xref: /linux-6.15/arch/um/kernel/exec.c (revision 512b6fb1)
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 "mem_user.h"
15 #include "skas.h"
16 #include "os.h"
17 
18 void flush_thread(void)
19 {
20 	void *data = NULL;
21 	unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
22 	int ret;
23 
24 	arch_flush_thread(&current->thread.arch);
25 
26 	ret = unmap(&current->mm->context.id, 0, end, 1, &data);
27 	if (ret) {
28 		printk(KERN_ERR "flush_thread - clearing address space failed, "
29 		       "err = %d\n", ret);
30 		force_sig(SIGKILL, current);
31 	}
32 
33 	__switch_mm(&current->mm->context.id);
34 }
35 
36 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
37 {
38 	set_fs(USER_DS);
39 	PT_REGS_IP(regs) = eip;
40 	PT_REGS_SP(regs) = esp;
41 }
42 
43 #ifdef CONFIG_TTY_LOG
44 extern void log_exec(char **argv, void *tty);
45 #endif
46 
47 static long execve1(char *file, char __user * __user *argv,
48 		    char __user *__user *env)
49 {
50 	long error;
51 #ifdef CONFIG_TTY_LOG
52 	struct tty_struct *tty;
53 
54 	mutex_lock(&tty_mutex);
55 	tty = get_current_tty();
56 	if (tty)
57 		log_exec(argv, tty);
58 	mutex_unlock(&tty_mutex);
59 #endif
60 	error = do_execve(file, argv, env, &current->thread.regs);
61 	if (error == 0) {
62 		task_lock(current);
63 		current->ptrace &= ~PT_DTRACE;
64 #ifdef SUBARCH_EXECVE1
65 		SUBARCH_EXECVE1(&current->thread.regs.regs);
66 #endif
67 		task_unlock(current);
68 	}
69 	return error;
70 }
71 
72 long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
73 {
74 	long err;
75 
76 	err = execve1(file, argv, env);
77 	if (!err)
78 		UML_LONGJMP(current->thread.exec_buf, 1);
79 	return err;
80 }
81 
82 long sys_execve(char __user *file, char __user *__user *argv,
83 		char __user *__user *env)
84 {
85 	long error;
86 	char *filename;
87 
88 	lock_kernel();
89 	filename = getname(file);
90 	error = PTR_ERR(filename);
91 	if (IS_ERR(filename)) goto out;
92 	error = execve1(filename, argv, env);
93 	putname(filename);
94  out:
95 	unlock_kernel();
96 	return error;
97 }
98