xref: /linux/arch/x86/um/syscalls_64.c (revision 2a6b6c9a226279b4f6668450ddb21ae655558087)
1 /*
2  * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Copyright 2003 PathScale, Inc.
4  *
5  * Licensed under the GPL
6  */
7 
8 #include <linux/sched.h>
9 #include <linux/sched/mm.h>
10 #include <linux/syscalls.h>
11 #include <linux/uaccess.h>
12 #include <asm/prctl.h> /* XXX This should get the constants from libc */
13 #include <registers.h>
14 #include <os.h>
15 
16 long arch_prctl(struct task_struct *task, int option,
17 		unsigned long __user *arg2)
18 {
19 	long ret = -EINVAL;
20 
21 	switch (option) {
22 	case ARCH_SET_FS:
23 		current->thread.regs.regs.gp[FS_BASE / sizeof(unsigned long)] =
24 			(unsigned long) arg2;
25 		ret = 0;
26 		break;
27 	case ARCH_SET_GS:
28 		current->thread.regs.regs.gp[GS_BASE / sizeof(unsigned long)] =
29 			(unsigned long) arg2;
30 		ret = 0;
31 		break;
32 	case ARCH_GET_FS:
33 		ret = put_user(current->thread.regs.regs.gp[FS_BASE / sizeof(unsigned long)], arg2);
34 		break;
35 	case ARCH_GET_GS:
36 		ret = put_user(current->thread.regs.regs.gp[GS_BASE / sizeof(unsigned long)], arg2);
37 		break;
38 	}
39 
40 	return ret;
41 }
42 
43 SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
44 {
45 	return arch_prctl(current, option, (unsigned long __user *) arg2);
46 }
47 
48 void arch_switch_to(struct task_struct *to)
49 {
50 	/*
51 	 * Nothing needs to be done on x86_64.
52 	 * The FS_BASE/GS_BASE registers are saved in the ptrace register set.
53 	 */
54 }
55 
56 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
57 		unsigned long, prot, unsigned long, flags,
58 		unsigned long, fd, unsigned long, off)
59 {
60 	if (off & ~PAGE_MASK)
61 		return -EINVAL;
62 
63 	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
64 }
65