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