Tvm v9

crypto/block/mc-config.cpp

@@ -2292,7 +2292,8 @@ Ref<vm::Cell> ConfigInfo::lookup_library(td::ConstBitPtr root_hash) const {
 td::Result<Ref<vm::Tuple>> ConfigInfo::get_prev_blocks_info() const {
   // [ wc:Integer shard:Integer seqno:Integer root_hash:Integer file_hash:Integer] = BlockId;
   // [ last_mc_blocks:[BlockId...]
-  //   prev_key_block:BlockId ] : PrevBlocksInfo
+  //   prev_key_block:BlockId
+  //   last_mc_blocks_100[BlockId...] ] : PrevBlocksInfo
   auto block_id_to_tuple = [](const ton::BlockIdExt& block_id) -> vm::Ref<vm::Tuple> {
     td::RefInt256 shard = td::make_refint(block_id.id.shard);
     if (shard->sgn() < 0) {
@@ -2302,25 +2303,44 @@ td::Result<Ref<vm::Tuple>> ConfigInfo::get_prev_blocks_info() const {
                               td::make_refint(block_id.id.seqno), td::bits_to_refint(block_id.root_hash.bits(), 256),
                               td::bits_to_refint(block_id.file_hash.bits(), 256));
   };
-  std::vector<vm::StackEntry> last_mc_blocks;
+  std::vector<vm::StackEntry> tuple;
 
+  std::vector<vm::StackEntry> last_mc_blocks;
   last_mc_blocks.push_back(block_id_to_tuple(block_id));
   for (ton::BlockSeqno seqno = block_id.id.seqno; seqno > 0 && last_mc_blocks.size() < 16;) {
     --seqno;
-    ton::BlockIdExt block_id;
-    if (!get_old_mc_block_id(seqno, block_id)) {
+    ton::BlockIdExt id;
+    if (!get_old_mc_block_id(seqno, id)) {
       return td::Status::Error("cannot fetch old mc block");
     }
-    last_mc_blocks.push_back(block_id_to_tuple(block_id));
+    last_mc_blocks.push_back(block_id_to_tuple(id));
   }
+  tuple.push_back(td::make_cnt_ref<std::vector<vm::StackEntry>>(std::move(last_mc_blocks)));
 
   ton::BlockIdExt last_key_block;
   ton::LogicalTime last_key_block_lt;
   if (!get_last_key_block(last_key_block, last_key_block_lt)) {
     return td::Status::Error("cannot fetch last key block");
   }
-  return vm::make_tuple_ref(td::make_cnt_ref<std::vector<vm::StackEntry>>(std::move(last_mc_blocks)),
-                            block_id_to_tuple(last_key_block));
+  tuple.push_back(block_id_to_tuple(last_key_block));
+
+  if (get_global_version() >= 9) {
+    std::vector<vm::StackEntry> last_mc_blocks_100;
+    for (ton::BlockSeqno seqno = block_id.id.seqno / 100 * 100; last_mc_blocks_100.size() < 16;) {
+      ton::BlockIdExt id;
+      if (!get_old_mc_block_id(seqno, id)) {
+        return td::Status::Error("cannot fetch old mc block");
+      }
+      last_mc_blocks_100.push_back(block_id_to_tuple(id));
+      if (seqno < 100) {
+        break;
+      }
+      seqno -= 100;
+    }
+    tuple.push_back(td::make_cnt_ref<std::vector<vm::StackEntry>>(std::move(last_mc_blocks_100)));
+  }
+
+  return td::make_cnt_ref<std::vector<vm::StackEntry>>(std::move(tuple));
 }
 
 td::optional<PrecompiledContractsConfig::Contract> PrecompiledContractsConfig::get_contract(

crypto/block/transaction.cpp

@@ -1145,31 +1145,64 @@ td::RefInt256 ComputePhaseConfig::compute_gas_price(td::uint64 gas_used) const {
 namespace transaction {
 
