utils: remove tal_tmpctx altogether, use global.

In particular, we now only free tmpctx at the end of main().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

channeld/channel.c

@@ -174,7 +174,6 @@ static void start_commit_timer(struct peer *peer);
 
 static void billboard_update(const struct peer *peer)
 {
-	const tal_t *tmpctx = tal_tmpctx(peer);
 	const char *funding_status, *announce_status, *shutdown_status;
 
 	if (peer->funding_locked[LOCAL] && peer->funding_locked[REMOTE])
@@ -338,7 +337,6 @@ static void gossip_in(struct peer *peer, const u8 *msg)
  * our own outgoing payments */
 static void send_temporary_announcement(struct peer *peer)
 {
-	tal_t *tmpctx;
 	u8 *msg;
 
 	/* If we are supposed to send a real announcement, don't do a
@@ -347,23 +345,18 @@ static void send_temporary_announcement(struct peer *peer)
 	    !peer->funding_locked[REMOTE])
 		return;
 
-	tmpctx = tal_tmpctx(peer);
-
 	msg = towire_gossip_local_add_channel(
 	    tmpctx, &peer->short_channel_ids[LOCAL], &peer->chain_hash,
 	    &peer->node_ids[REMOTE], peer->cltv_delta,
 	    peer->conf[REMOTE].htlc_minimum_msat, peer->fee_base,
 	    peer->fee_per_satoshi);
 	wire_sync_write(GOSSIP_FD, take(msg));
-
-	tal_free(tmpctx);
 }
 
 static void send_announcement_signatures(struct peer *peer)
 {
 	/* First 2 + 256 byte are the signatures and msg type, skip them */
 	size_t offset = 258;
-	const tal_t *tmpctx;
 	struct sha256_double hash;
 	u8 *msg, *ca, *req;
 
@@ -378,7 +371,6 @@ static void send_announcement_signatures(struct peer *peer)
 	    !peer->funding_locked[REMOTE])
 		return;
 
-	tmpctx = tal_tmpctx(peer);
 	status_trace("Exchanging announcement signatures.");
 	ca = create_channel_announcement(tmpctx, peer);
 	req = towire_hsm_cannouncement_sig_req(
@@ -421,13 +413,11 @@ static void send_announcement_signatures(struct peer *peer)
 	    &peer->announcement_node_sigs[LOCAL],
 	    &peer->announcement_bitcoin_sigs[LOCAL]);
 	enqueue_peer_msg(peer, take(msg));
-	tal_free(tmpctx);
 }
 
 static u8 *create_channel_update(const tal_t *ctx,
 				 struct peer *peer, bool disabled)
 {
-	tal_t *tmpctx = tal_tmpctx(ctx);
 	u32 timestamp = time_now().ts.tv_sec;
 	u16 flags;
 	u8 *cupdate, *msg;
@@ -460,7 +450,6 @@ static u8 *create_channel_update(const tal_t *ctx,
 		status_failed(STATUS_FAIL_HSM_IO,
 			      "Reading cupdate_sig_req: %s",
 			      strerror(errno));
-	tal_free(tmpctx);
 	return cupdate;
 }
 
@@ -557,7 +546,6 @@ static void check_short_ids_match(struct peer *peer)
 
 static void announce_channel(struct peer *peer)
 {
-	tal_t *tmpctx = tal_tmpctx(peer);
 	u8 *cannounce, *cupdate;
 
 	check_short_ids_match(peer);
@@ -567,8 +555,6 @@ static void announce_channel(struct peer *peer)
 
 	wire_sync_write(GOSSIP_FD, cannounce);
 	wire_sync_write(GOSSIP_FD, cupdate);
-
-	tal_free(tmpctx);
 }
 
 static void handle_peer_announcement_signatures(struct peer *peer, const u8 *msg)
@@ -606,7 +592,6 @@ static void handle_peer_announcement_signatures(struct peer *peer, const u8 *msg
 static bool get_shared_secret(const struct htlc *htlc,
 			      struct secret *shared_secret)
 {
-	tal_t *tmpctx = tal_tmpctx(htlc);
 	struct pubkey ephemeral;
 	struct onionpacket *op;
 	u8 *msg;
@@ -616,7 +601,6 @@ static bool get_shared_secret(const struct htlc *htlc,
 	if (!op) {
 		/* Return an invalid shared secret. */
 		memset(shared_secret, 0, sizeof(*shared_secret));
-		tal_free(tmpctx);
 		return false;
 	}
 
@@ -629,7 +613,6 @@ static bool get_shared_secret(const struct htlc *htlc,
 	/* Gives all-zero shares_secret if it was invalid. */
 	if (!msg || !fromwire_hsm_ecdh_resp(msg, shared_secret))
 		status_failed(STATUS_FAIL_HSM_IO, "Reading ecdh response");
-	tal_free(tmpctx);
 
 	return !memeqzero(shared_secret, sizeof(*shared_secret));
 }
@@ -745,7 +728,6 @@ static u8 *sending_commitsig_msg(const tal_t *ctx,
 				 const secp256k1_ecdsa_signature *commit_sig,
 				 const secp256k1_ecdsa_signature *htlc_sigs)
 {
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	struct changed_htlc *changed;
 	u8 *msg;
 
@@ -755,7 +737,6 @@ static u8 *sending_commitsig_msg(const tal_t *ctx,
 	msg = towire_channel_sending_commitsig(ctx, remote_commit_index,
 					       remote_feerate,
 					       changed, commit_sig, htlc_sigs);
-	tal_free(tmpctx);
 	return msg;
 }
 
@@ -852,7 +833,6 @@ static struct commit_sigs *calc_commitsigs(const tal_t *ctx,
 					   const struct peer *peer,
 					   u64 commit_index)
 {
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	size_t i;
 	struct bitcoin_tx **txs;
 	const u8 **wscripts;
@@ -929,13 +909,11 @@ static struct commit_sigs *calc_commitsigs(const tal_t *ctx,
 				    &commit_sigs->htlc_sigs[i]));
 	}
 
-	tal_free(tmpctx);
 	return commit_sigs;
 }
 
 static void send_commit(struct peer *peer)
 {
-	tal_t *tmpctx = tal_tmpctx(peer);
 	u8 *msg;
 	const struct htlc **changed_htlcs;
 
@@ -943,7 +921,6 @@ static void send_commit(struct peer *peer)
 	/* Hack to suppress all commit sends if dev_disconnect says to */
 	if (dev_suppress_commit) {
 		peer->commit_timer = NULL;
-		tal_free(tmpctx);
 		return;
 	}
 #endif
@@ -963,7 +940,6 @@ static void send_commit(struct peer *peer)
 		/* Mark this as done and try again. */
 		peer->commit_timer = NULL;
 		start_commit_timer(peer);
-		tal_free(tmpctx);
 		return;
 	}
 
@@ -976,7 +952,6 @@ static void send_commit(struct peer *peer)
 		status_trace("Can't send commit: final shutdown phase");
 
 		peer->commit_timer = NULL;
-		tal_free(tmpctx);
 		return;
 	}
 
@@ -1016,7 +991,6 @@ static void send_commit(struct peer *peer)
 		maybe_send_shutdown(peer);
 
 		peer->commit_timer = NULL;
-		tal_free(tmpctx);
 		return;
 	}
 
@@ -1050,7 +1024,6 @@ static void send_commit(struct peer *peer)
 	/* Timer now considered expired, you can add a new one. */
 	peer->commit_timer = NULL;
 	start_commit_timer(peer);
-	tal_free(tmpctx);
 }
 
 static void start_commit_timer(struct peer *peer)
@@ -1124,7 +1097,6 @@ static u8 *got_commitsig_msg(const tal_t *ctx,
 			     const struct htlc **changed_htlcs,
 			     const struct bitcoin_tx *committx)
 {
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	struct changed_htlc *changed;
 	struct fulfilled_htlc *fulfilled;
 	const struct failed_htlc **failed;
@@ -1187,13 +1159,11 @@ static u8 *got_commitsig_msg(const tal_t *ctx,
 					   failed,
 					   changed,
 					   committx);
-	tal_free(tmpctx);
 	return msg;
 }
 
 static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 {
-	const tal_t *tmpctx = tal_tmpctx(peer);
 	struct channel_id channel_id;
 	secp256k1_ecdsa_signature commit_sig, *htlc_sigs;
 	struct pubkey remote_htlckey, point;
@@ -1312,7 +1282,6 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 
 	master_wait_sync_reply(tmpctx, peer, take(msg),
 			       WIRE_CHANNEL_GOT_COMMITSIG_REPLY);
-	tal_free(tmpctx);
 	return send_revocation(peer);
 }
 
@@ -1321,7 +1290,6 @@ static u8 *got_revoke_msg(const tal_t *ctx, u64 revoke_num,
 			  const struct pubkey *next_per_commit_point,
 			  const struct htlc **changed_htlcs)
 {
-	tal_t *tmpctx = tal_tmpctx(ctx);
 	u8 *msg;
 	struct changed_htlc *changed = tal_arr(tmpctx, struct changed_htlc, 0);
 
@@ -1339,7 +1307,6 @@ static u8 *got_revoke_msg(const tal_t *ctx, u64 revoke_num,
 
 	msg = towire_channel_got_revoke(ctx, revoke_num, per_commitment_secret,
 					next_per_commit_point, changed);
-	tal_free(tmpctx);
 	return msg;
 }
 
@@ -1349,7 +1316,6 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 	struct privkey privkey;
 	struct channel_id channel_id;
 	struct pubkey per_commit_point, next_per_commit;
-	tal_t *tmpctx = tal_tmpctx(msg);
 	const struct htlc **changed_htlcs = tal_arr(msg, const struct htlc *, 0);
 
 	if (!fromwire_revoke_and_ack(msg, &channel_id, &old_commit_secret,
@@ -1416,8 +1382,6 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 				    &peer->old_remote_per_commit));
 
 	start_commit_timer(peer);
-
-	tal_free(tmpctx);
 }
 
 static void handle_peer_fulfill_htlc(struct peer *peer, const u8 *msg)
@@ -2201,7 +2165,6 @@ static u8 *foreign_channel_update(const tal_t *ctx,
 				  struct peer *peer,
 				  const struct short_channel_id *scid)
 {
-	tal_t *tmpctx = tal_tmpctx(ctx);
 	u8 *msg, *update;
 
 	msg = towire_gossip_get_update(tmpctx, scid);
@@ -2210,7 +2173,6 @@ static u8 *foreign_channel_update(const tal_t *ctx,
 	if (!fromwire_gossip_get_update_reply(ctx, msg, &update))
 		status_failed(STATUS_FAIL_GOSSIP_IO,
 			      "Invalid update reply");
-	tal_free(tmpctx);
 	return update;
 }
 

channeld/commit_tx.c

@@ -101,7 +101,6 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 			     u64 obscured_commitment_number,
 			     enum side side)
 {
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	u64 base_fee_msat;
 	struct bitcoin_tx *tx;
 	size_t i, n, untrimmed;
@@ -287,6 +286,5 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 	/* Input amount needed for signature code. */
 	tx->input[0].amount = tal_dup(tx->input, u64, &funding_satoshis);
 
-	tal_free(tmpctx);
 	return tx;
 }

channeld/full_channel.c

@@ -293,12 +293,10 @@ static enum channel_add_err add_htlc(struct channel *channel,
 				     struct htlc **htlcp,
 				     bool enforce_aggregate_limits)
 {
-	const tal_t *tmpctx = tal_tmpctx(channel);
 	struct htlc *htlc, *old;
 	s64 msat_in_htlcs, fee_msat, balance_msat;
 	enum side sender = htlc_state_owner(state), recipient = !sender;
 	const struct htlc **committed, **adding, **removing;
-	enum channel_add_err e;
 	const struct channel_view *view;
 	size_t i;
 
@@ -317,8 +315,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 * `cltv_expiry` to greater or equal to 500000000.
 	 */
 	if (!blocks_to_abs_locktime(cltv_expiry, &htlc->expiry)) {
-		e = CHANNEL_ERR_INVALID_EXPIRY;
+		return CHANNEL_ERR_INVALID_EXPIRY;
-		goto out;
 	}
 
 	htlc->rhash = *payment_hash;
@@ -333,10 +330,9 @@ static enum channel_add_err add_htlc(struct channel *channel,
 		    || old->msatoshi != htlc->msatoshi
 		    || old->expiry.locktime != htlc->expiry.locktime
 		    || !structeq(&old->rhash, &htlc->rhash))
-			e = CHANNEL_ERR_DUPLICATE_ID_DIFFERENT;
+			return CHANNEL_ERR_DUPLICATE_ID_DIFFERENT;
 		else
-			e = CHANNEL_ERR_DUPLICATE;
+			return CHANNEL_ERR_DUPLICATE;
-		goto out;
 	}
 
