Fix script loading synchronization issue (no workqueue approach)

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "lib/luarcu"]
 	path = lib/luarcu
 	url = https://github.com/luainkernel/luarcu
+[submodule "lib/luaunpack"]
+	path = lib/luaunpack
+	url = https://github.com/VictorNogueiraRio/luaunpack.git

include/linux/filter.h

@@ -1229,14 +1229,4 @@ struct bpf_sockopt_kern {
 	s32		retval;
 };
 
-#ifdef CONFIG_XDPLUA
-extern struct list_head lua_state_cpu_list;
-
-struct lua_state_cpu {
-	struct lua_State 	*L;
-	int			cpu;
-	struct list_head	list;
-};
-#endif /* CONFIG_XDPLUA */
-
 #endif /* __LINUX_FILTER_H__ */

include/linux/netdevice.h

@@ -3684,9 +3684,9 @@ u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op,
 		    enum bpf_netdev_command cmd);
 int xdp_umem_query(struct net_device *dev, u16 queue_id);
 
-#ifdef CONFIG_XDPLUA
+#ifdef CONFIG_XDP_LUA
 int generic_xdp_lua_install_prog(char *lua_prog);
-#endif /* CONFIG_XDPLUA */
+#endif /* CONFIG_XDP_LUA */
 
 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

include/net/xdp.h

@@ -63,17 +63,27 @@ struct xdp_rxq_info {
 	struct xdp_mem_info mem;
 } ____cacheline_aligned; /* perf critical, avoid false-sharing */
 
+#ifdef CONFIG_XDP_LUA
+struct xdplua {
+	struct lua_State	*L;
+	spinlock_t		lock;
+	bool			used_lua;
+};
+
+DECLARE_PER_CPU(struct xdplua, xdplua_per_cpu);
+#endif /* CONFIG_XDP_LUA */
+
 struct xdp_buff {
 	void *data;
 	void *data_end;
 	void *data_meta;
 	void *data_hard_start;
 	unsigned long handle;
 	struct xdp_rxq_info *rxq;
-#ifdef CONFIG_XDPLUA
+#ifdef CONFIG_XDP_LUA
 	struct sk_buff *skb;
 	struct lua_State *L;
-#endif /* CONFIG_XDPLUA */
+#endif /* CONFIG_XDP_LUA */
 };
 
 struct xdp_frame {

include/uapi/linux/bpf.h

@@ -2825,21 +2825,23 @@ union bpf_attr {
 	FN(sk_storage_get),		\
 	FN(sk_storage_delete),		\
 	FN(send_signal),		\
-	/* #ifdef CONFIG_XDPLUA */	\
+	/* #ifdef CONFIG_XDP_LUA */	\
 	FN(lua_dataref),		\
 	FN(lua_dataunref),		\
 	FN(lua_pcall),			\
+	FN(lua_tostring),		\
 	FN(lua_pop),			\
 	FN(lua_pushinteger),		\
 	FN(lua_pushlightuserdata),	\
 	FN(lua_pushlstring),		\
 	FN(lua_pushmap),		\
 	FN(lua_pushskb),		\
 	FN(lua_pushstring),		\
-	FN(lua_setstate),		\
 	FN(lua_toboolean),		\
-	FN(lua_tointeger),
-	/* #endif CONFIG_XDPLUA */
+	FN(lua_tointeger),		\
+	FN(lua_newpacket),		\
+	FN(lua_type),
+	/* #endif CONFIG_XDP_LUA */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

include/uapi/linux/if_link.h

@@ -974,9 +974,9 @@ enum {
 	IFLA_XDP_DRV_PROG_ID,
 	IFLA_XDP_SKB_PROG_ID,
 	IFLA_XDP_HW_PROG_ID,
-#ifdef CONFIG_XDPLUA
+#ifdef CONFIG_XDP_LUA
 	IFLA_XDP_LUA_PROG,
-#endif /* CONFIG_XDPLUA */
+#endif /* CONFIG_XDP_LUA */
 	__IFLA_XDP_MAX,
 };
 

