1 files changed, 508 insertions, 238 deletions

diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index db6176fb64dc..43356faaa057 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -13,26 +13,17 @@
 #include <linux/btf_ids.h>
 #include <linux/rcupdate_wait.h>
 
-enum bpf_struct_ops_state {
-	BPF_STRUCT_OPS_STATE_INIT,
-	BPF_STRUCT_OPS_STATE_INUSE,
-	BPF_STRUCT_OPS_STATE_TOBEFREE,
-	BPF_STRUCT_OPS_STATE_READY,
-};
-
-#define BPF_STRUCT_OPS_COMMON_VALUE			\
-	refcount_t refcnt;				\
-	enum bpf_struct_ops_state state
-
 struct bpf_struct_ops_value {
-	BPF_STRUCT_OPS_COMMON_VALUE;
+	struct bpf_struct_ops_common_value common;
 	char data[] ____cacheline_aligned_in_smp;
 };
 
+#define MAX_TRAMP_IMAGE_PAGES 8
+
 struct bpf_struct_ops_map {
 	struct bpf_map map;
 	struct rcu_head rcu;
-	const struct bpf_struct_ops *st_ops;
+	const struct bpf_struct_ops_desc *st_ops_desc;
 	/* protect map_update */
 	struct mutex lock;
 	/* link has all the bpf_links that is populated
@@ -40,12 +31,14 @@ struct bpf_struct_ops_map {
 	 * (in kvalue.data).
 	 */
 	struct bpf_link **links;
-	/* image is a page that has all the trampolines
+	u32 links_cnt;
+	u32 image_pages_cnt;
+	/* image_pages is an array of pages that has all the trampolines
 	 * that stores the func args before calling the bpf_prog.
-	 * A PAGE_SIZE "image" is enough to store all trampoline for
-	 * "links[]".
 	 */
-	void *image;
+	void *image_pages[MAX_TRAMP_IMAGE_PAGES];
+	/* The owner moduler's btf. */
+	struct btf *btf;
 	/* uvalue->data stores the kernel struct
 	 * (e.g. tcp_congestion_ops) that is more useful
 	 * to userspace than the kvalue.  For example,
@@ -70,35 +63,6 @@ static DEFINE_MUTEX(update_mutex);
 #define VALUE_PREFIX "bpf_struct_ops_"
 #define VALUE_PREFIX_LEN (sizeof(VALUE_PREFIX) - 1)
 
-/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is
- * the map's value exposed to the userspace and its btf-type-id is
- * stored at the map->btf_vmlinux_value_type_id.
- *
- */
-#define BPF_STRUCT_OPS_TYPE(_name)				\
-extern struct bpf_struct_ops bpf_##_name;			\
-								\
-struct bpf_struct_ops_##_name {						\
-	BPF_STRUCT_OPS_COMMON_VALUE;				\
-	struct _name data ____cacheline_aligned_in_smp;		\
-};
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-
-enum {
-#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name,
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-	__NR_BPF_STRUCT_OPS_TYPE,
-};
-
-static struct bpf_struct_ops * const bpf_struct_ops[] = {
-#define BPF_STRUCT_OPS_TYPE(_name)				\
-	[BPF_STRUCT_OPS_TYPE_##_name] = &bpf_##_name,
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-};
-
 const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
 };
 
@@ -108,138 +72,355 @@ const struct bpf_prog_ops bpf_struct_ops_prog_ops = {
 #endif
 };
 
-static const struct btf_type *module_type;
+BTF_ID_LIST(st_ops_ids)
+BTF_ID(struct, module)
+BTF_ID(struct, bpf_struct_ops_common_value)
+
+enum {
+	IDX_MODULE_ID,
+	IDX_ST_OPS_COMMON_VALUE_ID,
+};
+
+extern struct btf *btf_vmlinux;
 
-void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
+static bool is_valid_value_type(struct btf *btf, s32 value_id,
+				const struct btf_type *type,
+				const char *value_name)
 {
-	s32 type_id, value_id, module_id;
+	const struct btf_type *common_value_type;
 	const struct btf_member *member;
-	struct bpf_struct_ops *st_ops;
-	const struct btf_type *t;
-	char value_name[128];
-	const char *mname;
-	u32 i, j;
+	const struct btf_type *vt, *mt;
+
+	vt = btf_type_by_id(btf, value_id);
+	if (btf_vlen(vt) != 2) {
+		pr_warn("The number of %s's members should be 2, but we get %d\n",
+			value_name, btf_vlen(vt));
+		return false;
+	}
+	member = btf_type_member(vt);
+	mt = btf_type_by_id(btf, member->type);
+	common_value_type = btf_type_by_id(btf_vmlinux,
+					   st_ops_ids[IDX_ST_OPS_COMMON_VALUE_ID]);
+	if (mt != common_value_type) {
+		pr_warn("The first member of %s should be bpf_struct_ops_common_value\n",
+			value_name);
+		return false;
+	}
+	member++;
+	mt = btf_type_by_id(btf, member->type);
+	if (mt != type) {
+		pr_warn("The second member of %s should be %s\n",
+			value_name, btf_name_by_offset(btf, type->name_off));
+		return false;
+	}
 
-	/* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */
-#define BPF_STRUCT_OPS_TYPE(_name) BTF_TYPE_EMIT(struct bpf_struct_ops_##_name);
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
+	return true;
+}
 
