_type, map_id, index)
 );
 
 TRACE_EVENT(xdp_cpumap_kthread,
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 7352d4160b7f..0cf2791d5099 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -543,7 +543,6 @@ static void cpu_map_free(struct bpf_map *map)
 	 * complete.
 	 */
 
-	bpf_clear_redirect_map(map);
 	synchronize_rcu();
 
 	/* For cpu_map the remote CPUs can still be using the entries
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f7f42448259f..7a5ad7331c3b 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -197,7 +197,6 @@ static void dev_map_free(struct bpf_map *map)
 	list_del_rcu(&dtab->list);
 	spin_unlock(&dev_map_lock);
 
-	bpf_clear_redirect_map(map);
 	synchronize_rcu();
 
 	/* Make sure prior __dev_map_entry_free() have completed. */
diff --git a/net/core/filter.c b/net/core/filter.c
index 183b0aa6b027..b6732000d8a2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3918,23 +3918,6 @@ static const struct bpf_func_proto bpf_xdp_adjust_meta_proto = {
 	.arg2_type	= ARG_ANYTHING,
 };
 
-static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
-			    struct bpf_map *map, struct xdp_buff *xdp)
-{
-	switch (map->map_type) {
-	case BPF_MAP_TYPE_DEVMAP:
-	case BPF_MAP_TYPE_DEVMAP_HASH:
-		return dev_map_enqueue(fwd, xdp, dev_rx);
-	case BPF_MAP_TYPE_CPUMAP:
-		return cpu_map_enqueue(fwd, xdp, dev_rx);
-	case BPF_MAP_TYPE_XSKMAP:
-		return __xsk_map_redirect(fwd, xdp);
-	default:
-		return -EBADRQC;
-	}
-	return 0;
-}
-
 void xdp_do_flush(void)
 {
 	__dev_flush();
@@ -3943,55 +3926,52 @@ void xdp_do_flush(void)
 }
 EXPORT_SYMBOL_GPL(xdp_do_flush);
 
-void bpf_clear_redirect_map(struct bpf_map *map)
-{
-	struct bpf_redirect_info *ri;
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		ri = per_cpu_ptr(&bpf_redirect_info, cpu);
-		/* Avoid polluting remote cacheline due to writes if
-		 * not needed. Once we pass this test, we need the
-		 * cmpxchg() to make sure it hasn't been changed in
-		 * the meantime by remote CPU.
-		 */
-		if (unlikely(READ_ONCE(ri->map) == map))
-			cmpxchg(&ri->map, map, NULL);
-	}
-}
-
 int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
 		    struct bpf_prog *xdp_prog)
 {
 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
-	struct bpf_map *map = READ_ONCE(ri->map);
-	u32 index = ri->tgt_index;
+	enum bpf_map_type map_type = ri->map_type;
 	void *fwd = ri->tgt_value;
+	u32 map_id = ri->map_id;
 	int err;
 
-	ri->tgt_index = 0;
-	ri->tgt_value = NULL;
-	WRITE_ONCE(ri->map, NULL);
+	ri->map_id = 0; /* Valid map id idr range: [1,INT_MAX[ */
+	ri->map_type = BPF_MAP_TYPE_UNSPEC;
 
-	if (unlikely(!map)) {
-		fwd = dev_get_by_index_rcu(dev_net(dev), index);
-		if (unlikely(!fwd)) {
-			err = -EINVAL;
-			goto err;
+	switch (map_type) {
+	case BPF_MAP_TYPE_DEVMAP:
+		fallthrough;
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+		err = dev_map_enqueue(fwd, xdp, dev);
+		break;
+	case BPF_MAP_TYPE_CPUMAP:
+		err = cpu_map_enqueue(fwd, xdp, dev);
+		break;
+	case BPF_MAP_TYPE_XSKMAP:
+		err = __xsk_map_redirect(fwd, xdp);
+		break;
+	case BPF_MAP_TYPE_UNSPEC:
+		if (map_id == INT_MAX) {
+			fwd = dev_get_by_index_rcu(dev_net(dev), ri->tgt_index);
+			if (unlikely(!fwd)) {
+				err = -EINVAL;
+				break;
+			}
+			err = dev_xdp_enqueue(fwd, xdp, dev);
+			break;
 		}
-
-		err = dev_xdp_enqueue(fwd, xdp, dev);
-	} else {
-		err = __bpf_tx_xdp_map(dev, fwd, map, xdp);
+		fallthrough;
+	default:
+		err = -EBADRQC;
 	}
 
 	if (unlikely(err))
 		goto err;
 
-	_trace_xdp_redirect_map(dev, xdp_prog, fwd, map, index);
+	_trace_xdp_redirect_map(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index);
 	return 0;
 err:
-	_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map, index, err);
+	_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index, err);
 	return err;
 }
 EXPORT_SYMBOL_GPL(xdp_do_redirect);
@@ -4000,41 +3980,36 @@ static int xdp_do_generic_redirect_map(struct net_device *dev,
 				       struct sk_buff *skb,
 				       struct xdp_buff *xdp,
 				       struct bpf_prog *xdp_prog,
-				       struct bpf_map *map)
+				       void *fwd,
+				       enum bpf_map_type map_type, u32 map_id)
 {
 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
-	u32 index = ri->tgt_index;
-	void *fwd = ri->tgt_value;
-	int err = 0;
-
-	ri->tgt_index = 0;
-	ri->tgt_value = NULL;
-	WRITE_ONCE(ri->map, NULL);
-
-	if (map->map_type == BPF_MAP_TYPE_DEVMAP ||
-	    map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
-		struct bpf_dtab_netdev *dst = fwd;
+	int err;
 
-		err = dev_map_generic_redirect(dst, skb, xdp_prog);
+	switch (map_type) {
+	case BPF_MAP_TYPE_DEVMAP:
+		fallthrough;
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+		err = dev_map_generic_redirect(fwd, skb, xdp_prog);
 		if (unlikely(err))
 			goto err;
-	} else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
-		struct xdp_sock *xs = fwd;
-
-		err = xsk_generic_rcv(xs, xdp);
+		break;
+	case BPF_MAP_TYPE_XSKMAP:
+		err = xsk_generic_rcv(fwd, xdp);
 		if (err)
 			goto err;
 		consume_skb(skb);
-	} else {
+		break;
+	default:
 		/* TODO: Handle BPF_MAP_TYPE_CPUMAP */
 		err = -EBADRQC;
 		goto err;
 	}
 
-	_trace_xdp_redirect_map(dev, xdp_prog, fwd, map, index);
+	_trace_xdp_redirect_map(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index);
 	return 0;
 err:
-	_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map, index, err);
+	_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map_type, map_id, ri->tgt_index, err);
 	return err;
 }
 
