static int restore_thread_common(struct rt_sigframe *sigframe,
struct thread_restore_args *args)
{
sys_set_tid_address((int *)decode_pointer(args->clear_tid_addr));
if (args->has_futex && args->futex_rla_len) {
int ret;
ret = sys_set_robust_list(decode_pointer(args->futex_rla),
args->futex_rla_len);
if (ret) {
pr_err("Failed to recover futex robust list: %d\n", ret);
return -1;
}
}
restore_sched_info(&args->sp);
if (restore_nonsigframe_gpregs(&args->gpregs))
return -1;
restore_tls(&args->tls);
return 0;
}
static unsigned long restore_mapping(const VmaEntry *vma_entry)
{
int prot = vma_entry->prot;
int flags = vma_entry->flags | MAP_FIXED;
unsigned long addr;
if (vma_entry_is(vma_entry, VMA_AREA_SYSVIPC))
return sys_shmat(vma_entry->fd, decode_pointer(vma_entry->start),
(vma_entry->prot & PROT_WRITE) ? 0 : SHM_RDONLY);
/*
* Restore or shared mappings are tricky, since
* we open anonymous mapping via map_files/
* MAP_ANONYMOUS should be eliminated so fd would
* be taken into account by a kernel.
*/
if (vma_entry_is(vma_entry, VMA_ANON_SHARED) && (vma_entry->fd != -1UL))
flags &= ~MAP_ANONYMOUS;
/* A mapping of file with MAP_SHARED is up to date */
if (vma_entry->fd == -1 || !(vma_entry->flags & MAP_SHARED))
prot |= PROT_WRITE;
pr_debug("\tmmap(%"PRIx64" -> %"PRIx64", %x %x %d)\n",
vma_entry->start, vma_entry->end,
prot, flags, (int)vma_entry->fd);
/*
* Should map memory here. Note we map them as
* writable since we're going to restore page
* contents.
*/
addr = sys_mmap(decode_pointer(vma_entry->start),
vma_entry_len(vma_entry),
prot, flags,
vma_entry->fd,
vma_entry->pgoff);
if (vma_entry->fd != -1)
sys_close(vma_entry->fd);
return addr;
}
static inline void setup_sas(struct rt_sigframe* sigframe, ThreadSasEntry *sas)
{
if (sas) {
#define UC RT_SIGFRAME_UC(sigframe)
UC->uc_stack.ss_sp = (void *)decode_pointer((sas)->ss_sp);
UC->uc_stack.ss_flags = (int)(sas)->ss_flags;
UC->uc_stack.ss_size = (size_t)(sas)->ss_size;
#undef UC
}
}
int
cb_erase(critbit_tree* cb, const void* key, size_t keylen) {
void** iter = NULL;
void* ptr = cb->root;
struct critbit_node* parent = 0;
unsigned char* bytes = (unsigned char*)key;
int branch = 0;
if(!cb->root)
return CB_NOTFOUND;
for(;;) {
int type;
type = decode_pointer(&ptr);
if(type == INTERNAL_NODE) {
iter = parent ? &parent->child[branch] : &cb->root;
parent = (struct critbit_node*)ptr;
branch = (keylen <= parent->byte) ? 0 : ((1 + ((bytes[parent->byte] | parent->mask) & 0xFF)) >> 8);
ptr = parent->child[branch];
} else {
static int
cb_foreach_i(void* ptr, const void* key, size_t keylen, int (*match_cb)(const void* match, const void* key, size_t keylen, void*), void* data) {
int result = 0;
if(decode_pointer(&ptr) == INTERNAL_NODE) {
struct critbit_node* node = (struct critbit_node*)ptr;
result = cb_foreach_i(node->child[0], key, keylen, match_cb, data);
if(!result) {
result = cb_foreach_i(node->child[1], key, keylen, match_cb, data);
}
} else {
/* reached an external node */
void* match;
size_t len;
from_external_node(ptr, &match, &len);
if(len >= keylen && byte_diff(key, keylen, match) == 0) {
return match_cb(match, key, keylen, data);
}
}
return result;
}
static void psi2iovec(struct page_server_iov *ps, struct iovec *iov)
{
iov->iov_base = decode_pointer(ps->vaddr);
