xref: /openbmc/linux/arch/um/kernel/exec.c (revision 384740dc)
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 #ifdef CONFIG_TTY_LOG
46 extern void log_exec(char **argv, void *tty);
47 #endif
48 
49 static long execve1(char *file, char __user * __user *argv,
50 		    char __user *__user *env)
51 {
52 	long error;
53 #ifdef CONFIG_TTY_LOG
54 	struct tty_struct *tty;
55 
56 	mutex_lock(&tty_mutex);
57 	tty = get_current_tty();
58 	if (tty)
59 		log_exec(argv, tty);
60 	mutex_unlock(&tty_mutex);
61 #endif
62 	error = do_execve(file, argv, env, &current->thread.regs);
63 	if (error == 0) {
64 		task_lock(current);
65 		current->ptrace &= ~PT_DTRACE;
66 #ifdef SUBARCH_EXECVE1
67 		SUBARCH_EXECVE1(&current->thread.regs.regs);
68 #endif
69 		task_unlock(current);
70 	}
71 	return error;
72 }
73 
74 long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
75 {
76 	long err;
77 
78 	err = execve1(file, argv, env);
79 	if (!err)
80 		UML_LONGJMP(current->thread.exec_buf, 1);
81 	return err;
82 }
83 
84 long sys_execve(char __user *file, char __user *__user *argv,
85 		char __user *__user *env)
86 {
87 	long error;
88 	char *filename;
89 
90 	lock_kernel();
91 	filename = getname(file);
92 	error = PTR_ERR(filename);
93 	if (IS_ERR(filename)) goto out;
94 	error = execve1(filename, argv, env);
95 	putname(filename);
96  out:
97 	unlock_kernel();
98 	return error;
99 }
100