bpf: Consolidate spin_lock, timer management into btf_record

Now that kptr_off_tab has been refactored into btf_record, and can hold
more than one specific field type, accomodate bpf_spin_lock and
bpf_timer as well.

While they don't require any more metadata than offset, having all
special fields in one place allows us to share the same code for
allocated user defined types and handle both map values and these
allocated objects in a similar fashion.

As an optimization, we still keep spin_lock_off and timer_off offsets in
the btf_record structure, just to avoid having to find the btf_field
struct each time their offset is needed. This is mostly needed to
manipulate such objects in a map value at runtime. It's ok to hardcode
just one offset as more than one field is disallowed.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-8-memxor@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

include/linux/bpf.h

@@ -166,13 +166,13 @@ struct bpf_map_ops {
 
 enum {
 	/* Support at most 8 pointers in a BTF type */
-	BTF_FIELDS_MAX	      = 8,
-	BPF_MAP_OFF_ARR_MAX   = BTF_FIELDS_MAX +
-				1 + /* for bpf_spin_lock */
-				1,  /* for bpf_timer */
+	BTF_FIELDS_MAX	      = 10,
+	BPF_MAP_OFF_ARR_MAX   = BTF_FIELDS_MAX,
 };
 
 enum btf_field_type {
+	BPF_SPIN_LOCK  = (1 << 0),
+	BPF_TIMER      = (1 << 1),
 	BPF_KPTR_UNREF = (1 << 2),
 	BPF_KPTR_REF   = (1 << 3),
 	BPF_KPTR       = BPF_KPTR_UNREF | BPF_KPTR_REF,
@@ -196,6 +196,8 @@ struct btf_field {
 struct btf_record {
 	u32 cnt;
 	u32 field_mask;
+	int spin_lock_off;
+	int timer_off;
 	struct btf_field fields[];
 };
 
@@ -220,10 +222,8 @@ struct bpf_map {
 	u32 max_entries;
 	u64 map_extra; /* any per-map-type extra fields */
 	u32 map_flags;
-	int spin_lock_off; /* >=0 valid offset, <0 error */
-	struct btf_record *record;
-	int timer_off; /* >=0 valid offset, <0 error */
 	u32 id;
+	struct btf_record *record;
 	int numa_node;
 	u32 btf_key_type_id;
 	u32 btf_value_type_id;
@@ -257,9 +257,29 @@ struct bpf_map {
 	bool frozen; /* write-once; write-protected by freeze_mutex */
 };
 
+static inline const char *btf_field_type_name(enum btf_field_type type)
+{
+	switch (type) {
+	case BPF_SPIN_LOCK:
+		return "bpf_spin_lock";
+	case BPF_TIMER:
+		return "bpf_timer";
+	case BPF_KPTR_UNREF:
+	case BPF_KPTR_REF:
+		return "kptr";
+	default:
+		WARN_ON_ONCE(1);
+		return "unknown";
+	}
+}
+
 static inline u32 btf_field_type_size(enum btf_field_type type)
 {
 	switch (type) {
+	case BPF_SPIN_LOCK:
+		return sizeof(struct bpf_spin_lock);
+	case BPF_TIMER:
+		return sizeof(struct bpf_timer);
 	case BPF_KPTR_UNREF:
 	case BPF_KPTR_REF:
 		return sizeof(u64);
@@ -272,6 +292,10 @@ static inline u32 btf_field_type_size(enum btf_field_type type)
 static inline u32 btf_field_type_align(enum btf_field_type type)
 {
 	switch (type) {
+	case BPF_SPIN_LOCK:
+		return __alignof__(struct bpf_spin_lock);
+	case BPF_TIMER:
+		return __alignof__(struct bpf_timer);
 	case BPF_KPTR_UNREF:
 	case BPF_KPTR_REF:
 		return __alignof__(u64);
@@ -288,22 +312,8 @@ static inline bool btf_record_has_field(const struct btf_record *rec, enum btf_f
 	return rec->field_mask & type;
 }
 
