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Commit a7bc5774 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'xdp-bpf-fixes' 



John Fastabend says:

====================
net: Fixes for XDP/BPF

The following fixes, UAPI updates, and small improvement,

i. XDP needs to be called inside RCU with preempt disabled.

ii. Not strictly a bug fix but we have an attach command in the
sockmap UAPI already to avoid having a single kernel released with
only the attach and not the detach I'm pushing this into net branch.
Its early in the RC cycle so I think this is OK (not ideal but better
than supporting a UAPI with a missing detach forever).

iii. Final patch replace cpu_relax with cond_resched in devmap.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 109980b8 374fb014

include/linux/bpf.h

+4 −4
Original line number Diff line number Diff line
@@ -385,14 +385,14 @@ static inline void __dev_map_flush(struct bpf_map *map) 


#if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL)

struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key);

int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);

int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);

#else

static inline struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key)

{

	return NULL;

}



static inline int sock_map_attach_prog(struct bpf_map *map,

static inline int sock_map_prog(struct bpf_map *map,

				struct bpf_prog *prog,

				u32 type)

{

kernel/bpf/devmap.c

+1 −1
Original line number Diff line number Diff line
@@ -159,7 +159,7 @@ static void dev_map_free(struct bpf_map *map) 
		unsigned long *bitmap = per_cpu_ptr(dtab->flush_needed, cpu);



		while (!bitmap_empty(bitmap, dtab->map.max_entries))

			cpu_relax();

			cond_resched();

	}



	for (i = 0; i < dtab->map.max_entries; i++) {

kernel/bpf/sockmap.c

+1 −1
Original line number Diff line number Diff line
@@ -792,7 +792,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, 
	return err;

}



int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)

int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)

{

	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);

	struct bpf_prog *orig;

kernel/bpf/syscall.c

+17 −10
Original line number Diff line number Diff line
@@ -1096,10 +1096,10 @@ static int bpf_obj_get(const union bpf_attr *attr) 


#define BPF_PROG_ATTACH_LAST_FIELD attach_flags



static int sockmap_get_from_fd(const union bpf_attr *attr)

static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)

{

	struct bpf_prog *prog = NULL;

	int ufd = attr->target_fd;

	struct bpf_prog *prog;

	struct bpf_map *map;

	struct fd f;

	int err;
@@ -1109,15 +1109,19 @@ static int sockmap_get_from_fd(const union bpf_attr *attr) 
	if (IS_ERR(map))

		return PTR_ERR(map);



	prog = bpf_prog_get_type(attr->attach_bpf_fd, BPF_PROG_TYPE_SK_SKB);

	if (attach) {

		prog = bpf_prog_get_type(attr->attach_bpf_fd,

					 BPF_PROG_TYPE_SK_SKB);

		if (IS_ERR(prog)) {

			fdput(f);

			return PTR_ERR(prog);

		}

	}



	err = sock_map_attach_prog(map, prog, attr->attach_type);

	err = sock_map_prog(map, prog, attr->attach_type);

	if (err) {

		fdput(f);

		if (prog)

			bpf_prog_put(prog);

		return err;

	}
@@ -1155,7 +1159,7 @@ static int bpf_prog_attach(const union bpf_attr *attr) 
		break;

	case BPF_SK_SKB_STREAM_PARSER:

	case BPF_SK_SKB_STREAM_VERDICT:

		return sockmap_get_from_fd(attr);

		return sockmap_get_from_fd(attr, true);

	default:

		return -EINVAL;

	}
@@ -1204,7 +1208,10 @@ static int bpf_prog_detach(const union bpf_attr *attr) 
		ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);

		cgroup_put(cgrp);

		break;



	case BPF_SK_SKB_STREAM_PARSER:

	case BPF_SK_SKB_STREAM_VERDICT:

		ret = sockmap_get_from_fd(attr, false);

		break;

	default:

		return -EINVAL;

	}

net/core/dev.c

+16 −9
Original line number Diff line number Diff line
@@ -3981,8 +3981,13 @@ static int netif_rx_internal(struct sk_buff *skb) 
	trace_netif_rx(skb);



	if (static_key_false(&generic_xdp_needed)) {

		int ret = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog),

					 skb);

		int ret;



		preempt_disable();

		rcu_read_lock();

		ret = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);

		rcu_read_unlock();

		preempt_enable();



		/* Consider XDP consuming the packet a success from

		 * the netdev point of view we do not want to count
@@ -4500,18 +4505,20 @@ static int netif_receive_skb_internal(struct sk_buff *skb) 
	if (skb_defer_rx_timestamp(skb))

		return NET_RX_SUCCESS;



	rcu_read_lock();



	if (static_key_false(&generic_xdp_needed)) {

		int ret = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog),

					 skb);

		int ret;



		if (ret != XDP_PASS) {

		preempt_disable();

		rcu_read_lock();

		ret = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);

		rcu_read_unlock();

		preempt_enable();



		if (ret != XDP_PASS)

			return NET_RX_DROP;

	}

	}



	rcu_read_lock();

#ifdef CONFIG_RPS

	if (static_key_false(&rps_needed)) {

		struct rps_dev_flow voidflow, *rflow = &voidflow;