 	/* We're always considering the recipient's view of the channel here */
@@ -349,12 +345,10 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 * or...
 	 */
 	if (htlc->msatoshi == 0) {
-		e = CHANNEL_ERR_HTLC_BELOW_MINIMUM;
+		return CHANNEL_ERR_HTLC_BELOW_MINIMUM;
-		goto out;
 	}
 	if (htlc->msatoshi < htlc_minimum_msat(channel, recipient)) {
-		e = CHANNEL_ERR_HTLC_BELOW_MINIMUM;
+		return CHANNEL_ERR_HTLC_BELOW_MINIMUM;
-		goto out;
 	}
 
 	/* BOLT #2:
@@ -364,8 +358,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 * `amount_msat` to zero.
 	 */
 	if (htlc->msatoshi & 0xFFFFFFFF00000000ULL) {
-		e = CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED;
+		return CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED;
-		goto out;
 	}
 
 	/* Figure out what receiver will already be committed to. */
@@ -380,8 +373,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	if (enforce_aggregate_limits
 	    && tal_count(committed) - tal_count(removing) + tal_count(adding)
 	    > max_accepted_htlcs(channel, recipient)) {
-		e = CHANNEL_ERR_TOO_MANY_HTLCS;
+		return CHANNEL_ERR_TOO_MANY_HTLCS;
-		goto out;
 	}
 
 	msat_in_htlcs = total_offered_msatoshis(committed, htlc_owner(htlc))
@@ -395,8 +387,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 * HTLCs to its local commitment transaction */
 	if (enforce_aggregate_limits
 	    && msat_in_htlcs > max_htlc_value_in_flight_msat(channel, recipient)) {
-		e = CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED;
+		return CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED;
-		goto out;
 	}
 
 	/* BOLT #2:
@@ -446,13 +437,11 @@ static enum channel_add_err add_htlc(struct channel *channel,
 			     ", reserve is %"PRIu64,
 			     balance_msat, fee_msat,
 			     channel_reserve_msat(channel, sender));
-		e = CHANNEL_ERR_CHANNEL_CAPACITY_EXCEEDED;
+		return CHANNEL_ERR_CHANNEL_CAPACITY_EXCEEDED;
-		goto out;
 	}
 
 	dump_htlc(htlc, "NEW:");
 	htlc_map_add(channel->htlcs, tal_steal(channel, htlc));
-	e = CHANNEL_ERR_ADD_OK;
 	if (htlcp)
 		*htlcp = htlc;
 
@@ -463,9 +452,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	if (htlc_state_flags(htlc->state) & HTLC_REMOTE_F_PENDING)
 		channel->changes_pending[REMOTE] = true;
 
-out:
+	return CHANNEL_ERR_ADD_OK;
-	tal_free(tmpctx);
-	return e;
 }
 
 enum channel_add_err channel_add_htlc(struct channel *channel,
@@ -694,14 +681,12 @@ u32 approx_max_feerate(const struct channel *channel)
 	size_t num;
 	u64 weight;
 	const struct htlc **committed, **adding, **removing;
-	const tal_t *tmpctx = tal_tmpctx(channel);
 
 	gather_htlcs(tmpctx, channel, !channel->funder,
 		     &committed, &removing, &adding);
 
 	/* Assume none are trimmed; this gives lower bound on feerate. */
 	num = tal_count(committed) + tal_count(adding) - tal_count(removing);
-	tal_free(tmpctx);
 
 	weight = 724 + 172 * num;
 
@@ -714,8 +699,6 @@ bool can_funder_afford_feerate(const struct channel *channel, u32 feerate_per_kw
 	u64 fee_msat, dust = dust_limit_satoshis(channel, !channel->funder);
 	size_t untrimmed;
 	const struct htlc **committed, **adding, **removing;
-	const tal_t *tmpctx = tal_tmpctx(channel);
-
 	gather_htlcs(tmpctx, channel, !channel->funder,
 		     &committed, &removing, &adding);
 
@@ -728,8 +711,6 @@ bool can_funder_afford_feerate(const struct channel *channel, u32 feerate_per_kw
 
 	fee_msat = commit_tx_base_fee(feerate_per_kw, untrimmed);
 
-	tal_free(tmpctx);
-
 	/* BOLT #2:
 	 *
 	 * A receiving node SHOULD fail the channel if the sender cannot afford

channeld/test/run-full_channel.c

@@ -24,8 +24,6 @@ void status_fmt(enum log_level level UNUSED, const char *fmt, ...)
 	va_end(ap);
 }
 
-const void *trc;
-
 /* bitcoind loves its backwards txids! */
 static struct bitcoin_txid txid_from_hex(const char *hex)
 {
@@ -183,7 +181,6 @@ static struct pubkey pubkey_from_hex(const char *hex)
 static void tx_must_be_eq(const struct bitcoin_tx *a,
 			  const struct bitcoin_tx *b)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 *lina, *linb;
 	size_t i;
 
@@ -211,7 +208,6 @@ static void tx_must_be_eq(const struct bitcoin_tx *a,
 		     "%s",
 		     tal_hex(tmpctx, lina),
 		     tal_hex(tmpctx, linb));
-	tal_free(tmpctx);
 }
 
 static void txs_must_be_eq(struct bitcoin_tx **a, struct bitcoin_tx **b)
@@ -321,21 +317,19 @@ static void update_feerate(struct channel *channel, u32 feerate)
 
 int main(void)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	struct bitcoin_txid funding_txid;
 	/* We test from both sides. */
 	struct channel *lchannel, *rchannel;
 	u64 funding_amount_satoshi;
-	u32 *feerate_per_kw = tal_arr(tmpctx, u32, NUM_SIDES);
+	u32 *feerate_per_kw;
 	unsigned int funding_output_index;
 	struct keyset keyset;
 	struct pubkey local_funding_pubkey, remote_funding_pubkey;
 	struct pubkey local_per_commitment_point;
 	struct basepoints localbase, remotebase;
-	struct pubkey *unknown = tal(tmpctx, struct pubkey);
+	struct pubkey *unknown;
 	struct bitcoin_tx *raw_tx, **txs, **txs2;
-	struct channel_config *local_config = tal(tmpctx, struct channel_config);
+	struct channel_config *local_config, *remote_config;
-	struct channel_config *remote_config = tal(tmpctx, struct channel_config);
 	u64 to_local_msat, to_remote_msat;
 	const struct htlc **htlc_map, **htlcs;
 	const u8 *funding_wscript, **wscripts;
@@ -343,8 +337,12 @@ int main(void)
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
-	trc = tmpctx;
+	feerate_per_kw = tal_arr(tmpctx, u32, NUM_SIDES);
+	unknown = tal(tmpctx, struct pubkey);
+	local_config = tal(tmpctx, struct channel_config);
+	remote_config = tal(tmpctx, struct channel_config);
 
 	/* BOLT #3:
 	 *

common/bolt11.c

@@ -410,7 +410,6 @@ static char *decode_r(struct bolt11 *b11,
                       u5 **data, size_t *data_len,
                       size_t data_length)
 {
-        tal_t *tmpctx = tal_tmpctx(b11);
         size_t rlen = data_length * 5 / 8;
         u8 *r8 = tal_arr(tmpctx, u8, rlen);
         size_t n = 0;
@@ -423,7 +422,6 @@ static char *decode_r(struct bolt11 *b11,
         do {
                 tal_resize(&r, n+1);
                 if (!fromwire_route_info(&cursor, &rlen, &r[n])) {
-                        tal_free(tmpctx);
                         return tal_fmt(b11, "r: hop %zu truncated", n);
                 }
                 n++;
@@ -434,7 +432,6 @@ static char *decode_r(struct bolt11 *b11,
         tal_resize(&b11->routes, n+1);
         b11->routes[n] = tal_steal(b11, r);
 
-        tal_free(tmpctx);
         return NULL;
 }
 
@@ -464,7 +461,6 @@ struct bolt11 *bolt11_decode(const tal_t *ctx, const char *str,
         u5 *data;
         size_t data_len;
         struct bolt11 *b11 = new_bolt11(ctx, NULL);
-        tal_t *tmpctx = tal_tmpctx(b11);
         u8 sig_and_recid[65];
         secp256k1_ecdsa_recoverable_signature sig;
         struct hash_u5 hu5;
@@ -701,7 +697,6 @@ struct bolt11 *bolt11_decode(const tal_t *ctx, const char *str,
                         return decode_fail(b11, fail, "invalid signature");
         }
 
-        tal_free(tmpctx);
         return b11;
 }
 
@@ -893,7 +888,6 @@ char *bolt11_encode_(const tal_t *ctx,
                                   void *arg),
 		     void *arg)
 {
-        tal_t *tmpctx = tal_tmpctx(ctx);
         u5 *data = tal_arr(tmpctx, u5, 0);
         char *hrp, *output;
         char postfix;
@@ -971,12 +965,12 @@ char *bolt11_encode_(const tal_t *ctx,
 
         /* FIXME: towire_ should check this? */
         if (tal_len(data) > 65535)
-                return tal_free(tmpctx);
+                return NULL;
 
         /* Need exact length here */
         hrpu8 = tal_dup_arr(tmpctx, u8, (const u8 *)hrp, strlen(hrp), 0);
         if (!sign(data, hrpu8, &rsig, arg))
-                return tal_free(tmpctx);
+                return NULL;
 
         secp256k1_ecdsa_recoverable_signature_serialize_compact(
                 secp256k1_ctx,
@@ -991,7 +985,6 @@ char *bolt11_encode_(const tal_t *ctx,
         if (!bech32_encode(output, hrp, data, tal_count(data), (size_t)-1))
                 output = tal_free(output);
 
-        tal_free(tmpctx);
         return output;
 }
 

common/initial_commit_tx.c

@@ -68,7 +68,6 @@ struct bitcoin_tx *initial_commit_tx(const tal_t *ctx,
 				     u64 obscured_commitment_number,
 				     enum side side)
 {
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	u64 base_fee_msat;
 	struct bitcoin_tx *tx;
 	size_t n, untrimmed;
@@ -195,6 +194,5 @@ struct bitcoin_tx *initial_commit_tx(const tal_t *ctx,
 	/* Input amount needed for signature code. */
 	tx->input[0].amount = tal_dup(tx->input, u64, &funding_satoshis);
 
-	tal_free(tmpctx);
 	return tx;
 }

common/sphinx.c

@@ -530,7 +530,6 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 				     const struct secret *shared_secrets,
 				     const int numhops, const u8 *reply)
 {
-	tal_t *tmpctx = tal_tmpctx(ctx);
 	struct onionreply *oreply = tal(tmpctx, struct onionreply);
 	u8 *msg = tal_arr(oreply, u8, tal_len(reply));
 	u8 key[KEY_LEN], hmac[HMAC_SIZE];
@@ -539,7 +538,7 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 	u16 msglen;
 
 	if (tal_len(reply) != ONION_REPLY_SIZE + sizeof(hmac) + 4) {
-		goto fail;
+		return NULL;
 	}
 
 	memcpy(msg, reply, tal_len(reply));
@@ -561,7 +560,7 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 		}
 	}
 	if (oreply->origin_index == -1) {
-		goto fail;
+		return NULL;
 	}
 
 	cursor = msg + sizeof(hmac);
@@ -569,15 +568,13 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 	msglen = fromwire_u16(&cursor, &max);
 
 	if (msglen > ONION_REPLY_SIZE) {
-		goto fail;
+		return NULL;
 	}
 
 	oreply->msg = tal_arr(oreply, u8, msglen);
 	fromwire(&cursor, &max, oreply->msg, msglen);
 
 	tal_steal(ctx, oreply);
-	tal_free(tmpctx);
 	return oreply;
-fail:
+
-	return tal_free(tmpctx);
 }

common/test/run-bolt11.c

@@ -68,7 +68,6 @@ static void test_b11(const char *b11str,
 		     const char *hashed_desc)
 {
 	struct bolt11 *b11;
-	const void *tmpctx = tal_tmpctx(NULL);
 	char *fail;
 	char *reproduce;
 