 /**
- * Checks if it is required to increase gas_limit (from GasLimitsPrices config) to special_gas_limit * 2
- * from masterchain GasLimitsPrices config for the transaction.
+ * Checks if it is required to increase gas_limit (from GasLimitsPrices config) for the transaction
  *
  * In January 2024 a highload wallet of @wallet Telegram bot in mainnet was stuck because current gas limit (1M) is
  * not enough to clean up old queires, thus locking funds inside.
  * See comment in crypto/smartcont/highload-wallet-v2-code.fc for details on why this happened.
  * Account address: EQD_v9j1rlsuHHw2FIhcsCFFSD367ldfDdCKcsNmNpIRzUlu
- * It was proposed to validators to increase gas limit for this account for a limited amount of time (until 2024-02-29).
+ * It was proposed to validators to increase gas limit for this account to 70M for a limited amount
+ * of time (until 2024-02-29).
  * It is activated by setting global version to 5 in ConfigParam 8.
  * This config change also activates new behavior for special accounts in masterchain.
  *
+ * In Augost 2024 it was decided to unlock other old highload wallets that got into the same situation.
+ * See https://t.me/tondev_news/129
+ * It is activated by setting global version to 9.
+ *
  * @param cfg The compute phase configuration.
  * @param now The Unix time of the transaction.
  * @param account The account of the transaction.
  *
- * @returns True if gas_limit override is required, false otherwise
+ * @returns Overridden gas limit or empty td::optional
  */
-static bool override_gas_limit(const ComputePhaseConfig& cfg, ton::UnixTime now, const Account& account) {
-  if (!cfg.special_gas_full) {
-    return false;
+static td::optional<td::uint64> override_gas_limit(const ComputePhaseConfig& cfg, ton::UnixTime now,
+                                                   const Account& account) {
+  struct OverridenGasLimit {
+    td::uint64 new_limit;
+    int from_version;
+    ton::UnixTime until;
+  };
+  static std::map<std::pair<ton::WorkchainId, ton::StdSmcAddress>, OverridenGasLimit> accounts = []() {
+    auto parse_addr = [](const char* s) -> std::pair<ton::WorkchainId, ton::StdSmcAddress> {
+      auto r_addr = StdAddress::parse(td::Slice(s));
+      r_addr.ensure();
+      return {r_addr.ok().workchain, r_addr.ok().addr};
+    };
+    std::map<std::pair<ton::WorkchainId, ton::StdSmcAddress>, OverridenGasLimit> accounts;
+
+    // Increase limit for EQD_v9j1rlsuHHw2FIhcsCFFSD367ldfDdCKcsNmNpIRzUlu until 2024-02-29 00:00:00 UTC
+    accounts[parse_addr("0:FFBFD8F5AE5B2E1C7C3614885CB02145483DFAEE575F0DD08A72C366369211CD")] = {
+        .new_limit = 70'000'000, .from_version = 5, .until = 1709164800};
+
+    // Increase limit for multiple accounts (https://t.me/tondev_news/129) until 2025-03-01 00:00:00 UTC
+    accounts[parse_addr("UQBeSl-dumOHieZ3DJkNKVkjeso7wZ0VpzR4LCbLGTQ8xr57")] = {
+        .new_limit = 70'000'000, .from_version = 9, .until = 1740787200};
+    accounts[parse_addr("EQC3VcQ-43klww9UfimR58TBjBzk7GPupXQ3CNuthoNp-uTR")] = {
+        .new_limit = 70'000'000, .from_version = 9, .until = 1740787200};
+    accounts[parse_addr("EQBhwBb8jvokGvfreHRRoeVxI237PrOJgyrsAhLA-4rBC_H5")] = {
+        .new_limit = 70'000'000, .from_version = 9, .until = 1740787200};
+    accounts[parse_addr("EQCkoRp4OE-SFUoMEnYfL3vF43T3AzNfW8jyTC4yzk8cJqMS")] = {
+        .new_limit = 70'000'000, .from_version = 9, .until = 1740787200};
+    accounts[parse_addr("EQBDanbCeUqI4_v-xrnAN0_I2wRvEIaLg1Qg2ZN5c6Zl1KOh")] = {
+        .new_limit = 225'000'000, .from_version = 9, .until = 1740787200};
+    return accounts;
+  }();
+  auto it = accounts.find({account.workchain, account.addr});
+  if (it == accounts.end() || cfg.global_version < it->second.from_version || now >= it->second.until) {
+    return {};
   }
-  ton::UnixTime until = 1709164800;  // 2024-02-29 00:00:00 UTC
-  ton::WorkchainId wc = 0;
-  const char* addr_hex = "FFBFD8F5AE5B2E1C7C3614885CB02145483DFAEE575F0DD08A72C366369211CD";
-  return now < until && account.workchain == wc && account.addr.to_hex() == addr_hex;
+  return it->second.new_limit;
 }
 
