From: Kyle Hale <kh@u.northwestern.edu>
Date: Mon, 7 Oct 2013 20:29:12 +0000 (-0500)
Subject: more paranoid error checking
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=5a8d27bb121cfde8da7098c36984e16aa21db594

more paranoid error checking

These changes handle the case in which v3_free_vm is called
before several subsystems have been initialized. The ones that are particularly
prone are the non-pointers in the v3_vm_info struct that have list_head elements.
---

diff --git a/palacios/src/palacios/vmm_dev_mgr.c b/palacios/src/palacios/vmm_dev_mgr.c
index 976f41d..c75e633 100644
--- a/palacios/src/palacios/vmm_dev_mgr.c
+++ b/palacios/src/palacios/vmm_dev_mgr.c
@@ -129,7 +129,7 @@ int v3_free_vm_devices(struct v3_vm_info * vm) {
     struct vm_device * dev;
     struct vm_device * tmp;
 
-    if (mgr) { 
+    if (mgr && mgr->num_devs > 0) { 
 	list_for_each_entry_safe(dev, tmp, &(mgr->dev_list), dev_link) {
 	    v3_remove_device(dev);
 	}
diff --git a/palacios/src/palacios/vmm_intr.c b/palacios/src/palacios/vmm_intr.c
index ee54bef..fa8c69f 100644
--- a/palacios/src/palacios/vmm_intr.c
+++ b/palacios/src/palacios/vmm_intr.c
@@ -69,11 +69,13 @@ void v3_deinit_intr_controllers(struct guest_info * core) {
     struct intr_controller * tmp;
 
     // clear out any controllers that were left around
-    list_for_each_entry_safe(ctrlr, tmp, &(intr_state->controller_list), ctrl_node) {
-	v3_remove_intr_controller(core, ctrlr);
-    }
+    if (*(void**)&intr_state->controller_list) {
+        list_for_each_entry_safe(ctrlr, tmp, &(intr_state->controller_list), ctrl_node) {
+        v3_remove_intr_controller(core, ctrlr);
+        }
 
-    v3_lock_deinit(&(intr_state->irq_lock));
+        v3_lock_deinit(&(intr_state->irq_lock));
+    }
 
 }
 
@@ -92,12 +94,14 @@ void v3_deinit_intr_routers(struct v3_vm_info * vm) {
     struct intr_router * rtr = NULL;
     struct intr_router * tmp = NULL;
 
-    // clear out any controllers that were left around
-    list_for_each_entry_safe(rtr, tmp, &(vm->intr_routers.router_list), router_node) {
-	v3_remove_intr_router(vm, rtr);
-    }  
+    // clear out any routers that were left around
+    if (*(void**)&vm->intr_routers.router_list) {
+        list_for_each_entry_safe(rtr, tmp, &(vm->intr_routers.router_list), router_node) {
+        v3_remove_intr_router(vm, rtr);
+        }  
 
-    v3_lock_deinit(&(vm->intr_routers.irq_lock));
+        v3_lock_deinit(&(vm->intr_routers.irq_lock));
+    }
 }
 
 void * v3_register_intr_controller(struct guest_info * info, struct intr_ctrl_ops * ops, void * priv_data) {
diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c
index 444af7d..38dcc64 100644
--- a/palacios/src/palacios/vmm_shadow_paging.c
+++ b/palacios/src/palacios/vmm_shadow_paging.c
@@ -170,9 +170,15 @@ int v3_init_shdw_pg_state(struct guest_info * core) {
 
 
 int v3_deinit_shdw_pg_state(struct guest_info * core) {
-    struct v3_shdw_pg_impl * impl = core->vm_info->shdw_impl.current_impl;
+    struct v3_shdw_pg_impl * impl = NULL;
+
+    if (!core || !core->vm_info) {
+        return -1;
+    }
+
+    impl = core->vm_info->shdw_impl.current_impl;
 
-    if (impl->local_deinit(core) == -1) {
+    if (impl && impl->local_deinit(core) == -1) {
 	PrintError(core->vm_info, core, "Error deinitializing shadow paging state\n");
 	return -1;
     }
diff --git a/palacios/src/palacios/vmm_time.c b/palacios/src/palacios/vmm_time.c
index b2f31a4..f7cbb9e 100644
--- a/palacios/src/palacios/vmm_time.c
+++ b/palacios/src/palacios/vmm_time.c
@@ -530,7 +530,9 @@ void v3_deinit_time_core(struct guest_info * core) {
     struct v3_timer * tmr = NULL;
     struct v3_timer * tmp = NULL;
 
-    list_for_each_entry_safe(tmr, tmp, &(time_state->timers), timer_link) {
-	v3_remove_timer(core, tmr);
+    if (*(void**)&time_state->timers) {
+        list_for_each_entry_safe(tmr, tmp, &(time_state->timers), timer_link) {
+        v3_remove_timer(core, tmr);
+        }
     }
 }