From 9b7da2e3c3a7127d39e6ba94be9dadc9ac3f273e Mon Sep 17 00:00:00 2001
From: Nick Bofferding <bofferdn@us.ibm.com>
Date: Thu, 25 Oct 2018 16:59:50 -0500
Subject: Support for putting fences around mallocs

This commit implements a compile time feature (set MALLOC_FENCING to
y in the src/lib/HBconfig file) which puts check bytes around each malloc.
Whenever an allocation is freed, if the check bytes have changed, the memory
manager immediate crashes Hostboot.  It also fixes a heap corruption in
the SBE get capabilities command.

Change-Id: I3df96d5fce43c34d3574c47f3c674076842d90e1
CQ: SW442980
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/68214
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Ilya Smirnov <ismirno@us.ibm.com>
Reviewed-by: Roland Veloz <rveloz@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
---
 src/lib/HBconfig |  5 +++++
 src/lib/stdlib.C | 15 ++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)
 create mode 100644 src/lib/HBconfig

(limited to 'src/lib')

diff --git a/src/lib/HBconfig b/src/lib/HBconfig
new file mode 100644
index 000000000..05added71
--- /dev/null
+++ b/src/lib/HBconfig
@@ -0,0 +1,5 @@
+config MALLOC_FENCING
+    default n
+    help
+        Enable generating check bytes around each malloc and
+        enforcing that those bytes are undisturbed on every matching free
diff --git a/src/lib/stdlib.C b/src/lib/stdlib.C
index 610a045a3..a7c694f9d 100644
--- a/src/lib/stdlib.C
+++ b/src/lib/stdlib.C
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2010,2014                        */
+/* Contributors Listed Below - COPYRIGHT 2010,2018                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
 /*                                                                        */
@@ -28,6 +28,7 @@
 #include <kernel/heapmgr.H>
 #include <kernel/pagemgr.H>
 #include <kernel/console.H>
+#include <config.h>
 
 #ifdef HOSTBOOT_MEMORY_LEAKS
 #include <arch/ppc.H>
@@ -114,10 +115,12 @@ void* malloc(size_t s)
     return result;
 }
 
-
 void free(void* p)
 {
-    if (NULL == p) return;
+    if (nullptr == p)
+    {
+        return;
+    }
 
 #ifdef HOSTBOOT_MEMORY_LEAKS
     memoryleak_magic_instruction(MEMORYLEAK_FREE, 0, p, NULL);
@@ -126,10 +129,12 @@ void free(void* p)
     HeapManager::free(p);
 }
 
-
 void* realloc(void* p, size_t s)
 {
-    if (NULL == p) return malloc(s);
+    if (nullptr == p)
+    {
+        return malloc(s);
+    }
 
     void* result = HeapManager::realloc(p,s);
 
-- 
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