stub_clone_handler(void)
{
long err;
struct stub_data *from = (struct stub_data *) UML_CONFIG_STUB_DATA;
err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
UML_CONFIG_STUB_DATA + PAGE_SIZE / 2 -
sizeof(void *));
if(err != 0)
goto out;
err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
if(err)
goto out;
err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
(long) &from->timer, 0);
if(err)
goto out;
err = stub_syscall6(STUB_MMAP_NR, UML_CONFIG_STUB_DATA, PAGE_SIZE,
PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED,
from->fd, from->offset);
out:
/* save current result. Parent: pid; child: retcode of mmap */
from->err = err;
trap_myself();
}
stub_clone_handler(void)
{
struct stub_data *data = (struct stub_data *) STUB_DATA;
long err;
err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
if(err != 0)
goto out;
err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
if(err)
goto out;
err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
(long) &data->timer, 0);
if(err)
goto out;
remap_stack(data->fd, data->offset);
goto done;
out:
/* save current result.
* Parent: pid;
* child: retcode of mmap already saved and it jumps around this
* assignment
*/
data->err = err;
done:
trap_myself();
}
stub_segv_handler(int sig)
{
struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
int pid;
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
sc);
pid = stub_syscall0(__NR_getpid);
stub_syscall2(__NR_kill, pid, SIGUSR1);
/* Load pointer to sigcontext into esp, since we need to leave
* the stack in its original form when we do the sigreturn here, by
* hand.
*/
__asm__ __volatile__("mov %0,%%esp ; movl %1, %%eax ; "
"int $0x80" : : "a" (sc), "g" (__NR_sigreturn));
}
