xref: /openbmc/linux/arch/um/kernel/exec.c (revision c7887325230aec47d47a32562a6e26014a0fafca) 
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 "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 
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 
40 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
41 {
42 	set_fs(USER_DS);
43 	PT_REGS_IP(regs) = eip;
44 	PT_REGS_SP(regs) = esp;
45 }
46 
47 static long execve1(const char *file, char __user * __user *argv,
48 		    char __user *__user *env)
49 {
50 	long error;
51 
52 	error = do_execve(file, argv, env, &current->thread.regs);
53 	if (error == 0) {
54 		task_lock(current);
55 		current->ptrace &= ~PT_DTRACE;
56 #ifdef SUBARCH_EXECVE1
57 		SUBARCH_EXECVE1(&current->thread.regs.regs);
58 #endif
59 		task_unlock(current);
60 	}
61 	return error;
62 }
63 
64 long um_execve(const char *file, char __user *__user *argv, char __user *__user *env)
65 {
66 	long err;
67 
68 	err = execve1(file, argv, env);
69 	if (!err)
70 		UML_LONGJMP(current->thread.exec_buf, 1);
71 	return err;
72 }
73 
74 long sys_execve(const char __user *file, char __user *__user *argv,
75 		char __user *__user *env)
76 {
77 	long error;
78 	char *filename;
79 
80 	lock_kernel();
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 	unlock_kernel();
88 	return error;
89 }
90