init/Kconfig

@@ -1288,6 +1288,12 @@ config HAVE_PCSPKR_PLATFORM
 config BPF
 	bool
 
+config LUNATIK
+	bool "Lunatik"
+	default n
+	help
+	  Support for the Lua interpreter
+
 menuconfig EXPERT
 	bool "Configure standard kernel features (expert users)"
 	# Unhide debug options, to make the on-by-default options visible

lib/Makefile

@@ -296,9 +296,10 @@ obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
 obj-$(CONFIG_OBJAGG) += objagg.o
 
 subdir-ccflags-y += -I$(srctree)/lib/lunatik/lua \
-	            -I$(srctree)/lib/luadata/ \
+	            -I$(srctree)/lib/luadata/ -I$(srctree)/lib/luaunpack/ \
 	            -D_KERNEL
 obj-$(CONFIG_LUNATIK) += lunatik/
 obj-$(CONFIG_LUADATA) += luadata/
 obj-$(CONFIG_LUAXDP) += luaxdp/
 obj-$(CONFIG_LUARCU) += luarcu/
+obj-$(CONFIG_LUAUNPACK) += luaunpack/

net/core/Makefile

@@ -8,8 +8,10 @@ obj-y := sock.o request_sock.o skbuff.o datagram.o stream.o scm.o \
 
 obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
 
-CFLAGS_dev.o = -Ilib/lunatik/lua/ -D_KERNEL
-CFLAGS_filter.o = -Ilib/lunatik/lua/ -D_KERNEL
+CFLAGS_dev.o = -Ilib/lunatik/lua/ -D_KERNEL \
+		-Ilib/luadata/
+CFLAGS_filter.o = -Ilib/lunatik/lua/ -D_KERNEL \
+		-Ilib/luadata/ -Ilib/luaunpack/
 obj-y		     += dev.o ethtool.o dev_addr_lists.o dst.o netevent.o \
 			neighbour.o rtnetlink.o utils.o link_watch.o filter.o \
 			sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \

net/core/dev.c

@@ -68,6 +68,13 @@
  *				        - netif_rx() feedback
  */
 
+#ifdef CONFIG_XDP_LUA
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+#include <luadata.h>
+#endif /* CONFIG_XDP_LUA */
+
 #include <linux/uaccess.h>
 #include <linux/bitops.h>
 #include <linux/capability.h>
@@ -143,12 +150,6 @@
 #include <linux/indirect_call_wrapper.h>
 #include <net/devlink.h>
 
-#ifdef CONFIG_XDPLUA
-#include <lua.h>
-#include <lauxlib.h>
-#include <lualib.h>
-#endif /* CONFIG_XDPLUA */
-
 #include "net-sysfs.h"
 
 #define MAX_GRO_SKBS 8
@@ -170,10 +171,6 @@ static int call_netdevice_notifiers_extack(unsigned long val,
 					   struct netlink_ext_ack *extack);
 static struct napi_struct *napi_by_id(unsigned int napi_id);
 
-#ifdef CONFIG_XDPLUA
-struct list_head lua_state_cpu_list;
-#endif /* CONFIG_XDPLUA */
-
 /*
  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
  * semaphore.
@@ -4337,6 +4334,9 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
 	bool orig_bcast;
 	int hlen, off;
 	u32 mac_len;
+#ifdef CONFIG_XDP_LUA
+	struct xdplua *sc;
+#endif
 
 	/* Reinjected packets coming from act_mirred or similar should
 	 * not get XDP generic processing.
@@ -4381,12 +4381,21 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
 
 	rxqueue = netif_get_rxqueue(skb);
 	xdp->rxq = &rxqueue->xdp_rxq;
-#ifdef CONFIG_XDPLUA
+#ifdef CONFIG_XDP_LUA
+	sc = this_cpu_ptr(&xdplua_per_cpu);
 	xdp->skb = skb;
-#endif /* CONFIG_XDPLUA */
+	xdp->L = sc->L;
+#endif /* CONFIG_XDP_LUA */
 
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 
+#ifdef CONFIG_XDP_LUA
+	if (sc->used_lua) {
+		sc->used_lua = false;
+		spin_unlock(&sc->lock);
+	}
+#endif /* CONFIG_XDP_LUA */
+
 	/* check if bpf_xdp_adjust_head was used */
 	off = xdp->data - orig_data;
 	if (off) {
@@ -5196,21 +5205,29 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
 	return ret;
 }
 
