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- /* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
- /* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
- /* Copyright (C) 2014 Stony Brook University
- This file is part of Graphene Library OS.
- Graphene Library OS is free software: you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public License
- as published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
- Graphene Library OS is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /*
- * shim_migrate.c
- *
- * Implementation of system call "checkpoint" and "restore".
- */
- #include <shim_internal.h>
- #include <shim_table.h>
- #include <shim_thread.h>
- #include <shim_handle.h>
- #include <shim_vma.h>
- #include <shim_fs.h>
- #include <shim_ipc.h>
- #include <shim_checkpoint.h>
- #include <pal.h>
- #include <pal_error.h>
- #include <errno.h>
- #include <linux/fcntl.h>
- #include <asm/mman.h>
- /* cp_session objects are on the cp_sessions list, by the list field */
- /* cp_threads are organized onto a list, handing off of the
- * cp_session->registered_threads list. */
- DEFINE_LIST(cp_thread);
- struct cp_thread {
- struct shim_thread * thread;
- LIST_TYPE(cp_thread) list;
- };
- DEFINE_LIST(cp_session);
- DEFINE_LISTP(cp_thread);
- struct cp_session {
- IDTYPE sid;
- struct shim_handle * cpfile;
- LISTP_TYPE(cp_thread) registered_threads;
- LIST_TYPE(cp_session) list;
- PAL_HANDLE finish_event;
- struct shim_cp_store cpstore;
- };
- DEFINE_LISTP(cp_session);
- LISTP_TYPE(cp_session) cp_sessions;
- int create_checkpoint (const char * cpdir, IDTYPE * sid)
- {
- struct cp_session * cpsession = malloc(sizeof(struct cp_session));
- if (!cpsession)
- return -ENOMEM;
- int ret = 0;
- INIT_LISTP(&cpsession->registered_threads);
- INIT_LIST_HEAD(cpsession, list);
- cpsession->finish_event = DkNotificationEventCreate(PAL_FALSE);
- cpsession->cpfile = NULL;
- int len = strlen(cpdir);
- char * filename = __alloca(len + 10);
- memcpy(filename, cpdir, len);
- filename[len] = '/';
- snprintf(filename + len + 1, 9, "%08x", cur_process.vmid);
- cpsession->cpfile = get_new_handle();
- if (!cpsession->cpfile) {
- ret = -ENOMEM;
- goto err;
- }
- /* the directory might not be created. At least try to create it */
- if ((ret = open_namei(NULL, NULL, cpdir, O_CREAT|O_DIRECTORY, 0700,
- NULL)) < 0
- && ret != -EEXIST)
- goto err;
- if ((ret = open_namei(cpsession->cpfile, NULL, filename,
- O_CREAT|O_EXCL|O_RDWR, 0600, NULL)) < 0)
- goto err;
- open_handle(cpsession->cpfile);
- master_lock();
- struct cp_session * s;
- if (*sid) {
- listp_for_each_entry(s, &cp_sessions, list)
- if (s->sid == *sid) {
- ret = 0;
- goto err_locked;
- }
- } else {
- retry:
- getrand(&cpsession->sid, sizeof(IDTYPE));
- listp_for_each_entry(s, &cp_sessions, list)
- if (s->sid == cpsession->sid)
- goto retry;
- *sid = cpsession->sid;
- }
- listp_add_tail(cpsession, &cp_sessions, list);
- master_unlock();
- return 0;
- err_locked:
- master_unlock();
- err:
- if (cpsession->cpfile)
- close_handle(cpsession->cpfile);
- DkObjectClose(cpsession->finish_event);
- free(cpsession);
- return ret;
- }
- static int finish_checkpoint (struct cp_session * session);
- static int check_thread (struct shim_thread * thread, void * arg,
- bool * unlocked)
- {
- LISTP_TYPE(cp_thread) * registered = (LISTP_TYPE(cp_thread) *) arg;
- struct cp_thread * t;
