Commit ab1b3a95 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'xskmap-lookup' 



Jonathan Lemon says:

====================
Currently, the AF_XDP code uses a separate map in order to
determine if an xsk is bound to a queue.  Have the xskmap
lookup return a XDP_SOCK pointer on the kernel side, which
the verifier uses to extract relevant values.

Patches:
 1 - adds XSK_SOCK type
 2 - sync bpf.h with tools
 3 - add tools selftest
 4 - update lib/bpf, removing qidconf

v4->v5:
 - xskmap lookup now returns XDP_SOCK type instead of pointer to element.
 - no changes lib/bpf/xsk.c

v3->v4:
 - Clarify error handling path.

v2->v3:
 - Use correct map type.
====================

Acked-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 4ecabd55 10a13bb4

include/linux/bpf.h

+8 −0
Original line number Diff line number Diff line
@@ -280,6 +280,7 @@ enum bpf_reg_type { 
	PTR_TO_TCP_SOCK,	 /* reg points to struct tcp_sock */

	PTR_TO_TCP_SOCK_OR_NULL, /* reg points to struct tcp_sock or NULL */

	PTR_TO_TP_BUFFER,	 /* reg points to a writable raw tp's buffer */

	PTR_TO_XDP_SOCK,	 /* reg points to struct xdp_sock */

};



/* The information passed from prog-specific *_is_valid_access
@@ -727,6 +728,13 @@ void __cpu_map_insert_ctx(struct bpf_map *map, u32 index); 
void __cpu_map_flush(struct bpf_map *map);

int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp,

		    struct net_device *dev_rx);

bool bpf_xdp_sock_is_valid_access(int off, int size, enum bpf_access_type type,

				  struct bpf_insn_access_aux *info);

u32 bpf_xdp_sock_convert_ctx_access(enum bpf_access_type type,

				    const struct bpf_insn *si,

				    struct bpf_insn *insn_buf,

				    struct bpf_prog *prog,

				    u32 *target_size);



/* Return map's numa specified by userspace */

static inline int bpf_map_attr_numa_node(const union bpf_attr *attr)

include/net/xdp_sock.h

+2 −2
Original line number Diff line number Diff line
@@ -58,11 +58,11 @@ struct xdp_sock { 
	struct xdp_umem *umem;

	struct list_head flush_node;

	u16 queue_id;

	struct xsk_queue *tx ____cacheline_aligned_in_smp;

	struct list_head list;

	bool zc;

	/* Protects multiple processes in the control path */

	struct mutex mutex;

	struct xsk_queue *tx ____cacheline_aligned_in_smp;

	struct list_head list;

	/* Mutual exclusion of NAPI TX thread and sendmsg error paths

	 * in the SKB destructor callback.

	 */

include/uapi/linux/bpf.h

+4 −0
Original line number Diff line number Diff line
@@ -3083,6 +3083,10 @@ struct bpf_sock_tuple { 
	};

};



struct bpf_xdp_sock {

	__u32 queue_id;

};



#define XDP_PACKET_HEADROOM 256



/* User return codes for XDP prog type.

kernel/bpf/verifier.c

+24 −2
Original line number Diff line number Diff line
@@ -334,7 +334,8 @@ static bool type_is_sk_pointer(enum bpf_reg_type type) 
{

	return type == PTR_TO_SOCKET ||

		type == PTR_TO_SOCK_COMMON ||

		type == PTR_TO_TCP_SOCK;

		type == PTR_TO_TCP_SOCK ||

		type == PTR_TO_XDP_SOCK;

}



static bool reg_type_may_be_null(enum bpf_reg_type type)
@@ -406,6 +407,7 @@ static const char * const reg_type_str[] = { 
	[PTR_TO_TCP_SOCK]	= "tcp_sock",

	[PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",

	[PTR_TO_TP_BUFFER]	= "tp_buffer",

	[PTR_TO_XDP_SOCK]	= "xdp_sock",

};



static char slot_type_char[] = {
@@ -1363,6 +1365,7 @@ static bool is_spillable_regtype(enum bpf_reg_type type) 
	case PTR_TO_SOCK_COMMON_OR_NULL:

	case PTR_TO_TCP_SOCK:

	case PTR_TO_TCP_SOCK_OR_NULL:

	case PTR_TO_XDP_SOCK:

		return true;

	default:

		return false;
@@ -1843,6 +1846,9 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx, 
	case PTR_TO_TCP_SOCK:

		valid = bpf_tcp_sock_is_valid_access(off, size, t, &info);

		break;

	case PTR_TO_XDP_SOCK:

		valid = bpf_xdp_sock_is_valid_access(off, size, t, &info);

		break;

	default:

		valid = false;

