1 files changed, 187 insertions, 29 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2c4cfeaa8d5e..e24aa3241387 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -94,18 +94,34 @@ static int check_uarg_tail_zero(void __user *uaddr,
 	return 0;
 }
 
+const struct bpf_map_ops bpf_map_offload_ops = {
+	.map_alloc = bpf_map_offload_map_alloc,
+	.map_free = bpf_map_offload_map_free,
+};
+
 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 {
+	const struct bpf_map_ops *ops;
 	struct bpf_map *map;
+	int err;
 
-	if (attr->map_type >= ARRAY_SIZE(bpf_map_types) ||
-	    !bpf_map_types[attr->map_type])
+	if (attr->map_type >= ARRAY_SIZE(bpf_map_types))
+		return ERR_PTR(-EINVAL);
+	ops = bpf_map_types[attr->map_type];
+	if (!ops)
 		return ERR_PTR(-EINVAL);
 
-	map = bpf_map_types[attr->map_type]->map_alloc(attr);
+	if (ops->map_alloc_check) {
+		err = ops->map_alloc_check(attr);
+		if (err)
+			return ERR_PTR(err);
+	}
+	if (attr->map_ifindex)
+		ops = &bpf_map_offload_ops;
+	map = ops->map_alloc(attr);
 	if (IS_ERR(map))
 		return map;
-	map->ops = bpf_map_types[attr->map_type];
+	map->ops = ops;
 	map->map_type = attr->map_type;
 	return map;
 }
@@ -134,6 +150,16 @@ void bpf_map_area_free(void *area)
 	kvfree(area);
 }
 
+void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
+{
+	map->map_type = attr->map_type;
+	map->key_size = attr->key_size;
+	map->value_size = attr->value_size;
+	map->max_entries = attr->max_entries;
+	map->map_flags = attr->map_flags;
+	map->numa_node = bpf_map_attr_numa_node(attr);
+}
+
 int bpf_map_precharge_memlock(u32 pages)
 {
 	struct user_struct *user = get_current_user();
@@ -189,16 +215,25 @@ static int bpf_map_alloc_id(struct bpf_map *map)
 	return id > 0 ? 0 : id;
 }
 
-static void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
+void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
 {
 	unsigned long flags;
 
+	/* Offloaded maps are removed from the IDR store when their device
+	 * disappears - even if someone holds an fd to them they are unusable,
+	 * the memory is gone, all ops will fail; they are simply waiting for
+	 * refcnt to drop to be freed.
+	 */
+	if (!map->id)
+		return;
+
 	if (do_idr_lock)
 		spin_lock_irqsave(&map_idr_lock, flags);
 	else
 		__acquire(&map_idr_lock);
 
 	idr_remove(&map_idr, map->id);
+	map->id = 0;
 
 	if (do_idr_lock)
 		spin_unlock_irqrestore(&map_idr_lock, flags);
@@ -378,7 +413,7 @@ static int bpf_obj_name_cpy(char *dst, const char *src)
 	return 0;
 }
 
-#define BPF_MAP_CREATE_LAST_FIELD map_name
+#define BPF_MAP_CREATE_LAST_FIELD map_ifindex
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
@@ -566,8 +601,10 @@ static int map_lookup_elem(union bpf_attr *attr)
 	if (!value)
 		goto free_key;
 
-	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
-	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_lookup_elem(map, key, value);
+	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
+		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
 		err = bpf_percpu_hash_copy(map, key, value);
 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
 		err = bpf_percpu_array_copy(map, key, value);
@@ -654,7 +691,10 @@ static int map_update_elem(union bpf_attr *attr)
 		goto free_value;
 
 	/* Need to create a kthread, thus must support schedule */
-	if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_update_elem(map, key, value, attr->flags);
+		goto out;
+	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
 		err = map->ops->map_update_elem(map, key, value, attr->flags);
 		goto out;
 	}
@@ -669,10 +709,7 @@ static int map_update_elem(union bpf_attr *attr)
 		err = bpf_percpu_hash_update(map, key, value, attr->flags);
 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
 		err = bpf_percpu_array_update(map, key, value, attr->flags);
-	} else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||
-		   map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
-		   map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY ||
-		   map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) {
+	} else if (IS_FD_ARRAY(map)) {
 		rcu_read_lock();
 		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
 						   attr->flags);
@@ -731,6 +768,11 @@ static int map_delete_elem(union bpf_attr *attr)
 		goto err_put;
 	}
 
