1 /*
2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5 
6 #include <linux/stddef.h>
7 #include <linux/module.h>
8 #include <linux/fs.h>
9 #include <linux/ptrace.h>
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <asm/current.h>
13 #include <asm/processor.h>
14 #include <asm/uaccess.h>
15 #include "as-layout.h"
16 #include "mem_user.h"
17 #include "skas.h"
18 #include "os.h"
19 #include "internal.h"
20 
flush_thread(void)21 void flush_thread(void)
22 {
23 	void *data = NULL;
24 	int ret;
25 
26 	arch_flush_thread(&current->thread.arch);
27 
28 	ret = unmap(&current->mm->context.id, 0, STUB_START, 0, &data);
29 	ret = ret || unmap(&current->mm->context.id, STUB_END,
30 			   host_task_size - STUB_END, 1, &data);
31 	if (ret) {
32 		printk(KERN_ERR "flush_thread - clearing address space failed, "
33 		       "err = %d\n", ret);
34 		force_sig(SIGKILL, current);
35 	}
36 
37 	__switch_mm(&current->mm->context.id);
38 }
39 
start_thread(struct pt_regs * regs,unsigned long eip,unsigned long esp)40 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
41 {
42 	PT_REGS_IP(regs) = eip;
43 	PT_REGS_SP(regs) = esp;
44 }
45 EXPORT_SYMBOL(start_thread);
46 
execve1(const char * file,const char __user * const __user * argv,const char __user * const __user * env)47 static long execve1(const char *file,
48 		    const char __user *const __user *argv,
49 		    const char __user *const __user *env)
50 {
51 	long error;
52 
53 	error = do_execve(file, argv, env, &current->thread.regs);
54 	if (error == 0) {
55 		task_lock(current);
56 		current->ptrace &= ~PT_DTRACE;
57 #ifdef SUBARCH_EXECVE1
58 		SUBARCH_EXECVE1(&current->thread.regs.regs);
59 #endif
60 		task_unlock(current);
61 	}
62 	return error;
63 }
64 
um_execve(const char * file,const char __user * const __user * argv,const char __user * const __user * env)65 long um_execve(const char *file, const char __user *const __user *argv, const char __user *const __user *env)
66 {
67 	long err;
68 
69 	err = execve1(file, argv, env);
70 	if (!err)
71 		UML_LONGJMP(current->thread.exec_buf, 1);
72 	return err;
73 }
74 
sys_execve(const char __user * file,const char __user * const __user * argv,const char __user * const __user * env)75 long sys_execve(const char __user *file, const char __user *const __user *argv,
76 		const char __user *const __user *env)
77 {
78 	long error;
79 	char *filename;
80 
81 	filename = getname(file);
82 	error = PTR_ERR(filename);
83 	if (IS_ERR(filename)) goto out;
84 	error = execve1(filename, argv, env);
85 	putname(filename);
86  out:
87 	return error;
88 }
89