 /**
@@ -1183,10 +1216,12 @@ static bool override_gas_limit(const ComputePhaseConfig& cfg, ton::UnixTime now,
  * @returns The amount of gas.
  */
 td::uint64 Transaction::gas_bought_for(const ComputePhaseConfig& cfg, td::RefInt256 nanograms) {
-  if (override_gas_limit(cfg, now, account)) {
+  if (auto new_limit = override_gas_limit(cfg, now, account)) {
     gas_limit_overridden = true;
     // Same as ComputePhaseConfig::gas_bought for, but with other gas_limit and max_gas_threshold
-    auto gas_limit = cfg.mc_gas_prices.special_gas_limit * 2;
+    auto gas_limit = new_limit.value();
+    LOG(INFO) << "overridding gas limit for account " << account.workchain << ":" << account.addr.to_hex() << " to "
+              << gas_limit;
     auto max_gas_threshold =
         compute_max_gas_threshold(cfg.gas_price256, gas_limit, cfg.flat_gas_limit, cfg.flat_gas_price);
     if (nanograms.is_null() || sgn(nanograms) < 0) {
@@ -1336,7 +1371,8 @@ Ref<vm::Tuple> Transaction::prepare_vm_c7(const ComputePhaseConfig& cfg) const {
     // See crypto/block/mc-config.cpp#2223 (get_prev_blocks_info)
     // [ wc:Integer shard:Integer seqno:Integer root_hash:Integer file_hash:Integer] = BlockId;
     // [ last_mc_blocks:[BlockId...]
-    //   prev_key_block:BlockId ] : PrevBlocksInfo
+    //   prev_key_block:BlockId
+    //   last_mc_blocks_100:[BlockId...] ] : PrevBlocksInfo
     // The only context where PrevBlocksInfo (13 parameter of c7) is null is inside emulator
     // where it need to be set via transaction_emulator_set_prev_blocks_info (see emulator/emulator-extern.cpp)
     // Inside validator, collator and liteserver checking external message  contexts
@@ -1691,9 +1727,8 @@ bool Transaction::prepare_compute_phase(const ComputePhaseConfig& cfg) {
       }
     }
   }
-  vm::VmState vm{new_code, std::move(stack), gas, 1, new_data, vm_log, compute_vm_libraries(cfg)};
+  vm::VmState vm{new_code, cfg.global_version, std::move(stack), gas, 1, new_data, vm_log, compute_vm_libraries(cfg)};
   vm.set_max_data_depth(cfg.max_vm_data_depth);
-  vm.set_global_version(cfg.global_version);
   vm.set_c7(prepare_vm_c7(cfg));  // tuple with SmartContractInfo
   vm.set_chksig_always_succeed(cfg.ignore_chksig);
   vm.set_stop_on_accept_message(cfg.stop_on_accept_message);

crypto/fift/lib/Asm.fif

@@ -1312,6 +1312,7 @@ x{F832} @Defop CONFIGPARAM
 x{F833} @Defop CONFIGOPTPARAM
 x{F83400} @Defop PREVMCBLOCKS
 x{F83401} @Defop PREVKEYBLOCK
+x{F83402} @Defop PREVMCBLOCKS_100
 x{F835} @Defop GLOBALID
 x{F836} @Defop GETGASFEE
 x{F837} @Defop GETSTORAGEFEE

crypto/smc-envelope/SmartContract.cpp

@@ -223,14 +223,14 @@ SmartContract::Answer run_smartcont(SmartContract::State state, td::Ref<vm::Stac
     stack->dump(os, 2);
     LOG(DEBUG) << "VM stack:\n" << os.str();
   }
-  vm::VmState vm{state.code, std::move(stack), gas, 1, state.data, log};
+  int global_version = config ? config->get_global_version() : 0;
+  vm::VmState vm{state.code, global_version, std::move(stack), gas, 1, state.data, log};
   vm.set_c7(std::move(c7));
   vm.set_chksig_always_succeed(ignore_chksig);
   if (!libraries.is_null()) {
     vm.register_library_collection(libraries);
   }
   if (config) {
-    vm.set_global_version(config->get_global_version());
     auto r_limits = config->get_size_limits_config();
     if (r_limits.is_ok()) {
       vm.set_max_data_depth(r_limits.ok().max_vm_data_depth);

