xref: /openbmc/linux/arch/um/kernel/skas/clone.c (revision 1ac731c529cd4d6adbce134754b51ff7d822b145)
10d1fb0a4SAlex Dewar // SPDX-License-Identifier: GPL-2.0
2ee56314bSJeff Dike /*
32eb5f31bSAnton Ivanov  * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
4ee56314bSJeff Dike  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
5ee56314bSJeff Dike  */
69786a8f3SBodo Stroesser 
7ee56314bSJeff Dike #include <signal.h>
8ee56314bSJeff Dike #include <sched.h>
9ee56314bSJeff Dike #include <asm/unistd.h>
10ee56314bSJeff Dike #include <sys/time.h>
1137185b33SAl Viro #include <as-layout.h>
1237185b33SAl Viro #include <ptrace_user.h>
1337185b33SAl Viro #include <stub-data.h>
1437185b33SAl Viro #include <sysdep/stub.h>
15ee56314bSJeff Dike 
16ee56314bSJeff Dike /*
17ee56314bSJeff Dike  * This is in a separate file because it needs to be compiled with any
189786a8f3SBodo Stroesser  * extraneous gcc flags (-pg, -fprofile-arcs, -ftest-coverage) disabled
19aa1a64eeSJeff Dike  *
20aa1a64eeSJeff Dike  * Use UM_KERN_PAGE_SIZE instead of PAGE_SIZE because that calls getpagesize
21aa1a64eeSJeff Dike  * on some systems.
229786a8f3SBodo Stroesser  */
2339d730abSJeff Dike 
24bf9a76a4SLinus Torvalds void __attribute__ ((__section__ (".__syscall_stub")))
stub_clone_handler(void)259786a8f3SBodo Stroesser stub_clone_handler(void)
269786a8f3SBodo Stroesser {
27*6032aca0SJohannes Berg 	struct stub_data *data = get_stub_data();
289786a8f3SBodo Stroesser 	long err;
299786a8f3SBodo Stroesser 
309786a8f3SBodo Stroesser 	err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
31*6032aca0SJohannes Berg 			    (unsigned long)data +
32*6032aca0SJohannes Berg 				STUB_DATA_PAGES * UM_KERN_PAGE_SIZE / 2);
3384b2789dSJohannes Berg 	if (err) {
3484b2789dSJohannes Berg 		data->parent_err = err;
3584b2789dSJohannes Berg 		goto done;
3684b2789dSJohannes Berg 	}
379786a8f3SBodo Stroesser 
389786a8f3SBodo Stroesser 	err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0);
3984b2789dSJohannes Berg 	if (err) {
4084b2789dSJohannes Berg 		data->child_err = err;
4184b2789dSJohannes Berg 		goto done;
4284b2789dSJohannes Berg 	}
439786a8f3SBodo Stroesser 
449f0b4807SJohannes Berg 	remap_stack_and_trap();
455b7b15afSJeff Dike 
465b7b15afSJeff Dike  done:
479786a8f3SBodo Stroesser 	trap_myself();
489786a8f3SBodo Stroesser }
49