selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 350 insertions, 0 deletions

diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h
new file mode 100644
index 000000000..b2c2b8da1
--- /dev/null
+++ b/net/openvswitch/datapath.h
@@ -0,0 +1,350 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2007-2014 Nicira, Inc.
+ */
+
+#ifndef DATAPATH_H
+#define DATAPATH_H 1
+
+#include <asm/page.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/u64_stats_sync.h>
+#include <net/ip_tunnels.h>
+#include <net/mpls.h>
+
+#include "conntrack.h"
+#include "flow.h"
+#include "flow_table.h"
+#include "meter.h"
+#include "vport-internal_dev.h"
+
+#define DP_MAX_PORTS                USHRT_MAX
+#define DP_VPORT_HASH_BUCKETS       1024
+#define DP_MASKS_REBALANCE_INTERVAL 4000
+
+/**
+ * struct dp_stats_percpu - per-cpu packet processing statistics for a given
+ * datapath.
+ * @n_hit: Number of received packets for which a matching flow was found in
+ * the flow table.
+ * @n_missed: Number of received packets that had no matching flow in the flow
+ * table.  The sum of @n_hit and @n_missed is the number of packets that have
+ * been received by the datapath.
+ * @n_lost: Number of received packets that had no matching flow in the flow
+ * table that could not be sent to userspace (normally due to an overflow in
+ * one of the datapath's queues).
+ * @n_mask_hit: Number of masks looked up for flow match.
+ *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
+ *   up per packet.
+ * @n_cache_hit: The number of received packets that had their mask found using
+ * the mask cache.
+ * @syncp: Synchronization point for 64bit counters.
+ */
+struct dp_stats_percpu {
+	u64 n_hit;
+	u64 n_missed;
+	u64 n_lost;
+	u64 n_mask_hit;
+	u64 n_cache_hit;
+	struct u64_stats_sync syncp;
+};
+
+/**
+ * struct dp_nlsk_pids - array of netlink portids of for a datapath.
+ *                       This is used when OVS_DP_F_DISPATCH_UPCALL_PER_CPU
+ *                       is enabled and must be protected by rcu.
+ * @rcu: RCU callback head for deferred destruction.
+ * @n_pids: Size of @pids array.
+ * @pids: Array storing the Netlink socket PIDs indexed by CPU ID for packets
+ *       that miss the flow table.
+ */
+struct dp_nlsk_pids {
+	struct rcu_head rcu;
+	u32 n_pids;
+	u32 pids[];
+};
+
+/**
+ * struct datapath - datapath for flow-based packet switching
+ * @rcu: RCU callback head for deferred destruction.
+ * @list_node: Element in global 'dps' list.
+ * @table: flow table.
+ * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
+ * ovs_mutex and RCU.
+ * @stats_percpu: Per-CPU datapath statistics.
+ * @net: Reference to net namespace.
+ * @user_features: Bitmap of enabled %OVS_DP_F_* features.
+ * @max_headroom: The maximum headroom of all vports in this datapath; it will
+ * be used by all the internal vports in this dp.
+ * @meter_tbl: Meter table.
+ * @upcall_portids: RCU protected 'struct dp_nlsk_pids'.
+ *
+ * Context: See the comment on locking at the top of datapath.c for additional
+ * locking information.
+ */
+struct datapath {
+	struct rcu_head rcu;
+	struct list_head list_node;
+
+	/* Flow table. */
+	struct flow_table table;
+
+	/* Switch ports. */
+	struct hlist_head *ports;
+
+	/* Stats. */
+	struct dp_stats_percpu __percpu *stats_percpu;
+
+	/* Network namespace ref. */
+	possible_net_t net;
+
+	u32 user_features;
+
+	u32 max_headroom;
+
+	/* Switch meters. */
+	struct dp_meter_table meter_tbl;
+
+	struct dp_nlsk_pids __rcu *upcall_portids;
+};
+
+/**
+ * struct ovs_skb_cb - OVS data in skb CB
+ * @input_vport: The original vport packet came in on. This value is cached
+ * when a packet is received by OVS.