crypto/vm/contops.cpp

@@ -261,10 +261,10 @@ int exec_runvm_common(VmState* st, unsigned mode) {
   vm::GasLimits gas{gas_limit, gas_max};
 
   VmStateInterface::Guard guard{nullptr}; // Don't consume gas for creating/loading cells during VM init
-  VmState new_state{std::move(code), std::move(new_stack),     gas,          (int)mode & 3, std::move(data),
-                    VmLog{},         std::vector<Ref<Cell>>{}, std::move(c7)};
+  VmState new_state{
+      std::move(code), st->get_global_version(), std::move(new_stack), gas, (int)mode & 3, std::move(data),
+      VmLog{},         std::vector<Ref<Cell>>{}, std::move(c7)};
   new_state.set_chksig_always_succeed(st->get_chksig_always_succeed());
-  new_state.set_global_version(st->get_global_version());
   st->run_child_vm(std::move(new_state), with_data, mode & 32, mode & 8, mode & 128, ret_vals);
   return 0;
 }

crypto/vm/dictops.cpp

@@ -566,7 +566,7 @@ int exec_dict_getnear(VmState* st, unsigned args) {
 int exec_pfx_dict_set(VmState* st, Dictionary::SetMode mode, const char* name) {
   Stack& stack = st->get_stack();
   VM_LOG(st) << "execute PFXDICT" << name;
-  stack.check_underflow(3);
+  stack.check_underflow(st->get_global_version() >= 9 ? 4 : 3);
   int n = stack.pop_smallint_range(PrefixDictionary::max_key_bits);
   PrefixDictionary dict{stack.pop_maybe_cell(), n};
   auto key_slice = stack.pop_cellslice();
@@ -580,7 +580,7 @@ int exec_pfx_dict_set(VmState* st, Dictionary::SetMode mode, const char* name) {
 int exec_pfx_dict_delete(VmState* st) {
   Stack& stack = st->get_stack();
   VM_LOG(st) << "execute PFXDICTDEL\n";
-  stack.check_underflow(2);
+  stack.check_underflow(st->get_global_version() >= 9 ? 3 : 2);
   int n = stack.pop_smallint_range(PrefixDictionary::max_key_bits);
   PrefixDictionary dict{stack.pop_maybe_cell(), n};
   auto key_slice = stack.pop_cellslice();

