xref: /linux/arch/um/kernel/exec.c (revision 930cc144a043ff95e56b6888fa51c618b33f89e7)
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 
19 void flush_thread(void)
20 {
21 	void *data = NULL;
22 	int ret;
23 
24 	arch_flush_thread(&current->thread.arch);
25 
26 	ret = unmap(&current->mm->context.id, 0, STUB_START, 0, &data);
27 	ret = ret || unmap(&current->mm->context.id, STUB_END,
28 			   host_task_size - STUB_END, 1, &data);
29 	if (ret) {
30 		printk(KERN_ERR "flush_thread - clearing address space failed, "
31 		       "err = %d\n", ret);
32 		force_sig(SIGKILL, current);
33 	}
34 
35 	__switch_mm(&current->mm->context.id);
36 }
37 
38 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
39 {
40 	set_fs(USER_DS);
41 	PT_REGS_IP(regs) = eip;
42 	PT_REGS_SP(regs) = esp;
43 }
44 
45 static long execve1(char *file, char __user * __user *argv,
46 		    char __user *__user *env)
47 {
48 	long error;
49 
50 	error = do_execve(file, argv, env, &current->thread.regs);
51 	if (error == 0) {
52 		task_lock(current);
53 		current->ptrace &= ~PT_DTRACE;
54 #ifdef SUBARCH_EXECVE1
55 		SUBARCH_EXECVE1(&current->thread.regs.regs);
56 #endif
57 		task_unlock(current);
58 	}
59 	return error;
60 }
61 
62 long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
63 {
64 	long err;
65 
66 	err = execve1(file, argv, env);
67 	if (!err)
68 		UML_LONGJMP(current->thread.exec_buf, 1);
69 	return err;
70 }
71 
72 long sys_execve(char __user *file, char __user *__user *argv,
73 		char __user *__user *env)
74 {
75 	long error;
76 	char *filename;
77 
78 	lock_kernel();
79 	filename = getname(file);
80 	error = PTR_ERR(filename);
81 	if (IS_ERR(filename)) goto out;
82 	error = execve1(filename, argv, env);
83 	putname(filename);
84  out:
85 	unlock_kernel();
86 	return error;
87 }
88