From df9fac4e61aec3e71f70e82ba508be244115421d Mon Sep 17 00:00:00 2001
From: krcroft <krcroft@users.noreply.github.com>
Date: Wed, 15 Jan 2020 07:43:10 -0800
Subject: [PATCH] Fix NULL issues in CPU emulation code

---
 src/cpu/core_dyn_x86.cpp       |  2 +-
 src/cpu/core_dyn_x86/cache.h   | 22 ++++++++++++++++++++--
 src/cpu/core_dyn_x86/decoder.h | 15 ++++++++++++---
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/cpu/core_dyn_x86.cpp b/src/cpu/core_dyn_x86.cpp
index be572528..a93d2ac8 100644
--- a/src/cpu/core_dyn_x86.cpp
+++ b/src/cpu/core_dyn_x86.cpp
@@ -361,7 +361,7 @@ run_block:
 			CodePageHandler * temp_handler=(CodePageHandler *)get_tlb_readhandler(temp_ip);
 			if (temp_handler->flags & (cpu.code.big ? PFLAG_HASCODE32:PFLAG_HASCODE16)) {
 				block=temp_handler->FindCacheBlock(temp_ip & 4095);
-				if (!block) goto restart_core;
+				if (!block || !cache.block.running) goto restart_core;
 				cache.block.running->LinkTo(ret==BR_Link2,block);
 				goto run_block;
 			}
diff --git a/src/cpu/core_dyn_x86/cache.h b/src/cpu/core_dyn_x86/cache.h
index 3dca3eb1..ccf809af 100644
--- a/src/cpu/core_dyn_x86/cache.h
+++ b/src/cpu/core_dyn_x86/cache.h
@@ -121,6 +121,9 @@ public:
 			return;
 		} else if (!invalidation_map) {
 			invalidation_map=(Bit8u*)malloc(4096);
+			if (!invalidation_map) {
+				E_Exit("wb:failed to allocate invalidation_map's memory");
+			}
 			memset(invalidation_map,0,4096);
 		}
 		invalidation_map[addr]++;
@@ -141,6 +144,9 @@ public:
 			return;
 		} else if (!invalidation_map) {
 			invalidation_map=(Bit8u*)malloc(4096);
+			if (!invalidation_map) {
+				E_Exit("ww:failed to allocate invalidation_map's memory");
+			}
 			memset(invalidation_map,0,4096);
 		}
 		(*(Bit16u*)&invalidation_map[addr])+=0x101;
@@ -161,6 +167,9 @@ public:
 			return;
 		} else if (!invalidation_map) {
 			invalidation_map=(Bit8u*)malloc(4096);
+			if (!invalidation_map) {
+				E_Exit("wd:failed to allocate invalidation_map's memory");
+			}
 			memset(invalidation_map,0,4096);
 		}
 		(*(Bit32u*)&invalidation_map[addr])+=0x1010101;
@@ -181,6 +190,9 @@ public:
 		} else {
 			if (!invalidation_map) {
 				invalidation_map=(Bit8u*)malloc(4096);
+				if (!invalidation_map) {
+					E_Exit("cb:failed to allocate invalidation_map's memory");
+				}
 				memset(invalidation_map,0,4096);
 			}
 			invalidation_map[addr]++;
@@ -207,6 +219,9 @@ public:
 		} else {
 			if (!invalidation_map) {
 				invalidation_map=(Bit8u*)malloc(4096);
+				if (!invalidation_map) {
+					E_Exit("cw:failed to allocate invalidation_map's memory");
+				}
 				memset(invalidation_map,0,4096);
 			}
 			(*(Bit16u*)&invalidation_map[addr])+=0x101;
@@ -233,6 +248,9 @@ public:
 		} else {
 			if (!invalidation_map) {
 				invalidation_map=(Bit8u*)malloc(4096);
+				if (!invalidation_map) {
+					E_Exit("cd:failed to allocate invalidation_map's memory");
+				}
 				memset(invalidation_map,0,4096);
 			}
 			(*(Bit32u*)&invalidation_map[addr])+=0x1010101;
@@ -428,10 +446,10 @@ static void cache_closeblock(void) {
 	if (written>block->cache.size) {
 		if (!block->cache.next) {
 			if (written>block->cache.size+CACHE_MAXSIZE)
-				E_Exit("CacheBlock overrun 1 %lu",
+				E_Exit("CacheBlock overrun 1 %" PRIuPTR,
 				       written-block->cache.size);
 		} else {
-			E_Exit("CacheBlock overrun 2 written %lu size %lu",
+			E_Exit("CacheBlock overrun 2 written %" PRIuPTR " size %" PRIuPTR,
 			       written, block->cache.size);
 		}
 	} else {
diff --git a/src/cpu/core_dyn_x86/decoder.h b/src/cpu/core_dyn_x86/decoder.h
index 3d33e04b..273925a3 100644
--- a/src/cpu/core_dyn_x86/decoder.h
+++ b/src/cpu/core_dyn_x86/decoder.h
@@ -86,10 +86,11 @@ static bool MakeCodePage(Bitu lin_addr,CodePageHandler * &cph) {
 		cph=0;		return false;
 	}
 	/* Find a free CodePage */
-	if (!cache.free_pages) {
-		if (cache.used_pages!=decode.page.code) cache.used_pages->ClearRelease();
+	if (!cache.free_pages && cache.used_pages) {
+		if (cache.used_pages != decode.page.code)
+			cache.used_pages->ClearRelease();
 		else {
-			if ((cache.used_pages->next) && (cache.used_pages->next!=decode.page.code))
+			if ((cache.used_pages->next) && (cache.used_pages->next != decode.page.code))
 				cache.used_pages->next->ClearRelease();
 			else {
 				LOG_MSG("DYNX86:Invalid cache links");
@@ -97,6 +98,10 @@ static bool MakeCodePage(Bitu lin_addr,CodePageHandler * &cph) {
 			}
 		}
 	}
+	if (!cache.free_pages) {
+		LOG_MSG("DYNX86:cache.free_pages is not useable");
+		return false;
+	}
 	CodePageHandler * cpagehandler=cache.free_pages;
 	cache.free_pages=cache.free_pages->next;
 	cpagehandler->prev=cache.last_page;
@@ -176,6 +181,10 @@ static INLINE void decode_increase_wmapmask(Bitu size) {
 			Bitu newmasklen=activecb->cache.masklen*4;
 			if (newmasklen<mapidx+size) newmasklen=((mapidx+size)&~3)*2;
 			Bit8u* tempmem=(Bit8u*)malloc(newmasklen);
+			if (tempmem == nullptr) {
+				LOG_MSG("Unable to allocate %" PRIuPTR " bytes for tempmem", newmasklen);
+				return;
+			}
 			memset(tempmem,0,newmasklen);
 			memcpy(tempmem,activecb->cache.wmapmask,activecb->cache.masklen);
 			free(activecb->cache.wmapmask);