iov->iov_len = ps->nr_pages * PAGE_SIZE;
}
static int restore_shmem_content(void *addr, struct shmem_info *si)
{
int fd, fd_pg, ret = 0;
fd = open_image(CR_FD_SHMEM_PAGEMAP, O_RSTR, si->shmid);
if (fd < 0) {
fd_pg = open_image(CR_FD_SHM_PAGES_OLD, O_RSTR, si->shmid);
if (fd_pg < 0)
goto err_unmap;
} else {
fd_pg = open_pages_image(O_RSTR, fd);
if (fd_pg < 0)
goto out_close;
}
while (1) {
unsigned long vaddr;
unsigned nr_pages;
if (fd >= 0) {
PagemapEntry *pe;
ret = pb_read_one_eof(fd, &pe, PB_PAGEMAP);
if (ret <= 0)
break;
vaddr = (unsigned long)decode_pointer(pe->vaddr);
nr_pages = pe->nr_pages;
pagemap_entry__free_unpacked(pe, NULL);
} else {
__u64 img_vaddr;
ret = read_img_eof(fd_pg, &img_vaddr);
if (ret <= 0)
break;
vaddr = (unsigned long)decode_pointer(img_vaddr);
nr_pages = 1;
}
if (vaddr + nr_pages * PAGE_SIZE > si->size)
break;
ret = read(fd_pg, addr + vaddr, nr_pages * PAGE_SIZE);
if (ret != nr_pages * PAGE_SIZE) {
ret = -1;
break;
}
}
close_safe(&fd_pg);
close_safe(&fd);
return ret;
out_close:
close_safe(&fd);
err_unmap:
munmap(addr, si->size);
return -1;
}
/*
* The main routine to restore task via sigreturn.
* This one is very special, we never return there
* but use sigreturn facility to restore core registers
* and jump execution to some predefined ip read from
* core file.
*/
long __export_restore_task(struct task_restore_args *args)
{
long ret = -1;
int i;
VmaEntry *vma_entry;
unsigned long va;
struct rt_sigframe *rt_sigframe;
unsigned long new_sp;
k_rtsigset_t to_block;
pid_t my_pid = sys_getpid();
rt_sigaction_t act;
bootstrap_start = args->bootstrap_start;
bootstrap_len = args->bootstrap_len;
#ifdef CONFIG_VDSO
vdso_rt_size = args->vdso_rt_size;
#endif
task_entries = args->task_entries;
helpers = args->helpers;
n_helpers = args->n_helpers;
*args->breakpoint = rst_sigreturn;
ksigfillset(&act.rt_sa_mask);
act.rt_sa_handler = sigchld_handler;
act.rt_sa_flags = SA_SIGINFO | SA_RESTORER | SA_RESTART;
act.rt_sa_restorer = cr_restore_rt;
sys_sigaction(SIGCHLD, &act, NULL, sizeof(k_rtsigset_t));
log_set_fd(args->logfd);
log_set_loglevel(args->loglevel);
cap_last_cap = args->cap_last_cap;
pr_info("Switched to the restorer %d\n", my_pid);
#ifdef CONFIG_VDSO
if (vdso_do_park(&args->vdso_sym_rt, args->vdso_rt_parked_at, vdso_rt_size))
goto core_restore_end;
#endif
if (unmap_old_vmas((void *)args->premmapped_addr, args->premmapped_len,
bootstrap_start, bootstrap_len))
goto core_restore_end;
/* Shift private vma-s to the left */
for (i = 0; i < args->nr_vmas; i++) {
vma_entry = args->tgt_vmas + i;
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
if (!vma_priv(vma_entry))
continue;
if (vma_entry->end >= TASK_SIZE)
continue;
if (vma_entry->start > vma_entry->shmid)
break;
if (vma_remap(vma_premmaped_start(vma_entry),
vma_entry->start, vma_entry_len(vma_entry)))
goto core_restore_end;
}
/* Shift private vma-s to the right */
for (i = args->nr_vmas - 1; i >= 0; i--) {
vma_entry = args->tgt_vmas + i;
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
if (!vma_priv(vma_entry))
continue;
if (vma_entry->start > TASK_SIZE)
continue;
if (vma_entry->start < vma_entry->shmid)
break;
if (vma_remap(vma_premmaped_start(vma_entry),
vma_entry->start, vma_entry_len(vma_entry)))
goto core_restore_end;
}
/*
* OK, lets try to map new one.