	}
@@ -2007,6 +2013,9 @@ static int check_ptr_alignment(struct bpf_verifier_env *env, 
	case PTR_TO_TCP_SOCK:

		pointer_desc = "tcp_sock ";

		break;

	case PTR_TO_XDP_SOCK:

		pointer_desc = "xdp_sock ";

		break;

	default:

		break;

	}
@@ -2905,10 +2914,14 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, 
	 * appear.

	 */

	case BPF_MAP_TYPE_CPUMAP:

	case BPF_MAP_TYPE_XSKMAP:

		if (func_id != BPF_FUNC_redirect_map)

			goto error;

		break;

	case BPF_MAP_TYPE_XSKMAP:

		if (func_id != BPF_FUNC_redirect_map &&

		    func_id != BPF_FUNC_map_lookup_elem)

			goto error;

		break;

	case BPF_MAP_TYPE_ARRAY_OF_MAPS:

	case BPF_MAP_TYPE_HASH_OF_MAPS:

		if (func_id != BPF_FUNC_map_lookup_elem)
@@ -3799,6 +3812,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, 
	case PTR_TO_SOCK_COMMON_OR_NULL:

	case PTR_TO_TCP_SOCK:

	case PTR_TO_TCP_SOCK_OR_NULL:

	case PTR_TO_XDP_SOCK:

		verbose(env, "R%d pointer arithmetic on %s prohibited\n",

			dst, reg_type_str[ptr_reg->type]);

		return -EACCES;
@@ -5038,6 +5052,9 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, 
			if (reg->map_ptr->inner_map_meta) {

				reg->type = CONST_PTR_TO_MAP;

				reg->map_ptr = reg->map_ptr->inner_map_meta;

			} else if (reg->map_ptr->map_type ==

				   BPF_MAP_TYPE_XSKMAP) {

				reg->type = PTR_TO_XDP_SOCK;

			} else {

				reg->type = PTR_TO_MAP_VALUE;

			}
@@ -6299,6 +6316,7 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur, 
	case PTR_TO_SOCK_COMMON_OR_NULL:

	case PTR_TO_TCP_SOCK:

	case PTR_TO_TCP_SOCK_OR_NULL:

	case PTR_TO_XDP_SOCK:

		/* Only valid matches are exact, which memcmp() above

		 * would have accepted

		 */
@@ -6693,6 +6711,7 @@ static bool reg_type_mismatch_ok(enum bpf_reg_type type) 
	case PTR_TO_SOCK_COMMON_OR_NULL:

	case PTR_TO_TCP_SOCK:

	case PTR_TO_TCP_SOCK_OR_NULL:

	case PTR_TO_XDP_SOCK:

		return false;

	default:

		return true;
@@ -7826,6 +7845,9 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) 
		case PTR_TO_TCP_SOCK:

			convert_ctx_access = bpf_tcp_sock_convert_ctx_access;

			break;

		case PTR_TO_XDP_SOCK:

			convert_ctx_access = bpf_xdp_sock_convert_ctx_access;

			break;

		default:

			continue;

		}

kernel/bpf/xskmap.c

+7 −0
Original line number Diff line number Diff line
@@ -151,6 +151,12 @@ void __xsk_map_flush(struct bpf_map *map) 
}



static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)

{

	WARN_ON_ONCE(!rcu_read_lock_held());

	return __xsk_map_lookup_elem(map, *(u32 *)key);

}



static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key)

{

	return ERR_PTR(-EOPNOTSUPP);

}
@@ -218,6 +224,7 @@ const struct bpf_map_ops xsk_map_ops = { 
	.map_free = xsk_map_free,

	.map_get_next_key = xsk_map_get_next_key,

	.map_lookup_elem = xsk_map_lookup_elem,

	.map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only,

	.map_update_elem = xsk_map_update_elem,

	.map_delete_elem = xsk_map_delete_elem,

	.map_check_btf = map_check_no_btf,

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