@@ -111,7 +110,6 @@ static void test_b11(const char *b11str,
 			abort();
 	}
 	assert(streq(reproduce, b11str));
-	tal_free(tmpctx);
 }
 
 int main(void)
@@ -119,10 +117,10 @@ int main(void)
 	struct bolt11 *b11;
 	struct pubkey node;
 	u64 msatoshi;
-	const void *ctx = tal_tmpctx(NULL);
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 	/* BOLT #11:
 	 *
@@ -159,7 +157,7 @@ int main(void)
 	 * * `8rkx3yf5tcsyz3d73gafnh3cax9rn449d9p5uxz9ezhhypd0elx87sjle52x86fux2ypatgddc6k63n7erqz25le42c4u4ecky03ylcq`: signature
 	 * * `ca784w`: Bech32 checksum
 	 */
-	b11 = new_bolt11(ctx, NULL);
+	b11 = new_bolt11(tmpctx, NULL);
 	b11->chain = chainparams_for_network("bitcoin");
 	b11->timestamp = 1496314658;
 	if (!hex_decode("0001020304050607080900010203040506070809000102030405060708090102",
@@ -193,7 +191,7 @@ int main(void)
 	 * * `fj9srp`: Bech32 checksum
 	 */
 	msatoshi = 2500 * (1000ULL * 100000000) / 1000000;
-	b11 = new_bolt11(ctx, &msatoshi);
+	b11 = new_bolt11(tmpctx, &msatoshi);
 	b11->chain = chainparams_for_network("bitcoin");
 	b11->timestamp = 1496314658;
 	if (!hex_decode("0001020304050607080900010203040506070809000102030405060708090102",
@@ -225,7 +223,7 @@ int main(void)
 	 * * `2yxxz7`: Bech32 checksum
 	 */
 	msatoshi = 20 * (1000ULL * 100000000) / 1000;
-	b11 = new_bolt11(ctx, &msatoshi);
+	b11 = new_bolt11(tmpctx, &msatoshi);
 	b11->chain = chainparams_for_network("bitcoin");
 	b11->timestamp = 1496314658;
 	if (!hex_decode("0001020304050607080900010203040506070809000102030405060708090102",
@@ -239,6 +237,6 @@ int main(void)
 	/* FIXME: Test the others! */
 
 	secp256k1_context_destroy(secp256k1_ctx);
-	tal_free(ctx);
+	tal_free(tmpctx);
 	return 0;
 }

common/test/run-ip_port_parsing.c

@@ -28,48 +28,49 @@ void towire_u8(u8 **pptr UNNEEDED, u8 v UNNEEDED)
 int main(void)
 {
 	struct wireaddr addr;
-	tal_t *ctx = tal_tmpctx(NULL);
 	char *ip;
 	u16 port;
 
+	setup_tmpctx();
+
 	/* Grossly invalid. */
-	assert(!separate_address_and_port(ctx, "[", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "[", &ip, &port));
-	assert(!separate_address_and_port(ctx, "[123", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "[123", &ip, &port));
-	assert(!separate_address_and_port(ctx, "[::1]:8f", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "[::1]:8f", &ip, &port));
-	assert(!separate_address_and_port(ctx, "127.0.0.1:8f", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "127.0.0.1:8f", &ip, &port));
-	assert(!separate_address_and_port(ctx, "127.0.0.1:0", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "127.0.0.1:0", &ip, &port));
-	assert(!separate_address_and_port(ctx, "127.0.0.1:ff", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "127.0.0.1:ff", &ip, &port));
 
 	/* ret = getaddrinfo("[::1]:80", NULL, NULL, &res); */
-	assert(separate_address_and_port(ctx, "[::1]:80", &ip, &port));
+	assert(separate_address_and_port(tmpctx, "[::1]:80", &ip, &port));
 	assert(streq(ip, "::1"));
 	assert(port == 80);
 
 	port = 0;
-	assert(separate_address_and_port(ctx, "ip6-localhost", &ip, &port));
+	assert(separate_address_and_port(tmpctx, "ip6-localhost", &ip, &port));
 	assert(streq(ip, "ip6-localhost"));
 	assert(port == 0);
 
-	assert(separate_address_and_port(ctx, "::1", &ip, &port));
+	assert(separate_address_and_port(tmpctx, "::1", &ip, &port));
 	assert(streq(ip, "::1"));
 	assert(port == 0);
 
-	assert(separate_address_and_port(ctx, "192.168.1.1:8000", &ip, &port));
+	assert(separate_address_and_port(tmpctx, "192.168.1.1:8000", &ip, &port));
 	assert(streq(ip, "192.168.1.1"));
 	assert(port == 8000);
 
 	port = 0;
-	assert(separate_address_and_port(ctx, "192.168.2.255", &ip, &port));
+	assert(separate_address_and_port(tmpctx, "192.168.2.255", &ip, &port));
 	assert(streq(ip, "192.168.2.255"));
 	assert(port == 0);
 
 	// unusual but possibly valid case
-	assert(separate_address_and_port(ctx, "[::1]", &ip, &port));
+	assert(separate_address_and_port(tmpctx, "[::1]", &ip, &port));
 	assert(streq(ip, "::1"));
 	assert(port == 0);
 
 	// service names not supported yet
-	assert(!separate_address_and_port(ctx, "[::1]:http", &ip, &port));
+	assert(!separate_address_and_port(tmpctx, "[::1]:http", &ip, &port));
 
 	// localhost hostnames for backward compat
 	parse_wireaddr("localhost", &addr, 200, NULL);
@@ -78,18 +79,18 @@ int main(void)
 	// string should win the port battle
 	parse_wireaddr("[::1]:9735", &addr, 500, NULL);
 	assert(addr.port == 9735);
-	ip = fmt_wireaddr(ctx, &addr);
+	ip = fmt_wireaddr(tmpctx, &addr);
 	assert(streq(ip, "[::1]:9735"));
 
 	// should use argument if we have no port in string
 	parse_wireaddr("2001:db8:85a3::8a2e:370:7334", &addr, 9777, NULL);
 	assert(addr.port == 9777);
 
-	ip = fmt_wireaddr(ctx, &addr);
+	ip = fmt_wireaddr(tmpctx, &addr);
 	assert(streq(ip, "[2001:db8:85a3::8a2e:370:7334]:9777"));
 
 	assert(parse_wireaddr("[::ffff:127.0.0.1]:49150", &addr, 1, NULL));
 	assert(addr.port == 49150);
-	tal_free(ctx);
+	tal_free(tmpctx);
 	return 0;
 }

common/test/run-sphinx.c

@@ -72,7 +72,6 @@ static struct secret secret_from_hex(const char *hex)
  * we match the test vectors and that we can also unwrap it. */
 static void run_unit_tests(void)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	struct onionreply *oreply;
 	u8 *reply;
 	u8 *raw = tal_hexdata(tmpctx, "2002", 4);
@@ -155,19 +154,17 @@ static void run_unit_tests(void)
 	oreply = unwrap_onionreply(tmpctx, ss, 5, reply);
 	printf("unwrapped %s\n", tal_hex(tmpctx, oreply->msg));
 	assert(memcmp(raw, oreply->msg, tal_len(raw)) == 0);
-
-	tal_free(tmpctx);
 }
 
 int main(int argc, char **argv)
 {
 	bool generate = false, decode = false, unit = false;
-	const tal_t *ctx = talz(NULL, tal_t);
 	u8 assocdata[32];
 	memset(assocdata, 'B', sizeof(assocdata));
 
 	secp256k1_ctx = secp256k1_context_create(
 		SECP256K1_CONTEXT_VERIFY | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 	opt_register_noarg("--help|-h", opt_usage_and_exit,
 			   "--generate <pubkey1> <pubkey2>... OR\n"
@@ -194,6 +191,6 @@ int main(int argc, char **argv)
 	}
 	secp256k1_context_destroy(secp256k1_ctx);
 	opt_free_table();
-	tal_free(ctx);
+	tal_free(tmpctx);
 	return 0;
 }

common/timeout.c

@@ -33,10 +33,8 @@ struct oneshot *new_reltimer_(struct timers *timers,
 void timer_expired(tal_t *ctx, struct timer *timer)
 {
 	struct oneshot *t = container_of(timer, struct oneshot, timer);
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 
 	/* If it doesn't free itself, freeing tmpctx will do it */
 	tal_steal(tmpctx, t);
 	t->cb(t->arg);
-	tal_free(tmpctx);
 }

common/utils.h

@@ -16,9 +16,6 @@ char *tal_hex(const tal_t *ctx, const tal_t *data);
 /* Allocate and fill a buffer with the data of this hex string. */
 u8 *tal_hexdata(const tal_t *ctx, const void *str, size_t len);
 
-/* FIXME: Remove in favor of global */
-#define tal_tmpctx(ctx) tal((ctx), char)
-
 /* Global temporary convenience context: freed in io loop core. */
 extern const tal_t *tmpctx;
 

common/wireaddr.c

@@ -77,7 +77,7 @@ REGISTER_TYPE_TO_STRING(wireaddr, fmt_wireaddr);
  * Returns false if it wasn't one of these forms.  If it returns true,
  * it only overwrites *port if it was specified by <number> above.
  */
-static bool separate_address_and_port(tal_t *ctx, const char *arg,
+static bool separate_address_and_port(const tal_t *ctx, const char *arg,
 				      char **addr, u16 *port)
 {
 	char *portcolon;
@@ -126,7 +126,6 @@ bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport,
 	u16 port;
 	char *ip;
 	bool res;
-	tal_t *tmpctx = tal_tmpctx(NULL);
 
 	res = false;
 	port = defport;
@@ -195,6 +194,5 @@ bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport,
 finish:
 	if (!res && err_msg && !*err_msg)
 		*err_msg = "Error parsing hostname";
-	tal_free(tmpctx);
 	return res;
 }

gossipd/gossip.c

@@ -456,7 +456,6 @@ static u8 *create_node_announcement(const tal_t *ctx, struct daemon *daemon,
 
 static void send_node_announcement(struct daemon *daemon)
 {
-	tal_t *tmpctx = tal_tmpctx(daemon);
 	u32 timestamp = time_now().ts.tv_sec;
 	secp256k1_ecdsa_signature sig;
 	u8 *msg, *nannounce, *err;
@@ -484,7 +483,6 @@ static void send_node_announcement(struct daemon *daemon)
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
 			      "rejected own node announcement: %s",
 			      tal_hex(tmpctx, err));
-	tal_free(tmpctx);
 }
 
 /* Returns error if we should send an error. */
@@ -1092,7 +1090,6 @@ static struct io_plan *release_peer(struct io_conn *conn, struct daemon *daemon,
 static struct io_plan *getroute_req(struct io_conn *conn, struct daemon *daemon,
 				    u8 *msg)
 {
-	tal_t *tmpctx = tal_tmpctx(msg);
 	struct pubkey source, destination;
 	u32 msatoshi, final_cltv;
 	u16 riskfactor;
@@ -1114,7 +1111,6 @@ static struct io_plan *getroute_req(struct io_conn *conn, struct daemon *daemon,
 			 fuzz, &seed);
 
 	out = towire_gossip_getroute_reply(msg, hops);
-	tal_free(tmpctx);
 	daemon_conn_send(&daemon->master, out);
 	return daemon_conn_read_next(conn, &daemon->master);
 }
@@ -1163,7 +1159,6 @@ static void append_channel(struct gossip_getchannels_entry **entries,
 static struct io_plan *getchannels_req(struct io_conn *conn, struct daemon *daemon,
 				    u8 *msg)
 {
-	tal_t *tmpctx = tal_tmpctx(daemon);
 	u8 *out;
 	struct gossip_getchannels_entry *entries;
 	struct chan *chan;
@@ -1188,7 +1183,6 @@ static struct io_plan *getchannels_req(struct io_conn *conn, struct daemon *daem
 
 	out = towire_gossip_getchannels_reply(daemon, entries);
 	daemon_conn_send(&daemon->master, take(out));
-	tal_free(tmpctx);
 	return daemon_conn_read_next(conn, &daemon->master);
 }
 
@@ -1215,7 +1209,6 @@ static void append_node(const struct gossip_getnodes_entry ***nodes,
 static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon,
 				const u8 *msg)
 {
-	tal_t *tmpctx = tal_tmpctx(daemon);
 	u8 *out;
 	struct node *n;
 	const struct gossip_getnodes_entry **nodes;
@@ -1240,7 +1233,6 @@ static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon,
 	}
 	out = towire_gossip_getnodes_reply(daemon, nodes);
 	daemon_conn_send(&daemon->master, take(out));
-	tal_free(tmpctx);
 	return daemon_conn_read_next(conn, &daemon->master);
 }
 
@@ -1326,7 +1318,6 @@ fail:
 static void gossip_send_keepalive_update(struct routing_state *rstate,
 					 struct half_chan *hc)
 {
-	tal_t *tmpctx = tal_tmpctx(rstate);
 	secp256k1_ecdsa_signature sig;
 	struct bitcoin_blkid chain_hash;
 	struct short_channel_id scid;
@@ -1377,8 +1368,6 @@ static void gossip_send_keepalive_update(struct routing_state *rstate,
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
 			      "rejected keepalive channel_update: %s",
 			      tal_hex(tmpctx, err));
-	tal_free(tmpctx);
-
 }
 
 static void gossip_refresh_network(struct daemon *daemon)
@@ -1860,7 +1849,6 @@ static struct io_plan *handle_txout_reply(struct io_conn *conn,
 static struct io_plan *handle_disable_channel(struct io_conn *conn,
 					      struct daemon *daemon, u8 *msg)
 {
-	tal_t *tmpctx = tal_tmpctx(msg);
 	struct short_channel_id scid;
 	u8 direction;
 	struct chan *chan;
@@ -1947,7 +1935,6 @@ static struct io_plan *handle_disable_channel(struct io_conn *conn,
 			      tal_hex(tmpctx, err));
 
 fail:
-	tal_free(tmpctx);
 	return daemon_conn_read_next(conn, &daemon->master);
 }
 static struct io_plan *handle_routing_failure(struct io_conn *conn,

gossipd/routing.c

@@ -893,7 +893,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 	u64 htlc_minimum_msat;
 	u32 fee_base_msat;
 	u32 fee_proportional_millionths;
-	const tal_t *tmpctx = tal_tmpctx(rstate);
 	struct bitcoin_blkid chain_hash;
 	struct chan *chan;
 	u8 direction;
@@ -909,7 +908,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 		err = towire_errorfmt(rstate, NULL,
 				      "Malformed channel_update %s",
 				      tal_hex(tmpctx, serialized));
-		tal_free(tmpctx);
 		return err;
 	}
 	direction = flags & 0x1;
@@ -923,7 +921,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 		status_trace("Received channel_update for unknown chain %s",
 			     type_to_string(tmpctx, struct bitcoin_blkid,
 					    &chain_hash));
-		tal_free(tmpctx);
 		return NULL;
 	}
 