@@ -4042,31 +4017,34 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
 			    struct xdp_buff *xdp, struct bpf_prog *xdp_prog)
 {
 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
-	struct bpf_map *map = READ_ONCE(ri->map);
-	u32 index = ri->tgt_index;
-	struct net_device *fwd;
-	int err = 0;
-
-	if (map)
-		return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog,
-						   map);
-	ri->tgt_index = 0;
-	fwd = dev_get_by_index_rcu(dev_net(dev), index);
-	if (unlikely(!fwd)) {
-		err = -EINVAL;
-		goto err;
-	}
+	enum bpf_map_type map_type = ri->map_type;
+	void *fwd = ri->tgt_value;
+	u32 map_id = ri->map_id;
+	int err;
 
-	err = xdp_ok_fwd_dev(fwd, skb->len);
-	if (unlikely(err))
-		goto err;
+	ri->map_id = 0; /* Valid map id idr range: [1,INT_MAX[ */
+	ri->map_type = BPF_MAP_TYPE_UNSPEC;
 
-	skb->dev = fwd;
-	_trace_xdp_redirect(dev, xdp_prog, index);
-	generic_xdp_tx(skb, xdp_prog);
-	return 0;
+	if (map_type == BPF_MAP_TYPE_UNSPEC && map_id == INT_MAX) {
+		fwd = dev_get_by_index_rcu(dev_net(dev), ri->tgt_index);
+		if (unlikely(!fwd)) {
+			err = -EINVAL;
+			goto err;
+		}
+
+		err = xdp_ok_fwd_dev(fwd, skb->len);
+		if (unlikely(err))
+			goto err;
+
+		skb->dev = fwd;
+		_trace_xdp_redirect(dev, xdp_prog, ri->tgt_index);
+		generic_xdp_tx(skb, xdp_prog);
+		return 0;
+	}
+
+	return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog, fwd, map_type, map_id);
 err:
-	_trace_xdp_redirect_err(dev, xdp_prog, index, err);
+	_trace_xdp_redirect_err(dev, xdp_prog, ri->tgt_index, err);
 	return err;
 }
 
@@ -4077,10 +4055,12 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags)
 	if (unlikely(flags))
 		return XDP_ABORTED;
 
-	ri->flags = flags;
+	/* NB! Map type UNSPEC and map_id == INT_MAX (never generated
+	 * by map_idr) is used for ifindex based XDP redirect.
+	 */
 	ri->tgt_index = ifindex;
-	ri->tgt_value = NULL;
-	WRITE_ONCE(ri->map, NULL);
+	ri->map_id = INT_MAX;
+	ri->map_type = BPF_MAP_TYPE_UNSPEC;
 
 	return XDP_REDIRECT;
 }
diff --git a/net/xdp/xskmap.c b/net/xdp/xskmap.c
index fbeb4870f798..67b4ce504852 100644
--- a/net/xdp/xskmap.c
+++ b/net/xdp/xskmap.c
@@ -87,7 +87,6 @@ static void xsk_map_free(struct bpf_map *map)
 {
 	struct xsk_map *m = container_of(map, struct xsk_map, map);
 
-	bpf_clear_redirect_map(map);
 	synchronize_net();
 	bpf_map_area_free(m);
 }
-- 
cgit v1.3-18-gd494


From e16301fbe1837c9594f9c1957c28fd1bb18fbd15 Mon Sep 17 00:00:00 2001
From: Martin KaFai Lau <kafai@fb.com>
Date: Wed, 24 Mar 2021 18:51:30 -0700
Subject: bpf: Simplify freeing logic in linfo and jited_linfo

This patch simplifies the linfo freeing logic by combining
"bpf_prog_free_jited_linfo()" and "bpf_prog_free_unused_jited_linfo()"
into the new "bpf_prog_jit_attempt_done()".
It is a prep work for the kernel function call support.  In a later
patch, freeing the kernel function call descriptors will also
be done in the "bpf_prog_jit_attempt_done()".

"bpf_prog_free_linfo()" is removed since it is only called by
"__bpf_prog_put_noref()".  The kvfree() are directly called
instead.

It also takes this chance to s/kcalloc/kvcalloc/ for the jited_linfo
allocation.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015130.1544323-1-kafai@fb.com
---
 include/linux/filter.h |  3 +--
 kernel/bpf/core.c      | 35 ++++++++++++-----------------------
 kernel/bpf/syscall.c   |  3 ++-
 kernel/bpf/verifier.c  |  4 ++--
 4 files changed, 17 insertions(+), 28 deletions(-)

(limited to 'include/linux/filter.h')

diff --git a/include/linux/filter.h b/include/linux/filter.h
index b2b85b2cad8e..0d9c710eb050 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -877,8 +877,7 @@ void bpf_prog_free_linfo(struct bpf_prog *prog);
 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 			       const u32 *insn_to_jit_off);
 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog);
-void bpf_prog_free_jited_linfo(struct bpf_prog *prog);
-void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog);
+void bpf_prog_jit_attempt_done(struct bpf_prog *prog);
 
 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 75244ecb2389..a35eb3d7b126 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -143,25 +143,22 @@ int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
 	if (!prog->aux->nr_linfo || !prog->jit_requested)
 		return 0;
 
-	prog->aux->jited_linfo = kcalloc(prog->aux->nr_linfo,
-					 sizeof(*prog->aux->jited_linfo),
-					 GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
+	prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
+					  sizeof(*prog->aux->jited_linfo),
+					  GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
 	if (!prog->aux->jited_linfo)
 		return -ENOMEM;
 
 	return 0;
 }
 
-void bpf_prog_free_jited_linfo(struct bpf_prog *prog)
+void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
 {
-	kfree(prog->aux->jited_linfo);
-	prog->aux->jited_linfo = NULL;
-}
-
-void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog)
-{
-	if (prog->aux->jited_linfo && !prog->aux->jited_linfo[0])
-		bpf_prog_free_jited_linfo(prog);
+	if (prog->aux->jited_linfo &&
+	    (!prog->jited || !prog->aux->jited_linfo[0])) {
+		kvfree(prog->aux->jited_linfo);
+		prog->aux->jited_linfo = NULL;
+	}
 }
 
 /* The jit engine is responsible to provide an array
@@ -217,12 +214,6 @@ void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 			insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
 }
 