*/
for (i = 0; i < args->nr_vmas; i++) {
vma_entry = args->tgt_vmas + i;
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
if (vma_priv(vma_entry))
continue;
va = restore_mapping(vma_entry);
if (va != vma_entry->start) {
pr_err("Can't restore %"PRIx64" mapping with %lx\n", vma_entry->start, va);
goto core_restore_end;
}
}
#ifdef CONFIG_VDSO
/*
* Proxify vDSO.
*/
for (i = 0; i < args->nr_vmas; i++) {
if (vma_entry_is(&args->tgt_vmas[i], VMA_AREA_VDSO) ||
vma_entry_is(&args->tgt_vmas[i], VMA_AREA_VVAR)) {
if (vdso_proxify("dumpee", &args->vdso_sym_rt,
args->vdso_rt_parked_at,
i, args->tgt_vmas, args->nr_vmas))
goto core_restore_end;
break;
}
}
#endif
/*
* Walk though all VMAs again to drop PROT_WRITE
* if it was not there.
*/
for (i = 0; i < args->nr_vmas; i++) {
vma_entry = args->tgt_vmas + i;
if (!(vma_entry_is(vma_entry, VMA_AREA_REGULAR)))
continue;
if (vma_entry_is(vma_entry, VMA_ANON_SHARED)) {
struct shmem_info *entry;
entry = find_shmem(args->shmems, args->nr_shmems,
vma_entry->shmid);
if (entry && entry->pid == my_pid &&
entry->start == vma_entry->start)
futex_set_and_wake(&entry->lock, 1);
}
if (vma_entry->prot & PROT_WRITE)
continue;
sys_mprotect(decode_pointer(vma_entry->start),
vma_entry_len(vma_entry),
vma_entry->prot);
}
/*
* Finally restore madivse() bits
*/
for (i = 0; i < args->nr_vmas; i++) {
unsigned long m;
vma_entry = args->tgt_vmas + i;
if (!vma_entry->has_madv || !vma_entry->madv)
continue;
for (m = 0; m < sizeof(vma_entry->madv) * 8; m++) {
if (vma_entry->madv & (1ul << m)) {
ret = sys_madvise(vma_entry->start,
vma_entry_len(vma_entry),
m);
if (ret) {
pr_err("madvise(%"PRIx64", %"PRIu64", %ld) "
"failed with %ld\n",
vma_entry->start,
vma_entry_len(vma_entry),
m, ret);
goto core_restore_end;
}
}
}
}
ret = 0;
/*
* Tune up the task fields.
*/
ret |= sys_prctl_safe(PR_SET_NAME, (long)args->comm, 0, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_CODE, (long)args->mm.mm_start_code, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_END_CODE, (long)args->mm.mm_end_code, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_DATA, (long)args->mm.mm_start_data, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_END_DATA, (long)args->mm.mm_end_data, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_STACK, (long)args->mm.mm_start_stack, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_BRK, (long)args->mm.mm_start_brk, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_BRK, (long)args->mm.mm_brk, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ARG_START, (long)args->mm.mm_arg_start, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ARG_END, (long)args->mm.mm_arg_end, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ENV_START, (long)args->mm.mm_env_start, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ENV_END, (long)args->mm.mm_env_end, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_AUXV, (long)args->mm_saved_auxv, args->mm_saved_auxv_size);
if (ret)
goto core_restore_end;
/*
* Because of requirements applied from kernel side
* we need to restore /proc/pid/exe symlink late,
* after old existing VMAs are superseded with
* new ones from image file.
*/
ret = restore_self_exe_late(args);
if (ret)
goto core_restore_end;
/*
* We need to prepare a valid sigframe here, so
* after sigreturn the kernel will pick up the
* registers from the frame, set them up and
* finally pass execution to the new IP.
*/
rt_sigframe = (void *)args->t->mem_zone.rt_sigframe;
if (restore_thread_common(rt_sigframe, args->t))
goto core_restore_end;
/*
* Threads restoration. This requires some more comments. This
* restorer routine and thread restorer routine has the following
* memory map, prepared by a caller code.
