test: chainloading via a multiboot module

Author: alfreb

vmbuild/elf.h api/util/elf.hvmbuild/elf.h renamed to api/util/elf.h

@@ -37,7 +37,7 @@ set(OS_OBJECTS
   util/memstream.c util/async.cpp util/statman.cpp util/logger.cpp
   util/os_statman.cpp util/sha1.cpp
   util/syslog_facility.cpp util/syslogd.cpp util/uri.cpp util/percent_encoding.cpp
-  util/tar.cpp util/path_to_regex.cpp
+  util/tar.cpp util/path_to_regex.cpp util/elf_binary.cpp
   crt/c_abi.c crt/string.c crt/quick_exit.cpp crt/cxx_abi.cpp
   hw/ide.cpp hw/pci_device.cpp hw/ps2.cpp hw/serial.cpp hw/serial1.cpp
   hw/cmos.cpp hw/block_device.cpp hw/msi.cpp hw/pci_msi.cpp

vmbuild/elf_binary.hpp api/util/elf_binary.hppvmbuild/elf_binary.hpp renamed to api/util/elf_binary.hpp

@@ -24,7 +24,7 @@
 #include <string>
 #include <unistd.h>
 #include <vector>
-#include "../../vmbuild/elf.h"
+#include <util/elf.h>
 
 static const char* boot_stringz = "Bootloader area";
 extern "C" char _ELF_START_;

src/CMakeLists.txt

@@ -1,4 +1,21 @@
-#include "elf_binary.hpp"
+// This file is a part of the IncludeOS unikernel - www.includeos.org
+//
+// Copyright 2015-2017 Oslo and Akershus University College of Applied Sciences
+// and Alfred Bratterud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "../api/util/elf_binary.hpp"
 
 #include <cstdlib>
 #include <iostream>

src/kernel/elf.cpp

@@ -14,7 +14,7 @@ set(SERVICE_NAME "Kernel modules test")
 set(BINARY       "test_mods")
 set(MAX_MEM 128)
 set(SOURCES
-    service.cpp
+    service.cpp hotswap.cpp
   )
 #set(LOCAL_INCLUDES ".")
 

vmbuild/elf_binary.cpp src/util/elf_binary.cppvmbuild/elf_binary.cpp renamed to src/util/elf_binary.cpp

@@ -0,0 +1,40 @@
+// This file is a part of the IncludeOS unikernel - www.includeos.org
+//
+// Copyright 2017 Oslo and Akershus University College of Applied Sciences
+// and Alfred Bratterud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+ * Self sufficient Utility function that will copy a binary to a certain 
+ * location and then jump to it. The idea (from fwsgonzo) is to have this 
+ * function copied to an otherwise unused place in memory so that we can
+ * overwrite the currently running binary with a new one.
+ */
+
+asm(".org 0x8000");
+#define BOOT_MAGIC   0x1
+
+extern "C" __attribute__((noreturn))
+void hotswap(const char* base, int len, char* dest, void* start)
+{
+  // replace old kernel with new
+  for (int i = 0; i < len; i++)
+    dest[i] = base[i];
+  
+  // jump to _start
+  asm volatile("jmp *%1" : : "a" (BOOT_MAGIC), "b" (start) : "eax", "ebx");
+
+  // we can never get here!
+  __builtin_unreachable();
+}

test/kernel/integration/modules/CMakeLists.txt

@@ -19,5 +19,6 @@
 
 void Service::start()
 {
-  printf("Hello world - OS included!\n");
+  printf("IncludeOS was just chainloaded by IncludeOS\n");
+  exit(0);
 }

test/kernel/integration/modules/hotswap.cpp

@@ -16,21 +16,29 @@
 // limitations under the License.
 
 #include <os>
+#include <util/elf_binary.hpp>
+#include <util/sha1.hpp>
+
+bool verb = true;
+
+#define MYINFO(X,...) INFO("Service", X, ##__VA_ARGS__)
+
+extern "C" void hotswap(const char* base, int len, char* dest, void* start);
 
 void Service::start(const std::string& args)
 {
-  printf("Testing kernel modules. Args: %s \n", args.c_str());
+  MYINFO("Testing kernel modules. Args: %s", args.c_str());
 
   auto mods = OS::modules();
 
-  Expects(mods.size() == 3);
+  //Expects(mods.size() == 3);
 
   printf("Found %i modules: \n", mods.size());
 
   for (auto mod : mods)
-    printf("\t* %s @ 0x%x - 0x%x, size: %ib \n",
+    INFO2("* %s @ 0x%x - 0x%x, size: %ib",
            reinterpret_cast<char*>(mod.cmdline),
-           mod.mod_start, mod.mod_end, mod.mod_end - mod.mod_start);
+          mod.mod_start, mod.mod_end, mod.mod_end - mod.mod_start);
 
   // Verify module cmdlines
   Expects(std::string((char*)mods[0].cmdline) == "../mod1.json");
@@ -44,11 +52,34 @@ void Service::start(const std::string& args)
   Expects(std::string((char*)mods[2].mod_start)
           == "{\"module3\" : \"More JSON data, for mod2 service\" }\n");
 
-  // TODO: Properly verify mod2 as ELF binary
-  Expects(((uint8_t*) mods[1].mod_start)[0] == 0x7f);
-  Expects(((char*) mods[1].mod_start)[1] == 'E');
-  Expects(((char*) mods[1].mod_start)[2] == 'L');
-  Expects(((char*) mods[1].mod_start)[3] == 'F');
+  multiboot_module_t binary = mods[1];
+
+  MYINFO("Verifying mod2 as ELF binary");
+  Elf_binary elf ({(char*)binary.mod_start, (int)(binary.mod_end - binary.mod_start)});
+
+  MYINFO("Moving hotswap function (now at %p)", &hotswap);
+  memcpy((void*)0x8000, (void*)&hotswap, 1024);
+
+  MYINFO("Preparing for jump to %s", (char*)binary.cmdline);
+
+  char* base  = (char*)binary.mod_start;
+  int len = (int)(binary.mod_end - binary.mod_start);
+  char* dest = (char*)0x100000;
+  void* start = (void*)elf.entry();
+
+  SHA1 sha;
+  sha.update(base, len);
+  MYINFO("Sha1 of ELF binary module: %s", sha.as_hex().c_str());
+
+
+  MYINFO("Jump params: base: %p, len: %i, dest: %p, start: %p",
+         base, len, dest, start);
+
+  MYINFO("Disabling interrupts and calling hotswap...");
+
+  asm("cli");
+  ((decltype(&hotswap))0x8000)(base, len, dest, start);
+
+  panic("Should have jumped\n");
 
-  exit(0);
 }

test/kernel/integration/modules/mod2/service.cpp

@@ -11,5 +11,21 @@
 
 vm = vmrunner.vms[0];
 
+chainloaded = False
+
+
+def chainload_ok(string):
+    global chainloaded
+    chainloaded = True
+    return chainloaded
+
+
+def verify_chainload():
+    print "<test.py>", "Chainloaded: ", chainloaded
+    return chainloaded
+
+vm.on_output("IncludeOS was just chainloaded", chainload_ok);
+vm.on_exit(verify_chainload)
+
 # Build, run and clean
 vm.cmake().boot().clean()