-void bpf_prog_free_linfo(struct bpf_prog *prog)
-{
-	bpf_prog_free_jited_linfo(prog);
-	kvfree(prog->aux->linfo);
-}
-
 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 				  gfp_t gfp_extra_flags)
 {
@@ -1866,15 +1857,13 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
 			return fp;
 
 		fp = bpf_int_jit_compile(fp);
-		if (!fp->jited) {
-			bpf_prog_free_jited_linfo(fp);
+		bpf_prog_jit_attempt_done(fp);
 #ifdef CONFIG_BPF_JIT_ALWAYS_ON
+		if (!fp->jited) {
 			*err = -ENOTSUPP;
 			return fp;
-#endif
-		} else {
-			bpf_prog_free_unused_jited_linfo(fp);
 		}
+#endif
 	} else {
 		*err = bpf_prog_offload_compile(fp);
 		if (*err)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 250503482cda..eaf85bf51c5a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1694,7 +1694,8 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
 {
 	bpf_prog_kallsyms_del_all(prog);
 	btf_put(prog->aux->btf);
-	bpf_prog_free_linfo(prog);
+	kvfree(prog->aux->jited_linfo);
+	kvfree(prog->aux->linfo);
 	if (prog->aux->attach_btf)
 		btf_put(prog->aux->attach_btf);
 
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 85f9f842d15c..b7df3f06a279 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11741,7 +11741,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 	prog->bpf_func = func[0]->bpf_func;
 	prog->aux->func = func;
 	prog->aux->func_cnt = env->subprog_cnt;
-	bpf_prog_free_unused_jited_linfo(prog);
+	bpf_prog_jit_attempt_done(prog);
 	return 0;
 out_free:
 	for (i = 0; i < env->subprog_cnt; i++) {
@@ -11764,7 +11764,7 @@ out_undo_insn:
 		insn->off = 0;
 		insn->imm = env->insn_aux_data[i].call_imm;
 	}
-	bpf_prog_free_jited_linfo(prog);
+	bpf_prog_jit_attempt_done(prog);
 	return err;
 }
 
-- 
cgit v1.3-18-gd494


From e6ac2450d6dee3121cd8bbf2907b78a68a8a353d Mon Sep 17 00:00:00 2001
From: Martin KaFai Lau <kafai@fb.com>
Date: Wed, 24 Mar 2021 18:51:42 -0700
Subject: bpf: Support bpf program calling kernel function

This patch adds support to BPF verifier to allow bpf program calling
kernel function directly.

The use case included in this set is to allow bpf-tcp-cc to directly
call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()").  Those
functions have already been used by some kernel tcp-cc implementations.

This set will also allow the bpf-tcp-cc program to directly call the
kernel tcp-cc implementation,  For example, a bpf_dctcp may only want to
implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly
from the kernel tcp_dctcp.c instead of reimplementing (or
copy-and-pasting) them.

The tcp-cc kernel functions mentioned above will be white listed
for the struct_ops bpf-tcp-cc programs to use in a later patch.
The white listed functions are not bounded to a fixed ABI contract.
Those functions have already been used by the existing kernel tcp-cc.
If any of them has changed, both in-tree and out-of-tree kernel tcp-cc
implementations have to be changed.  The same goes for the struct_ops
bpf-tcp-cc programs which have to be adjusted accordingly.

This patch is to make the required changes in the bpf verifier.

First change is in btf.c, it adds a case in "btf_check_func_arg_match()".
When the passed in "btf->kernel_btf == true", it means matching the
verifier regs' states with a kernel function.  This will handle the
PTR_TO_BTF_ID reg.  It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET,
and PTR_TO_TCP_SOCK to its kernel's btf_id.

In the later libbpf patch, the insn calling a kernel function will
look like:

insn->code == (BPF_JMP | BPF_CALL)
insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */
insn->imm == func_btf_id /* btf_id of the running kernel */

[ For the future calling function-in-kernel-module support, an array
  of module btf_fds can be passed at the load time and insn->off
  can be used to index into this array. ]

At the early stage of verifier, the verifier will collect all kernel
function calls into "struct bpf_kfunc_desc".  Those
descriptors are stored in "prog->aux->kfunc_tab" and will
be available to the JIT.  Since this "add" operation is similar
to the current "add_subprog()" and looking for the same insn->code,
they are done together in the new "add_subprog_and_kfunc()".

In the "do_check()" stage, the new "check_kfunc_call()" is added
to verify the kernel function call instruction:
1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE.
   A new bpf_verifier_ops "check_kfunc_call" is added to do that.
   The bpf-tcp-cc struct_ops program will implement this function in
   a later patch.
2. Call "btf_check_kfunc_args_match()" to ensure the regs can be
   used as the args of a kernel function.
3. Mark the regs' type, subreg_def, and zext_dst.

At the later do_misc_fixups() stage, the new fixup_kfunc_call()
will replace the insn->imm with the function address (relative
to __bpf_call_base).  If needed, the jit can find the btf_func_model
by calling the new bpf_jit_find_kfunc_model(prog, insn).
With the imm set to the function address, "bpftool prog dump xlated"
will be able to display the kernel function calls the same way as
it displays other bpf helper calls.

gpl_compatible program is required to call kernel function.

This feature currently requires JIT.

The verifier selftests are adjusted because of the changes in
the verbose log in add_subprog_and_kfunc().

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
---
 arch/x86/net/bpf_jit_comp.c                      |   5 +
 include/linux/bpf.h                              |  24 ++
 include/linux/btf.h                              |   1 +
 include/linux/filter.h                           |   1 +
 include/uapi/linux/bpf.h                         |   4 +
 kernel/bpf/btf.c                                 |  65 +++-
 kernel/bpf/core.c                                |  18 +-
 kernel/bpf/disasm.c                              |  13 +-
 kernel/bpf/syscall.c                             |   1 +
 kernel/bpf/verifier.c                            | 368 +++++++++++++++++++++--
 tools/include/uapi/linux/bpf.h                   |   4 +
 tools/testing/selftests/bpf/verifier/calls.c     |  12 +-
 tools/testing/selftests/bpf/verifier/dead_code.c |  10 +-
 13 files changed, 480 insertions(+), 46 deletions(-)

(limited to 'include/linux/filter.h')

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index b35fc8023884..9eead60f0301 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -2346,3 +2346,8 @@ out:
 					   tmp : orig_prog);
 	return prog;
 }
+
+bool bpf_jit_supports_kfunc_call(void)
+{
+	return true;
+}
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index eaae618a90b5..b5b7967e3ff3 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -427,6 +427,7 @@ enum bpf_reg_type {
 	PTR_TO_PERCPU_BTF_ID,	 /* reg points to a percpu kernel variable */
 	PTR_TO_FUNC,		 /* reg points to a bpf program function */
 	PTR_TO_MAP_KEY,		 /* reg points to a map element key */
+	__BPF_REG_TYPE_MAX,
 };
 