-static inline bool map_value_has_spin_lock(const struct bpf_map *map)
-{
-	return map->spin_lock_off >= 0;
-}
-
-static inline bool map_value_has_timer(const struct bpf_map *map)
-{
-	return map->timer_off >= 0;
-}
-
 static inline void check_and_init_map_value(struct bpf_map *map, void *dst)
 {
-	if (unlikely(map_value_has_spin_lock(map)))
-		memset(dst + map->spin_lock_off, 0, sizeof(struct bpf_spin_lock));
-	if (unlikely(map_value_has_timer(map)))
-		memset(dst + map->timer_off, 0, sizeof(struct bpf_timer));
 	if (!IS_ERR_OR_NULL(map->record)) {
 		struct btf_field *fields = map->record->fields;
 		u32 cnt = map->record->cnt;
@@ -1740,6 +1750,7 @@ void btf_record_free(struct btf_record *rec);
 void bpf_map_free_record(struct bpf_map *map);
 struct btf_record *btf_record_dup(const struct btf_record *rec);
 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b);
+void bpf_obj_free_timer(const struct btf_record *rec, void *obj);
 void bpf_obj_free_fields(const struct btf_record *rec, void *obj);
 
 struct bpf_map *bpf_map_get(u32 ufd);

include/linux/btf.h

@@ -163,7 +163,8 @@ bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
 			   u32 expected_offset, u32 expected_size);
 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
 int btf_find_timer(const struct btf *btf, const struct btf_type *t);
-struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t);
+struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
+				    u32 field_mask, u32 value_size);
 bool btf_type_is_void(const struct btf_type *t);
 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,

kernel/bpf/arraymap.c

@@ -306,13 +306,6 @@ static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key
 	return 0;
 }
 
-static void check_and_free_fields(struct bpf_array *arr, void *val)
-{
-	if (map_value_has_timer(&arr->map))
-		bpf_timer_cancel_and_free(val + arr->map.timer_off);
-	bpf_obj_free_fields(arr->map.record, val);
-}
-
 /* Called from syscall or from eBPF program */
 static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
 				 u64 map_flags)
@@ -334,13 +327,13 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
 		return -EEXIST;
 
 	if (unlikely((map_flags & BPF_F_LOCK) &&
-		     !map_value_has_spin_lock(map)))
+		     !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
 		return -EINVAL;
 
 	if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
 		val = this_cpu_ptr(array->pptrs[index & array->index_mask]);
 		copy_map_value(map, val, value);
-		check_and_free_fields(array, val);
+		bpf_obj_free_fields(array->map.record, val);
 	} else {
 		val = array->value +
 			(u64)array->elem_size * (index & array->index_mask);
@@ -348,7 +341,7 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
 			copy_map_value_locked(map, val, value, false);
 		else
 			copy_map_value(map, val, value);
-		check_and_free_fields(array, val);
+		bpf_obj_free_fields(array->map.record, val);
 	}
 	return 0;
 }
@@ -385,7 +378,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
 	pptr = array->pptrs[index & array->index_mask];
 	for_each_possible_cpu(cpu) {
 		copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off);
-		check_and_free_fields(array, per_cpu_ptr(pptr, cpu));
+		bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu));
 		off += size;
 	}
 	rcu_read_unlock();
@@ -409,11 +402,11 @@ static void array_map_free_timers(struct bpf_map *map)
 	int i;
 
 	/* We don't reset or free fields other than timer on uref dropping to zero. */
-	if (!map_value_has_timer(map))
+	if (!btf_record_has_field(map->record, BPF_TIMER))
 		return;
 
 	for (i = 0; i < array->map.max_entries; i++)
-		bpf_timer_cancel_and_free(array_map_elem_ptr(array, i) + map->timer_off);
+		bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i));
 }
 