+ * @mru: The maximum received fragement size; 0 if the packet is not
+ * fragmented.
+ * @acts_origlen: The netlink size of the flow actions applied to this skb.
+ * @cutlen: The number of bytes in the packet to preserve on output.
+ * @probability: The sampling probability that was applied to this skb; 0 means
+ * no sampling has occurred; U32_MAX means 100% probability.
+ * @upcall_pid: Netlink socket PID to use for sending this packet to userspace;
+ * 0 means "not set" and default per-CPU or per-vport dispatch should be used.
+ */
+struct ovs_skb_cb {
+	struct vport		*input_vport;
+	u16			mru;
+	u16			acts_origlen;
+	u32			cutlen;
+	u32			probability;
+	u32			upcall_pid;
+};
+#define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
+
+/**
+ * struct dp_upcall_info - metadata to include with a packet sent to userspace
+ * @cmd: One of %OVS_PACKET_CMD_*.
+ * @userdata: If nonnull, its variable-length value is passed to userspace as
+ * %OVS_PACKET_ATTR_USERDATA.
+ * @actions: If nonnull, its variable-length value is passed to userspace as
+ * %OVS_PACKET_ATTR_ACTIONS.
+ * @actions_len: The length of the @actions.
+ * @portid: Netlink portid to which packet should be sent.  If @portid is 0
+ * then no packet is sent and the packet is accounted in the datapath's @n_lost
+ * counter.
+ * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
+ * @mru: If not zero, Maximum received IP fragment size.
+ */
+struct dp_upcall_info {
+	struct ip_tunnel_info *egress_tun_info;
+	const struct nlattr *userdata;
+	const struct nlattr *actions;
+	int actions_len;
+	u32 portid;
+	u8 cmd;
+	u16 mru;
+};
+
+/**
+ * struct ovs_net - Per net-namespace data for ovs.
+ * @dps: List of datapaths to enable dumping them all out.
+ * Protected by genl_mutex.
+ * @dp_notify_work: A work notifier to handle port unregistering.
+ * @masks_rebalance: A work to periodically optimize flow table caches.
+ * @ct_limit_info: Hash table of conntrack zone connection limits. Protected
+ * by RCU; updates and teardown are serialized by ovs_mutex. May be NULL during
+ * netns teardown.
+ * @ct_limit_exit_data: CT limit state detached at .pre_exit, freed at .exit.
+ * @xt_label: Whether connlables are configured for the network or not.
+ */
+struct ovs_net {
+	struct list_head dps;
+	struct work_struct dp_notify_work;
+	struct delayed_work masks_rebalance;
+#if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
+	struct ovs_ct_limit_info __rcu *ct_limit_info;
+	struct ovs_ct_limit_info *ct_limit_exit_data;
+#endif
+	bool xt_label;
+};
+
+#define MAX_L2_LEN	(VLAN_ETH_HLEN + 3 * MPLS_HLEN)
+struct ovs_frag_data {
+	unsigned long dst;
+	struct vport *vport;
+	struct ovs_skb_cb cb;
+	__be16 inner_protocol;
+	u16 network_offset;	/* valid only for MPLS */
+	u16 vlan_tci;
+	__be16 vlan_proto;
+	unsigned int l2_len;
+	u8 mac_proto;
+	u8 l2_data[MAX_L2_LEN];
+};
+
+struct deferred_action {
+	struct sk_buff *skb;
+	const struct nlattr *actions;
+	int actions_len;
+
+	/* Store pkt_key clone when creating deferred action. */
+	struct sw_flow_key pkt_key;
+};
+
+#define DEFERRED_ACTION_FIFO_SIZE 10
+#define OVS_RECURSION_LIMIT 5
+#define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
+
+struct action_fifo {
+	int head;
+	int tail;
+	/* Deferred action fifo queue storage. */
+	struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
+};
+
+struct action_flow_keys {
+	struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
+};
+
+struct ovs_pcpu_storage {
+	struct action_fifo action_fifos;
+	struct action_flow_keys flow_keys;
+	struct ovs_frag_data frag_data;
+	int exec_level;
+	struct task_struct *owner;
+	local_lock_t bh_lock;
+};
+
+extern struct ovs_pcpu_storage __percpu *ovs_pcpu_storage;
+
+/**
+ * enum ovs_pkt_hash_types - hash info to include with a packet
+ * to send to userspace.
