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/uaccess.h>
10#include <asm/prctl.h> /* XXX This should get the constants from libc */
 
11#include <os.h>
12
13long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
 
14{
15	unsigned long *ptr = addr, tmp;
16	long ret;
17	int pid = task->mm->context.id.u.pid;
18
19	/*
20	 * With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
21	 * be safe), we need to call arch_prctl on the host because
22	 * setting %fs may result in something else happening (like a
23	 * GDT or thread.fs being set instead).  So, we let the host
24	 * fiddle the registers and thread struct and restore the
25	 * registers afterwards.
26	 *
27	 * So, the saved registers are stored to the process (this
28	 * needed because a stub may have been the last thing to run),
29	 * arch_prctl is run on the host, then the registers are read
30	 * back.
31	 */
32	switch (code) {
33	case ARCH_SET_FS:
34	case ARCH_SET_GS:
35		ret = restore_registers(pid, &current->thread.regs.regs);
36		if (ret)
37			return ret;
38		break;
39	case ARCH_GET_FS:
40	case ARCH_GET_GS:
41		/*
42		 * With these two, we read to a local pointer and
43		 * put_user it to the userspace pointer that we were
44		 * given.  If addr isn't valid (because it hasn't been
45		 * faulted in or is just bogus), we want put_user to
46		 * fault it in (or return -EFAULT) instead of having
47		 * the host return -EFAULT.
48		 */
49		ptr = &tmp;
50	}
51
52	ret = os_arch_prctl(pid, code, ptr);
53	if (ret)
54		return ret;
55
56	switch (code) {
57	case ARCH_SET_FS:
58		current->thread.arch.fs = (unsigned long) ptr;
59		ret = save_registers(pid, &current->thread.regs.regs);
60		break;
61	case ARCH_SET_GS:
62		ret = save_registers(pid, &current->thread.regs.regs);
 
 
63		break;
64	case ARCH_GET_FS:
65		ret = put_user(tmp, addr);
66		break;
67	case ARCH_GET_GS:
68		ret = put_user(tmp, addr);
69		break;
70	}
71
72	return ret;
73}
74
75long sys_arch_prctl(int code, unsigned long addr)
76{
77	return arch_prctl(current, code, (unsigned long __user *) addr);
78}
79
80void arch_switch_to(struct task_struct *to)
81{
82	if ((to->thread.arch.fs == 0) || (to->mm == NULL))
83		return;
 
 
 
 
 
 
 
 
 
 
84
85	arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
86}

 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
16long 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
43SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
44{
45	return arch_prctl(current, option, (unsigned long __user *) arg2);
46}
47
48void 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
56SYSCALL_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}