xref: /linux/arch/um/kernel/exec.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
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/fs.h"
8 #include "linux/smp_lock.h"
9 #include "linux/ptrace.h"
10 #include "linux/sched.h"
11 #include "asm/current.h"
12 #include "asm/processor.h"
13 #include "asm/uaccess.h"
14 #include "as-layout.h"
15 #include "mem_user.h"
16 #include "skas.h"
17 #include "os.h"
18 #include "internal.h"
19 
20 void flush_thread(void)
21 {
22 	void *data = NULL;
23 	int ret;
24 
25 	arch_flush_thread(&current->thread.arch);
26 
27 	ret = unmap(&current->mm->context.id, 0, STUB_START, 0, &data);
28 	ret = ret || unmap(&current->mm->context.id, STUB_END,
29 			   host_task_size - STUB_END, 1, &data);
30 	if (ret) {
31 		printk(KERN_ERR "flush_thread - clearing address space failed, "
32 		       "err = %d\n", ret);
33 		force_sig(SIGKILL, current);
34 	}
35 
36 	__switch_mm(&current->mm->context.id);
37 }
38 
39 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
40 {
41 	set_fs(USER_DS);
42 	PT_REGS_IP(regs) = eip;
43 	PT_REGS_SP(regs) = esp;
44 }
45 
46 static long execve1(char *file, char __user * __user *argv,
47 		    char __user *__user *env)
48 {
49 	long error;
50 
51 	error = do_execve(file, argv, env, &current->thread.regs);
52 	if (error == 0) {
53 		task_lock(current);
54 		current->ptrace &= ~PT_DTRACE;
55 #ifdef SUBARCH_EXECVE1
56 		SUBARCH_EXECVE1(&current->thread.regs.regs);
57 #endif
58 		task_unlock(current);
59 	}
60 	return error;
61 }
62 
63 long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
64 {
65 	long err;
66 
67 	err = execve1(file, argv, env);
68 	if (!err)
69 		UML_LONGJMP(current->thread.exec_buf, 1);
70 	return err;
71 }
72 
73 long sys_execve(char __user *file, char __user *__user *argv,
74 		char __user *__user *env)
75 {
76 	long error;
77 	char *filename;
78 
79 	lock_kernel();
80 	filename = getname(file);
81 	error = PTR_ERR(filename);
82 	if (IS_ERR(filename)) goto out;
83 	error = execve1(filename, argv, env);
84 	putname(filename);
85  out:
86 	unlock_kernel();
87 	return error;
88 }
89