-	module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);
-	if (module_id < 0) {
-		pr_warn("Cannot find struct module in btf_vmlinux\n");
-		return;
+static void *bpf_struct_ops_image_alloc(void)
+{
+	void *image;
+	int err;
+
+	err = bpf_jit_charge_modmem(PAGE_SIZE);
+	if (err)
+		return ERR_PTR(err);
+	image = arch_alloc_bpf_trampoline(PAGE_SIZE);
+	if (!image) {
+		bpf_jit_uncharge_modmem(PAGE_SIZE);
+		return ERR_PTR(-ENOMEM);
 	}
-	module_type = btf_type_by_id(btf, module_id);
 
-	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
-		st_ops = bpf_struct_ops[i];
+	return image;
+}
+
+void bpf_struct_ops_image_free(void *image)
+{
+	if (image) {
+		arch_free_bpf_trampoline(image, PAGE_SIZE);
+		bpf_jit_uncharge_modmem(PAGE_SIZE);
+	}
+}
 
-		if (strlen(st_ops->name) + VALUE_PREFIX_LEN >=
-		    sizeof(value_name)) {
-			pr_warn("struct_ops name %s is too long\n",
-				st_ops->name);
-			continue;
-		}
-		sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name);
+#define MAYBE_NULL_SUFFIX "__nullable"
+#define MAX_STUB_NAME 128
 
-		value_id = btf_find_by_name_kind(btf, value_name,
-						 BTF_KIND_STRUCT);
-		if (value_id < 0) {
-			pr_warn("Cannot find struct %s in btf_vmlinux\n",
-				value_name);
+/* Return the type info of a stub function, if it exists.
+ *
+ * The name of a stub function is made up of the name of the struct_ops and
+ * the name of the function pointer member, separated by "__". For example,
+ * if the struct_ops type is named "foo_ops" and the function pointer
+ * member is named "bar", the stub function name would be "foo_ops__bar".
+ */
+static const struct btf_type *
+find_stub_func_proto(const struct btf *btf, const char *st_op_name,
+		     const char *member_name)
+{
+	char stub_func_name[MAX_STUB_NAME];
+	const struct btf_type *func_type;
+	s32 btf_id;
+	int cp;
+
+	cp = snprintf(stub_func_name, MAX_STUB_NAME, "%s__%s",
+		      st_op_name, member_name);
+	if (cp >= MAX_STUB_NAME) {
+		pr_warn("Stub function name too long\n");
+		return NULL;
+	}
+	btf_id = btf_find_by_name_kind(btf, stub_func_name, BTF_KIND_FUNC);
+	if (btf_id < 0)
+		return NULL;
+	func_type = btf_type_by_id(btf, btf_id);
+	if (!func_type)
+		return NULL;
+
+	return btf_type_by_id(btf, func_type->type); /* FUNC_PROTO */
+}
+
+/* Prepare argument info for every nullable argument of a member of a
+ * struct_ops type.
+ *
+ * Initialize a struct bpf_struct_ops_arg_info according to type info of
+ * the arguments of a stub function. (Check kCFI for more information about
+ * stub functions.)
+ *
+ * Each member in the struct_ops type has a struct bpf_struct_ops_arg_info
+ * to provide an array of struct bpf_ctx_arg_aux, which in turn provides
+ * the information that used by the verifier to check the arguments of the
+ * BPF struct_ops program assigned to the member. Here, we only care about
+ * the arguments that are marked as __nullable.
+ *
+ * The array of struct bpf_ctx_arg_aux is eventually assigned to
+ * prog->aux->ctx_arg_info of BPF struct_ops programs and passed to the
+ * verifier. (See check_struct_ops_btf_id())
+ *
+ * arg_info->info will be the list of struct bpf_ctx_arg_aux if success. If
+ * fails, it will be kept untouched.
+ */
+static int prepare_arg_info(struct btf *btf,
+			    const char *st_ops_name,
+			    const char *member_name,
+			    const struct btf_type *func_proto,
+			    struct bpf_struct_ops_arg_info *arg_info)
+{
+	const struct btf_type *stub_func_proto, *pointed_type;
+	const struct btf_param *stub_args, *args;
+	struct bpf_ctx_arg_aux *info, *info_buf;
+	u32 nargs, arg_no, info_cnt = 0;
+	u32 arg_btf_id;
+	int offset;
+
+	stub_func_proto = find_stub_func_proto(btf, st_ops_name, member_name);
+	if (!stub_func_proto)
+		return 0;
+
+	/* Check if the number of arguments of the stub function is the same
+	 * as the number of arguments of the function pointer.
+	 */
+	nargs = btf_type_vlen(func_proto);
+	if (nargs != btf_type_vlen(stub_func_proto)) {
+		pr_warn("the number of arguments of the stub function %s__%s does not match the number of arguments of the member %s of struct %s\n",
+			st_ops_name, member_name, member_name, st_ops_name);
+		return -EINVAL;
+	}
+
+	if (!nargs)
+		return 0;
+
+	args = btf_params(func_proto);
+	stub_args = btf_params(stub_func_proto);
+
+	info_buf = kcalloc(nargs, sizeof(*info_buf), GFP_KERNEL);
+	if (!info_buf)
+		return -ENOMEM;
+
+	/* Prepare info for every nullable argument */
+	info = info_buf;
+	for (arg_no = 0; arg_no < nargs; arg_no++) {
+		/* Skip arguments that is not suffixed with
+		 * "__nullable".
+		 */
+		if (!btf_param_match_suffix(btf, &stub_args[arg_no],
+					    MAYBE_NULL_SUFFIX))
 			continue;
+
+		/* Should be a pointer to struct */
+		pointed_type = btf_type_resolve_ptr(btf,
+						    args[arg_no].type,
+						    &arg_btf_id);
+		if (!pointed_type ||
+		    !btf_type_is_struct(pointed_type)) {
+			pr_warn("stub function %s__%s has %s tagging to an unsupported type\n",
+				st_ops_name, member_name, MAYBE_NULL_SUFFIX);
+			goto err_out;
 		}
 