 /* The information passed from prog-specific *_is_valid_access
@@ -480,6 +481,7 @@ struct bpf_verifier_ops {
 				 const struct btf_type *t, int off, int size,
 				 enum bpf_access_type atype,
 				 u32 *next_btf_id);
+	bool (*check_kfunc_call)(u32 kfunc_btf_id);
 };
 
 struct bpf_prog_offload_ops {
@@ -796,6 +798,8 @@ struct btf_mod_pair {
 	struct module *module;
 };
 
+struct bpf_kfunc_desc_tab;
+
 struct bpf_prog_aux {
 	atomic64_t refcnt;
 	u32 used_map_cnt;
@@ -832,6 +836,7 @@ struct bpf_prog_aux {
 	struct bpf_prog **func;
 	void *jit_data; /* JIT specific data. arch dependent */
 	struct bpf_jit_poke_descriptor *poke_tab;
+	struct bpf_kfunc_desc_tab *kfunc_tab;
 	u32 size_poke_tab;
 	struct bpf_ksym ksym;
 	const struct bpf_prog_ops *ops;
@@ -1547,6 +1552,9 @@ int btf_distill_func_proto(struct bpf_verifier_log *log,
 struct bpf_reg_state;
 int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
 				struct bpf_reg_state *regs);
+int btf_check_kfunc_arg_match(struct bpf_verifier_env *env,
+			      const struct btf *btf, u32 func_id,
+			      struct bpf_reg_state *regs);
 int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
 			  struct bpf_reg_state *reg);
 int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
@@ -1557,6 +1565,10 @@ struct bpf_link *bpf_link_by_id(u32 id);
 
 const struct bpf_func_proto *bpf_base_func_proto(enum bpf_func_id func_id);
 void bpf_task_storage_free(struct task_struct *task);
+bool bpf_prog_has_kfunc_call(const struct bpf_prog *prog);
+const struct btf_func_model *
+bpf_jit_find_kfunc_model(const struct bpf_prog *prog,
+			 const struct bpf_insn *insn);
 #else /* !CONFIG_BPF_SYSCALL */
 static inline struct bpf_prog *bpf_prog_get(u32 ufd)
 {
@@ -1737,6 +1749,18 @@ bpf_base_func_proto(enum bpf_func_id func_id)
 static inline void bpf_task_storage_free(struct task_struct *task)
 {
 }
+
+static inline bool bpf_prog_has_kfunc_call(const struct bpf_prog *prog)
+{
+	return false;
+}
+
+static inline const struct btf_func_model *
+bpf_jit_find_kfunc_model(const struct bpf_prog *prog,
+			 const struct bpf_insn *insn)
+{
+	return NULL;
+}
 #endif /* CONFIG_BPF_SYSCALL */
 
 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 8a05687a4ee2..3bac66e0183a 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -110,6 +110,7 @@ const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
 const struct btf_type *
 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
 		 u32 *type_size);
+const char *btf_type_str(const struct btf_type *t);
 
 #define for_each_member(i, struct_type, member)			\
 	for (i = 0, member = btf_type_member(struct_type);	\
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 0d9c710eb050..eecfd82db648 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -918,6 +918,7 @@ u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
 void bpf_jit_compile(struct bpf_prog *prog);
 bool bpf_jit_needs_zext(void);
+bool bpf_jit_supports_kfunc_call(void);
 bool bpf_helper_changes_pkt_data(void *func);
 
 static inline bool bpf_dump_raw_ok(const struct cred *cred)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 008edc1dc8c1..598716742593 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1117,6 +1117,10 @@ enum bpf_link_type {
  * offset to another bpf function
  */
 #define BPF_PSEUDO_CALL		1
+/* when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL,
+ * bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel
+ */
+#define BPF_PSEUDO_KFUNC_CALL	2
 
 /* flags for BPF_MAP_UPDATE_ELEM command */
 enum {
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 3c489adacf3b..ec8afc4bc560 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -283,7 +283,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_FLOAT]	= "FLOAT",
 };
 
-static const char *btf_type_str(const struct btf_type *t)
+const char *btf_type_str(const struct btf_type *t)
 {
 	return btf_kind_str[BTF_INFO_KIND(t->info)];
 }
@@ -5362,6 +5362,14 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr
 	return btf_check_func_type_match(log, btf1, t1, btf2, t2);
 }
 
+static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = {
+#ifdef CONFIG_NET
+	[PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK],
+	[PTR_TO_SOCK_COMMON] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON],
+	[PTR_TO_TCP_SOCK] = &btf_sock_ids[BTF_SOCK_TYPE_TCP],
+#endif
+};
+
 static int btf_check_func_arg_match(struct bpf_verifier_env *env,
 				    const struct btf *btf, u32 func_id,
 				    struct bpf_reg_state *regs,
@@ -5371,12 +5379,12 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
 	const char *func_name, *ref_tname;
 	const struct btf_type *t, *ref_t;
 	const struct btf_param *args;
-	u32 i, nargs;
+	u32 i, nargs, ref_id;
 
 	t = btf_type_by_id(btf, func_id);
 	if (!t || !btf_type_is_func(t)) {
 		/* These checks were already done by the verifier while loading
-		 * struct bpf_func_info
+		 * struct bpf_func_info or in add_kfunc_call().
 		 */
 		bpf_log(log, "BTF of func_id %u doesn't point to KIND_FUNC\n",
 			func_id);
@@ -5418,9 +5426,49 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env,
 			return -EINVAL;
 		}
 
-		ref_t = btf_type_skip_modifiers(btf, t->type, NULL);
+		ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
 		ref_tname = btf_name_by_offset(btf, ref_t->name_off);
-		if (btf_get_prog_ctx_type(log, btf, t, env->prog->type, i)) {
+		if (btf_is_kernel(btf)) {
+			const struct btf_type *reg_ref_t;
+			const struct btf *reg_btf;
+			const char *reg_ref_tname;
+			u32 reg_ref_id;
+
+			if (!btf_type_is_struct(ref_t)) {
+				bpf_log(log, "kernel function %s args#%d pointer type %s %s is not supported\n",
+					func_name, i, btf_type_str(ref_t),
+					ref_tname);
+				return -EINVAL;
+			}
+
+			if (reg->type == PTR_TO_BTF_ID) {
+				reg_btf = reg->btf;
+				reg_ref_id = reg->btf_id;
+			} else if (reg2btf_ids[reg->type]) {
+				reg_btf = btf_vmlinux;
+				reg_ref_id = *reg2btf_ids[reg->type];
+			} else {
+				bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d is not a pointer to btf_id\n",
+					func_name, i,
+					btf_type_str(ref_t), ref_tname, regno);
+				return -EINVAL;
+			}
+
+			reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id,
+							    &reg_ref_id);
+			reg_ref_tname = btf_name_by_offset(reg_btf,
+							   reg_ref_t->name_off);
+			if (!btf_struct_ids_match(log, reg_btf, reg_ref_id,
+						  reg->off, btf, ref_id)) {
+				bpf_log(log, "kernel function %s args#%d expected pointer to %s %s but R%d has a pointer to %s %s\n",
+					func_name, i,
+					btf_type_str(ref_t), ref_tname,
+					regno, btf_type_str(reg_ref_t),
+					reg_ref_tname);
+				return -EINVAL;
+			}
+		} else if (btf_get_prog_ctx_type(log, btf, t,
+						 env->prog->type, i)) {
 			/* If function expects ctx type in BTF check that caller
 			 * is passing PTR_TO_CTX.
 			 */
@@ -5493,6 +5541,13 @@ int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
 	return err;
 }
 