@@ -937,7 +934,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 		if (pending) {
 			update_pending(pending,
 				       timestamp, serialized, direction);
-			tal_free(tmpctx);
 			return NULL;
 		}
 
@@ -945,7 +941,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 			SUPERVERBOSE("Ignoring update for unknown channel %s",
 				     type_to_string(tmpctx, struct short_channel_id,
 						    &short_channel_id));
-			tal_free(tmpctx);
 			return NULL;
 		}
 	}
@@ -954,7 +949,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 
 	if (c->last_timestamp >= timestamp) {
 		SUPERVERBOSE("Ignoring outdated update.");
-		tal_free(tmpctx);
 		return NULL;
 	}
 
@@ -970,7 +964,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 		 *    - MUST NOT process the message further.
 		 *    - SHOULD fail the connection.
 		 */
-		tal_free(tmpctx);
 		return err;
 	}
 
@@ -992,7 +985,6 @@ u8 *handle_channel_update(struct routing_state *rstate, const u8 *update)
 			  &chan->half[direction].channel_update_msgidx,
 			  take(serialized));
 
-	tal_free(tmpctx);
 	return NULL;
 }
 
@@ -1041,7 +1033,6 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 	u8 rgb_color[3];
 	u8 alias[32];
 	u8 *features, *addresses;
-	const tal_t *tmpctx = tal_tmpctx(rstate);
 	struct wireaddr *wireaddrs;
 	struct pending_node_announce *pna;
 	size_t len = tal_len(node_ann);
@@ -1060,7 +1051,6 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 		u8 *err = towire_errorfmt(rstate, NULL,
 					  "Malformed node_announcement %s",
 					  tal_hex(tmpctx, node_ann));
-		tal_free(tmpctx);
 		return err;
 	}
 
@@ -1074,7 +1064,6 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 		status_trace("Ignoring node announcement for node %s, unsupported features %s.",
 			     type_to_string(tmpctx, struct pubkey, &node_id),
 			     tal_hex(tmpctx, features));
-		tal_free(tmpctx);
 		return NULL;
 	}
 
@@ -1099,7 +1088,6 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 							 struct sha256_double,
 							 &hash),
 					  tal_hex(tmpctx, node_ann));
-		tal_free(tmpctx);
 		return err;
 	}
 
@@ -1115,7 +1103,6 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 					  "Malformed wireaddrs %s in %s.",
 					  tal_hex(tmpctx, wireaddrs),
 					  tal_hex(tmpctx, node_ann));
-		tal_free(tmpctx);
 		return err;
 	}
 
@@ -1135,7 +1122,6 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 			tal_free(pna->node_announcement);
 			pna->node_announcement = tal_dup_arr(pna, u8, node_ann, tal_len(node_ann), 0);
 		}
-		tal_free(tmpctx);
 		return NULL;
 	}
 
@@ -1151,11 +1137,9 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 			     "node %s preceded by at least "
 			     "channel_announcement?",
 			     type_to_string(tmpctx, struct pubkey, &node_id));
-		tal_free(tmpctx);
 		return NULL;
 	} else if (node->last_timestamp >= timestamp) {
 		SUPERVERBOSE("Ignoring node announcement, it's outdated.");
-		tal_free(tmpctx);
 		return NULL;
 	}
 
@@ -1174,11 +1158,10 @@ u8 *handle_node_announcement(struct routing_state *rstate, const u8 *node_ann)
 	replace_broadcast(node, rstate->broadcasts,
 			  &node->node_announce_msgidx,
 			  take(serialized));
-	tal_free(tmpctx);
 	return NULL;
 }
 
-struct route_hop *get_route(tal_t *ctx, struct routing_state *rstate,
+struct route_hop *get_route(const tal_t *ctx, struct routing_state *rstate,
 			    const struct pubkey *source,
 			    const struct pubkey *destination,
 			    const u32 msatoshi, double riskfactor,
@@ -1258,7 +1241,6 @@ void routing_failure(struct routing_state *rstate,
 		     enum onion_type failcode,
 		     const u8 *channel_update)
 {
-	const tal_t *tmpctx = tal_tmpctx(rstate);
 	struct node *node;
 	int i;
 	time_t now = time_now().ts.tv_sec;
@@ -1277,7 +1259,7 @@ void routing_failure(struct routing_state *rstate,
 					      erring_node_pubkey));
 		/* No node, so no channel, so any channel_update
 		 * can also be ignored. */
-		goto out;
+		return;
 	}
 
 	/* BOLT #4:
@@ -1325,12 +1307,12 @@ void routing_failure(struct routing_state *rstate,
 			/* Suppress UNUSUAL log if local failure */
 			if (structeq(&erring_node_pubkey->pubkey,
 				     &rstate->local_id.pubkey))
-				goto out;
+				return;
 			status_unusual("routing_failure: "
 				       "UPDATE bit set, no channel_update. "
 				       "failcode: 0x%04x",
 				       (int) failcode);
-			goto out;
+			return;
 		}
 		err = handle_channel_update(rstate, channel_update);
 		if (err) {
@@ -1338,7 +1320,7 @@ void routing_failure(struct routing_state *rstate,
 				       "bad channel_update %s",
 				       sanitize_error(err, err, NULL));
 			tal_free(err);
-			goto out;
+			return;
 		}
 	} else {
 		if (tal_len(channel_update) != 0)
@@ -1347,15 +1329,11 @@ void routing_failure(struct routing_state *rstate,
 				       "failcode: 0x%04x",
 				       (int) failcode);
 	}
-
-out:
-	tal_free(tmpctx);
 }
 
 void mark_channel_unroutable(struct routing_state *rstate,
 			     const struct short_channel_id *channel)
 {
-	const tal_t *tmpctx = tal_tmpctx(rstate);
 	struct chan *chan;
 	time_t now = time_now().ts.tv_sec;
 	const char *scid = type_to_string(tmpctx, struct short_channel_id,
@@ -1369,12 +1347,10 @@ void mark_channel_unroutable(struct routing_state *rstate,
 		status_unusual("mark_channel_unroutable: "
 			       "channel %s not in routemap",
 			       scid);
-		tal_free(tmpctx);
 		return;
 	}
 	chan->half[0].unroutable_until = now + 20;
 	chan->half[1].unroutable_until = now + 20;
-	tal_free(tmpctx);
 }
 
 void route_prune(struct routing_state *rstate)
@@ -1382,7 +1358,7 @@ void route_prune(struct routing_state *rstate)
 	u64 now = time_now().ts.tv_sec;
 	/* Anything below this highwater mark ought to be pruned */
 	const s64 highwater = now - rstate->prune_timeout;
-	const tal_t *pruned = tal_tmpctx(rstate);
+	const tal_t *pruned = tal(NULL, char);
 	struct chan *chan;
 	u64 idx;
 

gossipd/routing.h

@@ -230,7 +230,7 @@ void set_connection_values(struct chan *chan,
 struct node *get_node(struct routing_state *rstate, const struct pubkey *id);
 
 /* Compute a route to a destination, for a given amount and riskfactor. */
-struct route_hop *get_route(tal_t *ctx, struct routing_state *rstate,
+struct route_hop *get_route(const tal_t *ctx, struct routing_state *rstate,
 			    const struct pubkey *source,
 			    const struct pubkey *destination,
 			    const u32 msatoshi, double riskfactor,

gossipd/test/run-bench-find_route.c

@@ -94,8 +94,6 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 { fprintf(stderr, "towire_errorfmt called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
-const void *trc;
-
 /* Updates existing route if required. */
 static struct half_chan *add_connection(struct routing_state *rstate,
 					const struct pubkey *from,
@@ -172,7 +170,6 @@ static void run(const char *name)
 int main(int argc, char *argv[])
 {
 	static const struct bitcoin_blkid zerohash;
-	const tal_t *ctx = trc = tal_tmpctx(NULL);
 	struct routing_state *rstate;
 	size_t num_nodes = 100, num_runs = 1;
 	struct timemono start, end;
@@ -184,8 +181,9 @@ int main(int argc, char *argv[])
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
-	rstate = new_routing_state(ctx, &zerohash, &me, 0);
+	rstate = new_routing_state(tmpctx, &zerohash, &me, 0);
 	opt_register_noarg("--perfme", opt_set_bool, &perfme,
 			   "Run perfme-start and perfme-stop around benchmark");
 
@@ -214,7 +212,7 @@ int main(int argc, char *argv[])
 		u64 fee;
 		struct chan **route;
 
-		route = find_route(ctx, rstate, &from, &to,
+		route = find_route(tmpctx, rstate, &from, &to,
 				  pseudorand(100000),
 				  riskfactor,
 				  0.75, &base_seed,
@@ -232,7 +230,7 @@ int main(int argc, char *argv[])
 	       time_to_msec(timemono_between(end, start)),
 	       time_to_nsec(time_divide(timemono_between(end, start), num_runs)));
 
-	tal_free(ctx);
+	tal_free(tmpctx);
 	secp256k1_context_destroy(secp256k1_ctx);
 	opt_free_table();
 	return 0;

gossipd/test/run-find_route-specific.c

@@ -58,8 +58,6 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 { fprintf(stderr, "towire_errorfmt called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
-const void *trc;
-
 bool short_channel_id_from_str(const char *str, size_t strlen,
 			       struct short_channel_id *dst);
 
@@ -98,7 +96,6 @@ static bool channel_is_between(const struct chan *chan,
 int main(void)
 {
 	static const struct bitcoin_blkid zerohash;
-	const tal_t *ctx = trc = tal_tmpctx(NULL);
 	struct half_chan *nc;
 	struct routing_state *rstate;
 	struct pubkey a, b, c;
@@ -108,6 +105,7 @@ int main(void)
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 	pubkey_from_hexstr("03c173897878996287a8100469f954dd820fcd8941daed91c327f168f3329be0bf",
 			   strlen("03c173897878996287a8100469f954dd820fcd8941daed91c327f168f3329be0bf"),
@@ -119,7 +117,7 @@ int main(void)
 			   strlen("02ea622d5c8d6143f15ed3ce1d501dd0d3d09d3b1c83a44d0034949f8a9ab60f06"),
 			   &c);
 
-	rstate = new_routing_state(ctx, &zerohash, &a, 0);
+	rstate = new_routing_state(tmpctx, &zerohash, &a, 0);
 
 	/* [{'active': True, 'short_id': '6990:2:1/1', 'fee_per_kw': 10, 'delay': 5, 'flags': 1, 'destination': '0230ad0e74ea03976b28fda587bb75bdd357a1938af4424156a18265167f5e40ae', 'source': '02ea622d5c8d6143f15ed3ce1d501dd0d3d09d3b1c83a44d0034949f8a9ab60f06', 'last_update': 1504064344}, */
 	nc = get_or_make_connection(rstate, &c, &b, "6990:2:1");
@@ -157,13 +155,13 @@ int main(void)
 	nc->flags = 1;
 	nc->last_timestamp = 1504064344;
 
-	route = find_route(ctx, rstate, &a, &c, 100000, riskfactor, 0.0, NULL, &fee);
+	route = find_route(tmpctx, rstate, &a, &c, 100000, riskfactor, 0.0, NULL, &fee);
 	assert(route);
 	assert(tal_count(route) == 2);
 	assert(channel_is_between(route[0], &a, &b));
 	assert(channel_is_between(route[1], &b, &c));
 
-	tal_free(ctx);
+	tal_free(tmpctx);
 	secp256k1_context_destroy(secp256k1_ctx);
 	return 0;
 }

gossipd/test/run-find_route.c

@@ -56,8 +56,6 @@ u8 *towire_errorfmt(const tal_t *ctx UNNEEDED,
 { fprintf(stderr, "towire_errorfmt called!\n"); abort(); }
 /* AUTOGENERATED MOCKS END */
 
