libvmm: add more error-checking to guest images setup

src/arch/aarch64/linux.c

@@ -18,6 +18,33 @@ uintptr_t linux_setup_images(uintptr_t ram_start,
                              uintptr_t initrd_dest,
                              size_t initrd_size)
 {
+    // Before doing any copying, let's sanity check the addresses.
+    // First we'll check that everything actually lives inside RAM.
+    // @ivanv: TODO
+    // Check that the kernel and DTB to do not overlap
+    uintptr_t dtb_start = dtb_dest;
+    uintptr_t dtb_end = dtb_start + dtb_size;
+    uintptr_t kernel_start = kernel;
+    uintptr_t kernel_end = kernel_start + kernel_size;
+    if (!(dtb_start >= kernel_end || dtb_end <= kernel_start)) {
+        LOG_VMM_ERR("Linux kernel image [0x%lx..0x%lx) overlaps with the destination of the DTB [0x%lx)\n",
+            kernel_start, kernel_end, dtb_start, dtb_end);
+        return 0;
+    }
+    // Check that the kernel and initrd do not overlap
+    uintptr_t initrd_start = initrd_dest;
+    uintptr_t initrd_end = initrd_start + initrd_size;
+    if (!(initrd_start >= kernel_end || initrd_end <= kernel_start)) {
+        LOG_VMM_ERR("Linux kernel image [0x%lx..0x%lx) overlaps with the destination of the initial RAM disk [0x%lx)\n",
+            kernel_start, kernel_end, initrd_start, initrd_end);
+        return 0;
+    }
+    // Check that the DTB and initrd do not overlap
+    if (!(initrd_start >= dtb_end || initrd_end <= dtb_start)) {
+        LOG_VMM_ERR("DTB [0x%lx..0x%lx) overlaps with the destination of the initial RAM disk [0x%lx)\n",
+            dtb_start, dtb_end, initrd_start, initrd_end);
+        return 0;
+    }
     // @ivanv: is there a initrd magic to check?
     // First we inspect the kernel image header to confirm it is a valid image
     // and to determine where in memory to place the image.