 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */

kernel/bpf/bpf_local_storage.c

@@ -382,7 +382,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap,
 	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST) ||
 	    /* BPF_F_LOCK can only be used in a value with spin_lock */
 	    unlikely((map_flags & BPF_F_LOCK) &&
-		     !map_value_has_spin_lock(&smap->map)))
+		     !btf_record_has_field(smap->map.record, BPF_SPIN_LOCK)))
 		return ERR_PTR(-EINVAL);
 
 	if (gfp_flags == GFP_KERNEL && (map_flags & ~BPF_F_LOCK) != BPF_NOEXIST)

kernel/bpf/hashtab.c

@@ -222,7 +222,7 @@ static void htab_free_prealloced_timers(struct bpf_htab *htab)
 	u32 num_entries = htab->map.max_entries;
 	int i;
 
-	if (!map_value_has_timer(&htab->map))
+	if (!btf_record_has_field(htab->map.record, BPF_TIMER))
 		return;
 	if (htab_has_extra_elems(htab))
 		num_entries += num_possible_cpus();
@@ -231,9 +231,7 @@ static void htab_free_prealloced_timers(struct bpf_htab *htab)
 		struct htab_elem *elem;
 
 		elem = get_htab_elem(htab, i);
-		bpf_timer_cancel_and_free(elem->key +
-					  round_up(htab->map.key_size, 8) +
-					  htab->map.timer_off);
+		bpf_obj_free_timer(htab->map.record, elem->key + round_up(htab->map.key_size, 8));
 		cond_resched();
 	}
 }
@@ -763,8 +761,6 @@ static void check_and_free_fields(struct bpf_htab *htab,
 {
 	void *map_value = elem->key + round_up(htab->map.key_size, 8);
 
-	if (map_value_has_timer(&htab->map))
-		bpf_timer_cancel_and_free(map_value + htab->map.timer_off);
 	bpf_obj_free_fields(htab->map.record, map_value);
 }
 
@@ -1089,7 +1085,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
 	head = &b->head;
 
 	if (unlikely(map_flags & BPF_F_LOCK)) {
-		if (unlikely(!map_value_has_spin_lock(map)))
+		if (unlikely(!btf_record_has_field(map->record, BPF_SPIN_LOCK)))
 			return -EINVAL;
 		/* find an element without taking the bucket lock */
 		l_old = lookup_nulls_elem_raw(head, hash, key, key_size,
@@ -1472,12 +1468,8 @@ static void htab_free_malloced_timers(struct bpf_htab *htab)
 		struct htab_elem *l;
 
 		hlist_nulls_for_each_entry(l, n, head, hash_node) {
-			/* We don't reset or free kptr on uref dropping to zero,
-			 * hence just free timer.
-			 */
-			bpf_timer_cancel_and_free(l->key +
-						  round_up(htab->map.key_size, 8) +
-						  htab->map.timer_off);
+			/* We only free timer on uref dropping to zero */
+			bpf_obj_free_timer(htab->map.record, l->key + round_up(htab->map.key_size, 8));
 		}
 		cond_resched_rcu();
 	}
@@ -1488,8 +1480,8 @@ static void htab_map_free_timers(struct bpf_map *map)
 {
 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 
-	/* We don't reset or free kptr on uref dropping to zero. */
-	if (!map_value_has_timer(&htab->map))
+	/* We only free timer on uref dropping to zero */
+	if (!btf_record_has_field(htab->map.record, BPF_TIMER))
 		return;
 	if (!htab_is_prealloc(htab))
 		htab_free_malloced_timers(htab);
@@ -1673,7 +1665,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map,
 
 	elem_map_flags = attr->batch.elem_flags;
 	if ((elem_map_flags & ~BPF_F_LOCK) ||
-	    ((elem_map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
+	    ((elem_map_flags & BPF_F_LOCK) && !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
 		return -EINVAL;
 
 	map_flags = attr->batch.flags;

