sched: allocate memory for signal context in fork()

src/sched/fork.c

@@ -53,14 +53,15 @@ pid_t fork(Thread *t) {
     p->threads[0]->pid = pid;
     p->threads[0]->tid = pid;
     p->threads[0]->context = calloc(1, PLATFORM_CONTEXT_SIZE);
+    p->threads[0]->signalContext = calloc(1, PLATFORM_CONTEXT_SIZE);
     p->threads[0]->highest = t->highest;
     p->threads[0]->pages = t->pages;
 
     // NOTE: fork() only clones one thread, which is why we're not cloning the
     // entire process memory, but just the calling thread
     p->pages = t->pages;
 
-    if(!p->threads[0]->context) {
+    if(!p->threads[0]->context || !p->threads[0]->signalContext) {
         free(p->threads[0]);
         free(p->threads);
         free(p);