From: Jack Lange <jacklange@cs.pitt.edu>
Date: Tue, 16 Aug 2011 23:41:39 +0000 (-0400)
Subject: added memory unhooking error checking to fix CGA deinit crash
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=47d42b85720b6388c7cd59554a9e458bd72664c4

added memory unhooking error checking to fix CGA deinit crash
---

diff --git a/palacios/src/devices/cga.c b/palacios/src/devices/cga.c
index e9556c8..7997818 100644
--- a/palacios/src/devices/cga.c
+++ b/palacios/src/devices/cga.c
@@ -1153,12 +1153,14 @@ static int cga_init(struct v3_vm_info * vm, v3_cfg_tree_t * cfg) {
 	PrintDebug("Enabling CGA Passthrough\n");
 	if (v3_hook_write_mem(vm, V3_MEM_CORE_ANY, START_ADDR, END_ADDR, 
 			      START_ADDR, &video_write_mem, dev) == -1) {
-	    PrintDebug("\n\nVideo Hook failed.\n\n");
+	    PrintError("\n\nVideo Hook failed.\n\n");
+	    return -1;
 	}
     } else {
 	if (v3_hook_write_mem(vm, V3_MEM_CORE_ANY, START_ADDR, END_ADDR, 
 			      video_state->framebuf_pa, &video_write_mem, dev) == -1) {
-	    PrintDebug("\n\nVideo Hook failed.\n\n");
+	    PrintError("\n\nVideo Hook failed.\n\n");
+	    return -1;
 	}
     }
 
diff --git a/palacios/src/palacios/vmm_mem_hook.c b/palacios/src/palacios/vmm_mem_hook.c
index 298bc8f..a0753cf 100644
--- a/palacios/src/palacios/vmm_mem_hook.c
+++ b/palacios/src/palacios/vmm_mem_hook.c
@@ -394,7 +394,20 @@ static int free_hook(struct v3_vm_info * vm, struct mem_hook * hook) {
 // We do not support unhooking subregions
 int v3_unhook_mem(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr_start) {
     struct v3_mem_region * reg = v3_get_mem_region(vm, core_id, guest_addr_start);
-    struct mem_hook * hook = reg->priv_data;
+    struct mem_hook * hook = NULL;
+
+    if (reg == NULL) {
+	PrintError("Could not find region at %p\n", (void *)guest_addr_start);
+	return -1;
+    }
+
+    hook = reg->priv_data;
+
+    if (hook == NULL) {
+	PrintError("Trying to unhook region that is not a hook at %p\n", (void *)guest_addr_start);
+	return -1;
+    }
+
 
     free_hook(vm, hook);