kernel/bpf/helpers.c

@@ -366,9 +366,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
 	struct bpf_spin_lock *lock;
 
 	if (lock_src)
-		lock = src + map->spin_lock_off;
+		lock = src + map->record->spin_lock_off;
 	else
-		lock = dst + map->spin_lock_off;
+		lock = dst + map->record->spin_lock_off;
 	preempt_disable();
 	__bpf_spin_lock_irqsave(lock);
 	copy_map_value(map, dst, src);
@@ -1169,7 +1169,7 @@ BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map
 		ret = -ENOMEM;
 		goto out;
 	}
-	t->value = (void *)timer - map->timer_off;
+	t->value = (void *)timer - map->record->timer_off;
 	t->map = map;
 	t->prog = NULL;
 	rcu_assign_pointer(t->callback_fn, NULL);

kernel/bpf/local_storage.c

@@ -151,7 +151,7 @@ static int cgroup_storage_update_elem(struct bpf_map *map, void *key,
 		return -EINVAL;
 
 	if (unlikely((flags & BPF_F_LOCK) &&
-		     !map_value_has_spin_lock(map)))
+		     !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
 		return -EINVAL;
 
 	storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,

kernel/bpf/map_in_map.c

@@ -29,7 +29,7 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
 		return ERR_PTR(-ENOTSUPP);
 	}
 
-	if (map_value_has_spin_lock(inner_map)) {
+	if (btf_record_has_field(inner_map->record, BPF_SPIN_LOCK)) {
 		fdput(f);
 		return ERR_PTR(-ENOTSUPP);
 	}
@@ -50,8 +50,6 @@ struct bpf_map *bpf_map_meta_alloc(int inner_map_ufd)
 	inner_map_meta->value_size = inner_map->value_size;
 	inner_map_meta->map_flags = inner_map->map_flags;
 	inner_map_meta->max_entries = inner_map->max_entries;
-	inner_map_meta->spin_lock_off = inner_map->spin_lock_off;
-	inner_map_meta->timer_off = inner_map->timer_off;
 	inner_map_meta->record = btf_record_dup(inner_map->record);
 	if (IS_ERR(inner_map_meta->record)) {
 		/* btf_record_dup returns NULL or valid pointer in case of
@@ -92,7 +90,6 @@ bool bpf_map_meta_equal(const struct bpf_map *meta0,
 	return meta0->map_type == meta1->map_type &&
 		meta0->key_size == meta1->key_size &&
 		meta0->value_size == meta1->value_size &&
-		meta0->timer_off == meta1->timer_off &&
 		meta0->map_flags == meta1->map_flags &&
 		btf_record_equal(meta0->record, meta1->record);
 }

kernel/bpf/syscall.c

@@ -527,6 +527,9 @@ void btf_record_free(struct btf_record *rec)
 		return;
 	for (i = 0; i < rec->cnt; i++) {
 		switch (rec->fields[i].type) {
+		case BPF_SPIN_LOCK:
+		case BPF_TIMER:
+			break;
 		case BPF_KPTR_UNREF:
 		case BPF_KPTR_REF:
 			if (rec->fields[i].kptr.module)
@@ -564,6 +567,9 @@ struct btf_record *btf_record_dup(const struct btf_record *rec)
 	new_rec->cnt = 0;
 	for (i = 0; i < rec->cnt; i++) {
 		switch (fields[i].type) {
+		case BPF_SPIN_LOCK:
+		case BPF_TIMER:
+			break;
 		case BPF_KPTR_UNREF:
 		case BPF_KPTR_REF:
 			btf_get(fields[i].kptr.btf);
@@ -600,6 +606,13 @@ bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *r
 	return !memcmp(rec_a, rec_b, size);
 }
 