*
* | <-- low addresses high addresses --> |
* +-------------------------------------------------------+-----------------------+
* | this proc body | own stack | rt_sigframe space | thread restore zone |
* +-------------------------------------------------------+-----------------------+
*
* where each thread restore zone is the following
*
* | <-- low addresses high addresses --> |
* +--------------------------------------------------------------------------+
* | thread restore proc | thread1 stack | thread1 rt_sigframe |
* +--------------------------------------------------------------------------+
*/
if (args->nr_threads > 1) {
struct thread_restore_args *thread_args = args->thread_args;
long clone_flags = CLONE_VM | CLONE_FILES | CLONE_SIGHAND |
CLONE_THREAD | CLONE_SYSVSEM;
long last_pid_len;
long parent_tid;
int i, fd;
fd = args->fd_last_pid;
ret = sys_flock(fd, LOCK_EX);
if (ret) {
pr_err("Can't lock last_pid %d\n", fd);
goto core_restore_end;
}
for (i = 0; i < args->nr_threads; i++) {
char last_pid_buf[16], *s;
/* skip self */
if (thread_args[i].pid == args->t->pid)
continue;
new_sp = restorer_stack(thread_args + i);
last_pid_len = vprint_num(last_pid_buf, sizeof(last_pid_buf), thread_args[i].pid - 1, &s);
sys_lseek(fd, 0, SEEK_SET);
ret = sys_write(fd, s, last_pid_len);
if (ret < 0) {
pr_err("Can't set last_pid %ld/%s\n", ret, last_pid_buf);
goto core_restore_end;
}
/*
* To achieve functionality like libc's clone()
* we need a pure assembly here, because clone()'ed
* thread will run with own stack and we must not
* have any additional instructions... oh, dear...
*/
RUN_CLONE_RESTORE_FN(ret, clone_flags, new_sp, parent_tid, thread_args, args->clone_restore_fn);
}
ret = sys_flock(fd, LOCK_UN);
if (ret) {
pr_err("Can't unlock last_pid %ld\n", ret);
goto core_restore_end;
}
}
sys_close(args->fd_last_pid);
restore_rlims(args);
ret = create_posix_timers(args);
if (ret < 0) {
pr_err("Can't restore posix timers %ld\n", ret);
goto core_restore_end;
}
ret = timerfd_arm(args);
if (ret < 0) {
pr_err("Can't restore timerfd %ld\n", ret);
goto core_restore_end;
}
pr_info("%ld: Restored\n", sys_getpid());
futex_set(&zombies_inprogress, args->nr_zombies);
restore_finish_stage(CR_STATE_RESTORE);
futex_wait_while_gt(&zombies_inprogress, 0);
if (wait_helpers(args) < 0)
goto core_restore_end;
ksigfillset(&to_block);
ret = sys_sigprocmask(SIG_SETMASK, &to_block, NULL, sizeof(k_rtsigset_t));
if (ret) {
pr_err("Unable to block signals %ld", ret);
goto core_restore_end;
}
sys_sigaction(SIGCHLD, &args->sigchld_act, NULL, sizeof(k_rtsigset_t));
ret = restore_signals(args->siginfo, args->siginfo_nr, true);
if (ret)
goto core_restore_end;
ret = restore_signals(args->t->siginfo, args->t->siginfo_nr, false);
if (ret)
goto core_restore_end;
restore_finish_stage(CR_STATE_RESTORE_SIGCHLD);
rst_tcp_socks_all(args);
/*
* Writing to last-pid is CAP_SYS_ADMIN protected,
* turning off TCP repair is CAP_SYS_NED_ADMIN protected,
* thus restore* creds _after_ all of the above.
*/
ret = restore_creds(&args->creds);
ret = ret || restore_dumpable_flag(&args->mm);
ret = ret || restore_pdeath_sig(args->t);
futex_set_and_wake(&thread_inprogress, args->nr_threads);
restore_finish_stage(CR_STATE_RESTORE_CREDS);
if (ret)
BUG();
/* Wait until children stop to use args->task_entries */
futex_wait_while_gt(&thread_inprogress, 1);
log_set_fd(-1);
/*
* The code that prepared the itimers makes shure the
* code below doesn't fail due to bad timing values.
*/
#define itimer_armed(args, i) \
(args->itimers[i].it_interval.tv_sec || \
args->itimers[i].it_interval.tv_usec)
if (itimer_armed(args, 0))
sys_setitimer(ITIMER_REAL, &args->itimers[0], NULL);
if (itimer_armed(args, 1))
sys_setitimer(ITIMER_VIRTUAL, &args->itimers[1], NULL);
if (itimer_armed(args, 2))
sys_setitimer(ITIMER_PROF, &args->itimers[2], NULL);
restore_posix_timers(args);
sys_munmap(args->rst_mem, args->rst_mem_size);
/*
* Sigframe stack.