-const void *trc;
-
 /* Updates existing route if required. */
 static struct half_chan *add_connection(struct routing_state *rstate,
 					      const struct pubkey *from,
@@ -141,7 +139,6 @@ static bool channel_is_between(const struct chan *chan,
 int main(void)
 {
 	static const struct bitcoin_blkid zerohash;
-	const tal_t *ctx = trc = tal_tmpctx(NULL);
 	struct routing_state *rstate;
 	struct pubkey a, b, c, d;
 	struct privkey tmp;
@@ -151,9 +148,10 @@ int main(void)
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 	memset(&tmp, 'a', sizeof(tmp));
-	rstate = new_routing_state(ctx, &zerohash, &a, 0);
+	rstate = new_routing_state(tmpctx, &zerohash, &a, 0);
 
 	pubkey_from_privkey(&tmp, &a);
 	new_node(rstate, &a);
@@ -165,7 +163,7 @@ int main(void)
 	/* A<->B */
 	add_connection(rstate, &a, &b, 1, 1, 1);
 
-	route = find_route(ctx, rstate, &a, &b, 1000, riskfactor, 0.0, NULL, &fee);
+	route = find_route(tmpctx, rstate, &a, &b, 1000, riskfactor, 0.0, NULL, &fee);
 	assert(tal_count(route) == 1);
 	assert(fee == 0);
 
@@ -174,12 +172,12 @@ int main(void)
 	pubkey_from_privkey(&tmp, &c);
 	new_node(rstate, &c);
 
-	status_trace("A = %s", type_to_string(trc, struct pubkey, &a));
+	status_trace("A = %s", type_to_string(tmpctx, struct pubkey, &a));
-	status_trace("B = %s", type_to_string(trc, struct pubkey, &b));
+	status_trace("B = %s", type_to_string(tmpctx, struct pubkey, &b));
-	status_trace("C = %s", type_to_string(trc, struct pubkey, &c));
+	status_trace("C = %s", type_to_string(tmpctx, struct pubkey, &c));
 	add_connection(rstate, &b, &c, 1, 1, 1);
 
-	route = find_route(ctx, rstate, &a, &c, 1000, riskfactor, 0.0, NULL, &fee);
+	route = find_route(tmpctx, rstate, &a, &c, 1000, riskfactor, 0.0, NULL, &fee);
 	assert(tal_count(route) == 2);
 	assert(fee == 1);
 
@@ -187,20 +185,20 @@ int main(void)
 	memset(&tmp, 'd', sizeof(tmp));
 	pubkey_from_privkey(&tmp, &d);
 	new_node(rstate, &d);
-	status_trace("D = %s", type_to_string(trc, struct pubkey, &d));
+	status_trace("D = %s", type_to_string(tmpctx, struct pubkey, &d));
 
 	add_connection(rstate, &a, &d, 0, 2, 1);
 	add_connection(rstate, &d, &c, 0, 2, 1);
 
 	/* Will go via D for small amounts. */
-	route = find_route(ctx, rstate, &a, &c, 1000, riskfactor, 0.0, NULL, &fee);
+	route = find_route(tmpctx, rstate, &a, &c, 1000, riskfactor, 0.0, NULL, &fee);
 	assert(tal_count(route) == 2);
 	assert(channel_is_between(route[0], &a, &d));
 	assert(channel_is_between(route[1], &d, &c));
 	assert(fee == 0);
 
 	/* Will go via B for large amounts. */
-	route = find_route(ctx, rstate, &a, &c, 3000000, riskfactor, 0.0, NULL, &fee);
+	route = find_route(tmpctx, rstate, &a, &c, 3000000, riskfactor, 0.0, NULL, &fee);
 	assert(tal_count(route) == 2);
 	assert(channel_is_between(route[0], &a, &b));
 	assert(channel_is_between(route[1], &b, &c));
@@ -208,13 +206,13 @@ int main(void)
 
 	/* Make B->C inactive, force it back via D */
 	get_connection(rstate, &b, &c)->active = false;
-	route = find_route(ctx, rstate, &a, &c, 3000000, riskfactor, 0.0, NULL, &fee);
+	route = find_route(tmpctx, rstate, &a, &c, 3000000, riskfactor, 0.0, NULL, &fee);
 	assert(tal_count(route) == 2);
 	assert(channel_is_between(route[0], &a, &d));
 	assert(channel_is_between(route[1], &d, &c));
 	assert(fee == 0 + 6);
 
-	tal_free(ctx);
+	tal_free(tmpctx);
 	secp256k1_context_destroy(secp256k1_ctx);
 	return 0;
 }

gossipd/test/run-initiator-success.c

@@ -178,7 +178,7 @@ static struct io_plan *success(struct io_conn *conn UNUSED,
 			       const struct pubkey *them,
 			       const struct wireaddr *addr UNUSED,
 			       const struct crypto_state *cs,
-			       void *ctx)
+			       void *unused UNUSED)
 {
 	assert(pubkey_eq(them, &rs_pub));
 
@@ -187,7 +187,7 @@ static struct io_plan *success(struct io_conn *conn UNUSED,
 
 	/* No memory leaks please */
 	secp256k1_context_destroy(secp256k1_ctx);
-	tal_free(ctx);
+	tal_free(tmpctx);
 	exit(0);
 }
 
@@ -199,13 +199,11 @@ bool hsm_do_ecdh(struct secret *ss, const struct pubkey *point)
 
 int main(void)
 {
-	tal_t *ctx = tal_tmpctx(NULL);
 	struct wireaddr dummy;
 
-	trc = tal_tmpctx(ctx);
-
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 
 	/* BOLT #8:
@@ -224,7 +222,7 @@ int main(void)
 	e_pub = pubkey("036360e856310ce5d294e8be33fc807077dc56ac80d95d9cd4ddbd21325eff73f7");
 
 	dummy.addrlen = 0;
-	initiator_handshake(ctx, &ls_pub, &rs_pub, &dummy, success, ctx);
+	initiator_handshake((void *)tmpctx, &ls_pub, &rs_pub, &dummy, success, NULL);
 	/* Should not exit! */
 	abort();
 }

gossipd/test/run-responder-success.c

@@ -81,7 +81,6 @@ static bool secret_eq(const struct secret *s, const char *str)
 }
 
 secp256k1_context *secp256k1_ctx;
-const void *trc;
 static struct pubkey ls_pub, e_pub;
 static struct privkey ls_priv, e_priv;
 
@@ -178,14 +177,14 @@ static struct io_plan *success(struct io_conn *conn UNUSED,
 			       const struct pubkey *them UNUSED,
 			       const struct wireaddr *addr UNUSED,
 			       const struct crypto_state *cs,
-			       void *ctx)
+			       void *unused UNUSED)
 {
 	assert(secret_eq(&cs->sk, expect_sk));
 	assert(secret_eq(&cs->rk, expect_rk));
 
 	/* No memory leaks please */
 	secp256k1_context_destroy(secp256k1_ctx);
-	tal_free(ctx);
+	tal_free(tmpctx);
 	exit(0);
 }
 
@@ -197,13 +196,11 @@ bool hsm_do_ecdh(struct secret *ss, const struct pubkey *point)
 
 int main(void)
 {
-	tal_t *ctx = tal_tmpctx(NULL);
 	struct wireaddr dummy;
 
-	trc = tal_tmpctx(ctx);
-
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 
 	/* BOLT #8:
@@ -220,7 +217,7 @@ int main(void)
 	e_pub = pubkey("02466d7fcae563e5cb09a0d1870bb580344804617879a14949cf22285f1bae3f27");
 
 	dummy.addrlen = 0;
-	responder_handshake(ctx, &ls_pub, &dummy, success, ctx);
+	responder_handshake((void *)tmpctx, &ls_pub, &dummy, success, NULL);
 	/* Should not exit! */
 	abort();
 }

hsmd/hsm.c

@@ -150,7 +150,6 @@ static struct io_plan *handle_ecdh(struct io_conn *conn, struct daemon_conn *dc)
 static struct io_plan *handle_cannouncement_sig(struct io_conn *conn,
 						struct daemon_conn *dc)
 {
-	tal_t *ctx = tal_tmpctx(conn);
 	/* First 2 + 256 byte are the signatures and msg type, skip them */
 	size_t offset = 258;
 	struct privkey node_pkey;
@@ -160,7 +159,7 @@ static struct io_plan *handle_cannouncement_sig(struct io_conn *conn,
 	u8 *ca;
 	struct pubkey bitcoin_id;
 
-	if (!fromwire_hsm_cannouncement_sig_req(ctx, dc->msg_in,
+	if (!fromwire_hsm_cannouncement_sig_req(tmpctx, dc->msg_in,
 						&bitcoin_id, &ca)) {
 		status_broken("Failed to parse cannouncement_sig_req: %s",
 			      tal_hex(tmpctx, dc->msg_in));
@@ -182,14 +181,12 @@ static struct io_plan *handle_cannouncement_sig(struct io_conn *conn,
 	reply = towire_hsm_cannouncement_sig_reply(ca, &node_sig);
 	daemon_conn_send(dc, take(reply));
 
-	tal_free(ctx);
 	return daemon_conn_read_next(conn, dc);
 }
 
 static struct io_plan *handle_channel_update_sig(struct io_conn *conn,
 						 struct daemon_conn *dc)
 {
-	tal_t *tmpctx = tal_tmpctx(conn);
 	/* 2 bytes msg type + 64 bytes signature */
 	size_t offset = 66;
 	struct privkey node_pkey;
@@ -234,7 +231,6 @@ static struct io_plan *handle_channel_update_sig(struct io_conn *conn,
 				   fee_base_msat, fee_proportional_mill);
 
 	daemon_conn_send(dc, take(towire_hsm_cupdate_sig_reply(tmpctx, cu)));
-	tal_free(tmpctx);
 	return daemon_conn_read_next(conn, dc);
 }
 
@@ -607,7 +603,6 @@ static void hsm_key_for_utxo(struct privkey *privkey, struct pubkey *pubkey,
  * can broadcast it. */
 static void sign_funding_tx(struct daemon_conn *master, const u8 *msg)
 {
-	const tal_t *tmpctx = tal_tmpctx(master);
 	u64 satoshi_out, change_out;
 	u32 change_keyindex;
 	struct pubkey local_pubkey, remote_pubkey;
@@ -668,7 +663,6 @@ static void sign_funding_tx(struct daemon_conn *master, const u8 *msg)
 
 	daemon_conn_send(master,
 			 take(towire_hsm_sign_funding_reply(tmpctx, tx)));
-	tal_free(tmpctx);
 }
 
 /**
@@ -676,7 +670,6 @@ static void sign_funding_tx(struct daemon_conn *master, const u8 *msg)
  */
 static void sign_withdrawal_tx(struct daemon_conn *master, const u8 *msg)
 {
-	const tal_t *tmpctx = tal_tmpctx(master);
 	u64 satoshi_out, change_out;
 	u32 change_keyindex;
 	struct utxo **utxos;
@@ -741,7 +734,6 @@ static void sign_withdrawal_tx(struct daemon_conn *master, const u8 *msg)
 
 	daemon_conn_send(master,
 			 take(towire_hsm_sign_withdrawal_reply(tmpctx, tx)));
-	tal_free(tmpctx);
 }
 
 /**
@@ -749,7 +741,6 @@ static void sign_withdrawal_tx(struct daemon_conn *master, const u8 *msg)
  */
 static void sign_invoice(struct daemon_conn *master, const u8 *msg)
 {
-	const tal_t *tmpctx = tal_tmpctx(master);
 	u5 *u5bytes;
 	u8 *hrpu8;
 	char *hrp;
@@ -785,7 +776,6 @@ static void sign_invoice(struct daemon_conn *master, const u8 *msg)
 
 	daemon_conn_send(master,
 			 take(towire_hsm_sign_invoice_reply(tmpctx, &rsig)));
-	tal_free(tmpctx);
 }
 
 static void sign_node_announcement(struct daemon_conn *master, const u8 *msg)

lightningd/channel_control.c

@@ -168,7 +168,6 @@ bool peer_start_channeld(struct channel *channel,
 			 const u8 *funding_signed,
 			 bool reconnected)
 {
-	const tal_t *tmpctx = tal_tmpctx(channel);
 	u8 *msg, *initmsg;
 	int hsmfd;
 	struct added_htlc *htlcs;
@@ -209,7 +208,6 @@ bool peer_start_channeld(struct channel *channel,
 		log_unusual(channel->log, "Could not subdaemon channel: %s",
 			    strerror(errno));
 		channel_fail_transient(channel, "Failed to subdaemon channel");
-		tal_free(tmpctx);
 		return true;
 	}
 
@@ -281,6 +279,5 @@ bool peer_start_channeld(struct channel *channel,
 	/* We don't expect a response: we are triggered by funding_depth_cb. */
 	subd_send_msg(channel->owner, take(initmsg));
 
-	tal_free(tmpctx);
 	return true;
 }

lightningd/closing_control.c

@@ -140,7 +140,6 @@ void peer_start_closingd(struct channel *channel,
 			 int peer_fd, int gossip_fd,
 			 bool reconnected)
 {
-	const tal_t *tmpctx = tal_tmpctx(channel);
 	u8 *initmsg;
 	u64 minfee, startfee, feelimit;
 	u64 num_revocations;
@@ -150,7 +149,6 @@ void peer_start_closingd(struct channel *channel,
 	if (!channel->remote_shutdown_scriptpubkey) {
 		channel_internal_error(channel,
 				       "Can't start closing: no remote info");
-		tal_free(tmpctx);
 		return;
 	}
 