-		type_id = btf_find_by_name_kind(btf, st_ops->name,
-						BTF_KIND_STRUCT);
-		if (type_id < 0) {
-			pr_warn("Cannot find struct %s in btf_vmlinux\n",
-				st_ops->name);
-			continue;
+		offset = btf_ctx_arg_offset(btf, func_proto, arg_no);
+		if (offset < 0) {
+			pr_warn("stub function %s__%s has an invalid trampoline ctx offset for arg#%u\n",
+				st_ops_name, member_name, arg_no);
+			goto err_out;
 		}
-		t = btf_type_by_id(btf, type_id);
-		if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
-			pr_warn("Cannot support #%u members in struct %s\n",
-				btf_type_vlen(t), st_ops->name);
-			continue;
+
+		if (args[arg_no].type != stub_args[arg_no].type) {
+			pr_warn("arg#%u type in stub function %s__%s does not match with its original func_proto\n",
+				arg_no, st_ops_name, member_name);
+			goto err_out;
 		}
 
-		for_each_member(j, t, member) {
-			const struct btf_type *func_proto;
+		/* Fill the information of the new argument */
+		info->reg_type =
+			PTR_TRUSTED | PTR_TO_BTF_ID | PTR_MAYBE_NULL;
+		info->btf_id = arg_btf_id;
+		info->btf = btf;
+		info->offset = offset;
 
-			mname = btf_name_by_offset(btf, member->name_off);
-			if (!*mname) {
-				pr_warn("anon member in struct %s is not supported\n",
-					st_ops->name);
-				break;
-			}
+		info++;
+		info_cnt++;
+	}
 
-			if (__btf_member_bitfield_size(t, member)) {
-				pr_warn("bit field member %s in struct %s is not supported\n",
-					mname, st_ops->name);
-				break;
-			}
+	if (info_cnt) {
+		arg_info->info = info_buf;
+		arg_info->cnt = info_cnt;
+	} else {
+		kfree(info_buf);
+	}
 
-			func_proto = btf_type_resolve_func_ptr(btf,
-							       member->type,
-							       NULL);
-			if (func_proto &&
-			    btf_distill_func_proto(log, btf,
-						   func_proto, mname,
-						   &st_ops->func_models[j])) {
-				pr_warn("Error in parsing func ptr %s in struct %s\n",
-					mname, st_ops->name);
-				break;
-			}
-		}
+	return 0;
 
-		if (j == btf_type_vlen(t)) {
-			if (st_ops->init(btf)) {
-				pr_warn("Error in init bpf_struct_ops %s\n",
-					st_ops->name);
-			} else {
-				st_ops->type_id = type_id;
-				st_ops->type = t;
-				st_ops->value_id = value_id;
-				st_ops->value_type = btf_type_by_id(btf,
-								    value_id);
-			}
-		}
-	}
+err_out:
+	kfree(info_buf);
+
+	return -EINVAL;
 }
 
-extern struct btf *btf_vmlinux;
+/* Clean up the arg_info in a struct bpf_struct_ops_desc. */
+void bpf_struct_ops_desc_release(struct bpf_struct_ops_desc *st_ops_desc)
+{
+	struct bpf_struct_ops_arg_info *arg_info;
+	int i;
+
+	arg_info = st_ops_desc->arg_info;
+	for (i = 0; i < btf_type_vlen(st_ops_desc->type); i++)
+		kfree(arg_info[i].info);
 
-static const struct bpf_struct_ops *
-bpf_struct_ops_find_value(u32 value_id)
+	kfree(arg_info);
+}
+
+int bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc,
+			     struct btf *btf,
+			     struct bpf_verifier_log *log)
 {
-	unsigned int i;
+	struct bpf_struct_ops *st_ops = st_ops_desc->st_ops;
+	struct bpf_struct_ops_arg_info *arg_info;
+	const struct btf_member *member;
+	const struct btf_type *t;
+	s32 type_id, value_id;
+	char value_name[128];
+	const char *mname;
+	int i, err;
 
-	if (!value_id || !btf_vmlinux)
-		return NULL;
+	if (strlen(st_ops->name) + VALUE_PREFIX_LEN >=
+	    sizeof(value_name)) {
+		pr_warn("struct_ops name %s is too long\n",
+			st_ops->name);
+		return -EINVAL;
+	}
+	sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name);
 
-	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
-		if (bpf_struct_ops[i]->value_id == value_id)
-			return bpf_struct_ops[i];
+	if (!st_ops->cfi_stubs) {
+		pr_warn("struct_ops for %s has no cfi_stubs\n", st_ops->name);
+		return -EINVAL;
 	}
 