*/
new_sp = (long)rt_sigframe + SIGFRAME_OFFSET;
/*
* Prepare the stack and call for sigreturn,
* pure assembly since we don't need any additional
* code insns from gcc.
*/
rst_sigreturn(new_sp);
core_restore_end:
futex_abort_and_wake(&task_entries->nr_in_progress);
pr_err("Restorer fail %ld\n", sys_getpid());
sys_exit_group(1);
return -1;
}
/*
* The main routine to restore task via sigreturn.
* This one is very special, we never return there
* but use sigreturn facility to restore core registers
* and jump execution to some predefined ip read from
* core file.
*/
long __export_restore_task(struct task_restore_core_args *args)
{
long ret = -1;
VmaEntry *vma_entry;
u64 va;
unsigned long premmapped_end = args->premmapped_addr + args->premmapped_len;
struct rt_sigframe *rt_sigframe;
unsigned long new_sp;
pid_t my_pid = sys_getpid();
rt_sigaction_t act;
task_entries = args->task_entries;
ksigfillset(&act.rt_sa_mask);
act.rt_sa_handler = sigchld_handler;
act.rt_sa_flags = SA_SIGINFO | SA_RESTORER | SA_RESTART;
act.rt_sa_restorer = cr_restore_rt;
sys_sigaction(SIGCHLD, &act, NULL, sizeof(k_rtsigset_t));
log_set_fd(args->logfd);
log_set_loglevel(args->loglevel);
cap_last_cap = args->cap_last_cap;
pr_info("Switched to the restorer %d\n", my_pid);
for (vma_entry = args->self_vmas; vma_entry->start != 0; vma_entry++) {
unsigned long addr = vma_entry->start;
unsigned long len;
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
pr_debug("Examine %"PRIx64"-%"PRIx64"\n", vma_entry->start, vma_entry->end);
if (addr < args->premmapped_addr) {
if (vma_entry->end >= args->premmapped_addr)
len = args->premmapped_addr - addr;
else
len = vma_entry->end - vma_entry->start;
if (sys_munmap((void *) addr, len)) {
pr_err("munmap fail for %lx - %lx\n", addr, addr + len);
goto core_restore_end;
}
}
if (vma_entry->end >= TASK_SIZE)
continue;
if (vma_entry->end > premmapped_end) {
if (vma_entry->start < premmapped_end)
addr = premmapped_end;
len = vma_entry->end - addr;
if (sys_munmap((void *) addr, len)) {
pr_err("munmap fail for %lx - %lx\n", addr, addr + len);
goto core_restore_end;
}
}
}
sys_munmap(args->self_vmas,
((void *)(vma_entry + 1) - ((void *)args->self_vmas)));
/* Shift private vma-s to the left */
for (vma_entry = args->tgt_vmas; vma_entry->start != 0; vma_entry++) {
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
if (!vma_priv(vma_entry))
continue;
if (vma_entry->end >= TASK_SIZE)
continue;
if (vma_entry->start > vma_entry->shmid)
break;
if (vma_remap(vma_premmaped_start(vma_entry),
vma_entry->start, vma_entry_len(vma_entry)))
goto core_restore_end;
}
/* Shift private vma-s to the right */
for (vma_entry = args->tgt_vmas + args->nr_vmas -1;
vma_entry >= args->tgt_vmas; vma_entry--) {
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
if (!vma_priv(vma_entry))
continue;
if (vma_entry->start > TASK_SIZE)
continue;
if (vma_entry->start < vma_entry->shmid)
break;
if (vma_remap(vma_premmaped_start(vma_entry),
vma_entry->start, vma_entry_len(vma_entry)))
goto core_restore_end;
}
/*
* OK, lets try to map new one.
*/
for (vma_entry = args->tgt_vmas; vma_entry->start != 0; vma_entry++) {
if (!vma_entry_is(vma_entry, VMA_AREA_REGULAR))
continue;
if (vma_priv(vma_entry))
continue;
va = restore_mapping(vma_entry);
if (va != vma_entry->start) {
pr_err("Can't restore %"PRIx64" mapping with %"PRIx64"\n", vma_entry->start, va);
goto core_restore_end;
}
}
/*
* Walk though all VMAs again to drop PROT_WRITE
* if it was not there.
