From a04f0c3c24efc8aeb524fb9e96f6a90345238e64 Mon Sep 17 00:00:00 2001
From: Peter Geoghegan <pg@bowt.ie>
Date: Wed, 22 Apr 2020 19:51:43 -0700
Subject: [PATCH 2/2] Valgrind instrumentation

---
 src/backend/storage/buffer/bufmgr.c | 44 +++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index f9980cf80c..774a161534 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -49,6 +49,7 @@
 #include "storage/proc.h"
 #include "storage/smgr.h"
 #include "storage/standby.h"
+#include "utils/memdebug.h"
 #include "utils/ps_status.h"
 #include "utils/rel.h"
 #include "utils/resowner_private.h"
@@ -875,6 +876,13 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 
 	bufBlock = isLocalBuf ? LocalBufHdrGetBlock(bufHdr) : BufHdrGetBlock(bufHdr);
 
+#ifdef USE_VALGRIND
+	if (!isLocalBuf)
+	{
+		Buffer b = BufferDescriptorGetBuffer(bufHdr);
+		VALGRIND_MAKE_MEM_DEFINED(BufferGetPage(b), BLCKSZ);
+	}
+#endif
 	if (isExtend)
 	{
 		/* new buffers are zero-filled */
@@ -1039,6 +1047,12 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 		buf = GetBufferDescriptor(buf_id);
 
 		valid = PinBuffer(buf, strategy);
+#ifdef USE_VALGRIND
+		{
+			Buffer b = BufferDescriptorGetBuffer(buf);
+			VALGRIND_MAKE_MEM_DEFINED(BufferGetPage(b), BLCKSZ);
+		}
+#endif
 
 		/* Can release the mapping lock as soon as we've pinned it */
 		LWLockRelease(newPartitionLock);
@@ -1136,6 +1150,12 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 
 					/* Read the LSN while holding buffer header lock */
 					buf_state = LockBufHdr(buf);
+#ifdef USE_VALGRIND
+					{
+						Buffer b = BufferDescriptorGetBuffer(buf);
+						VALGRIND_MAKE_MEM_DEFINED(BufferGetPage(b), BLCKSZ);
+					}
+#endif
 					lsn = BufferGetLSN(buf);
 					UnlockBufHdr(buf, buf_state);
 
@@ -1633,6 +1653,12 @@ PinBuffer(BufferDesc *buf, BufferAccessStrategy strategy)
 											   buf_state))
 			{
 				result = (buf_state & BM_VALID) != 0;
+#ifdef USE_VALGRIND
+				{
+					Buffer b = BufferDescriptorGetBuffer(buf);
+					VALGRIND_MAKE_MEM_DEFINED(BufferGetPage(b), BLCKSZ);
+				}
+#endif
 				break;
 			}
 		}
@@ -1731,6 +1757,12 @@ UnpinBuffer(BufferDesc *buf, bool fixOwner)
 		/* I'd better not still hold any locks on the buffer */
 		Assert(!LWLockHeldByMe(BufferDescriptorGetContentLock(buf)));
 		Assert(!LWLockHeldByMe(BufferDescriptorGetIOLock(buf)));
+#ifdef USE_VALGRIND
+		{
+			Buffer b = BufferDescriptorGetBuffer(buf);
+			VALGRIND_MAKE_MEM_NOACCESS(BufferGetPage(b), BLCKSZ);
+		}
+#endif
 
 		/*
 		 * Decrement the shared reference count.
@@ -2007,6 +2039,12 @@ BufferSync(int flags)
 		 */
 		if (pg_atomic_read_u32(&bufHdr->state) & BM_CHECKPOINT_NEEDED)
 		{
+#ifdef USE_VALGRIND
+			{
+				Buffer b = BufferDescriptorGetBuffer(bufHdr);
+				VALGRIND_MAKE_MEM_DEFINED(BufferGetPage(b), BLCKSZ);
+			}
+#endif
 			if (SyncOneBuffer(buf_id, false, &wb_context) & BUF_WRITTEN)
 			{
 				TRACE_POSTGRESQL_BUFFER_SYNC_WRITTEN(buf_id);
@@ -2730,6 +2768,12 @@ FlushBuffer(BufferDesc *buf, SMgrRelation reln)
 	 * Run PageGetLSN while holding header lock, since we don't have the
 	 * buffer locked exclusively in all cases.
 	 */
+#ifdef USE_VALGRIND
+	{
+		Buffer b = BufferDescriptorGetBuffer(buf);
+		VALGRIND_MAKE_MEM_DEFINED(BufferGetPage(b), BLCKSZ);
+	}
+#endif
 	recptr = BufferGetLSN(buf);
 
 	/* To check if block content changes while flushing. - vadim 01/17/97 */
-- 
2.25.1