+ * @OVS_PACKET_HASH_SW_BIT: indicates hash was computed in software stack.
+ * @OVS_PACKET_HASH_L4_BIT: indicates hash is a canonical 4-tuple hash
+ * over transport ports.
+ */
+enum ovs_pkt_hash_types {
+	OVS_PACKET_HASH_SW_BIT = (1ULL << 32),
+	OVS_PACKET_HASH_L4_BIT = (1ULL << 33),
+};
+
+extern unsigned int ovs_net_id;
+void ovs_lock(void);
+void ovs_unlock(void);
+
+#ifdef CONFIG_LOCKDEP
+int lockdep_ovsl_is_held(void);
+#else
+#define lockdep_ovsl_is_held()	1
+#endif
+
+#define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
+#define ovsl_dereference(p)					\
+	rcu_dereference_protected(p, lockdep_ovsl_is_held())
+#define rcu_dereference_ovsl(p)					\
+	rcu_dereference_check(p, lockdep_ovsl_is_held())
+
+static inline struct net *ovs_dp_get_net(const struct datapath *dp)
+{
+	return read_pnet(&dp->net);
+}
+
+static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
+{
+	write_pnet(&dp->net, net);
+}
+
+struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
+
+static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
+{
+	WARN_ON_ONCE(!rcu_read_lock_held());
+	return ovs_lookup_vport(dp, port_no);
+}
+
+static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
+{
+	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
+	return ovs_lookup_vport(dp, port_no);
+}
+
+static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
+{
+	ASSERT_OVSL();
+	return ovs_lookup_vport(dp, port_no);
+}
+
+/* Must be called with rcu_read_lock. */
+static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
+{
+	struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
+
+	if (dev) {
+		struct vport *vport = ovs_internal_dev_get_vport(dev);
+
+		if (vport)
+			return vport->dp;
+	}
+
+	return NULL;
+}
+
+/* The caller must hold either ovs_mutex or rcu_read_lock to keep the
+ * returned dp pointer valid.
+ */
+static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
+{
+	struct datapath *dp;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
+	rcu_read_lock();
+	dp = get_dp_rcu(net, dp_ifindex);
+	rcu_read_unlock();
+
+	return dp;
+}
+
+extern struct notifier_block ovs_dp_device_notifier;
+extern struct genl_family dp_vport_genl_family;
+
+void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
+void ovs_dp_detach_port(struct vport *);
+int ovs_dp_upcall(struct datapath *, struct sk_buff *,
+		  const struct sw_flow_key *, const struct dp_upcall_info *,
+		  uint32_t cutlen);
+
+u32 ovs_dp_get_upcall_portid(const struct datapath *dp, uint32_t cpu_id);
+
+const char *ovs_dp_name(const struct datapath *dp);
+struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
+					 u32 portid, u32 seq, u8 cmd);
+
+int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
+			const struct sw_flow_actions *, struct sw_flow_key *);
+
+void ovs_dp_notify_wq(struct work_struct *work);
+
+/* 'KEY' must not have any bits set outside of the 'MASK' */
+#define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
+#define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
+
+#define OVS_NLERR(logging_allowed, fmt, ...)			\
+do {								\
+	if (logging_allowed && net_ratelimit())			\
+		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
+} while (0)
+#endif /* datapath.h */