@@ -166,7 +164,6 @@ void peer_start_closingd(struct channel *channel,
 		log_unusual(channel->log, "Could not subdaemon closing: %s",
 			    strerror(errno));
 		channel_fail_transient(channel, "Failed to subdaemon closing");
-		tal_free(tmpctx);
 		return;
 	}
 
@@ -226,5 +223,4 @@ void peer_start_closingd(struct channel *channel,
 	/* We don't expect a response: it will give us feedback on
 	 * signatures sent and received, then closing_complete. */
 	subd_send_msg(channel->owner, take(initmsg));
-	tal_free(tmpctx);
 }

lightningd/gossip_control.c

@@ -178,7 +178,6 @@ static unsigned gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
  * message */
 void gossip_init(struct lightningd *ld)
 {
-	tal_t *tmpctx = tal_tmpctx(ld);
 	u8 *msg;
 	int hsmfd;
 	u64 capabilities = HSM_CAP_ECDH | HSM_CAP_SIGN_GOSSIP;
@@ -208,7 +207,6 @@ void gossip_init(struct lightningd *ld)
 	    get_offered_local_features(tmpctx), ld->wireaddrs, ld->rgb,
 	    ld->alias, ld->config.channel_update_interval);
 	subd_send_msg(ld->gossip, msg);
-	tal_free(tmpctx);
 }
 
 static void json_getnodes_reply(struct subd *gossip UNUSED, const u8 *reply,

lightningd/hsm_control.c

@@ -32,7 +32,6 @@ u8 *hsm_sync_read(const tal_t *ctx, struct lightningd *ld)
 
 void hsm_init(struct lightningd *ld, bool newdir)
 {
-	const tal_t *tmpctx = tal_tmpctx(ld);
 	u8 *msg;
 	bool create;
 
@@ -56,6 +55,4 @@ void hsm_init(struct lightningd *ld, bool newdir)
 					&ld->peer_seed,
 					ld->wallet->bip32_base))
 		errx(1, "HSM did not give init reply");
-
-	tal_free(tmpctx);
 }

lightningd/jsonrpc.c

@@ -281,7 +281,6 @@ static void connection_complete_error(struct json_connection *jcon,
 				      int code,
 				      const struct json_result *data)
 {
-	const tal_t *tmpctx = tal_tmpctx(jcon);
 	/* Use this to escape errmsg. */
 	struct json_result *errorres = new_json_result(tmpctx);
 	const char *data_str;
@@ -305,7 +304,6 @@ static void connection_complete_error(struct json_connection *jcon,
 					  json_result_string(errorres),
 					  data_str,
 					  id)));
-	tal_free(tmpctx);
 }
 
 struct json_result *null_response(const tal_t *ctx)

lightningd/lightningd.c

@@ -93,11 +93,9 @@ static const char *daemons[] = {
 void test_daemons(const struct lightningd *ld)
 {
 	size_t i;
-	const tal_t *ctx = tal_tmpctx(ld);
-
 	for (i = 0; i < ARRAY_SIZE(daemons); i++) {
 		int outfd;
-		const char *dpath = path_join(ctx, ld->daemon_dir, daemons[i]);
+		const char *dpath = path_join(tmpctx, ld->daemon_dir, daemons[i]);
 		const char *verstring;
 		pid_t pid = pipecmd(&outfd, NULL, &outfd,
 				    dpath, "--version", NULL);
@@ -105,21 +103,19 @@ void test_daemons(const struct lightningd *ld)
 		log_debug(ld->log, "testing %s", dpath);
 		if (pid == -1)
 			err(1, "Could not run %s", dpath);
-		verstring = grab_fd(ctx, outfd);
+		verstring = grab_fd(tmpctx, outfd);
 		if (!verstring)
 			err(1, "Could not get output from %s", dpath);
 		if (!strstarts(verstring, version())
 		    || verstring[strlen(version())] != '\n')
 			errx(1, "%s: bad version '%s'", daemons[i], verstring);
 	}
-	tal_free(ctx);
 }
 /* Check if all daemons exist in specified directory. */
 static bool has_all_daemons(const char* daemon_dir)
 {
 	size_t i;
 	bool missing_daemon = false;
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 
 	for (i = 0; i < ARRAY_SIZE(daemons); ++i) {
 		if (!path_is_file(path_join(tmpctx, daemon_dir, daemons[i]))) {
@@ -128,13 +124,12 @@ static bool has_all_daemons(const char* daemon_dir)
 		}
 	}
 
-	tal_free(tmpctx);
 	return !missing_daemon;
 }
 
 static const char *find_my_path(const tal_t *ctx, const char *argv0)
 {
-	char *me, *tmpctx = tal_tmpctx(ctx);
+	char *me;
 
 	if (strchr(argv0, PATH_SEP)) {
 		const char *path;
@@ -173,7 +168,6 @@ static const char *find_my_path(const tal_t *ctx, const char *argv0)
 			errx(1, "Cannot find %s in $PATH", argv0);
 	}
 
-	tal_free(tmpctx);
 	return path_dirname(ctx, take(me));
 }
 static const char *find_my_pkglibexec_path(const tal_t *ctx,
@@ -260,7 +254,6 @@ static void daemonize_but_keep_dir(struct lightningd *ld)
 static void pidfile_create(const struct lightningd *ld)
 {
 	char *pid;
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 
 	/* Create PID file */
 	pid_fd = open(ld->pidfile, O_WRONLY|O_CREAT, 0640);
@@ -275,8 +268,6 @@ static void pidfile_create(const struct lightningd *ld)
 	/* Get current PID and write to PID fie */
 	pid = tal_fmt(tmpctx, "%d\n", getpid());
 	write_all(pid_fd, pid, strlen(pid));
-
-	tal_free(tmpctx);
 }
 
 int main(int argc, char *argv[])

lightningd/onchain_control.c

@@ -347,7 +347,6 @@ enum watch_result funding_spent(struct channel *channel,
 	u8 *msg;
 	struct bitcoin_txid our_last_txid;
 	struct htlc_stub *stubs;
-	const tal_t *tmpctx = tal_tmpctx(channel);
 	struct lightningd *ld = channel->peer->ld;
 	struct pubkey final_key;
 
@@ -369,14 +368,12 @@ enum watch_result funding_spent(struct channel *channel,
 	if (!channel->owner) {
 		log_broken(channel->log, "Could not subdaemon onchain: %s",
 			   strerror(errno));
-		tal_free(tmpctx);
 		return KEEP_WATCHING;
 	}
 
 	stubs = wallet_htlc_stubs(tmpctx, ld->wallet, channel);
 	if (!stubs) {
 		log_broken(channel->log, "Could not load htlc_stubs");
-		tal_free(tmpctx);
 		return KEEP_WATCHING;
 	}
 
@@ -384,7 +381,6 @@ enum watch_result funding_spent(struct channel *channel,
 			  channel->final_key_idx)) {
 		log_broken(channel->log, "Could not derive onchain key %"PRIu64,
 			   channel->final_key_idx);
-		tal_free(tmpctx);
 		return KEEP_WATCHING;
 	}
 	/* This could be a mutual close, but it doesn't matter. */
@@ -434,7 +430,6 @@ enum watch_result funding_spent(struct channel *channel,
 
 	watch_tx_and_outputs(channel, tx);
 
-	tal_free(tmpctx);
 	/* We keep watching until peer finally deleted, for reorgs. */
 	return KEEP_WATCHING;
 }

lightningd/opening_control.c

@@ -229,7 +229,6 @@ static void opening_funder_finished(struct subd *openingd, const u8 *resp,
 				    const int *fds,
 				    struct funding_channel *fc)
 {
-	tal_t *tmpctx = tal_tmpctx(fc);
 	u8 *msg, *linear;
 	struct channel_info channel_info;
 	struct bitcoin_tx *fundingtx;
@@ -412,7 +411,6 @@ static void opening_fundee_finished(struct subd *openingd,
 	u64 gossip_index;
 	secp256k1_ecdsa_signature remote_commit_sig;
 	struct bitcoin_tx *remote_commit;
-	const tal_t *tmpctx = tal_tmpctx(uc);
 	struct lightningd *ld = openingd->ld;
 	struct bitcoin_txid funding_txid;
 	u16 funding_outnum;

lightningd/pay.c

@@ -105,14 +105,11 @@ static void payment_trigger_success(struct lightningd *ld,
 				    const struct sha256 *payment_hash,
 				    const struct preimage *payment_preimage)
 {
-	const tal_t *tmpctx = tal_tmpctx(ld);
 	struct sendpay_result *result;
 
 	result = sendpay_result_success(tmpctx, payment_preimage);
 
 	waitsendpay_resolve(tmpctx, ld, payment_hash, result);
-
-	tal_free(tmpctx);
 }
 
 static struct sendpay_result*
@@ -141,7 +138,6 @@ static void payment_route_failure(struct lightningd *ld,
 				  const u8 *onionreply,
 				  const char *details)
 {
-	const tal_t *tmpctx = tal_tmpctx(ld);
 	struct sendpay_result *result;
 
 	result = sendpay_result_route_failure(tmpctx,
@@ -151,8 +147,6 @@ static void payment_route_failure(struct lightningd *ld,
 					      details);
 
 	waitsendpay_resolve(tmpctx, ld, payment_hash, result);
-
-	tal_free(tmpctx);
 }
 
 static struct sendpay_result *
@@ -332,7 +326,6 @@ static void random_mark_channel_unroutable(struct log *log,
 					   struct subd *gossip,
 					   struct short_channel_id *route_channels)
 {
-	const tal_t *tmpctx = tal_tmpctx(gossip);
 	size_t num_channels = tal_count(route_channels);
 	size_t i;
 	const struct short_channel_id *channel;
@@ -352,15 +345,12 @@ static void random_mark_channel_unroutable(struct log *log,
 				 channel));
 	msg = towire_gossip_mark_channel_unroutable(tmpctx, channel);
 	subd_send_msg(gossip, msg);
-
-	tal_free(tmpctx);
 }
 
 static void report_routing_failure(struct log *log,
 				   struct subd *gossip,
 				   struct routing_failure *fail)
 {
-	const tal_t *tmpctx = tal_tmpctx(gossip);
 	u8 *gossip_msg;
 	assert(fail);
 
@@ -379,14 +369,11 @@ static void report_routing_failure(struct log *log,
 						   (u16) fail->failcode,
 						   fail->channel_update);
 	subd_send_msg(gossip, gossip_msg);
-
-	tal_free(tmpctx);
 }
 
 void payment_store(struct lightningd *ld,
 		   const struct sha256 *payment_hash)
 {
-	const tal_t *tmpctx = tal_tmpctx(ld);
 	struct sendpay_command *pc;
 	struct sendpay_command *next;
 	struct sendpay_result *result;
@@ -406,8 +393,6 @@ void payment_store(struct lightningd *ld,
 		tal_steal(tmpctx, pc);
 		pc->cb(result, pc->cbarg);
 	}
-
-	tal_free(tmpctx);
 }
 
 void payment_failed(struct lightningd *ld, const struct htlc_out *hout,
@@ -417,7 +402,6 @@ void payment_failed(struct lightningd *ld, const struct htlc_out *hout,
 	enum onion_type failcode;
 	struct secret *path_secrets;
 	struct wallet_payment *payment;
-	const tal_t *tmpctx = tal_tmpctx(ld);
 	struct routing_failure* fail = NULL;
 	const char *failmsg;
 	bool retry_plausible;
@@ -438,7 +422,6 @@ void payment_failed(struct lightningd *ld, const struct htlc_out *hout,
 					   &hout->payment_hash));
 		wallet_payment_set_status(ld->wallet, &hout->payment_hash,
 					  PAYMENT_FAILED, NULL);
-		tal_free(tmpctx);
 		return;
 	}
 #endif
@@ -516,7 +499,6 @@ void payment_failed(struct lightningd *ld, const struct htlc_out *hout,
 	payment_route_failure(ld, &hout->payment_hash,
 			      retry_plausible, fail, hout->failuremsg,
 			      failmsg);
-	tal_free(tmpctx);
 }
 
 /* Wait for a payment. If cxt is deleted, then cb will
@@ -529,7 +511,6 @@ bool wait_payment(const tal_t *cxt,
 		  void (*cb)(const struct sendpay_result *, void*),
 		  void *cbarg)
 {
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 	struct wallet_payment *payment;
 	struct sendpay_result *result;
 	char const *details;
@@ -610,7 +591,6 @@ bool wait_payment(const tal_t *cxt,
 	abort();
 
 end:
-	tal_free(tmpctx);
 	return cb_not_called;
 }
 
@@ -629,7 +609,6 @@ send_payment(const tal_t *ctx,
 	struct onionpacket *packet;
 	struct secret *path_secrets;
 	enum onion_type failcode;
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	size_t i, n_hops = tal_count(route);
 	struct hop_data *hop_data = tal_arr(tmpctx, struct hop_data, n_hops);
 	struct pubkey *ids = tal_arr(tmpctx, struct pubkey, n_hops);
@@ -776,7 +755,6 @@ send_payment(const tal_t *ctx,
 
 	add_sendpay_waiter(ctx, rhash, ld, cb, cbarg);
 
