kernel/skas/clone.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
0004  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
0005  */
0006
0007 #include <signal.h>
0008 #include <sched.h>
0009 #include <asm/unistd.h>
0010 #include <sys/time.h>
0011 #include <as-layout.h>
0012 #include <ptrace_user.h>
0013 #include <stub-data.h>
0014 #include <sysdep/stub.h>
0015
0016 /*
0017  * This is in a separate file because it needs to be compiled with any
0018  * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
0019  *
0020  * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
0021  * on some systems.
0022  */
0023
0024 void __attribute__ ((__section__ (".__syscall_stub")))
0025 stub_clone_handler(void)
0026 {
0027     struct stub_data *data = get_stub_page();
0028     long err;
0029
0030     err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
0031                 (unsigned long)data + UM_KERN_PAGE_SIZE / 2);
0032     if (err) {
0033         data->parent_err = err;
0034         goto done;
0035     }
0036
0037     err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
0038     if (err) {
0039         data->child_err = err;
0040         goto done;
0041     }
0042
0043     remap_stack_and_trap();
0044
0045  done:
0046     trap_myself();
0047 }