crypto/vm/tonops.cpp

@@ -279,6 +279,7 @@ int exec_get_global_id(VmState* st) {
 int exec_get_gas_fee(VmState* st) {
   VM_LOG(st) << "execute GETGASFEE";
   Stack& stack = st->get_stack();
+  stack.check_underflow(st->get_global_version() >= 9 ? 2 : 0);
   bool is_masterchain = stack.pop_bool();
   td::uint64 gas = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
   block::GasLimitsPrices prices = util::get_gas_prices(get_unpacked_config_tuple(st), is_masterchain);
@@ -289,6 +290,7 @@ int exec_get_gas_fee(VmState* st) {
 int exec_get_storage_fee(VmState* st) {
   VM_LOG(st) << "execute GETSTORAGEFEE";
   Stack& stack = st->get_stack();
+  stack.check_underflow(st->get_global_version() >= 9 ? 4 : 0);
   bool is_masterchain = stack.pop_bool();
   td::int64 delta = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
   td::uint64 bits = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
@@ -302,6 +304,7 @@ int exec_get_storage_fee(VmState* st) {
 int exec_get_forward_fee(VmState* st) {
   VM_LOG(st) << "execute GETFORWARDFEE";
   Stack& stack = st->get_stack();
+  stack.check_underflow(st->get_global_version() >= 9 ? 3 : 0);
   bool is_masterchain = stack.pop_bool();
   td::uint64 bits = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
   td::uint64 cells = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
@@ -320,6 +323,7 @@ int exec_get_precompiled_gas(VmState* st) {
 int exec_get_original_fwd_fee(VmState* st) {
   VM_LOG(st) << "execute GETORIGINALFWDFEE";
   Stack& stack = st->get_stack();
+  stack.check_underflow(st->get_global_version() >= 9 ? 2 : 0);
   bool is_masterchain = stack.pop_bool();
   td::RefInt256 fwd_fee = stack.pop_int_finite();
   if (fwd_fee->sgn() < 0) {
@@ -333,6 +337,7 @@ int exec_get_original_fwd_fee(VmState* st) {
 int exec_get_gas_fee_simple(VmState* st) {
   VM_LOG(st) << "execute GETGASFEESIMPLE";
   Stack& stack = st->get_stack();
+  stack.check_underflow(st->get_global_version() >= 9 ? 2 : 0);
   bool is_masterchain = stack.pop_bool();
   td::uint64 gas = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
   block::GasLimitsPrices prices = util::get_gas_prices(get_unpacked_config_tuple(st), is_masterchain);
@@ -343,6 +348,7 @@ int exec_get_gas_fee_simple(VmState* st) {
 int exec_get_forward_fee_simple(VmState* st) {
   VM_LOG(st) << "execute GETFORWARDFEESIMPLE";
   Stack& stack = st->get_stack();
+  stack.check_underflow(st->get_global_version() >= 9 ? 3 : 0);
   bool is_masterchain = stack.pop_bool();
   td::uint64 bits = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
   td::uint64 cells = stack.pop_long_range(std::numeric_limits<td::int64>::max(), 0);
@@ -373,6 +379,7 @@ void register_ton_config_ops(OpcodeTable& cp0) {
       .insert(OpcodeInstr::mksimple(0xf833, 16, "CONFIGOPTPARAM", std::bind(exec_get_config_param, _1, true)))
       .insert(OpcodeInstr::mksimple(0xf83400, 24, "PREVMCBLOCKS", std::bind(exec_get_prev_blocks_info, _1, 0, "PREVMCBLOCKS"))->require_version(4))
       .insert(OpcodeInstr::mksimple(0xf83401, 24, "PREVKEYBLOCK", std::bind(exec_get_prev_blocks_info, _1, 1, "PREVKEYBLOCK"))->require_version(4))
+      .insert(OpcodeInstr::mksimple(0xf83402, 24, "PREVMCBLOCKS_100", std::bind(exec_get_prev_blocks_info, _1, 2, "PREVMCBLOCKS_100"))->require_version(9))
       .insert(OpcodeInstr::mksimple(0xf835, 16, "GLOBALID", exec_get_global_id)->require_version(4))
       .insert(OpcodeInstr::mksimple(0xf836, 16, "GETGASFEE", exec_get_gas_fee)->require_version(6))
       .insert(OpcodeInstr::mksimple(0xf837, 16, "GETSTORAGEFEE", exec_get_storage_fee)->require_version(6))
@@ -538,9 +545,10 @@ int exec_hash_ext(VmState* st, unsigned args) {
   VM_LOG(st) << "execute HASHEXT" << (append ? "A" : "") << (rev ? "R" : "") << " " << (hash_id == 255 ? -1 : hash_id);
   Stack& stack = st->get_stack();
   if (hash_id == 255) {
+    stack.check_underflow(st->get_global_version() >= 9 ? 2 : 0);
     hash_id = stack.pop_smallint_range(254);
   }
-  int cnt = stack.pop_smallint_range(stack.depth() - 1);
+  int cnt = stack.pop_smallint_range(stack.depth() - 1 - (st->get_global_version() >= 9 ? (int)append : 0));
   Hasher hasher{hash_id};
   size_t total_bits = 0;
   long long gas_consumed = 0;

crypto/vm/vm.cpp

@@ -22,6 +22,8 @@
 #include "vm/log.h"
 #include "vm/vm.h"
 #include "cp0.h"
+#include "memo.h"
+
 #include <sodium.h>
 
 namespace vm {
@@ -31,33 +33,8 @@ VmState::VmState() : cp(-1), dispatch(&dummy_dispatch_table), quit0(true, 0), qu
   init_cregs();
 }
 
