0001-Add-logtape.c-Valgrind-suppression.patch

From e51b9d411a859072e6a3f8b2f77e32e0f47d409a Mon Sep 17 00:00:00 2001
From: Peter Geoghegan <pg@bowt.ie>
Date: Fri, 2 Feb 2018 17:47:13 -0800
Subject: [PATCH] Add logtape.c Valgrind suppression.

LogicalTapeFreeze() may write out its first block when it is dirty but
not full, and then immediately read the first block back in from its
BufFile as a BLCKSZ-width block.  This can only occur in rare cases
where next to no tuples were written out, which is only possible with
parallel external tuplesorts.  While this is pointless, it's also
harmless.

However, this issue causes Valgrind to complain about a write() of
uninitialized bytes, so a suppression is needed.  This is because
BufFile block reading will flush out its whole dirty stdio-style temp
buffer, writing bytes that include values originating from
poisoned/uninitialized logtape.c buffer bytes.

Author: Peter Geoghegan
---
 src/tools/valgrind.supp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/tools/valgrind.supp b/src/tools/valgrind.supp
index af03051..22039c0 100644
--- a/src/tools/valgrind.supp
+++ b/src/tools/valgrind.supp
@@ -112,6 +112,16 @@
 	fun:BootStrapXLOG
 }
 
+# LogicalTapeFreeze() needs this for calls from parallel worker with few tuples
+{
+	padding_buffile_dump_buffer
+	Memcheck:Param
+	write(buf)
+
+	...
+	fun:LogicalTapeFreeze
+}
+
 {
 	bootstrap_write_relmap_overlap
 	Memcheck:Overlap
-- 
2.7.4