-	tal_free(tmpctx);
 	return true;
 }
 

lightningd/payalgo.c

@@ -222,12 +222,8 @@ static char const *stringify_route(const tal_t *ctx, struct route_hop *route)
 
 static void log_route(struct pay *pay, struct route_hop *route)
 {
-	const tal_t *tmpctx = tal_tmpctx(pay->try_parent);
-
 	log_info(pay->cmd->ld->log, "pay(%p): sendpay via route: %s",
 			pay, stringify_route(tmpctx, route));
-
-	tal_free(tmpctx);
 }
 
 static void json_pay_sendpay_resume(const struct sendpay_result *r,

lightningd/peer_control.c

@@ -169,7 +169,6 @@ u32 feerate_max(struct lightningd *ld)
 
 static void sign_last_tx(struct channel *channel)
 {
-	const tal_t *tmpctx = tal_tmpctx(channel);
 	u8 *funding_wscript;
 	struct pubkey local_funding_pubkey;
 	struct secrets secrets;
@@ -197,8 +196,6 @@ static void sign_last_tx(struct channel *channel)
 				       &sig,
 				       &channel->channel_info.remote_fundingkey,
 				       &local_funding_pubkey);
-
-	tal_free(tmpctx);
 }
 
 static void remove_sig(struct bitcoin_tx *signed_tx)

lightningd/peer_htlcs.c

@@ -232,7 +232,6 @@ static void handle_localpay(struct htlc_in *hin,
 	struct invoice invoice;
 	struct invoice_details details;
 	struct lightningd *ld = hin->key.channel->peer->ld;
-	const tal_t *tmpctx = tal_tmpctx(ld);
 
 	/* BOLT #4:
 	 *
@@ -308,15 +307,12 @@ static void handle_localpay(struct htlc_in *hin,
 	fulfill_htlc(hin, &details.r);
 	wallet_invoice_resolve(ld->wallet, invoice, hin->msatoshi);
 
-	tal_free(tmpctx);
 	return;
 
 fail:
 	/* Final hop never sends an UPDATE. */
 	assert(!(failcode & UPDATE));
 	local_fail_htlc(hin, failcode, NULL);
-
-	tal_free(tmpctx);
 }
 
 /*
@@ -563,7 +559,6 @@ static bool peer_accepted_htlc(struct channel *channel,
 	u8 *req;
 	struct route_step *rs;
 	struct onionpacket *op;
-	const tal_t *tmpctx = tal_tmpctx(channel);
 	struct lightningd *ld = channel->peer->ld;
 
 	hin = find_htlc_in(&ld->htlcs_in, channel, id);
@@ -604,7 +599,6 @@ static bool peer_accepted_htlc(struct channel *channel,
 				   "bad onion in got_revoke: %s",
 				   tal_hexstr(channel, hin->onion_routing_packet,
 					     sizeof(hin->onion_routing_packet)));
-			tal_free(tmpctx);
 			return false;
 		}
 		/* FIXME: could be bad version, bad key. */
@@ -659,7 +653,6 @@ out:
 	log_debug(channel->log, "their htlc %"PRIu64" %s",
 		  id, *failcode ? onion_type_name(*failcode) : "locked");
 
-	tal_free(tmpctx);
 	return true;
 }
 

lightningd/subd.c

@@ -285,7 +285,6 @@ static struct io_plan *sd_msg_reply(struct io_conn *conn, struct subd *sd,
 {
 	int type = fromwire_peektype(sd->msg_in);
 	bool freed = false;
-	const tal_t *tmpctx = tal_tmpctx(conn);
 	int *fds_in;
 
 	log_debug(sd->log, "REPLY %s with %zu fds",
@@ -309,7 +308,6 @@ static struct io_plan *sd_msg_reply(struct io_conn *conn, struct subd *sd,
 	/* Find out if they freed it. */
 	tal_add_destructor2(sd, mark_freed, &freed);
 	sr->replycb(sd, sd->msg_in, fds_in, sr->replycb_data);
-	tal_free(tmpctx);
 
 	if (freed)
 		return io_close(conn);
@@ -428,7 +426,6 @@ static bool handle_set_billboard(struct subd *sd, const u8 *msg)
 static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 {
 	int type = fromwire_peektype(sd->msg_in);
-	const tal_t *tmpctx;
 	struct subd_req *sr;
 	struct db *db = sd->ld->wallet->db;
 	struct io_plan *plan;
@@ -452,8 +449,7 @@ static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 		goto out;
 	}
 
-	/* If not stolen, we'll free this below. */
+	/* If not stolen, we'll free this later. */
-	tmpctx = tal_tmpctx(sd);
 	tal_steal(tmpctx, sd->msg_in);
 
 	/* We handle status messages ourselves. */
@@ -487,7 +483,6 @@ static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 			if (!sd->fds_in) {
 				/* Don't free msg_in: we go around again. */
 				tal_steal(sd, sd->msg_in);
-				tal_free(tmpctx);
 				plan = sd_collect_fds(conn, sd, 2);
 				goto out;
 			}
@@ -518,7 +513,6 @@ static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 			assert(!sd->fds_in);
 			/* Don't free msg_in: we go around again. */
 			tal_steal(sd, sd->msg_in);
-			tal_free(tmpctx);
 			plan = sd_collect_fds(conn, sd, i);
 			goto out;
 		}
@@ -527,7 +521,6 @@ static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
 next:
 	sd->msg_in = NULL;
 	sd->fds_in = tal_free(sd->fds_in);
-	tal_free(tmpctx);
 
 	plan = io_read_wire(conn, sd, &sd->msg_in, sd_msg_read, sd);
 	goto out;

lightningd/test/run-commit_tx.c

@@ -60,7 +60,6 @@ static bool pubkey_from_secret(const struct secret *secret,
 static void tx_must_be_eq(const struct bitcoin_tx *a,
 			  const struct bitcoin_tx *b)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 *lina, *linb;
 	size_t i;
 
@@ -88,8 +87,6 @@ static void tx_must_be_eq(const struct bitcoin_tx *a,
 		     "%s",
 		     tal_hex(tmpctx, lina),
 		     tal_hex(tmpctx, linb));
-
-	tal_free(tmpctx);
 }
 
 /* BOLT #3:
@@ -189,7 +186,6 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 			 const struct pubkey *remote_revocation_key,
 			 u32 feerate_per_kw)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	size_t i, n;
 	struct bitcoin_txid txid;
 	struct bitcoin_tx **htlc_tx;
@@ -301,7 +297,6 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 		       htlc->id,
 		       tal_hex(tmpctx, linearize_tx(tmpctx, htlc_tx[i])));
 	}
-	tal_free(tmpctx);
 }
 
 static void report(struct bitcoin_tx *tx,
@@ -322,7 +317,6 @@ static void report(struct bitcoin_tx *tx,
 		   u32 feerate_per_kw,
 		   const struct htlc **htlc_map)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	char *txhex;
 	secp256k1_ecdsa_signature localsig, remotesig;
 
@@ -354,7 +348,6 @@ static void report(struct bitcoin_tx *tx,
 		     remotekey, remote_htlckey,
 		     remote_revocation_key,
 		     feerate_per_kw);
-	tal_free(tmpctx);
 }
 
 #ifdef DEBUG
@@ -425,7 +418,6 @@ static const struct htlc **invert_htlcs(const struct htlc **htlcs)
 
 int main(void)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	struct bitcoin_txid funding_txid;
 	u64 funding_amount_satoshi, dust_limit_satoshi;
 	u32 feerate_per_kw;
@@ -454,11 +446,14 @@ int main(void)
 	u8 *wscript;
 	unsigned int funding_output_index;
 	u64 commitment_number, cn_obscurer, to_local_msat, to_remote_msat;
-	const struct htlc **htlcs = setup_htlcs(tmpctx), **htlc_map, **htlc_map2,
+	const struct htlc **htlcs, **htlc_map, **htlc_map2, **inv_htlcs;
-		**inv_htlcs = invert_htlcs(htlcs);
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
+
+	htlcs = setup_htlcs(tmpctx);
+	inv_htlcs = invert_htlcs(htlcs);
 
 	/* BOLT #3:
 	 *

lightningd/test/run-cryptomsg.c

@@ -98,13 +98,13 @@ static struct secret secret_from_hex(const char *hex)
 
 int main(void)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	struct peer_crypto_state cs_out, cs_in;
 	struct secret sk, rk, ck;
-	const void *msg = tal_dup_arr(tmpctx, char, "hello", 5, 0);
+	const void *msg;
 	size_t i;
 
-	trc = tal_tmpctx(tmpctx);
+	setup_tmpctx();
+	msg = tal_dup_arr(tmpctx, char, "hello", 5, 0);
 
 	/* BOLT #8:
 	 *
@@ -125,8 +125,8 @@ int main(void)
 	cs_out.cs.sk = cs_in.cs.rk = sk;
 	cs_out.cs.rk = cs_in.cs.sk = rk;
 	cs_out.cs.s_ck = cs_out.cs.r_ck = cs_in.cs.s_ck = cs_in.cs.r_ck = ck;
-	init_peer_crypto_state(tmpctx, &cs_in);
+	init_peer_crypto_state((void *)tmpctx, &cs_in);
-	init_peer_crypto_state(tmpctx, &cs_out);
+	init_peer_crypto_state((void *)tmpctx, &cs_out);
 
 	for (i = 0; i < 1002; i++) {
 		write_buf = tal_arr(tmpctx, char, 0);

lightningd/test/run-find_my_path.c

@@ -136,10 +136,12 @@ char *opt_subd_dev_disconnect(const char *optarg UNNEEDED, struct lightningd *ld
 #undef main
 int main(int argc UNUSED, char *argv[] UNUSED)
 {
-	char *tmpctx = tal_tmpctx(NULL);
 	char *argv0;
 	/* We're assuming we're run from top build dir. */
-	const char *answer = path_canon(tmpctx, "lightningd/test");
+	const char *answer;
+
+	setup_tmpctx();
+	answer = path_canon(tmpctx, "lightningd/test");
 
 	/* Various different ways we could find ourselves. */
 	argv0 = path_join(tmpctx,

lightningd/test/run-funding_tx.c

@@ -41,7 +41,6 @@ static struct privkey privkey_from_hex(const char *hex)
 
 int main(void)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	struct bitcoin_tx *input, *funding;
 	u64 fee;
 	struct pubkey local_funding_pubkey, remote_funding_pubkey;
@@ -49,7 +48,7 @@ int main(void)
 	struct pubkey inputkey;
 	bool testnet;
 	struct utxo utxo;
-	const struct utxo **utxomap = tal_arr(tmpctx, const struct utxo *, 1);
+	const struct utxo **utxomap;
 	u64 funding_satoshis;
 	u16 funding_outnum;
 	u8 *subscript;
@@ -58,6 +57,7 @@ int main(void)
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
+	setup_tmpctx();
 
 	/* BOLT #3:
 	 *
@@ -109,6 +109,7 @@ int main(void)
 	printf("input[0] satoshis: %"PRIu64"\n", utxo.amount);
 	printf("funding satoshis: %"PRIu64"\n", funding_satoshis);
 
+	utxomap = tal_arr(tmpctx, const struct utxo *, 1);
 	utxomap[0] = &utxo;
 	funding = funding_tx(tmpctx, &funding_outnum, utxomap,
 			     funding_satoshis,

onchaind/onchain.c

@@ -1325,7 +1325,6 @@ static void handle_our_unilateral(const struct bitcoin_tx *tx,
 				  const secp256k1_ecdsa_signature *remote_htlc_sigs,
 				  struct tracked_output **outs)
 {
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 **htlc_scripts;
 	u8 *local_wscript, *script[NUM_SIDES];
 	struct pubkey local_per_commitment_point;
@@ -1550,7 +1549,6 @@ static void handle_our_unilateral(const struct bitcoin_tx *tx,
 	note_missing_htlcs(htlc_scripts, htlcs,
 			   tell_if_missing, tell_immediately);
 	wait_for_resolved(outs);
-	tal_free(tmpctx);
 }
 