+void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
+{
+	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
+		return;
+	bpf_timer_cancel_and_free(obj + rec->timer_off);
+}
+
 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
 {
 	const struct btf_field *fields;
@@ -613,6 +626,11 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
 		void *field_ptr = obj + field->offset;
 
 		switch (fields[i].type) {
+		case BPF_SPIN_LOCK:
+			break;
+		case BPF_TIMER:
+			bpf_timer_cancel_and_free(field_ptr);
+			break;
 		case BPF_KPTR_UNREF:
 			WRITE_ONCE(*(u64 *)field_ptr, 0);
 			break;
@@ -798,8 +816,7 @@ static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
 	struct bpf_map *map = filp->private_data;
 	int err;
 
-	if (!map->ops->map_mmap || map_value_has_spin_lock(map) ||
-	    map_value_has_timer(map) || !IS_ERR_OR_NULL(map->record))
+	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
 		return -ENOTSUPP;
 
 	if (!(vma->vm_flags & VM_SHARED))
@@ -954,48 +971,30 @@ static void map_field_offs_swap(void *_a, void *_b, int size, const void *priv)
 
 static int bpf_map_alloc_off_arr(struct bpf_map *map)
 {
-	bool has_spin_lock = map_value_has_spin_lock(map);
-	bool has_timer = map_value_has_timer(map);
 	bool has_fields = !IS_ERR_OR_NULL(map->record);
 	struct btf_field_offs *fo;
-	u32 i;
+	struct btf_record *rec;
+	u32 i, *off;
+	u8 *sz;
 
-	if (!has_spin_lock && !has_timer && !has_fields) {
+	if (!has_fields) {
 		map->field_offs = NULL;
 		return 0;
 	}
 
-	fo = kmalloc(sizeof(*map->field_offs), GFP_KERNEL | __GFP_NOWARN);
+	fo = kzalloc(sizeof(*map->field_offs), GFP_KERNEL | __GFP_NOWARN);
 	if (!fo)
 		return -ENOMEM;
 	map->field_offs = fo;
 
-	fo->cnt = 0;
-	if (has_spin_lock) {
-		i = fo->cnt;
-
-		fo->field_off[i] = map->spin_lock_off;
-		fo->field_sz[i] = sizeof(struct bpf_spin_lock);
-		fo->cnt++;
-	}
-	if (has_timer) {
-		i = fo->cnt;
-
-		fo->field_off[i] = map->timer_off;
-		fo->field_sz[i] = sizeof(struct bpf_timer);
-		fo->cnt++;
-	}
-	if (has_fields) {
-		struct btf_record *rec = map->record;
-		u32 *off = &fo->field_off[fo->cnt];
-		u8 *sz = &fo->field_sz[fo->cnt];
-
-		for (i = 0; i < rec->cnt; i++) {
-			*off++ = rec->fields[i].offset;
-			*sz++ = btf_field_type_size(rec->fields[i].type);
-		}
-		fo->cnt += rec->cnt;
+	rec = map->record;
+	off = fo->field_off;
+	sz = fo->field_sz;
+	for (i = 0; i < rec->cnt; i++) {
+		*off++ = rec->fields[i].offset;
+		*sz++ = btf_field_type_size(rec->fields[i].type);
 	}
+	fo->cnt = rec->cnt;
 
 	if (fo->cnt == 1)
 		return 0;
@@ -1026,39 +1025,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 	if (!value_type || value_size != map->value_size)
 		return -EINVAL;
 
-	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
-
-	if (map_value_has_spin_lock(map)) {
-		if (map->map_flags & BPF_F_RDONLY_PROG)
-			return -EACCES;
-		if (map->map_type != BPF_MAP_TYPE_HASH &&
-		    map->map_type != BPF_MAP_TYPE_ARRAY &&
-		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
-		    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
-		    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
-		    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
-		    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE)
-			return -ENOTSUPP;
-		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
-		    map->value_size) {
-			WARN_ONCE(1,
-				  "verifier bug spin_lock_off %d value_size %d\n",
-				  map->spin_lock_off, map->value_size);
-			return -EFAULT;
-		}
-	}
-
-	map->timer_off = btf_find_timer(btf, value_type);
-	if (map_value_has_timer(map)) {
-		if (map->map_flags & BPF_F_RDONLY_PROG)
-			return -EACCES;
-		if (map->map_type != BPF_MAP_TYPE_HASH &&
-		    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
-		    map->map_type != BPF_MAP_TYPE_ARRAY)
-			return -EOPNOTSUPP;
-	}
-
-	map->record = btf_parse_fields(btf, value_type);
+	map->record = btf_parse_fields(btf, value_type, BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR,
+				       map->value_size);
 	if (!IS_ERR_OR_NULL(map->record)) {
 		int i;
 