+int btf_check_kfunc_arg_match(struct bpf_verifier_env *env,
+			      const struct btf *btf, u32 func_id,
+			      struct bpf_reg_state *regs)
+{
+	return btf_check_func_arg_match(env, btf, func_id, regs, false);
+}
+
 /* Convert BTF of a function into bpf_reg_state if possible
  * Returns:
  * EFAULT - there is a verifier bug. Abort verification.
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index a35eb3d7b126..f5423251c118 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -159,6 +159,9 @@ void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
 		kvfree(prog->aux->jited_linfo);
 		prog->aux->jited_linfo = NULL;
 	}
+
+	kfree(prog->aux->kfunc_tab);
+	prog->aux->kfunc_tab = NULL;
 }
 
 /* The jit engine is responsible to provide an array
@@ -1840,9 +1843,15 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
 	/* In case of BPF to BPF calls, verifier did all the prep
 	 * work with regards to JITing, etc.
 	 */
+	bool jit_needed = false;
+
 	if (fp->bpf_func)
 		goto finalize;
 
+	if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
+	    bpf_prog_has_kfunc_call(fp))
+		jit_needed = true;
+
 	bpf_prog_select_func(fp);
 
 	/* eBPF JITs can rewrite the program in case constant
@@ -1858,12 +1867,10 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
 
 		fp = bpf_int_jit_compile(fp);
 		bpf_prog_jit_attempt_done(fp);
-#ifdef CONFIG_BPF_JIT_ALWAYS_ON
-		if (!fp->jited) {
+		if (!fp->jited && jit_needed) {
 			*err = -ENOTSUPP;
 			return fp;
 		}
-#endif
 	} else {
 		*err = bpf_prog_offload_compile(fp);
 		if (*err)
@@ -2343,6 +2350,11 @@ bool __weak bpf_jit_needs_zext(void)
 	return false;
 }
 
+bool __weak bpf_jit_supports_kfunc_call(void)
+{
+	return false;
+}
+
 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
  */
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index 3acc7e0b6916..dad821c8ecd0 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -19,16 +19,23 @@ static const char *__func_get_name(const struct bpf_insn_cbs *cbs,
 {
 	BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);
 
-	if (insn->src_reg != BPF_PSEUDO_CALL &&
+	if (!insn->src_reg &&
 	    insn->imm >= 0 && insn->imm < __BPF_FUNC_MAX_ID &&
 	    func_id_str[insn->imm])
 		return func_id_str[insn->imm];
 
-	if (cbs && cbs->cb_call)
-		return cbs->cb_call(cbs->private_data, insn);
+	if (cbs && cbs->cb_call) {
+		const char *res;
+
+		res = cbs->cb_call(cbs->private_data, insn);
+		if (res)
+			return res;
+	}
 
 	if (insn->src_reg == BPF_PSEUDO_CALL)
 		snprintf(buff, len, "%+d", insn->imm);
+	else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL)
+		snprintf(buff, len, "kernel-function");
 
 	return buff;
 }
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index eaf85bf51c5a..9603de81811a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1696,6 +1696,7 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
 	btf_put(prog->aux->btf);
 	kvfree(prog->aux->jited_linfo);
 	kvfree(prog->aux->linfo);
+	kfree(prog->aux->kfunc_tab);
 	if (prog->aux->attach_btf)
 		btf_put(prog->aux->attach_btf);
 
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b31e62daafbd..852541a435ef 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -234,6 +234,12 @@ static bool bpf_pseudo_call(const struct bpf_insn *insn)
 	       insn->src_reg == BPF_PSEUDO_CALL;
 }
 
+static bool bpf_pseudo_kfunc_call(const struct bpf_insn *insn)
+{
+	return insn->code == (BPF_JMP | BPF_CALL) &&
+	       insn->src_reg == BPF_PSEUDO_KFUNC_CALL;
+}
+
 static bool bpf_pseudo_func(const struct bpf_insn *insn)
 {
 	return insn->code == (BPF_LD | BPF_IMM | BPF_DW) &&
@@ -1554,47 +1560,205 @@ static int add_subprog(struct bpf_verifier_env *env, int off)
 		verbose(env, "too many subprograms\n");
 		return -E2BIG;
 	}
+	/* determine subprog starts. The end is one before the next starts */
 	env->subprog_info[env->subprog_cnt++].start = off;
 	sort(env->subprog_info, env->subprog_cnt,
 	     sizeof(env->subprog_info[0]), cmp_subprogs, NULL);
 	return env->subprog_cnt - 1;
 }
 
