1 /*
2 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
3 * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 * Licensed under the GPL
5 */
6
7 #include <signal.h>
8 #include <sched.h>
9 #include <asm/unistd.h>
10 #include <sys/time.h>
11 #include <as-layout.h>
12 #include <ptrace_user.h>
13 #include <stub-data.h>
14 #include <sysdep/stub.h>
15
16 /*
17 * This is in a separate file because it needs to be compiled with any
18 * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
19 *
20 * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
21 * on some systems.
22 */
23
24 void __attribute__ ((__section__ (".__syscall_stub")))
stub_clone_handler(void)25 stub_clone_handler(void)
26 {
27 struct stub_data *data = (struct stub_data *) STUB_DATA;
28 long err;
29
30 err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
31 STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
32 if (err != 0)
33 goto out;
34
35 err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
36 if (err)
37 goto out;
38
39 remap_stack(data->fd, data->offset);
40 goto done;
41
42 out:
43 /*
44 * save current result.
45 * Parent: pid;
46 * child: retcode of mmap already saved and it jumps around this
47 * assignment
48 */
49 data->err = err;
50 done:
51 trap_myself();
52 }
53