-#ifdef CONFIG_XDPLUA
+#ifdef CONFIG_XDP_LUA
+DEFINE_PER_CPU(struct xdplua, xdplua_per_cpu);
+
 int generic_xdp_lua_install_prog(char *lua_prog)
 {
-	struct lua_state_cpu *sc;
+	struct xdplua *sc;
+	int i;
 
-	list_for_each_entry(sc, &lua_state_cpu_list, list) {
+	for_each_possible_cpu(i) {
+		sc = per_cpu_ptr(&xdplua_per_cpu, i);
+		spin_lock_bh(&sc->lock);
 		if (luaL_dostring(sc->L, lua_prog)) {
 			pr_err(KERN_INFO "error: %s\nOn cpu: %d\n",
-				lua_tostring(sc->L, -1), sc->cpu);
+				lua_tostring(sc->L, -1), i);
+			spin_unlock_bh(&sc->lock);
 			return -EINVAL;
 		}
+
+		spin_unlock_bh(&sc->lock);
 	}
 	return 0;
 }
-#endif /* CONFIG_XDPLUA */
+#endif /* CONFIG_XDP_LUA */
 
 static int netif_receive_skb_internal(struct sk_buff *skb)
 {
@@ -9829,9 +9846,6 @@ static struct pernet_operations __net_initdata default_device_ops = {
 static int __init net_dev_init(void)
 {
 	int i, rc = -ENOMEM;
-#ifdef CONFIG_XDPLUA
-	struct lua_state_cpu *new_state_cpu;
-#endif /* CONFIG_XDPLUA */
 
 	BUG_ON(!dev_boot_phase);
 
@@ -9846,9 +9860,6 @@ static int __init net_dev_init(void)
 		INIT_LIST_HEAD(&ptype_base[i]);
 
 	INIT_LIST_HEAD(&offload_base);
-#ifdef CONFIG_XDPLUA
-	INIT_LIST_HEAD(&lua_state_cpu_list);
-#endif /* CONFIG_XDPLUA */
 
 	if (register_pernet_subsys(&netdev_net_ops))
 		goto out;
@@ -9860,6 +9871,7 @@ static int __init net_dev_init(void)
 	for_each_possible_cpu(i) {
 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
 		struct softnet_data *sd = &per_cpu(softnet_data, i);
+		struct xdplua *xdplua = per_cpu_ptr(&xdplua_per_cpu, i);
 
 		INIT_WORK(flush, flush_backlog);
 
@@ -9879,26 +9891,17 @@ static int __init net_dev_init(void)
 		init_gro_hash(&sd->backlog);
 		sd->backlog.poll = process_backlog;
 		sd->backlog.weight = weight_p;
+#ifdef CONFIG_XDP_LUA
+		xdplua->L = luaL_newstate();
+		WARN_ON(!xdplua->L);
 
-#ifdef CONFIG_XDPLUA
-		new_state_cpu = (struct lua_state_cpu *)
-			kmalloc(sizeof(lua_state_cpu), GFP_ATOMIC);
-		if (!new_state_cpu)
-			continue;
-
-		new_state_cpu->L = luaL_newstate();
-		if  (!new_state_cpu->L) {
-			kfree(new_state_cpu);
+		if (!xdplua->L)
 			continue;
-		}
-
-		luaL_openlibs(new_state_cpu->L);
-		luaL_requiref(new_state_cpu->L, "data", luaopen_data, 1);
-		lua_pop(new_state_cpu->L, 1);
-		new_state_cpu->cpu = i;
 
-		list_add(&new_state_cpu->list, &lua_state_cpu_list);
-#endif /* CONFIG_XDPLUA */
+		luaL_openlibs(xdplua->L);
+		luaL_requiref(xdplua->L, "data", luaopen_data, 1);
+		lua_pop(xdplua->L, 1);
+#endif /* CONFIG_XDP_LUA */
 	}
 
 	dev_boot_phase = 0;