-static int check_subprogs(struct bpf_verifier_env *env)
+struct bpf_kfunc_desc {
+	struct btf_func_model func_model;
+	u32 func_id;
+	s32 imm;
+};
+
+#define MAX_KFUNC_DESCS 256
+struct bpf_kfunc_desc_tab {
+	struct bpf_kfunc_desc descs[MAX_KFUNC_DESCS];
+	u32 nr_descs;
+};
+
+static int kfunc_desc_cmp_by_id(const void *a, const void *b)
+{
+	const struct bpf_kfunc_desc *d0 = a;
+	const struct bpf_kfunc_desc *d1 = b;
+
+	/* func_id is not greater than BTF_MAX_TYPE */
+	return d0->func_id - d1->func_id;
+}
+
+static const struct bpf_kfunc_desc *
+find_kfunc_desc(const struct bpf_prog *prog, u32 func_id)
+{
+	struct bpf_kfunc_desc desc = {
+		.func_id = func_id,
+	};
+	struct bpf_kfunc_desc_tab *tab;
+
+	tab = prog->aux->kfunc_tab;
+	return bsearch(&desc, tab->descs, tab->nr_descs,
+		       sizeof(tab->descs[0]), kfunc_desc_cmp_by_id);
+}
+
+static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id)
+{
+	const struct btf_type *func, *func_proto;
+	struct bpf_kfunc_desc_tab *tab;
+	struct bpf_prog_aux *prog_aux;
+	struct bpf_kfunc_desc *desc;
+	const char *func_name;
+	unsigned long addr;
+	int err;
+
+	prog_aux = env->prog->aux;
+	tab = prog_aux->kfunc_tab;
+	if (!tab) {
+		if (!btf_vmlinux) {
+			verbose(env, "calling kernel function is not supported without CONFIG_DEBUG_INFO_BTF\n");
+			return -ENOTSUPP;
+		}
+
+		if (!env->prog->jit_requested) {
+			verbose(env, "JIT is required for calling kernel function\n");
+			return -ENOTSUPP;
+		}
+
+		if (!bpf_jit_supports_kfunc_call()) {
+			verbose(env, "JIT does not support calling kernel function\n");
+			return -ENOTSUPP;
+		}
+
+		if (!env->prog->gpl_compatible) {
+			verbose(env, "cannot call kernel function from non-GPL compatible program\n");
+			return -EINVAL;
+		}
+
+		tab = kzalloc(sizeof(*tab), GFP_KERNEL);
+		if (!tab)
+			return -ENOMEM;
+		prog_aux->kfunc_tab = tab;
+	}
+
+	if (find_kfunc_desc(env->prog, func_id))
+		return 0;
+
+	if (tab->nr_descs == MAX_KFUNC_DESCS) {
+		verbose(env, "too many different kernel function calls\n");
+		return -E2BIG;
+	}
+
+	func = btf_type_by_id(btf_vmlinux, func_id);
+	if (!func || !btf_type_is_func(func)) {
+		verbose(env, "kernel btf_id %u is not a function\n",
+			func_id);
+		return -EINVAL;
+	}
+	func_proto = btf_type_by_id(btf_vmlinux, func->type);
+	if (!func_proto || !btf_type_is_func_proto(func_proto)) {
+		verbose(env, "kernel function btf_id %u does not have a valid func_proto\n",
+			func_id);
+		return -EINVAL;
+	}
+
+	func_name = btf_name_by_offset(btf_vmlinux, func->name_off);
+	addr = kallsyms_lookup_name(func_name);
+	if (!addr) {
+		verbose(env, "cannot find address for kernel function %s\n",
+			func_name);
+		return -EINVAL;
+	}
+
+	desc = &tab->descs[tab->nr_descs++];
+	desc->func_id = func_id;
+	desc->imm = BPF_CAST_CALL(addr) - __bpf_call_base;
+	err = btf_distill_func_proto(&env->log, btf_vmlinux,
+				     func_proto, func_name,
+				     &desc->func_model);
+	if (!err)
+		sort(tab->descs, tab->nr_descs, sizeof(tab->descs[0]),
+		     kfunc_desc_cmp_by_id, NULL);
+	return err;
+}
+
+static int kfunc_desc_cmp_by_imm(const void *a, const void *b)
+{
+	const struct bpf_kfunc_desc *d0 = a;
+	const struct bpf_kfunc_desc *d1 = b;
+
+	if (d0->imm > d1->imm)
+		return 1;
+	else if (d0->imm < d1->imm)
+		return -1;
+	return 0;
+}
+
+static void sort_kfunc_descs_by_imm(struct bpf_prog *prog)
+{
+	struct bpf_kfunc_desc_tab *tab;
+
+	tab = prog->aux->kfunc_tab;
+	if (!tab)
+		return;
+
+	sort(tab->descs, tab->nr_descs, sizeof(tab->descs[0]),
+	     kfunc_desc_cmp_by_imm, NULL);
+}
+
+bool bpf_prog_has_kfunc_call(const struct bpf_prog *prog)
+{
+	return !!prog->aux->kfunc_tab;
+}
+
+const struct btf_func_model *
+bpf_jit_find_kfunc_model(const struct bpf_prog *prog,
+			 const struct bpf_insn *insn)
+{
+	const struct bpf_kfunc_desc desc = {
+		.imm = insn->imm,
+	};
+	const struct bpf_kfunc_desc *res;
+	struct bpf_kfunc_desc_tab *tab;
+
+	tab = prog->aux->kfunc_tab;
+	res = bsearch(&desc, tab->descs, tab->nr_descs,
+		      sizeof(tab->descs[0]), kfunc_desc_cmp_by_imm);
+
+	return res ? &res->func_model : NULL;
+}
+
+static int add_subprog_and_kfunc(struct bpf_verifier_env *env)
 {
-	int i, ret, subprog_start, subprog_end, off, cur_subprog = 0;
 	struct bpf_subprog_info *subprog = env->subprog_info;
 	struct bpf_insn *insn = env->prog->insnsi;
-	int insn_cnt = env->prog->len;
+	int i, ret, insn_cnt = env->prog->len;
 
 	/* Add entry function. */
 	ret = add_subprog(env, 0);
-	if (ret < 0)
+	if (ret)
 		return ret;
 
-	/* determine subprog starts. The end is one before the next starts */
-	for (i = 0; i < insn_cnt; i++) {
-		if (bpf_pseudo_func(insn + i)) {
-			if (!env->bpf_capable) {
-				verbose(env,
-					"function pointers are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
-				return -EPERM;
-			}
-			ret = add_subprog(env, i + insn[i].imm + 1);
-			if (ret < 0)
-				return ret;
-			/* remember subprog */
-			insn[i + 1].imm = ret;
-			continue;
-		}
-		if (!bpf_pseudo_call(insn + i))
+	for (i = 0; i < insn_cnt; i++, insn++) {
+		if (!bpf_pseudo_func(insn) && !bpf_pseudo_call(insn) &&
+		    !bpf_pseudo_kfunc_call(insn))
 			continue;
+
 		if (!env->bpf_capable) {
-			verbose(env,
-				"function calls to other bpf functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
+			verbose(env, "loading/calling other bpf or kernel functions are allowed for CAP_BPF and CAP_SYS_ADMIN\n");
 			return -EPERM;
 		}
-		ret = add_subprog(env, i + insn[i].imm + 1);
+
+		if (bpf_pseudo_func(insn)) {
+			ret = add_subprog(env, i + insn->imm + 1);
+			if (ret >= 0)
+				/* remember subprog */
+				insn[1].imm = ret;
+		} else if (bpf_pseudo_call(insn)) {
+			ret = add_subprog(env, i + insn->imm + 1);
+		} else {
+			ret = add_kfunc_call(env, insn->imm);
+		}
+
 		if (ret < 0)
 			return ret;
 	}
@@ -1608,6 +1772,16 @@ static int check_subprogs(struct bpf_verifier_env *env)
 		for (i = 0; i < env->subprog_cnt; i++)
 			verbose(env, "func#%d @%d\n", i, subprog[i].start);
 
