xref: /openbmc/linux/arch/um/kernel/exec.c (revision 643d1f7f)
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 	unsigned long end = proc_mm ? task_size : STUB_START;
23 	int ret;
24 
25 	arch_flush_thread(&current->thread.arch);
26 
27 	ret = unmap(&current->mm->context.id, 0, end, 1, &data);
28 	if (ret) {
29 		printk(KERN_ERR "flush_thread - clearing address space failed, "
30 		       "err = %d\n", ret);
31 		force_sig(SIGKILL, current);
32 	}
33 
34 	__switch_mm(&current->mm->context.id);
35 }
36 
37 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
38 {
39 	set_fs(USER_DS);
40 	PT_REGS_IP(regs) = eip;
41 	PT_REGS_SP(regs) = esp;
42 }
43 
44 #ifdef CONFIG_TTY_LOG
45 extern void log_exec(char **argv, void *tty);
46 #endif
47 
48 static long execve1(char *file, char __user * __user *argv,
49 		    char __user *__user *env)
50 {
51 	long error;
52 #ifdef CONFIG_TTY_LOG
53 	struct tty_struct *tty;
54 
55 	mutex_lock(&tty_mutex);
56 	tty = get_current_tty();
57 	if (tty)
58 		log_exec(argv, tty);
59 	mutex_unlock(&tty_mutex);
60 #endif
61 	error = do_execve(file, argv, env, &current->thread.regs);
62 	if (error == 0) {
63 		task_lock(current);
64 		current->ptrace &= ~PT_DTRACE;
65 #ifdef SUBARCH_EXECVE1
66 		SUBARCH_EXECVE1(&current->thread.regs.regs);
67 #endif
68 		task_unlock(current);
69 	}
70 	return error;
71 }
72 
73 long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
74 {
75 	long err;
76 
77 	err = execve1(file, argv, env);
78 	if (!err)
79 		UML_LONGJMP(current->thread.exec_buf, 1);
80 	return err;
81 }
82 
83 long sys_execve(char __user *file, char __user *__user *argv,
84 		char __user *__user *env)
85 {
86 	long error;
87 	char *filename;
88 
89 	lock_kernel();
90 	filename = getname(file);
91 	error = PTR_ERR(filename);
92 	if (IS_ERR(filename)) goto out;
93 	error = execve1(filename, argv, env);
94 	putname(filename);
95  out:
96 	unlock_kernel();
97 	return error;
98 }
99