 /* We produce individual penalty txs.  It's less efficient, but avoids them
@@ -1558,7 +1556,6 @@ static void handle_our_unilateral(const struct bitcoin_tx *tx,
  * delay */
 static void steal_to_them_output(struct tracked_output *out)
 {
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 *wscript;
 	struct bitcoin_tx *tx;
 	enum tx_type tx_type = OUR_PENALTY_TX;
@@ -1582,7 +1579,6 @@ static void steal_to_them_output(struct tracked_output *out)
 		      &tx_type);
 
 	propose_resolution(out, tx, 0, tx_type);
-	tal_free(tmpctx);
 }
 
 static void steal_htlc(struct tracked_output *out)
@@ -1631,7 +1627,6 @@ static void handle_their_cheat(const struct bitcoin_tx *tx,
 			       const bool *tell_immediately,
 			       struct tracked_output **outs)
 {
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 **htlc_scripts;
 	u8 *remote_wscript, *script[NUM_SIDES];
 	struct keyset *ks;
@@ -1874,7 +1869,6 @@ static void handle_their_cheat(const struct bitcoin_tx *tx,
 	note_missing_htlcs(htlc_scripts, htlcs,
 			   tell_if_missing, tell_immediately);
 	wait_for_resolved(outs);
-	tal_free(tmpctx);
 }
 
 static void handle_their_unilateral(const struct bitcoin_tx *tx,
@@ -1894,7 +1888,6 @@ static void handle_their_unilateral(const struct bitcoin_tx *tx,
 				    const bool *tell_immediately,
 				    struct tracked_output **outs)
 {
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 **htlc_scripts;
 	u8 *remote_wscript, *script[NUM_SIDES];
 	struct keyset *ks;
@@ -2103,12 +2096,11 @@ static void handle_their_unilateral(const struct bitcoin_tx *tx,
 	note_missing_htlcs(htlc_scripts, htlcs,
 			   tell_if_missing, tell_immediately);
 	wait_for_resolved(outs);
-	tal_free(tmpctx);
 }
 
 int main(int argc, char *argv[])
 {
-	const tal_t *ctx = tal_tmpctx(NULL);
+	const tal_t *ctx = tal(NULL, char);
 	u8 *msg;
 	struct privkey seed;
 	struct pubkey remote_payment_basepoint, remote_htlc_basepoint,
@@ -2135,7 +2127,7 @@ int main(int argc, char *argv[])
 
 	missing_htlc_msgs = tal_arr(ctx, u8 *, 0);
 
-	msg = wire_sync_read(ctx, REQ_FD);
+	msg = wire_sync_read(tmpctx, REQ_FD);
 	if (!fromwire_onchain_init(ctx, msg,
 				   &seed, &shachain,
 				   &funding_amount_satoshi,
@@ -2174,7 +2166,7 @@ int main(int argc, char *argv[])
 			      "Can't allocate %"PRIu64" htlcs", num_htlcs);
 
 	for (u64 i = 0; i < num_htlcs; i++) {
-		msg = wire_sync_read(ctx, REQ_FD);
+		msg = wire_sync_read(tmpctx, REQ_FD);
 		if (!fromwire_onchain_htlc(msg, &htlcs[i],
 					   &tell_if_missing[i],
 					   &tell_immediately[i]))
@@ -2310,7 +2302,7 @@ int main(int argc, char *argv[])
 				      "Unknown commitment index %"PRIu64
 				      " for tx %s",
 				      commit_num,
-				      type_to_string(ctx, struct bitcoin_tx,
+				      type_to_string(tmpctx, struct bitcoin_tx,
 						     tx));
 	}
 

wallet/invoices.c

@@ -56,7 +56,6 @@ static void trigger_invoice_waiter_resolve(struct invoices *invoices,
 					   u64 id,
 					   const struct invoice *invoice)
 {
-	const tal_t *tmpctx = tal_tmpctx(invoices);
 	struct invoice_waiter *w;
 	struct invoice_waiter *n;
 
@@ -67,15 +66,12 @@ static void trigger_invoice_waiter_resolve(struct invoices *invoices,
 		tal_steal(tmpctx, w);
 		trigger_invoice_waiter(w, invoice);
 	}
-
-	tal_free(tmpctx);
 }
 static void
 trigger_invoice_waiter_expire_or_delete(struct invoices *invoices,
 					u64 id,
 					const struct invoice *invoice)
 {
-	const tal_t *tmpctx = tal_tmpctx(invoices);
 	struct invoice_waiter *w;
 	struct invoice_waiter *n;
 
@@ -86,8 +82,6 @@ trigger_invoice_waiter_expire_or_delete(struct invoices *invoices,
 		tal_steal(tmpctx, w);
 		trigger_invoice_waiter(w, invoice);
 	}
-
-	tal_free(tmpctx);
 }
 
 static void wallet_stmt2invoice_details(const tal_t *ctx,
@@ -162,7 +156,6 @@ struct invoice_id_node {
 static void install_expiration_timer(struct invoices *invoices);
 static void trigger_expiration(struct invoices *invoices)
 {
-	const tal_t *tmpctx = tal_tmpctx(invoices);
 	struct list_head idlist;
 	struct invoice_id_node *idn;
 	u64 now = time_now().ts.tv_sec;
@@ -201,8 +194,6 @@ static void trigger_expiration(struct invoices *invoices)
 	}
 
 	install_expiration_timer(invoices);
-
-	tal_free(tmpctx);
 }
 
 static void install_expiration_timer(struct invoices *invoices)
@@ -447,7 +438,6 @@ void invoices_resolve(struct invoices *invoices,
 	sqlite3_stmt *stmt;
 	s64 pay_index;
 	u64 paid_timestamp;
-	const tal_t *tmpctx = tal_tmpctx(NULL);
 
 	/* Assign a pay-index. */
 	pay_index = get_next_pay_index(invoices->db);
@@ -470,9 +460,6 @@ void invoices_resolve(struct invoices *invoices,
 
 	/* Tell all the waiters about the paid invoice. */
 	trigger_invoice_waiter_resolve(invoices, invoice.id, &invoice);
-
-	/* Free all watchers. */
-	tal_free(tmpctx);
 }
 
 /* Called when an invoice waiter is destructed. */

wallet/test/run-wallet.c

@@ -961,8 +961,10 @@ static bool test_payment_crud(struct lightningd *ld, const tal_t *ctx)
 int main(void)
 {
 	bool ok = true;
-	tal_t *tmpctx = tal_tmpctx(NULL);
+	struct lightningd *ld;
-	struct lightningd *ld = tal(tmpctx, struct lightningd);
+
+	setup_tmpctx();
+	ld = tal(tmpctx, struct lightningd);
 
 	/* Only elements in ld we should access */
 	list_head_init(&ld->peers);

wallet/txfilter.c

@@ -63,7 +63,6 @@ void txfilter_add_scriptpubkey(struct txfilter *filter, const u8 *script TAKES)
 void txfilter_add_derkey(struct txfilter *filter,
 			 const u8 derkey[PUBKEY_DER_LEN])
 {
-	tal_t *tmpctx = tal_tmpctx(filter);
 	u8 *skp, *p2sh;
 
 	skp = scriptpubkey_p2wpkh_derkey(tmpctx, derkey);
@@ -71,8 +70,6 @@ void txfilter_add_derkey(struct txfilter *filter,
 
 	txfilter_add_scriptpubkey(filter, take(skp));
 	txfilter_add_scriptpubkey(filter, take(p2sh));
-
-	tal_free(tmpctx);
 }
 
 

wallet/wallet.c

@@ -528,7 +528,6 @@ bool wallet_peer_by_nodeid(struct wallet *w, const struct pubkey *nodeid,
 {
 	bool ok;
 	const unsigned char *addrstr;
-	tal_t *tmpctx = tal_tmpctx(w);
 	sqlite3_stmt *stmt = db_prepare(w->db, "SELECT id, node_id, address FROM peers WHERE node_id=?;");
 	sqlite3_bind_pubkey(stmt, 1, nodeid);
 
@@ -545,7 +544,6 @@ bool wallet_peer_by_nodeid(struct wallet *w, const struct pubkey *nodeid,
 		peer->dbid = 0;
 	}
 	sqlite3_finalize(stmt);
-	tal_free(tmpctx);
 	return ok;
 }
 
@@ -584,7 +582,6 @@ static struct channel *wallet_stmt2channel(const tal_t *ctx, struct wallet *w, s
 	secp256k1_ecdsa_signature last_sig;
 	u8 *remote_shutdown_scriptpubkey;
 	struct changed_htlc *last_sent_commit;
-	const tal_t *tmpctx = tal_tmpctx(ctx);
 	s64 final_key_idx;
 
 	peer_dbid = sqlite3_column_int64(stmt, 1);
@@ -592,7 +589,6 @@ static struct channel *wallet_stmt2channel(const tal_t *ctx, struct wallet *w, s
 	if (!peer) {
 		peer = wallet_peer_load(w, peer_dbid);
 		if (!peer) {
-			tal_free(tmpctx);
 			return NULL;
 		}
 	}
@@ -638,14 +634,12 @@ static struct channel *wallet_stmt2channel(const tal_t *ctx, struct wallet *w, s
 				   &channel_info.their_config);
 
 	if (!ok) {
-		tal_free(tmpctx);
 		return NULL;
 	}
 
 	final_key_idx = sqlite3_column_int64(stmt, 29);
 	if (final_key_idx < 0) {
 		log_broken(w->log, "%s: Final key < 0", __func__);
-		tal_free(tmpctx);
 		return NULL;
 	}
 	chan = new_channel(peer, sqlite3_column_int64(stmt, 0),
@@ -678,7 +672,6 @@ static struct channel *wallet_stmt2channel(const tal_t *ctx, struct wallet *w, s
 			   last_sent_commit,
 			   sqlite3_column_int64(stmt, 35));
 
-	tal_free(tmpctx);
 	return chan;
 }
 
@@ -863,7 +856,6 @@ u64 wallet_get_channel_dbid(struct wallet *wallet)
 
 void wallet_channel_save(struct wallet *w, struct channel *chan)
 {
-	tal_t *tmpctx = tal_tmpctx(w);
 	sqlite3_stmt *stmt;
 	assert(chan->first_blocknum);
 
@@ -962,13 +954,10 @@ void wallet_channel_save(struct wallet *w, struct channel *chan)
 		sqlite3_bind_int64(stmt, 3, chan->dbid);
 		db_exec_prepared(w->db, stmt);
 	}
-
-	tal_free(tmpctx);
 }
 
 void wallet_channel_insert(struct wallet *w, struct channel *chan)
 {
-	tal_t *tmpctx = tal_tmpctx(w);
 	sqlite3_stmt *stmt;
 
 	if (chan->peer->dbid == 0) {
@@ -999,7 +988,6 @@ void wallet_channel_insert(struct wallet *w, struct channel *chan)
 
 	/* Now save path as normal */
 	wallet_channel_save(w, chan);
-	tal_free(tmpctx);
 }
 
 void wallet_channel_delete(struct wallet *w, u64 wallet_id)
@@ -1099,7 +1087,6 @@ int wallet_extract_owned_outputs(struct wallet *w, const struct bitcoin_tx *tx,
 void wallet_htlc_save_in(struct wallet *wallet,
 			 const struct channel *chan, struct htlc_in *in)
 {
-	tal_t *tmpctx = tal_tmpctx(wallet);
 	sqlite3_stmt *stmt;
 
 	stmt = db_prepare(
@@ -1136,14 +1123,12 @@ void wallet_htlc_save_in(struct wallet *wallet,
 
 	db_exec_prepared(wallet->db, stmt);
 	in->dbid = sqlite3_last_insert_rowid(wallet->db->sql);
-	tal_free(tmpctx);
 }
 
 void wallet_htlc_save_out(struct wallet *wallet,
 			  const struct channel *chan,
 			  struct htlc_out *out)
 {
-	tal_t *tmpctx = tal_tmpctx(wallet);
 	sqlite3_stmt *stmt;
 
 	/* We absolutely need the incoming HTLC to be persisted before
@@ -1184,7 +1169,6 @@ void wallet_htlc_save_out(struct wallet *wallet,
 	db_exec_prepared(wallet->db, stmt);
 
 	out->dbid = sqlite3_last_insert_rowid(wallet->db->sql);
-	tal_free(tmpctx);
 }
 
 void wallet_htlc_update(struct wallet *wallet, const u64 htlc_dbid,
@@ -1771,7 +1755,6 @@ void wallet_payment_set_failinfo(struct wallet *wallet,
 				 const u8 *failupdate /*tal_arr*/)
 {
 	sqlite3_stmt *stmt;
-	const tal_t *tmpctx = tal_tmpctx(wallet);
 	struct short_channel_id *scid;
 
 	stmt = db_prepare(wallet->db,
@@ -1815,8 +1798,6 @@ void wallet_payment_set_failinfo(struct wallet *wallet,
 	sqlite3_bind_sha256(stmt, 8, payment_hash);
 
 	db_exec_prepared(wallet->db, stmt);
-
-	tal_free(tmpctx);
 }
 
 const struct wallet_payment **

wire/towire.c

@@ -159,10 +159,8 @@ void towire_wirestring(u8 **pptr, const char *str)
 
 void towire_bitcoin_tx(u8 **pptr, const struct bitcoin_tx *tx)
 {
-	tal_t *tmpctx = tal_tmpctx(NULL);
 	u8 *lin = linearize_tx(tmpctx, tx);
 	towire_u8_array(pptr, lin, tal_len(lin));
-	tal_free(tmpctx);
 }
 
 void towire_siphash_seed(u8 **pptr, const struct siphash_seed *seed)