-	return NULL;
-}
+	type_id = btf_find_by_name_kind(btf, st_ops->name,
+					BTF_KIND_STRUCT);
+	if (type_id < 0) {
+		pr_warn("Cannot find struct %s in %s\n",
+			st_ops->name, btf_get_name(btf));
+		return -EINVAL;
+	}
+	t = btf_type_by_id(btf, type_id);
+	if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
+		pr_warn("Cannot support #%u members in struct %s\n",
+			btf_type_vlen(t), st_ops->name);
+		return -EINVAL;
+	}
 
-const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id)
-{
-	unsigned int i;
+	value_id = btf_find_by_name_kind(btf, value_name,
+					 BTF_KIND_STRUCT);
+	if (value_id < 0) {
+		pr_warn("Cannot find struct %s in %s\n",
+			value_name, btf_get_name(btf));
+		return -EINVAL;
+	}
+	if (!is_valid_value_type(btf, value_id, t, value_name))
+		return -EINVAL;
 
-	if (!type_id || !btf_vmlinux)
-		return NULL;
+	arg_info = kcalloc(btf_type_vlen(t), sizeof(*arg_info),
+			   GFP_KERNEL);
+	if (!arg_info)
+		return -ENOMEM;
+
+	st_ops_desc->arg_info = arg_info;
+	st_ops_desc->type = t;
+	st_ops_desc->type_id = type_id;
+	st_ops_desc->value_id = value_id;
+	st_ops_desc->value_type = btf_type_by_id(btf, value_id);
+
+	for_each_member(i, t, member) {
+		const struct btf_type *func_proto;
+
+		mname = btf_name_by_offset(btf, member->name_off);
+		if (!*mname) {
+			pr_warn("anon member in struct %s is not supported\n",
+				st_ops->name);
+			err = -EOPNOTSUPP;
+			goto errout;
+		}
 
-	for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
-		if (bpf_struct_ops[i]->type_id == type_id)
-			return bpf_struct_ops[i];
+		if (__btf_member_bitfield_size(t, member)) {
+			pr_warn("bit field member %s in struct %s is not supported\n",
+				mname, st_ops->name);
+			err = -EOPNOTSUPP;
+			goto errout;
+		}
+
+		func_proto = btf_type_resolve_func_ptr(btf,
+						       member->type,
+						       NULL);
+		if (!func_proto)
+			continue;
+
+		if (btf_distill_func_proto(log, btf,
+					   func_proto, mname,
+					   &st_ops->func_models[i])) {
+			pr_warn("Error in parsing func ptr %s in struct %s\n",
+				mname, st_ops->name);
+			err = -EINVAL;
+			goto errout;
+		}
+
+		err = prepare_arg_info(btf, st_ops->name, mname,
+				       func_proto,
+				       arg_info + i);
+		if (err)
+			goto errout;
+	}
+
+	if (st_ops->init(btf)) {
+		pr_warn("Error in init bpf_struct_ops %s\n",
+			st_ops->name);
+		err = -EINVAL;
+		goto errout;
 	}
 
-	return NULL;
+	return 0;
+
+errout:
+	bpf_struct_ops_desc_release(st_ops_desc);
+
+	return err;
 }
 
 static int bpf_struct_ops_map_get_next_key(struct bpf_map *map, void *key,
@@ -265,7 +446,7 @@ int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key,
 
 	kvalue = &st_map->kvalue;
 	/* Pair with smp_store_release() during map_update */
-	state = smp_load_acquire(&kvalue->state);
+	state = smp_load_acquire(&kvalue->common.state);
 	if (state == BPF_STRUCT_OPS_STATE_INIT) {
 		memset(value, 0, map->value_size);
 		return 0;
@@ -276,7 +457,7 @@ int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key,
 	 */
 	uvalue = value;
 	memcpy(uvalue, st_map->uvalue, map->value_size);
-	uvalue->state = state;
+	uvalue->common.state = state;
 
 	/* This value offers the user space a general estimate of how
 	 * many sockets are still utilizing this struct_ops for TCP
@@ -284,7 +465,7 @@ int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key,
 	 * should sufficiently meet our present goals.
 	 */
 	refcnt = atomic64_read(&map->refcnt) - atomic64_read(&map->usercnt);
-	refcount_set(&uvalue->refcnt, max_t(s64, refcnt, 0));
+	refcount_set(&uvalue->common.refcnt, max_t(s64, refcnt, 0));
 
 	return 0;
 }
@@ -296,10 +477,9 @@ static void *bpf_struct_ops_map_lookup_elem(struct bpf_map *map, void *key)
 
 static void bpf_struct_ops_map_put_progs(struct bpf_struct_ops_map *st_map)
 {
-	const struct btf_type *t = st_map->st_ops->type;
 	u32 i;
 
-	for (i = 0; i < btf_type_vlen(t); i++) {
+	for (i = 0; i < st_map->links_cnt; i++) {
 		if (st_map->links[i]) {
 			bpf_link_put(st_map->links[i]);
 			st_map->links[i] = NULL;
@@ -307,7 +487,16 @@ static void bpf_struct_ops_map_put_progs(struct bpf_struct_ops_map *st_map)
 	}
 }
 