- if (!thread->in_vm || !thread->is_alive)
- return 0;
- listp_for_each_entry(t, registered, list)
- if (t->thread == thread)
- return 0;
- return 1;
- }
- int join_checkpoint (struct shim_thread * thread, ucontext_t * context,
- IDTYPE sid)
- {
- struct cp_session * s, * cpsession = NULL;
- struct cp_thread cpthread;
- int ret = 0;
- bool do_checkpoint = false;
- master_lock();
- listp_for_each_entry(s, &cp_sessions, list)
- if (s->sid == sid) {
- cpsession = s;
- break;
- }
- if (!cpsession) {
- master_unlock();
- return -EINVAL;
- }
- INIT_LIST_HEAD(&cpthread, list);
- cpthread.thread = thread;
- listp_add_tail(&cpthread, &cpsession->registered_threads, list);
- /* find out if there is any thread that is not registered yet */
- ret = walk_thread_list(&check_thread,
- &cpsession->registered_threads,
- false);
- if (ret == -ESRCH)
- do_checkpoint = true;
- PAL_HANDLE finish_event = cpsession->finish_event;
- master_unlock();
- if (!do_checkpoint) {
- debug("waiting for checkpointing\n");
- DkObjectsWaitAny(1, &finish_event, NO_TIMEOUT);
- return 0;
- }
- debug("ready for checkpointing\n");
- ret = finish_checkpoint(cpsession);
- if (ret < 0)
- debug("failed creating checkpoint\n");
- else
- debug("finish checkpointing, time to wake up all threads\n");
- DkEventSet(finish_event);
- return ret;
- }
- static void * file_alloc (struct shim_cp_store * store, void * addr, size_t size)
- {
- assert(store->cp_file);
- struct shim_mount * fs = store->cp_file->fs;
- if (!fs || !fs->fs_ops ||
- !fs->fs_ops->truncate || !fs->fs_ops->mmap)
- return NULL;
- if (fs->fs_ops->truncate(store->cp_file, size) < 0)
- return NULL;
- if (fs->fs_ops->mmap(store->cp_file, &addr, size,
- PROT_READ|PROT_WRITE,
- MAP_FILE|MAP_SHARED, 0) < 0)
- return NULL;
- return addr;
- }
- static int finish_checkpoint (struct cp_session * cpsession)
- {
- struct shim_cp_store * cpstore = &cpsession->cpstore;
- int ret;
- cpstore->alloc = file_alloc;
- BEGIN_MIGRATION_DEF(checkpoint)
- {
- DEFINE_MIGRATE(process, &cur_process, sizeof(struct shim_process));
- DEFINE_MIGRATE(all_mounts, NULL, 0);
- DEFINE_MIGRATE(all_vmas, NULL, 0);
- DEFINE_MIGRATE(all_running_threads, NULL, 0);
- DEFINE_MIGRATE(brk, NULL, 0);
- DEFINE_MIGRATE(loaded_libraries, NULL, 0);
- #ifdef DEBUG
- DEFINE_MIGRATE(gdb_map, NULL, 0);
- #endif
- DEFINE_MIGRATE(migratable, NULL, 0);
- }
- END_MIGRATION_DEF(checkpoint)
- if ((ret = START_MIGRATE(cpstore, checkpoint)) < 0)
- return ret;
- struct cp_header * hdr = (struct cp_header *) cpstore->base;
- hdr->addr = (void *) cpstore->base;
- hdr->size = cpstore->offset;
- DkStreamUnmap((void *) cpstore->base, cpstore->bound);
- close_handle(cpstore->cp_file);
- return 0;
- }
- int shim_do_checkpoint (const char * filename)
- {
- IDTYPE session = 0;
- int ret = 0;
- ret = shim_do_mkdir(filename, 0700);
- if (ret < 0)
- return ret;
- shim_tcb_t * tcb = SHIM_GET_TLS();
- assert(tcb && tcb->tp);
- struct shim_signal signal;
- __store_context(tcb, NULL, &signal);
- ret = create_checkpoint(filename, &session);
- if (ret < 0) {
- shim_do_rmdir(filename);
- return ret;
- }
- ipc_checkpoint_send(filename, session);
- kill_all_threads(tcb->tp, session, SIGCP);
- ret = join_checkpoint(tcb->tp, &signal.context, session);
- if (ret < 0) {
- shim_do_rmdir(filename);
- return ret;
- }
- return 0;
- }
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