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_delete_elem(map, key);
+		goto out;
+	}
+
 	preempt_disable();
 	__this_cpu_inc(bpf_prog_active);
 	rcu_read_lock();
@@ -738,7 +780,7 @@ static int map_delete_elem(union bpf_attr *attr)
 	rcu_read_unlock();
 	__this_cpu_dec(bpf_prog_active);
 	preempt_enable();
-
+out:
 	if (!err)
 		trace_bpf_map_delete_elem(map, ufd, key);
 	kfree(key);
@@ -788,9 +830,15 @@ static int map_get_next_key(union bpf_attr *attr)
 	if (!next_key)
 		goto free_key;
 
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_get_next_key(map, key, next_key);
+		goto out;
+	}
+
 	rcu_read_lock();
 	err = map->ops->map_get_next_key(map, key, next_key);
 	rcu_read_unlock();
+out:
 	if (err)
 		goto free_next_key;
 
@@ -905,9 +953,13 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog)
 	return id > 0 ? 0 : id;
 }
 
-static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
+void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
 {
-	/* cBPF to eBPF migrations are currently not in the idr store. */
+	/* cBPF to eBPF migrations are currently not in the idr store.
+	 * Offloaded programs are removed from the store when their device
+	 * disappears - even if someone grabs an fd to them they are unusable,
+	 * simply waiting for refcnt to drop to be freed.
+	 */
 	if (!prog->aux->id)
 		return;
 
@@ -917,6 +969,7 @@ static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
 		__acquire(&prog_idr_lock);
 
 	idr_remove(&prog_idr, prog->aux->id);
+	prog->aux->id = 0;
 
 	if (do_idr_lock)
 		spin_unlock_bh(&prog_idr_lock);
@@ -937,10 +990,16 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
 {
 	if (atomic_dec_and_test(&prog->aux->refcnt)) {
+		int i;
+
 		trace_bpf_prog_put_rcu(prog);
 		/* bpf_prog_free_id() must be called first */
 		bpf_prog_free_id(prog, do_idr_lock);
+
+		for (i = 0; i < prog->aux->func_cnt; i++)
+			bpf_prog_kallsyms_del(prog->aux->func[i]);
 		bpf_prog_kallsyms_del(prog);
+
 		call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
 	}
 }
@@ -1057,7 +1116,7 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
 }
 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
 
-static bool bpf_prog_get_ok(struct bpf_prog *prog,
+bool bpf_prog_get_ok(struct bpf_prog *prog,
 			    enum bpf_prog_type *attach_type, bool attach_drv)
 {
 	/* not an attachment, just a refcount inc, always allow */
@@ -1151,6 +1210,8 @@ static int bpf_prog_load(union bpf_attr *attr)
 	if (!prog)
 		return -ENOMEM;
 
+	prog->aux->offload_requested = !!attr->prog_ifindex;
+
 	err = security_bpf_prog_alloc(prog->aux);
 	if (err)
 		goto free_prog_nouncharge;
@@ -1172,7 +1233,7 @@ static int bpf_prog_load(union bpf_attr *attr)
 	atomic_set(&prog->aux->refcnt, 1);
 	prog->gpl_compatible = is_gpl ? 1 : 0;
 
-	if (attr->prog_ifindex) {
+	if (bpf_prog_is_dev_bound(prog->aux)) {
 		err = bpf_prog_offload_init(prog, attr);
 		if (err)
 			goto free_prog;
@@ -1194,7 +1255,8 @@ static int bpf_prog_load(union bpf_attr *attr)
 		goto free_used_maps;
 
 	/* eBPF program is ready to be JITed */
-	prog = bpf_prog_select_runtime(prog, &err);
+	if (!prog->bpf_func)
+		prog = bpf_prog_select_runtime(prog, &err);
 	if (err < 0)
 		goto free_used_maps;
 
@@ -1439,6 +1501,8 @@ static int bpf_prog_test_run(const union bpf_attr *attr,
 	struct bpf_prog *prog;
 	int ret = -ENOTSUPP;
 
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
 		return -EINVAL;
 
@@ -1551,6 +1615,67 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
 	return fd;
 }
 