-static int check_zero_holes(const struct btf_type *t, void *data)
+static void bpf_struct_ops_map_free_image(struct bpf_struct_ops_map *st_map)
+{
+	int i;
+
+	for (i = 0; i < st_map->image_pages_cnt; i++)
+		bpf_struct_ops_image_free(st_map->image_pages[i]);
+	st_map->image_pages_cnt = 0;
+}
+
+static int check_zero_holes(const struct btf *btf, const struct btf_type *t, void *data)
 {
 	const struct btf_member *member;
 	u32 i, moff, msize, prev_mend = 0;
@@ -319,8 +508,8 @@ static int check_zero_holes(const struct btf_type *t, void *data)
 		    memchr_inv(data + prev_mend, 0, moff - prev_mend))
 			return -EINVAL;
 
-		mtype = btf_type_by_id(btf_vmlinux, member->type);
-		mtype = btf_resolve_size(btf_vmlinux, mtype, &msize);
+		mtype = btf_type_by_id(btf, member->type);
+		mtype = btf_resolve_size(btf, mtype, &msize);
 		if (IS_ERR(mtype))
 			return PTR_ERR(mtype);
 		prev_mend = moff + msize;
@@ -352,33 +541,64 @@ const struct bpf_link_ops bpf_struct_ops_link_lops = {
 int bpf_struct_ops_prepare_trampoline(struct bpf_tramp_links *tlinks,
 				      struct bpf_tramp_link *link,
 				      const struct btf_func_model *model,
-				      void *image, void *image_end)
+				      void *stub_func,
+				      void **_image, u32 *_image_off,
+				      bool allow_alloc)
 {
-	u32 flags;
+	u32 image_off = *_image_off, flags = BPF_TRAMP_F_INDIRECT;
+	void *image = *_image;
+	int size;
 
 	tlinks[BPF_TRAMP_FENTRY].links[0] = link;
 	tlinks[BPF_TRAMP_FENTRY].nr_links = 1;
-	/* BPF_TRAMP_F_RET_FENTRY_RET is only used by bpf_struct_ops,
-	 * and it must be used alone.
-	 */
-	flags = model->ret_size > 0 ? BPF_TRAMP_F_RET_FENTRY_RET : 0;
-	return arch_prepare_bpf_trampoline(NULL, image, image_end,
-					   model, flags, tlinks, NULL);
+
+	if (model->ret_size > 0)
+		flags |= BPF_TRAMP_F_RET_FENTRY_RET;
+
+	size = arch_bpf_trampoline_size(model, flags, tlinks, NULL);
+	if (size <= 0)
+		return size ? : -EFAULT;
+
+	/* Allocate image buffer if necessary */
+	if (!image || size > PAGE_SIZE - image_off) {
+		if (!allow_alloc)
+			return -E2BIG;
+
+		image = bpf_struct_ops_image_alloc();
+		if (IS_ERR(image))
+			return PTR_ERR(image);
+		image_off = 0;
+	}
+
+	size = arch_prepare_bpf_trampoline(NULL, image + image_off,
+					   image + PAGE_SIZE,
+					   model, flags, tlinks, stub_func);
+	if (size <= 0) {
+		if (image != *_image)
+			bpf_struct_ops_image_free(image);
+		return size ? : -EFAULT;
+	}
+
+	*_image = image;
+	*_image_off = image_off + size;
+	return 0;
 }
 
 static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 					   void *value, u64 flags)
 {
 	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
-	const struct bpf_struct_ops *st_ops = st_map->st_ops;
+	const struct bpf_struct_ops_desc *st_ops_desc = st_map->st_ops_desc;
+	const struct bpf_struct_ops *st_ops = st_ops_desc->st_ops;
 	struct bpf_struct_ops_value *uvalue, *kvalue;
+	const struct btf_type *module_type;
 	const struct btf_member *member;
-	const struct btf_type *t = st_ops->type;
+	const struct btf_type *t = st_ops_desc->type;
 	struct bpf_tramp_links *tlinks;
 	void *udata, *kdata;
 	int prog_fd, err;
-	void *image, *image_end;
-	u32 i;
+	u32 i, trampoline_start, image_off = 0;
+	void *cur_image = NULL, *image = NULL;
 
 	if (flags)
 		return -EINVAL;
@@ -386,16 +606,16 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 	if (*(u32 *)key != 0)
 		return -E2BIG;
 
-	err = check_zero_holes(st_ops->value_type, value);
+	err = check_zero_holes(st_map->btf, st_ops_desc->value_type, value);
 	if (err)
 		return err;
 
 	uvalue = value;
-	err = check_zero_holes(t, uvalue->data);
+	err = check_zero_holes(st_map->btf, t, uvalue->data);
 	if (err)
 		return err;
 
-	if (uvalue->state || refcount_read(&uvalue->refcnt))
+	if (uvalue->common.state || refcount_read(&uvalue->common.refcnt))
 		return -EINVAL;
 
 	tlinks = kcalloc(BPF_TRAMP_MAX, sizeof(*tlinks), GFP_KERNEL);
@@ -407,7 +627,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 
 	mutex_lock(&st_map->lock);
 
-	if (kvalue->state != BPF_STRUCT_OPS_STATE_INIT) {
+	if (kvalue->common.state != BPF_STRUCT_OPS_STATE_INIT) {
 		err = -EBUSY;
 		goto unlock;
 	}
@@ -416,9 +636,8 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 
 	udata = &uvalue->data;
 	kdata = &kvalue->data;
-	image = st_map->image;
-	image_end = st_map->image + PAGE_SIZE;
 
