From 1d04a59be31bf004b880226be0e3fe84acff2815 Mon Sep 17 00:00:00 2001
From: Fujii Masao <fujii@postgresql.org>
Date: Wed, 22 Feb 2017 03:11:58 +0900
Subject: [PATCH] Make walsender always initialize the buffers.
Walsender uses the local buffers for each outgoing and incoming message.
Previously when creating replication slot, walsender forgot to initialize
one of them and which can cause the segmentation fault error. To fix this
issue, this commit changes walsender so that it always initialize them
before it executes the requested replication command.
Back-patch to 9.4 where replication slot was introduced.
Problem report and initial patch by Stas Kelvich, modified by me.
Report: https://www.postgresql.org/message-id/A1E9CB90-1FAC-4CAD-8DBA-9AA62A6E97C5@postgrespro.ru
---
src/backend/replication/walsender.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index ba506e28bc2..7a40863384f 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -773,8 +773,6 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
cmd->temporary ? RS_TEMPORARY : RS_EPHEMERAL);
}
- initStringInfo(&output_message);
-
if (cmd->kind == REPLICATION_KIND_LOGICAL)
{
LogicalDecodingContext *ctx;
@@ -1258,6 +1256,14 @@ exec_replication_command(const char *cmd_string)
cmd_node = replication_parse_result;
+ /*
+ * Allocate buffers that will be used for each outgoing and incoming
+ * message. We do this just once per command to reduce palloc overhead.
+ */
+ initStringInfo(&output_message);
+ initStringInfo(&reply_message);
+ initStringInfo(&tmpbuf);
+
switch (cmd_node->type)
{
case T_IdentifySystemCmd:
@@ -1736,14 +1742,6 @@ WalSndCheckTimeOut(TimestampTz now)
static void
WalSndLoop(WalSndSendDataCallback send_data)
{
- /*
- * Allocate buffers that will be used for each outgoing and incoming
- * message. We do this just once to reduce palloc overhead.
- */
- initStringInfo(&output_message);
- initStringInfo(&reply_message);
- initStringInfo(&tmpbuf);
-
/*
* Initialize the last reply timestamp. That enables timeout processing
* from hereon.
--
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