+	return 0;
+}
+
+static int check_subprogs(struct bpf_verifier_env *env)
+{
+	int i, subprog_start, subprog_end, off, cur_subprog = 0;
+	struct bpf_subprog_info *subprog = env->subprog_info;
+	struct bpf_insn *insn = env->prog->insnsi;
+	int insn_cnt = env->prog->len;
+
 	/* now check that all jumps are within the same subprog */
 	subprog_start = subprog[cur_subprog].start;
 	subprog_end = subprog[cur_subprog + 1].start;
@@ -1916,6 +2090,17 @@ static int get_prev_insn_idx(struct bpf_verifier_state *st, int i,
 	return i;
 }
 
+static const char *disasm_kfunc_name(void *data, const struct bpf_insn *insn)
+{
+	const struct btf_type *func;
+
+	if (insn->src_reg != BPF_PSEUDO_KFUNC_CALL)
+		return NULL;
+
+	func = btf_type_by_id(btf_vmlinux, insn->imm);
+	return btf_name_by_offset(btf_vmlinux, func->name_off);
+}
+
 /* For given verifier state backtrack_insn() is called from the last insn to
  * the first insn. Its purpose is to compute a bitmask of registers and
  * stack slots that needs precision in the parent verifier state.
@@ -1924,6 +2109,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx,
 			  u32 *reg_mask, u64 *stack_mask)
 {
 	const struct bpf_insn_cbs cbs = {
+		.cb_call	= disasm_kfunc_name,
 		.cb_print	= verbose,
 		.private_data	= env,
 	};
@@ -5960,6 +6146,98 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 	return 0;
 }
 
+/* mark_btf_func_reg_size() is used when the reg size is determined by
+ * the BTF func_proto's return value size and argument.
+ */
+static void mark_btf_func_reg_size(struct bpf_verifier_env *env, u32 regno,
+				   size_t reg_size)
+{
+	struct bpf_reg_state *reg = &cur_regs(env)[regno];
+
+	if (regno == BPF_REG_0) {
+		/* Function return value */
+		reg->live |= REG_LIVE_WRITTEN;
+		reg->subreg_def = reg_size == sizeof(u64) ?
+			DEF_NOT_SUBREG : env->insn_idx + 1;
+	} else {
+		/* Function argument */
+		if (reg_size == sizeof(u64)) {
+			mark_insn_zext(env, reg);
+			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+		} else {
+			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ32);
+		}
+	}
+}
+
+static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn)
+{
+	const struct btf_type *t, *func, *func_proto, *ptr_type;
+	struct bpf_reg_state *regs = cur_regs(env);
+	const char *func_name, *ptr_type_name;
+	u32 i, nargs, func_id, ptr_type_id;
+	const struct btf_param *args;
+	int err;
+
+	func_id = insn->imm;
+	func = btf_type_by_id(btf_vmlinux, func_id);
+	func_name = btf_name_by_offset(btf_vmlinux, func->name_off);
+	func_proto = btf_type_by_id(btf_vmlinux, func->type);
+
+	if (!env->ops->check_kfunc_call ||
+	    !env->ops->check_kfunc_call(func_id)) {
+		verbose(env, "calling kernel function %s is not allowed\n",
+			func_name);
+		return -EACCES;
+	}
+
+	/* Check the arguments */
+	err = btf_check_kfunc_arg_match(env, btf_vmlinux, func_id, regs);
+	if (err)
+		return err;
+
+	for (i = 0; i < CALLER_SAVED_REGS; i++)
+		mark_reg_not_init(env, regs, caller_saved[i]);
+
+	/* Check return type */
+	t = btf_type_skip_modifiers(btf_vmlinux, func_proto->type, NULL);
+	if (btf_type_is_scalar(t)) {
+		mark_reg_unknown(env, regs, BPF_REG_0);
+		mark_btf_func_reg_size(env, BPF_REG_0, t->size);
+	} else if (btf_type_is_ptr(t)) {
+		ptr_type = btf_type_skip_modifiers(btf_vmlinux, t->type,
+						   &ptr_type_id);
+		if (!btf_type_is_struct(ptr_type)) {
+			ptr_type_name = btf_name_by_offset(btf_vmlinux,
+							   ptr_type->name_off);
+			verbose(env, "kernel function %s returns pointer type %s %s is not supported\n",
+				func_name, btf_type_str(ptr_type),
+				ptr_type_name);
+			return -EINVAL;
+		}
+		mark_reg_known_zero(env, regs, BPF_REG_0);
+		regs[BPF_REG_0].btf = btf_vmlinux;
+		regs[BPF_REG_0].type = PTR_TO_BTF_ID;
+		regs[BPF_REG_0].btf_id = ptr_type_id;
+		mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *));
+	} /* else { add_kfunc_call() ensures it is btf_type_is_void(t) } */
+
+	nargs = btf_type_vlen(func_proto);
+	args = (const struct btf_param *)(func_proto + 1);
+	for (i = 0; i < nargs; i++) {
+		u32 regno = i + 1;
+
+		t = btf_type_skip_modifiers(btf_vmlinux, args[i].type, NULL);
+		if (btf_type_is_ptr(t))
+			mark_btf_func_reg_size(env, regno, sizeof(void *));
+		else
+			/* scalar. ensured by btf_check_kfunc_arg_match() */
+			mark_btf_func_reg_size(env, regno, t->size);
+	}
+
+	return 0;
+}
+
 static bool signed_add_overflows(s64 a, s64 b)
 {
 	/* Do the add in u64, where overflow is well-defined */
@@ -10162,6 +10440,7 @@ static int do_check(struct bpf_verifier_env *env)
 