+	module_type = btf_type_by_id(btf_vmlinux, st_ops_ids[IDX_MODULE_ID]);
 	for_each_member(i, t, member) {
 		const struct btf_type *mtype, *ptype;
 		struct bpf_prog *prog;
@@ -426,7 +645,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 		u32 moff;
 
 		moff = __btf_member_bit_offset(t, member) / 8;
-		ptype = btf_type_resolve_ptr(btf_vmlinux, member->type, NULL);
+		ptype = btf_type_resolve_ptr(st_map->btf, member->type, NULL);
 		if (ptype == module_type) {
 			if (*(void **)(udata + moff))
 				goto reset_unlock;
@@ -451,8 +670,8 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 		if (!ptype || !btf_type_is_func_proto(ptype)) {
 			u32 msize;
 
-			mtype = btf_type_by_id(btf_vmlinux, member->type);
-			mtype = btf_resolve_size(btf_vmlinux, mtype, &msize);
+			mtype = btf_type_by_id(st_map->btf, member->type);
+			mtype = btf_resolve_size(st_map->btf, mtype, &msize);
 			if (IS_ERR(mtype)) {
 				err = PTR_ERR(mtype);
 				goto reset_unlock;
@@ -478,7 +697,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 		}
 
 		if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
-		    prog->aux->attach_btf_id != st_ops->type_id ||
+		    prog->aux->attach_btf_id != st_ops_desc->type_id ||
 		    prog->expected_attach_type != i) {
 			bpf_prog_put(prog);
 			err = -EINVAL;
@@ -495,36 +714,47 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 			      &bpf_struct_ops_link_lops, prog);
 		st_map->links[i] = &link->link;
 
+		trampoline_start = image_off;
 		err = bpf_struct_ops_prepare_trampoline(tlinks, link,
-							&st_ops->func_models[i],
-							image, image_end);
+						&st_ops->func_models[i],
+						*(void **)(st_ops->cfi_stubs + moff),
+						&image, &image_off,
+						st_map->image_pages_cnt < MAX_TRAMP_IMAGE_PAGES);
+		if (err)
+			goto reset_unlock;
+
+		if (cur_image != image) {
+			st_map->image_pages[st_map->image_pages_cnt++] = image;
+			cur_image = image;
+			trampoline_start = 0;
+		}
 		if (err < 0)
 			goto reset_unlock;
 
-		*(void **)(kdata + moff) = image;
-		image += err;
+		*(void **)(kdata + moff) = image + trampoline_start + cfi_get_offset();
 
 		/* put prog_id to udata */
 		*(unsigned long *)(udata + moff) = prog->aux->id;
 	}
 
+	if (st_ops->validate) {
+		err = st_ops->validate(kdata);
+		if (err)
+			goto reset_unlock;
+	}
+	for (i = 0; i < st_map->image_pages_cnt; i++)
+		arch_protect_bpf_trampoline(st_map->image_pages[i], PAGE_SIZE);
+
 	if (st_map->map.map_flags & BPF_F_LINK) {
 		err = 0;
-		if (st_ops->validate) {
-			err = st_ops->validate(kdata);
-			if (err)
-				goto reset_unlock;
-		}
-		set_memory_rox((long)st_map->image, 1);
 		/* Let bpf_link handle registration & unregistration.
 		 *
 		 * Pair with smp_load_acquire() during lookup_elem().
 		 */
-		smp_store_release(&kvalue->state, BPF_STRUCT_OPS_STATE_READY);
+		smp_store_release(&kvalue->common.state, BPF_STRUCT_OPS_STATE_READY);
 		goto unlock;
 	}
 
-	set_memory_rox((long)st_map->image, 1);
 	err = st_ops->reg(kdata);
 	if (likely(!err)) {
 		/* This refcnt increment on the map here after
@@ -538,7 +768,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 		 * It ensures the above udata updates (e.g. prog->aux->id)
 		 * can be seen once BPF_STRUCT_OPS_STATE_INUSE is set.
 		 */
-		smp_store_release(&kvalue->state, BPF_STRUCT_OPS_STATE_INUSE);
+		smp_store_release(&kvalue->common.state, BPF_STRUCT_OPS_STATE_INUSE);
 		goto unlock;
 	}
 
@@ -547,10 +777,9 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key,
 	 * there was a race in registering the struct_ops (under the same name) to
 	 * a sub-system through different struct_ops's maps.
 	 */
-	set_memory_nx((long)st_map->image, 1);
-	set_memory_rw((long)st_map->image, 1);
 
 reset_unlock:
+	bpf_struct_ops_map_free_image(st_map);
 	bpf_struct_ops_map_put_progs(st_map);
 	memset(uvalue, 0, map->value_size);
 	memset(kvalue, 0, map->value_size);
@@ -569,12 +798,12 @@ static long bpf_struct_ops_map_delete_elem(struct bpf_map *map, void *key)
 	if (st_map->map.map_flags & BPF_F_LINK)
 		return -EOPNOTSUPP;
 
