xref: /openbmc/linux/arch/um/kernel/exec.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd) 
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/ptrace.h"
9 #include "linux/sched.h"
10 #include "linux/slab.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(const char *file,
47 		    const char __user *const __user *argv,
48 		    const char __user *const __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, const char __user *const __user *argv, const char __user *const __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, const char __user *const __user *argv,
75 		const char __user *const __user *env)
76 {
77 	long error;
78 	char *filename;
79 
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 	return error;
87 }
88