From 59b919822ab060f721e235964d19b55a19c815f0 Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Mon, 2 Feb 2015 10:00:45 -0500
Subject: [PATCH] Prevent Valgrind Memcheck errors around
px_acquire_system_randomness().
This function uses uninitialized stack and heap buffers as supplementary
entropy sources. Mark them so Memcheck will not complain. Back-patch
to 9.4, where Valgrind Memcheck cooperation first appeared.
Marko Tiikkaja
---
contrib/pgcrypto/random.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/contrib/pgcrypto/random.c b/contrib/pgcrypto/random.c
index 3f092ca3461..d72679e412d 100644
--- a/contrib/pgcrypto/random.c
+++ b/contrib/pgcrypto/random.c
@@ -32,6 +32,7 @@
#include "postgres.h"
#include "px.h"
+#include "utils/memdebug.h"
/* how many bytes to ask from system random provider */
#define RND_BYTES 32
@@ -195,7 +196,7 @@ try_unix_std(uint8 *dst)
memcpy(dst, (uint8 *) &x, sizeof(x));
dst += sizeof(x);
- /* let's be desperate */
+ /* hash of uninitialized stack and heap allocations */
res = px_find_digest("sha1", &md);
if (res >= 0)
{
@@ -203,8 +204,10 @@ try_unix_std(uint8 *dst)
uint8 stack[8192];
int alloc = 32 * 1024;
+ VALGRIND_MAKE_MEM_DEFINED(stack, sizeof(stack));
px_md_update(md, stack, sizeof(stack));
ptr = px_alloc(alloc);
+ VALGRIND_MAKE_MEM_DEFINED(ptr, alloc);
px_md_update(md, ptr, alloc);
px_free(ptr);
--
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