*/
for (vma_entry = args->tgt_vmas; vma_entry->start != 0; vma_entry++) {
if (!(vma_entry_is(vma_entry, VMA_AREA_REGULAR)))
continue;
if (vma_entry_is(vma_entry, VMA_ANON_SHARED)) {
struct shmem_info *entry;
entry = find_shmem(args->shmems,
vma_entry->shmid);
if (entry && entry->pid == my_pid &&
entry->start == vma_entry->start)
futex_set_and_wake(&entry->lock, 1);
}
if (vma_entry->prot & PROT_WRITE)
continue;
sys_mprotect(decode_pointer(vma_entry->start),
vma_entry_len(vma_entry),
vma_entry->prot);
}
/*
* Finally restore madivse() bits
*/
for (vma_entry = args->tgt_vmas; vma_entry->start != 0; vma_entry++) {
unsigned long i;
if (!vma_entry->has_madv || !vma_entry->madv)
continue;
for (i = 0; i < sizeof(vma_entry->madv) * 8; i++) {
if (vma_entry->madv & (1ul << i)) {
ret = sys_madvise(vma_entry->start,
vma_entry_len(vma_entry),
i);
if (ret) {
pr_err("madvise(%"PRIx64", %"PRIu64", %ld) "
"failed with %ld\n",
vma_entry->start,
vma_entry_len(vma_entry),
i, ret);
goto core_restore_end;
}
}
}
}
sys_munmap(args->tgt_vmas,
((void *)(vma_entry + 1) - ((void *)args->tgt_vmas)));
ret = sys_munmap(args->shmems, SHMEMS_SIZE);
if (ret < 0) {
pr_err("Can't unmap shmem %ld\n", ret);
goto core_restore_end;
}
/*
* Tune up the task fields.
*/
ret |= sys_prctl_safe(PR_SET_NAME, (long)args->comm, 0, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_CODE, (long)args->mm.mm_start_code, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_END_CODE, (long)args->mm.mm_end_code, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_DATA, (long)args->mm.mm_start_data, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_END_DATA, (long)args->mm.mm_end_data, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_STACK, (long)args->mm.mm_start_stack, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_START_BRK, (long)args->mm.mm_start_brk, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_BRK, (long)args->mm.mm_brk, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ARG_START, (long)args->mm.mm_arg_start, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ARG_END, (long)args->mm.mm_arg_end, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ENV_START, (long)args->mm.mm_env_start, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_ENV_END, (long)args->mm.mm_env_end, 0);
ret |= sys_prctl_safe(PR_SET_MM, PR_SET_MM_AUXV, (long)args->mm_saved_auxv, args->mm_saved_auxv_size);
if (ret)
goto core_restore_end;
/*
* Because of requirements applied from kernel side
* we need to restore /proc/pid/exe symlink late,
* after old existing VMAs are superseded with
* new ones from image file.
*/
ret = restore_self_exe_late(args);
if (ret)
goto core_restore_end;
/*
* We need to prepare a valid sigframe here, so
* after sigreturn the kernel will pick up the
* registers from the frame, set them up and
* finally pass execution to the new IP.
*/
rt_sigframe = (void *)args->t->mem_zone.rt_sigframe + 8;
if (restore_thread_common(rt_sigframe, args->t))
goto core_restore_end;
/*
* Threads restoration. This requires some more comments. This
* restorer routine and thread restorer routine has the following
* memory map, prepared by a caller code.
