From 08bf4d797bc5f5143bd025895a6d618b7ca9fb12 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 3 Apr 2001 04:07:02 +0000
Subject: [PATCH] Check for failure of malloc() and realloc() when allocating
space for VFD entries. On platforms where dereferencing a null pointer
doesn't lead to coredump, it's possible that this omission could have led to
unpleasant behavior like deleting the wrong file.
---
src/backend/storage/file/fd.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 5967ae18050..27e53f41c8b 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.75 2001/04/03 02:31:52 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.76 2001/04/03 04:07:02 tgl Exp $
*
* NOTES:
*
@@ -484,7 +484,8 @@ AllocateVfd(void)
{
/* initialize header entry first time through */
VfdCache = (Vfd *) malloc(sizeof(Vfd));
- Assert(VfdCache != NULL);
+ if (VfdCache == NULL)
+ elog(FATAL, "AllocateVfd: no room for VFD array");
MemSet((char *) &(VfdCache[0]), 0, sizeof(Vfd));
VfdCache->fd = VFD_CLOSED;
@@ -506,17 +507,23 @@ AllocateVfd(void)
* However, there's not much point in starting *real* small.
*/
Size newCacheSize = SizeVfdCache * 2;
+ Vfd *newVfdCache;
if (newCacheSize < 32)
newCacheSize = 32;
- VfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
- Assert(VfdCache != NULL);
+ /*
+ * Be careful not to clobber VfdCache ptr if realloc fails;
+ * we will need it during proc_exit cleanup!
+ */
+ newVfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
+ if (newVfdCache == NULL)
+ elog(FATAL, "AllocateVfd: no room to enlarge VFD array");
+ VfdCache = newVfdCache;
/*
* Initialize the new entries and link them into the free list.
*/
-
for (i = SizeVfdCache; i < newCacheSize; i++)
{
MemSet((char *) &(VfdCache[i]), 0, sizeof(Vfd));
@@ -529,7 +536,6 @@ AllocateVfd(void)
/*
* Record the new size
*/
-
SizeVfdCache = newCacheSize;
}
@@ -553,6 +559,7 @@ FreeVfd(File file)
free(vfdP->fileName);
vfdP->fileName = NULL;
}
+ vfdP->fdstate = 0x0;
vfdP->nextFree = VfdCache[0].nextFree;
VfdCache[0].nextFree = file;
@@ -678,7 +685,9 @@ fileNameOpenFile(FileName fileName,
Insert(file);
- vfdP->fileName = malloc(strlen(fileName) + 1);
+ vfdP->fileName = (char *) malloc(strlen(fileName) + 1);
+ if (vfdP->fileName == NULL)
+ elog(FATAL, "fileNameOpenFile: no room to save VFD filename");
strcpy(vfdP->fileName, fileName);
/* Saved flags are adjusted to be OK for re-opening file */
--
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