@@ -1074,6 +1042,26 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
 			switch (map->record->field_mask & (1 << i)) {
 			case 0:
 				continue;
+			case BPF_SPIN_LOCK:
+				if (map->map_type != BPF_MAP_TYPE_HASH &&
+				    map->map_type != BPF_MAP_TYPE_ARRAY &&
+				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
+				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
+				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
+				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
+				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
+					ret = -EOPNOTSUPP;
+					goto free_map_tab;
+				}
+				break;
+			case BPF_TIMER:
+				if (map->map_type != BPF_MAP_TYPE_HASH &&
+				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
+				    map->map_type != BPF_MAP_TYPE_ARRAY) {
+					return -EOPNOTSUPP;
+					goto free_map_tab;
+				}
+				break;
 			case BPF_KPTR_UNREF:
 			case BPF_KPTR_REF:
 				if (map->map_type != BPF_MAP_TYPE_HASH &&
@@ -1153,8 +1141,6 @@ static int map_create(union bpf_attr *attr)
 	mutex_init(&map->freeze_mutex);
 	spin_lock_init(&map->owner.lock);
 
-	map->spin_lock_off = -EINVAL;
-	map->timer_off = -EINVAL;
 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
 	    /* Even the map's value is a kernel's struct,
 	     * the bpf_prog.o must have BTF to begin with
@@ -1368,7 +1354,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 	}
 
 	if ((attr->flags & BPF_F_LOCK) &&
-	    !map_value_has_spin_lock(map)) {
+	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		err = -EINVAL;
 		goto err_put;
 	}
@@ -1441,7 +1427,7 @@ static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
 	}
 
 	if ((attr->flags & BPF_F_LOCK) &&
-	    !map_value_has_spin_lock(map)) {
+	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		err = -EINVAL;
 		goto err_put;
 	}
@@ -1604,7 +1590,7 @@ int generic_map_delete_batch(struct bpf_map *map,
 		return -EINVAL;
 
 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
-	    !map_value_has_spin_lock(map)) {
+	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		return -EINVAL;
 	}
 
@@ -1661,7 +1647,7 @@ int generic_map_update_batch(struct bpf_map *map,
 		return -EINVAL;
 
 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
-	    !map_value_has_spin_lock(map)) {
+	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		return -EINVAL;
 	}
 
@@ -1724,7 +1710,7 @@ int generic_map_lookup_batch(struct bpf_map *map,
 		return -EINVAL;
 
 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
-	    !map_value_has_spin_lock(map))
+	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
 		return -EINVAL;
 
 	value_size = bpf_map_value_size(map);
@@ -1846,7 +1832,7 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
 	}
 
 	if ((attr->flags & BPF_F_LOCK) &&
-	    !map_value_has_spin_lock(map)) {
+	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		err = -EINVAL;
 		goto err_put;
 	}
@@ -1917,8 +1903,7 @@ static int map_freeze(const union bpf_attr *attr)
 	if (IS_ERR(map))
 		return PTR_ERR(map);
 
