From 6e4bf4ecd3c2a266870139462a079809dfe7ab8c Mon Sep 17 00:00:00 2001
From: Fujii Masao <fujii@postgresql.org>
Date: Fri, 3 Apr 2015 21:55:37 +0900
Subject: [PATCH] Fix error handling of XLogReaderAllocate in case of OOM
Similarly to previous fix 9b8d478, commit 2c03216 has switched
XLogReaderAllocate() to use a set of palloc calls instead of malloc,
causing any callers of this function to fail with an error instead of
receiving a NULL pointer in case of out-of-memory error. Fix this by
using palloc_extended with MCXT_ALLOC_NO_OOM that will safely return
NULL in case of an OOM.
Michael Paquier, slightly modified by me.
---
src/backend/access/transam/xlog.c | 7 ++++--
src/backend/access/transam/xlogreader.c | 30 +++++++++++++++++------
src/backend/replication/logical/logical.c | 5 ++++
src/bin/pg_rewind/parsexlog.c | 6 +++++
4 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 346a2b39f85..24cf520e579 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1062,8 +1062,11 @@ XLogInsertRecord(XLogRecData *rdata, XLogRecPtr fpw_lsn)
if (!debug_reader)
debug_reader = XLogReaderAllocate(NULL, NULL);
- if (!debug_reader ||
- !DecodeXLogRecord(debug_reader, (XLogRecord *) recordBuf.data,
+ if (!debug_reader)
+ {
+ appendStringInfo(&buf, "error decoding record: out of memory");
+ }
+ else if (!DecodeXLogRecord(debug_reader, (XLogRecord *) recordBuf.data,
&errormsg))
{
appendStringInfo(&buf, "error decoding record: %s",
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index ffdc9753ad7..a4124d90d1b 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -58,15 +58,18 @@ report_invalid_record(XLogReaderState *state, const char *fmt,...)
/*
* Allocate and initialize a new XLogReader.
*
- * The returned XLogReader is palloc'd. (In FRONTEND code, that means that
- * running out-of-memory causes an immediate exit(1).
+ * Returns NULL if the xlogreader couldn't be allocated.
*/
XLogReaderState *
XLogReaderAllocate(XLogPageReadCB pagereadfunc, void *private_data)
{
XLogReaderState *state;
- state = (XLogReaderState *) palloc0(sizeof(XLogReaderState));
+ state = (XLogReaderState *)
+ palloc_extended(sizeof(XLogReaderState),
+ MCXT_ALLOC_NO_OOM | MCXT_ALLOC_ZERO);
+ if (!state)
+ return NULL;
state->max_block_id = -1;
@@ -74,17 +77,30 @@ XLogReaderAllocate(XLogPageReadCB pagereadfunc, void *private_data)
* Permanently allocate readBuf. We do it this way, rather than just
* making a static array, for two reasons: (1) no need to waste the
* storage in most instantiations of the backend; (2) a static char array
- * isn't guaranteed to have any particular alignment, whereas palloc()
- * will provide MAXALIGN'd storage.
+ * isn't guaranteed to have any particular alignment, whereas
+ * palloc_extended() will provide MAXALIGN'd storage.
*/
- state->readBuf = (char *) palloc(XLOG_BLCKSZ);
+ state->readBuf = (char *) palloc_extended(XLOG_BLCKSZ,
+ MCXT_ALLOC_NO_OOM);
+ if (!state->readBuf)
+ {
+ pfree(state);
+ return NULL;
+ }
state->read_page = pagereadfunc;
/* system_identifier initialized to zeroes above */
state->private_data = private_data;
/* ReadRecPtr and EndRecPtr initialized to zeroes above */
/* readSegNo, readOff, readLen, readPageTLI initialized to zeroes above */
- state->errormsg_buf = palloc(MAX_ERRORMSG_LEN + 1);
+ state->errormsg_buf = palloc_extended(MAX_ERRORMSG_LEN + 1,
+ MCXT_ALLOC_NO_OOM);
+ if (!state->errormsg_buf)
+ {
+ pfree(state->readBuf);
+ pfree(state);
+ return NULL;
+ }
state->errormsg_buf[0] = '\0';
/*
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c
index 30baa45383a..774ebbc749c 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -163,6 +163,11 @@ StartupDecodingContext(List *output_plugin_options,
ctx->slot = slot;
ctx->reader = XLogReaderAllocate(read_page, ctx);
+ if (!ctx->reader)
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+
ctx->reader->private_data = ctx;
ctx->reorder = ReorderBufferAllocate();
diff --git a/src/bin/pg_rewind/parsexlog.c b/src/bin/pg_rewind/parsexlog.c
index 0787ca12a78..3cf96abd085 100644
--- a/src/bin/pg_rewind/parsexlog.c
+++ b/src/bin/pg_rewind/parsexlog.c
@@ -70,6 +70,8 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, TimeLineID tli,
private.datadir = datadir;
private.tli = tli;
xlogreader = XLogReaderAllocate(&SimpleXLogPageRead, &private);
+ if (xlogreader == NULL)
+ pg_fatal("out of memory");
do
{
@@ -121,6 +123,8 @@ readOneRecord(const char *datadir, XLogRecPtr ptr, TimeLineID tli)
private.datadir = datadir;
private.tli = tli;
xlogreader = XLogReaderAllocate(&SimpleXLogPageRead, &private);
+ if (xlogreader == NULL)
+ pg_fatal("out of memory");
record = XLogReadRecord(xlogreader, ptr, &errormsg);
if (record == NULL)
@@ -171,6 +175,8 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, TimeLineID tli,
private.datadir = datadir;
private.tli = tli;
xlogreader = XLogReaderAllocate(&SimpleXLogPageRead, &private);
+ if (xlogreader == NULL)
+ pg_fatal("out of memory");
searchptr = forkptr;
for (;;)
--
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