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 #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(char *file, char __user * __user *argv,
  47                     char __user *__user *env)
  48 {
  49         long error;
  50
  51         error = do_execve(file, argv, env, &current->thread.regs);
  52         if (error == 0) {
  53                 task_lock(current);
  54                 current->ptrace &= ~PT_DTRACE;
  55 #ifdef SUBARCH_EXECVE1
  56                 SUBARCH_EXECVE1(&current->thread.regs.regs);
  57 #endif
  58                 task_unlock(current);
  59         }
  60         return error;
  61 }
  62
  63 long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
  64 {
  65         long err;
  66
  67         err = execve1(file, argv, env);
  68         if (!err)
  69                 UML_LONGJMP(current->thread.exec_buf, 1);
  70         return err;
  71 }
  72
  73 long sys_execve(char __user *file, char __user *__user *argv,
  74                 char __user *__user *env)
  75 {
  76         long error;
  77         char *filename;
  78
  79         lock_kernel();
  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         unlock_kernel();
  87         return error;
  88 }