-	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS ||
-	    map_value_has_timer(map) || !IS_ERR_OR_NULL(map->record)) {
+	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) {
 		fdput(f);
 		return -ENOTSUPP;
 	}

kernel/bpf/verifier.c

@@ -454,7 +454,7 @@ static bool reg_type_not_null(enum bpf_reg_type type)
 static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
 {
 	return reg->type == PTR_TO_MAP_VALUE &&
-		map_value_has_spin_lock(reg->map_ptr);
+	       btf_record_has_field(reg->map_ptr->record, BPF_SPIN_LOCK);
 }
 
 static bool type_is_rdonly_mem(u32 type)
@@ -1388,7 +1388,7 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
 			/* transfer reg's id which is unique for every map_lookup_elem
 			 * as UID of the inner map.
 			 */
-			if (map_value_has_timer(map->inner_map_meta))
+			if (btf_record_has_field(map->inner_map_meta->record, BPF_TIMER))
 				reg->map_uid = reg->id;
 		} else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
 			reg->type = PTR_TO_XDP_SOCK;
@@ -3817,29 +3817,6 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
 	if (err)
 		return err;
 
-	if (map_value_has_spin_lock(map)) {
-		u32 lock = map->spin_lock_off;
-
-		/* if any part of struct bpf_spin_lock can be touched by
-		 * load/store reject this program.
-		 * To check that [x1, x2) overlaps with [y1, y2)
-		 * it is sufficient to check x1 < y2 && y1 < x2.
-		 */
-		if (reg->smin_value + off < lock + sizeof(struct bpf_spin_lock) &&
-		     lock < reg->umax_value + off + size) {
-			verbose(env, "bpf_spin_lock cannot be accessed directly by load/store\n");
-			return -EACCES;
-		}
-	}
-	if (map_value_has_timer(map)) {
-		u32 t = map->timer_off;
-
-		if (reg->smin_value + off < t + sizeof(struct bpf_timer) &&
-		     t < reg->umax_value + off + size) {
-			verbose(env, "bpf_timer cannot be accessed directly by load/store\n");
-			return -EACCES;
-		}
-	}
 	if (IS_ERR_OR_NULL(map->record))
 		return 0;
 	rec = map->record;
@@ -3847,6 +3824,10 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
 		struct btf_field *field = &rec->fields[i];
 		u32 p = field->offset;
 
