clone.c
#include <sched.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <asm/unistd.h>
#include <asm/page.h>
#include "ptrace_user.h"
#include "skas.h"
#include "stub-data.h"
#include "uml-config.h"
#include "sysdep/stub.h"
#include "kern_constants.h"
/* This is in a separate file because it needs to be compiled with any
* extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
*
* Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
* on some systems.
*/
void __attribute__ ((__section__ (".__syscall_stub")))
stub_clone_handler(void)
{
struct stub_data *data = (struct stub_data *) UML_CONFIG_STUB_DATA;
long err;
err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
UML_CONFIG_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();
}