-	prev_state = cmpxchg(&st_map->kvalue.state,
+	prev_state = cmpxchg(&st_map->kvalue.common.state,
 			     BPF_STRUCT_OPS_STATE_INUSE,
 			     BPF_STRUCT_OPS_STATE_TOBEFREE);
 	switch (prev_state) {
 	case BPF_STRUCT_OPS_STATE_INUSE:
-		st_map->st_ops->unreg(&st_map->kvalue.data);
+		st_map->st_ops_desc->st_ops->unreg(&st_map->kvalue.data);
 		bpf_map_put(map);
 		return 0;
 	case BPF_STRUCT_OPS_STATE_TOBEFREE:
@@ -591,6 +820,7 @@ static long bpf_struct_ops_map_delete_elem(struct bpf_map *map, void *key)
 static void bpf_struct_ops_map_seq_show_elem(struct bpf_map *map, void *key,
 					     struct seq_file *m)
 {
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
 	void *value;
 	int err;
 
@@ -600,7 +830,8 @@ static void bpf_struct_ops_map_seq_show_elem(struct bpf_map *map, void *key,
 
 	err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
 	if (!err) {
-		btf_type_seq_show(btf_vmlinux, map->btf_vmlinux_value_type_id,
+		btf_type_seq_show(st_map->btf,
+				  map->btf_vmlinux_value_type_id,
 				  value, m);
 		seq_puts(m, "\n");
 	}
@@ -615,16 +846,22 @@ static void __bpf_struct_ops_map_free(struct bpf_map *map)
 	if (st_map->links)
 		bpf_struct_ops_map_put_progs(st_map);
 	bpf_map_area_free(st_map->links);
-	if (st_map->image) {
-		bpf_jit_free_exec(st_map->image);
-		bpf_jit_uncharge_modmem(PAGE_SIZE);
-	}
+	bpf_struct_ops_map_free_image(st_map);
 	bpf_map_area_free(st_map->uvalue);
 	bpf_map_area_free(st_map);
 }
 
 static void bpf_struct_ops_map_free(struct bpf_map *map)
 {
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+
+	/* st_ops->owner was acquired during map_alloc to implicitly holds
+	 * the btf's refcnt. The acquire was only done when btf_is_module()
+	 * st_map->btf cannot be NULL here.
+	 */
+	if (btf_is_module(st_map->btf))
+		module_put(st_map->st_ops_desc->st_ops->owner);
+
 	/* The struct_ops's function may switch to another struct_ops.
 	 *
 	 * For example, bpf_tcp_cc_x->init() may switch to
@@ -648,29 +885,61 @@ static void bpf_struct_ops_map_free(struct bpf_map *map)
 static int bpf_struct_ops_map_alloc_check(union bpf_attr *attr)
 {
 	if (attr->key_size != sizeof(unsigned int) || attr->max_entries != 1 ||
-	    (attr->map_flags & ~BPF_F_LINK) || !attr->btf_vmlinux_value_type_id)
+	    (attr->map_flags & ~(BPF_F_LINK | BPF_F_VTYPE_BTF_OBJ_FD)) ||
+	    !attr->btf_vmlinux_value_type_id)
 		return -EINVAL;
 	return 0;
 }
 
 static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
 {
-	const struct bpf_struct_ops *st_ops;
+	const struct bpf_struct_ops_desc *st_ops_desc;
 	size_t st_map_size;
 	struct bpf_struct_ops_map *st_map;
 	const struct btf_type *t, *vt;
+	struct module *mod = NULL;
 	struct bpf_map *map;
+	struct btf *btf;
 	int ret;
 
-	st_ops = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id);
-	if (!st_ops)
-		return ERR_PTR(-ENOTSUPP);
+	if (attr->map_flags & BPF_F_VTYPE_BTF_OBJ_FD) {
+		/* The map holds btf for its whole life time. */
+		btf = btf_get_by_fd(attr->value_type_btf_obj_fd);
+		if (IS_ERR(btf))
+			return ERR_CAST(btf);
+		if (!btf_is_module(btf)) {
+			btf_put(btf);
+			return ERR_PTR(-EINVAL);
+		}
 
-	vt = st_ops->value_type;
-	if (attr->value_size != vt->size)
-		return ERR_PTR(-EINVAL);
+		mod = btf_try_get_module(btf);
+		/* mod holds a refcnt to btf. We don't need an extra refcnt
+		 * here.
+		 */
+		btf_put(btf);
+		if (!mod)
+			return ERR_PTR(-EINVAL);
+	} else {
+		btf = bpf_get_btf_vmlinux();
+		if (IS_ERR(btf))
+			return ERR_CAST(btf);
+		if (!btf)
+			return ERR_PTR(-ENOTSUPP);
+	}
+
+	st_ops_desc = bpf_struct_ops_find_value(btf, attr->btf_vmlinux_value_type_id);
+	if (!st_ops_desc) {
+		ret = -ENOTSUPP;
+		goto errout;
+	}
 
-	t = st_ops->type;
+	vt = st_ops_desc->value_type;
+	if (attr->value_size != vt->size) {
+		ret = -EINVAL;
+		goto errout;
+	}
+
+	t = st_ops_desc->type;
 
 	st_map_size = sizeof(*st_map) +
 		/* kvalue stores the
@@ -679,49 +948,43 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
 		(vt->size - sizeof(struct bpf_struct_ops_value));
 
 	st_map = bpf_map_area_alloc(st_map_size, NUMA_NO_NODE);
-	if (!st_map)
-		return ERR_PTR(-ENOMEM);
+	if (!st_map) {
+		ret = -ENOMEM;
+		goto errout;
+	}
 