+		/* If any part of a field  can be touched by load/store, reject
+		 * this program. To check that [x1, x2) overlaps with [y1, y2),
+		 * it is sufficient to check x1 < y2 && y1 < x2.
+		 */
 		if (reg->smin_value + off < p + btf_field_type_size(field->type) &&
 		    p < reg->umax_value + off + size) {
 			switch (field->type) {
@@ -3871,7 +3852,8 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
 				}
 				break;
 			default:
-				verbose(env, "field cannot be accessed directly by load/store\n");
+				verbose(env, "%s cannot be accessed directly by load/store\n",
+					btf_field_type_name(field->type));
 				return -EACCES;
 			}
 		}
@@ -5440,24 +5422,13 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno,
 			map->name);
 		return -EINVAL;
 	}
-	if (!map_value_has_spin_lock(map)) {
-		if (map->spin_lock_off == -E2BIG)
-			verbose(env,
-				"map '%s' has more than one 'struct bpf_spin_lock'\n",
-				map->name);
-		else if (map->spin_lock_off == -ENOENT)
-			verbose(env,
-				"map '%s' doesn't have 'struct bpf_spin_lock'\n",
-				map->name);
-		else
-			verbose(env,
-				"map '%s' is not a struct type or bpf_spin_lock is mangled\n",
-				map->name);
+	if (!btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
+		verbose(env, "map '%s' has no valid bpf_spin_lock\n", map->name);
 		return -EINVAL;
 	}
-	if (map->spin_lock_off != val + reg->off) {
-		verbose(env, "off %lld doesn't point to 'struct bpf_spin_lock'\n",
-			val + reg->off);
+	if (map->record->spin_lock_off != val + reg->off) {
+		verbose(env, "off %lld doesn't point to 'struct bpf_spin_lock' that is at %d\n",
+			val + reg->off, map->record->spin_lock_off);
 		return -EINVAL;
 	}
 	if (is_lock) {
@@ -5500,24 +5471,13 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
 			map->name);
 		return -EINVAL;
 	}
-	if (!map_value_has_timer(map)) {
-		if (map->timer_off == -E2BIG)
-			verbose(env,
-				"map '%s' has more than one 'struct bpf_timer'\n",
-				map->name);
-		else if (map->timer_off == -ENOENT)
-			verbose(env,
-				"map '%s' doesn't have 'struct bpf_timer'\n",
-				map->name);
-		else
-			verbose(env,
-				"map '%s' is not a struct type or bpf_timer is mangled\n",
-				map->name);
+	if (!btf_record_has_field(map->record, BPF_TIMER)) {
+		verbose(env, "map '%s' has no valid bpf_timer\n", map->name);
 		return -EINVAL;
 	}
-	if (map->timer_off != val + reg->off) {
+	if (map->record->timer_off != val + reg->off) {
 		verbose(env, "off %lld doesn't point to 'struct bpf_timer' that is at %d\n",
-			val + reg->off, map->timer_off);
+			val + reg->off, map->record->timer_off);
 		return -EINVAL;
 	}
 	if (meta->map_ptr) {
@@ -7470,7 +7430,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 		regs[BPF_REG_0].map_uid = meta.map_uid;
 		regs[BPF_REG_0].type = PTR_TO_MAP_VALUE | ret_flag;
 		if (!type_may_be_null(ret_type) &&
-		    map_value_has_spin_lock(meta.map_ptr)) {
+		    btf_record_has_field(meta.map_ptr->record, BPF_SPIN_LOCK)) {
 			regs[BPF_REG_0].id = ++env->id_gen;
 		}
 		break;
@@ -10381,7 +10341,7 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
 	    insn->src_reg == BPF_PSEUDO_MAP_IDX_VALUE) {
 		dst_reg->type = PTR_TO_MAP_VALUE;
 		dst_reg->off = aux->map_off;
-		if (map_value_has_spin_lock(map))
+		if (btf_record_has_field(map->record, BPF_SPIN_LOCK))
 			dst_reg->id = ++env->id_gen;
 	} else if (insn->src_reg == BPF_PSEUDO_MAP_FD ||
 		   insn->src_reg == BPF_PSEUDO_MAP_IDX) {
@@ -12659,7 +12619,7 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 {
 	enum bpf_prog_type prog_type = resolve_prog_type(prog);
 
-	if (map_value_has_spin_lock(map)) {
+	if (btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
 		if (prog_type == BPF_PROG_TYPE_SOCKET_FILTER) {
 			verbose(env, "socket filter progs cannot use bpf_spin_lock yet\n");
 			return -EINVAL;
@@ -12676,7 +12636,7 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
 		}
 	}
 
-	if (map_value_has_timer(map)) {
+	if (btf_record_has_field(map->record, BPF_TIMER)) {
 		if (is_tracing_prog_type(prog_type)) {
 			verbose(env, "tracing progs cannot use bpf_timer yet\n");
 			return -EINVAL;

net/core/bpf_sk_storage.c

@@ -147,7 +147,7 @@ bpf_sk_storage_clone_elem(struct sock *newsk,
 	if (!copy_selem)
 		return NULL;
 
-	if (map_value_has_spin_lock(&smap->map))
+	if (btf_record_has_field(smap->map.record, BPF_SPIN_LOCK))
 		copy_map_value_locked(&smap->map, SDATA(copy_selem)->data,
 				      SDATA(selem)->data, true);
 	else
@@ -566,7 +566,7 @@ static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb)
 	if (!nla_value)
 		goto errout;
 
-	if (map_value_has_spin_lock(&smap->map))
+	if (btf_record_has_field(smap->map.record, BPF_SPIN_LOCK))
 		copy_map_value_locked(&smap->map, nla_data(nla_value),
 				      sdata->data, true);
 	else