 		if (env->log.level & BPF_LOG_LEVEL) {
 			const struct bpf_insn_cbs cbs = {
+				.cb_call	= disasm_kfunc_name,
 				.cb_print	= verbose,
 				.private_data	= env,
 			};
@@ -10309,7 +10588,8 @@ static int do_check(struct bpf_verifier_env *env)
 				if (BPF_SRC(insn->code) != BPF_K ||
 				    insn->off != 0 ||
 				    (insn->src_reg != BPF_REG_0 &&
-				     insn->src_reg != BPF_PSEUDO_CALL) ||
+				     insn->src_reg != BPF_PSEUDO_CALL &&
+				     insn->src_reg != BPF_PSEUDO_KFUNC_CALL) ||
 				    insn->dst_reg != BPF_REG_0 ||
 				    class == BPF_JMP32) {
 					verbose(env, "BPF_CALL uses reserved fields\n");
@@ -10324,6 +10604,8 @@ static int do_check(struct bpf_verifier_env *env)
 				}
 				if (insn->src_reg == BPF_PSEUDO_CALL)
 					err = check_func_call(env, insn, &env->insn_idx);
+				else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL)
+					err = check_kfunc_call(env, insn);
 				else
 					err = check_helper_call(env, insn, &env->insn_idx);
 				if (err)
@@ -11634,6 +11916,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 		func[i]->aux->name[0] = 'F';
 		func[i]->aux->stack_depth = env->subprog_info[i].stack_depth;
 		func[i]->jit_requested = 1;
+		func[i]->aux->kfunc_tab = prog->aux->kfunc_tab;
 		func[i]->aux->linfo = prog->aux->linfo;
 		func[i]->aux->nr_linfo = prog->aux->nr_linfo;
 		func[i]->aux->jited_linfo = prog->aux->jited_linfo;
@@ -11773,6 +12056,7 @@ static int fixup_call_args(struct bpf_verifier_env *env)
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
 	struct bpf_prog *prog = env->prog;
 	struct bpf_insn *insn = prog->insnsi;
+	bool has_kfunc_call = bpf_prog_has_kfunc_call(prog);
 	int i, depth;
 #endif
 	int err = 0;
@@ -11786,6 +12070,10 @@ static int fixup_call_args(struct bpf_verifier_env *env)
 			return err;
 	}
 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
+	if (has_kfunc_call) {
+		verbose(env, "calling kernel functions are not allowed in non-JITed programs\n");
+		return -EINVAL;
+	}
 	if (env->subprog_cnt > 1 && env->prog->aux->tail_call_reachable) {
 		/* When JIT fails the progs with bpf2bpf calls and tail_calls
 		 * have to be rejected, since interpreter doesn't support them yet.
@@ -11814,6 +12102,26 @@ static int fixup_call_args(struct bpf_verifier_env *env)
 	return err;
 }
 
+static int fixup_kfunc_call(struct bpf_verifier_env *env,
+			    struct bpf_insn *insn)
+{
+	const struct bpf_kfunc_desc *desc;
+
+	/* insn->imm has the btf func_id. Replace it with
+	 * an address (relative to __bpf_base_call).
+	 */
+	desc = find_kfunc_desc(env->prog, insn->imm);
+	if (!desc) {
+		verbose(env, "verifier internal error: kernel function descriptor not found for func_id %u\n",
+			insn->imm);
+		return -EFAULT;
+	}
+
+	insn->imm = desc->imm;
+
+	return 0;
+}
+
 /* Do various post-verification rewrites in a single program pass.
  * These rewrites simplify JIT and interpreter implementations.
  */
@@ -11949,6 +12257,12 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
 			continue;
 		if (insn->src_reg == BPF_PSEUDO_CALL)
 			continue;
+		if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
+			ret = fixup_kfunc_call(env, insn);
+			if (ret)
+				return ret;
+			continue;
+		}
 
 		if (insn->imm == BPF_FUNC_get_route_realm)
 			prog->dst_needed = 1;
@@ -12178,6 +12492,8 @@ patch_call_imm:
 		}
 	}
 
+	sort_kfunc_descs_by_imm(env->prog);
+
 	return 0;
 }
 
@@ -12883,6 +13199,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
 	if (!env->explored_states)
 		goto skip_full_check;
 
+	ret = add_subprog_and_kfunc(env);
+	if (ret < 0)
+		goto skip_full_check;
+
 	ret = check_subprogs(env);
 	if (ret < 0)
 		goto skip_full_check;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 2d3036e292a9..ab9f2233607c 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1117,6 +1117,10 @@ enum bpf_link_type {
  * offset to another bpf function
  */
 #define BPF_PSEUDO_CALL		1
+/* when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL,
+ * bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel
+ */
+#define BPF_PSEUDO_KFUNC_CALL	2
 
 /* flags for BPF_MAP_UPDATE_ELEM command */
 enum {
diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c
index eb888c8479c3..336a749673d1 100644
--- a/tools/testing/selftests/bpf/verifier/calls.c
+++ b/tools/testing/selftests/bpf/verifier/calls.c
@@ -19,7 +19,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 2),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 1,
@@ -136,7 +136,7 @@
 {
 	"calls: wrong src reg",
 	.insns = {
-	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 2, 0, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 3, 0, 0),
 	BPF_MOV64_IMM(BPF_REG_0, 1),
 	BPF_EXIT_INSN(),
 	},
@@ -397,7 +397,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.fixup_map_hash_48b = { 3 },
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
@@ -1977,7 +1977,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 },
@@ -2003,7 +2003,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.errstr = "!read_ok",
 	.result = REJECT,
 },
@@ -2028,7 +2028,7 @@
 	BPF_EXIT_INSN(),
 	},
 	.prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.errstr = "!read_ok",
 	.result = REJECT,
 },
diff --git a/tools/testing/selftests/bpf/verifier/dead_code.c b/tools/testing/selftests/bpf/verifier/dead_code.c
index 5cf361d8eb1c..17fe33a75034 100644
--- a/tools/testing/selftests/bpf/verifier/dead_code.c
+++ b/tools/testing/selftests/bpf/verifier/dead_code.c
@@ -85,7 +85,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 12),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
@@ -103,7 +103,7 @@
 	BPF_MOV64_IMM(BPF_REG_0, 12),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
@@ -121,7 +121,7 @@
 	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, -5),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 7,
@@ -137,7 +137,7 @@
 	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
@@ -152,7 +152,7 @@
 	BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 	BPF_EXIT_INSN(),
 	},
-	.errstr_unpriv = "function calls to other bpf functions are allowed for",
+	.errstr_unpriv = "loading/calling other bpf or kernel functions are allowed for",
 	.result_unpriv = REJECT,
 	.result = ACCEPT,
 	.retval = 2,
-- 
cgit v1.3-18-gd494


From 913d55037616659c04763e756f948fcbaef0bbee Mon Sep 17 00:00:00 2001
From: He Fengqing <hefengqing@huawei.com>
Date: Tue, 30 Mar 2021 02:48:43 +0000
Subject: bpf: Remove unused bpf_load_pointer

Remove unused bpf_load_pointer function in filter.h. The last user of it has
been removed with 24dea04767e6 ("bpf, x32: remove ld_abs/ld_ind").

Signed-off-by: He Fengqing <hefengqing@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210330024843.3479844-1-hefengqing@huawei.com
---
 include/linux/filter.h | 9 ---------
 1 file changed, 9 deletions(-)

(limited to 'include/linux/filter.h')

diff --git a/include/linux/filter.h b/include/linux/filter.h
index eecfd82db648..9a09547bc7ba 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1246,15 +1246,6 @@ static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
 					   int k, unsigned int size);
 
-static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
-				     unsigned int size, void *buffer)
-{
-	if (k >= 0)
-		return skb_header_pointer(skb, k, size, buffer);
-
-	return bpf_internal_load_pointer_neg_helper(skb, k, size);
-}
-
 static inline int bpf_tell_extensions(void)
 {
 	return SKF_AD_MAX;
-- 
cgit v1.3-18-gd494