-	st_map->st_ops = st_ops;
+	st_map->st_ops_desc = st_ops_desc;
 	map = &st_map->map;
 
-	ret = bpf_jit_charge_modmem(PAGE_SIZE);
-	if (ret) {
-		__bpf_struct_ops_map_free(map);
-		return ERR_PTR(ret);
-	}
-
-	st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
-	if (!st_map->image) {
-		/* __bpf_struct_ops_map_free() uses st_map->image as flag
-		 * for "charged or not". In this case, we need to unchange
-		 * here.
-		 */
-		bpf_jit_uncharge_modmem(PAGE_SIZE);
-		__bpf_struct_ops_map_free(map);
-		return ERR_PTR(-ENOMEM);
-	}
 	st_map->uvalue = bpf_map_area_alloc(vt->size, NUMA_NO_NODE);
+	st_map->links_cnt = btf_type_vlen(t);
 	st_map->links =
-		bpf_map_area_alloc(btf_type_vlen(t) * sizeof(struct bpf_links *),
+		bpf_map_area_alloc(st_map->links_cnt * sizeof(struct bpf_links *),
 				   NUMA_NO_NODE);
 	if (!st_map->uvalue || !st_map->links) {
-		__bpf_struct_ops_map_free(map);
-		return ERR_PTR(-ENOMEM);
+		ret = -ENOMEM;
+		goto errout_free;
 	}
+	st_map->btf = btf;
 
 	mutex_init(&st_map->lock);
-	set_vm_flush_reset_perms(st_map->image);
 	bpf_map_init_from_attr(map, attr);
 
 	return map;
+
+errout_free:
+	__bpf_struct_ops_map_free(map);
+errout:
+	module_put(mod);
+
+	return ERR_PTR(ret);
 }
 
 static u64 bpf_struct_ops_map_mem_usage(const struct bpf_map *map)
 {
 	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
-	const struct bpf_struct_ops *st_ops = st_map->st_ops;
-	const struct btf_type *vt = st_ops->value_type;
+	const struct bpf_struct_ops_desc *st_ops_desc = st_map->st_ops_desc;
+	const struct btf_type *vt = st_ops_desc->value_type;
 	u64 usage;
 
 	usage = sizeof(*st_map) +
@@ -780,7 +1043,7 @@ static bool bpf_struct_ops_valid_to_reg(struct bpf_map *map)
 	return map->map_type == BPF_MAP_TYPE_STRUCT_OPS &&
 		map->map_flags & BPF_F_LINK &&
 		/* Pair with smp_store_release() during map_update */
-		smp_load_acquire(&st_map->kvalue.state) == BPF_STRUCT_OPS_STATE_READY;
+		smp_load_acquire(&st_map->kvalue.common.state) == BPF_STRUCT_OPS_STATE_READY;
 }
 
 static void bpf_struct_ops_map_link_dealloc(struct bpf_link *link)
@@ -795,7 +1058,7 @@ static void bpf_struct_ops_map_link_dealloc(struct bpf_link *link)
 		/* st_link->map can be NULL if
 		 * bpf_struct_ops_link_create() fails to register.
 		 */
-		st_map->st_ops->unreg(&st_map->kvalue.data);
+		st_map->st_ops_desc->st_ops->unreg(&st_map->kvalue.data);
 		bpf_map_put(&st_map->map);
 	}
 	kfree(st_link);
@@ -842,7 +1105,7 @@ static int bpf_struct_ops_map_link_update(struct bpf_link *link, struct bpf_map
 	if (!bpf_struct_ops_valid_to_reg(new_map))
 		return -EINVAL;
 
-	if (!st_map->st_ops->update)
+	if (!st_map->st_ops_desc->st_ops->update)
 		return -EOPNOTSUPP;
 
 	mutex_lock(&update_mutex);
@@ -855,12 +1118,12 @@ static int bpf_struct_ops_map_link_update(struct bpf_link *link, struct bpf_map
 
 	old_st_map = container_of(old_map, struct bpf_struct_ops_map, map);
 	/* The new and old struct_ops must be the same type. */
-	if (st_map->st_ops != old_st_map->st_ops) {
+	if (st_map->st_ops_desc != old_st_map->st_ops_desc) {
 		err = -EINVAL;
 		goto err_out;
 	}
 
-	err = st_map->st_ops->update(st_map->kvalue.data, old_st_map->kvalue.data);
+	err = st_map->st_ops_desc->st_ops->update(st_map->kvalue.data, old_st_map->kvalue.data);
 	if (err)
 		goto err_out;
 
@@ -911,7 +1174,7 @@ int bpf_struct_ops_link_create(union bpf_attr *attr)
 	if (err)
 		goto err_out;
 
-	err = st_map->st_ops->reg(st_map->kvalue.data);
+	err = st_map->st_ops_desc->st_ops->reg(st_map->kvalue.data);
 	if (err) {
 		bpf_link_cleanup(&link_primer);
 		link = NULL;
@@ -926,3 +1189,10 @@ err_out:
 	kfree(link);
 	return err;
 }
+
+void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struct bpf_map *map)
+{
+	struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map;
+
+	info->btf_vmlinux_id = btf_obj_id(st_map->btf);
+}