*
* | <-- low addresses high addresses --> |
* +-------------------------------------------------------+-----------------------+
* | this proc body | own stack | heap | rt_sigframe space | thread restore zone |
* +-------------------------------------------------------+-----------------------+
*
* where each thread restore zone is the following
*
* | <-- low addresses high addresses --> |
* +--------------------------------------------------------------------------+
* | thread restore proc | thread1 stack | thread1 heap | thread1 rt_sigframe |
* +--------------------------------------------------------------------------+
*/
if (args->nr_threads > 1) {
struct thread_restore_args *thread_args = args->thread_args;
long clone_flags = CLONE_VM | CLONE_FILES | CLONE_SIGHAND |
CLONE_THREAD | CLONE_SYSVSEM;
long last_pid_len;
long parent_tid;
int i, fd;
fd = sys_open(LAST_PID_PATH, O_RDWR, LAST_PID_PERM);
if (fd < 0) {
pr_err("Can't open last_pid %d\n", fd);
goto core_restore_end;
}
ret = sys_flock(fd, LOCK_EX);
if (ret) {
pr_err("Can't lock last_pid %d\n", fd);
goto core_restore_end;
}
for (i = 0; i < args->nr_threads; i++) {
char last_pid_buf[16], *s;
/* skip self */
if (thread_args[i].pid == args->t->pid)
continue;
mutex_lock(&args->rst_lock);
new_sp =
RESTORE_ALIGN_STACK((long)thread_args[i].mem_zone.stack,
sizeof(thread_args[i].mem_zone.stack));
last_pid_len = vprint_num(last_pid_buf, sizeof(last_pid_buf), thread_args[i].pid - 1, &s);
ret = sys_write(fd, s, last_pid_len);
if (ret < 0) {
pr_err("Can't set last_pid %ld/%s\n", ret, last_pid_buf);
goto core_restore_end;
}
/*
* To achieve functionality like libc's clone()
* we need a pure assembly here, because clone()'ed
* thread will run with own stack and we must not
* have any additional instructions... oh, dear...
*/
RUN_CLONE_RESTORE_FN(ret, clone_flags, new_sp, parent_tid, thread_args, args->clone_restore_fn);
}
ret = sys_flock(fd, LOCK_UN);
if (ret) {
pr_err("Can't unlock last_pid %ld\n", ret);
goto core_restore_end;
}
sys_close(fd);
}
restore_rlims(args);
pr_info("%ld: Restored\n", sys_getpid());
futex_set(&zombies_inprogress, args->nr_zombies);
restore_finish_stage(CR_STATE_RESTORE);
futex_wait_while_gt(&zombies_inprogress, 0);
sys_sigaction(SIGCHLD, &args->sigchld_act, NULL, sizeof(k_rtsigset_t));
ret = restore_signals(args->siginfo, args->siginfo_nr, true);
if (ret)
goto core_restore_end;
ret = restore_signals(args->t->siginfo, args->t->siginfo_nr, false);
if (ret)
goto core_restore_end;
restore_finish_stage(CR_STATE_RESTORE_SIGCHLD);
if (args->siginfo_size) {
ret = sys_munmap(args->siginfo, args->siginfo_size);
if (ret < 0) {
pr_err("Can't unmap signals %ld\n", ret);
goto core_restore_failed;
}
}
rst_tcp_socks_all(args->rst_tcp_socks, args->rst_tcp_socks_size);
/*
* Writing to last-pid is CAP_SYS_ADMIN protected,
* turning off TCP repair is CAP_SYS_NED_ADMIN protected,
* thus restore* creds _after_ all of the above.
*/
ret = restore_creds(&args->creds);
futex_set_and_wake(&thread_inprogress, args->nr_threads);
restore_finish_stage(CR_STATE_RESTORE_CREDS);
if (ret)
BUG();
/* Wait until children stop to use args->task_entries */
futex_wait_while_gt(&thread_inprogress, 1);
log_set_fd(-1);
/*
* The code that prepared the itimers makes shure the
* code below doesn't fail due to bad timing values.
*/
#define itimer_armed(args, i) \
(args->itimers[i].it_interval.tv_sec || \
args->itimers[i].it_interval.tv_usec)
if (itimer_armed(args, 0))
sys_setitimer(ITIMER_REAL, &args->itimers[0], NULL);
if (itimer_armed(args, 1))
sys_setitimer(ITIMER_VIRTUAL, &args->itimers[1], NULL);
if (itimer_armed(args, 2))
sys_setitimer(ITIMER_PROF, &args->itimers[2], NULL);
ret = sys_munmap(args->task_entries, TASK_ENTRIES_SIZE);
if (ret < 0) {
ret = ((long)__LINE__ << 16) | ((-ret) & 0xffff);
goto core_restore_failed;
}
/*
* Sigframe stack.
*/
new_sp = (long)rt_sigframe + SIGFRAME_OFFSET;
/*
* Prepare the stack and call for sigreturn,
* pure assembly since we don't need any additional
* code insns from gcc.
*/
ARCH_RT_SIGRETURN(new_sp);
core_restore_end:
futex_abort_and_wake(&task_entries->nr_in_progress);
pr_err("Restorer fail %ld\n", sys_getpid());
sys_exit_group(1);
return -1;
core_restore_failed:
ARCH_FAIL_CORE_RESTORE;
return ret;
}
