arch/um/kernel/exec.c

   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 }