+static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
+					      unsigned long addr)
+{
+	int i;
+
+	for (i = 0; i < prog->aux->used_map_cnt; i++)
+		if (prog->aux->used_maps[i] == (void *)addr)
+			return prog->aux->used_maps[i];
+	return NULL;
+}
+
+static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
+{
+	const struct bpf_map *map;
+	struct bpf_insn *insns;
+	u64 imm;
+	int i;
+
+	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
+			GFP_USER);
+	if (!insns)
+		return insns;
+
+	for (i = 0; i < prog->len; i++) {
+		if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
+			insns[i].code = BPF_JMP | BPF_CALL;
+			insns[i].imm = BPF_FUNC_tail_call;
+			/* fall-through */
+		}
+		if (insns[i].code == (BPF_JMP | BPF_CALL) ||
+		    insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
+			if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
+				insns[i].code = BPF_JMP | BPF_CALL;
+			if (!bpf_dump_raw_ok())
+				insns[i].imm = 0;
+			continue;
+		}
+
+		if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
+			continue;
+
+		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
+		map = bpf_map_from_imm(prog, imm);
+		if (map) {
+			insns[i].src_reg = BPF_PSEUDO_MAP_FD;
+			insns[i].imm = map->id;
+			insns[i + 1].imm = 0;
+			continue;
+		}
+
+		if (!bpf_dump_raw_ok() &&
+		    imm == (unsigned long)prog->aux) {
+			insns[i].imm = 0;
+			insns[i + 1].imm = 0;
+			continue;
+		}
+	}
+
+	return insns;
+}
+
 static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
 				   const union bpf_attr *attr,
 				   union bpf_attr __user *uattr)
@@ -1598,24 +1723,51 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
 		goto done;
 	}
 
-	ulen = info.jited_prog_len;
-	info.jited_prog_len = prog->jited_len;
-	if (info.jited_prog_len && ulen) {
-		uinsns = u64_to_user_ptr(info.jited_prog_insns);
-		ulen = min_t(u32, info.jited_prog_len, ulen);
-		if (copy_to_user(uinsns, prog->bpf_func, ulen))
-			return -EFAULT;
-	}
-
 	ulen = info.xlated_prog_len;
 	info.xlated_prog_len = bpf_prog_insn_size(prog);
 	if (info.xlated_prog_len && ulen) {
+		struct bpf_insn *insns_sanitized;
+		bool fault;
+
+		if (prog->blinded && !bpf_dump_raw_ok()) {
+			info.xlated_prog_insns = 0;
+			goto done;
+		}
+		insns_sanitized = bpf_insn_prepare_dump(prog);
+		if (!insns_sanitized)
+			return -ENOMEM;
 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
 		ulen = min_t(u32, info.xlated_prog_len, ulen);
-		if (copy_to_user(uinsns, prog->insnsi, ulen))
+		fault = copy_to_user(uinsns, insns_sanitized, ulen);
+		kfree(insns_sanitized);
+		if (fault)
 			return -EFAULT;
 	}
 
+	if (bpf_prog_is_dev_bound(prog->aux)) {
+		err = bpf_prog_offload_info_fill(&info, prog);
+		if (err)
+			return err;
+		goto done;
+	}
+
+	/* NOTE: the following code is supposed to be skipped for offload.
+	 * bpf_prog_offload_info_fill() is the place to fill similar fields
+	 * for offload.
+	 */
+	ulen = info.jited_prog_len;
+	info.jited_prog_len = prog->jited_len;
+	if (info.jited_prog_len && ulen) {
+		if (bpf_dump_raw_ok()) {
+			uinsns = u64_to_user_ptr(info.jited_prog_insns);
+			ulen = min_t(u32, info.jited_prog_len, ulen);
+			if (copy_to_user(uinsns, prog->bpf_func, ulen))
+				return -EFAULT;
+		} else {
+			info.jited_prog_insns = 0;
+		}
+	}
+
 done:
 	if (copy_to_user(uinfo, &info, info_len) ||
 	    put_user(info_len, &uattr->info.info_len))
@@ -1646,6 +1798,12 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map,
 	info.map_flags = map->map_flags;
 	memcpy(info.name, map->name, sizeof(map->name));
 
+	if (bpf_map_is_dev_bound(map)) {
+		err = bpf_map_offload_info_fill(&info, map);
+		if (err)
+			return err;
+	}
+
 	if (copy_to_user(uinfo, &info, info_len) ||
 	    put_user(info_len, &uattr->info.info_len))
 		return -EFAULT;