-VmState::VmState(Ref<CellSlice> _code)
-    : code(std::move(_code)), cp(-1), dispatch(&dummy_dispatch_table), quit0(true, 0), quit1(true, 1) {
-  ensure_throw(init_cp(0));
-  init_cregs();
-}
-
-VmState::VmState(Ref<CellSlice> _code, Ref<Stack> _stack, int flags, Ref<Cell> _data, VmLog log,
-                 std::vector<Ref<Cell>> _libraries, Ref<Tuple> init_c7)
-    : code(std::move(_code))
-    , stack(std::move(_stack))
-    , cp(-1)
-    , dispatch(&dummy_dispatch_table)
-    , quit0(true, 0)
-    , quit1(true, 1)
-    , log(log)
-    , libraries(std::move(_libraries))
-    , stack_trace((flags >> 2) & 1) {
-  ensure_throw(init_cp(0));
-  set_c4(std::move(_data));
-  if (init_c7.not_null()) {
-    set_c7(std::move(init_c7));
-  }
-  init_cregs(flags & 1, flags & 2);
-}
-
-VmState::VmState(Ref<CellSlice> _code, Ref<Stack> _stack, const GasLimits& gas, int flags, Ref<Cell> _data, VmLog log,
-                 std::vector<Ref<Cell>> _libraries, Ref<Tuple> init_c7)
+VmState::VmState(Ref<CellSlice> _code, int global_version, Ref<Stack> _stack, const GasLimits& gas, int flags,
+                 Ref<Cell> _data, VmLog log, std::vector<Ref<Cell>> _libraries, Ref<Tuple> init_c7)
     : code(std::move(_code))
     , stack(std::move(_stack))
     , cp(-1)
@@ -67,7 +44,8 @@ VmState::VmState(Ref<CellSlice> _code, Ref<Stack> _stack, const GasLimits& gas,
     , log(log)
     , gas(gas)
     , libraries(std::move(_libraries))
-    , stack_trace((flags >> 2) & 1) {
+    , stack_trace((flags >> 2) & 1)
+    , global_version(global_version) {
   ensure_throw(init_cp(0));
   set_c4(std::move(_data));
   if (init_c7.not_null()) {
@@ -102,12 +80,24 @@ void VmState::init_cregs(bool same_c3, bool push_0) {
   }
 }
 
-Ref<CellSlice> VmState::convert_code_cell(Ref<Cell> code_cell) {
+Ref<CellSlice> VmState::convert_code_cell(Ref<Cell> code_cell, int global_version,
+                                          const std::vector<Ref<Cell>>& libraries) {
   if (code_cell.is_null()) {
     return {};
   }
-  Ref<CellSlice> csr{true, NoVmOrd(), code_cell};
-  if (csr->is_valid()) {
+  Ref<CellSlice> csr;
+  if (global_version >= 9) {
+    // Use DummyVmState instead of this to avoid consuming gas for cell loading
+    DummyVmState dummy{libraries, global_version};
+    Guard guard(&dummy);
+    try {
+      csr = load_cell_slice_ref(code_cell);
+    } catch (VmError&) {  // NOLINT(*-empty-catch)
+    }
+  } else {
+    csr = td::Ref<CellSlice>{true, NoVmOrd(), code_cell};
+  }
+  if (csr.not_null() && csr->is_valid()) {
     return csr;
   }
   return load_cell_slice_ref(CellBuilder{}.store_ref(std::move(code_cell)).finalize());
@@ -577,14 +567,14 @@ int run_vm_code(Ref<CellSlice> code, Ref<Stack>& stack, int flags, Ref<Cell>* da
                 GasLimits* gas_limits, std::vector<Ref<Cell>> libraries, Ref<Tuple> init_c7, Ref<Cell>* actions_ptr,
                 int global_version) {
   VmState vm{code,
+             global_version,
              std::move(stack),
              gas_limits ? *gas_limits : GasLimits{},
              flags,
              data_ptr ? *data_ptr : Ref<Cell>{},
              log,
              std::move(libraries),
              std::move(init_c7)};
-  vm.set_global_version(global_version);
   int res = vm.run();
   stack = vm.get_stack_ref();
   if (vm.committed() && data_ptr) {