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 "linux/slab.h"
  12 #include "asm/current.h"
  13 #include "asm/processor.h"
  14 #include "asm/uaccess.h"
  15 #include "as-layout.h"
  16 #include "mem_user.h"
  17 #include "skas.h"
  18 #include "os.h"
  19 #include "internal.h"
  20
  21 void flush_thread(void)
  22 {
  23         void *data = NULL;
  24         int ret;
  25
  26         arch_flush_thread(&current->thread.arch);
  27
  28         ret = unmap(&current->mm->context.id, 0, STUB_START, 0, &data);
  29         ret = ret || unmap(&current->mm->context.id, STUB_END,
  30                            host_task_size - STUB_END, 1, &data);
  31         if (ret) {
  32                 printk(KERN_ERR "flush_thread - clearing address space failed, "
  33                        "err = %d\n", ret);
  34                 force_sig(SIGKILL, current);
  35         }
  36
  37         __switch_mm(&current->mm->context.id);
  38 }
  39
  40 void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
  41 {
  42         set_fs(USER_DS);
  43         PT_REGS_IP(regs) = eip;
  44         PT_REGS_SP(regs) = esp;
  45 }
  46
  47 static long execve1(const char *file,
  48                     const char __user *const __user *argv,
  49                     const char __user *const __user *env)
  50 {
  51         long error;
  52
  53         error = do_execve(file, argv, env, &current->thread.regs);
  54         if (error == 0) {
  55                 task_lock(current);
  56                 current->ptrace &= ~PT_DTRACE;
  57 #ifdef SUBARCH_EXECVE1
  58                 SUBARCH_EXECVE1(&current->thread.regs.regs);
  59 #endif
  60                 task_unlock(current);
  61         }
  62         return error;
  63 }
  64
  65 long um_execve(const char *file, char __user *__user *argv, char __user *__user *env)
  66 {
  67         long err;
  68
  69         err = execve1(file, argv, env);
  70         if (!err)
  71                 UML_LONGJMP(current->thread.exec_buf, 1);
  72         return err;
  73 }
  74
  75 long sys_execve(const char __user *file, char __user *__user *argv,
  76                 char __user *__user *env)
  77 {
  78         long error;
  79         char *filename;
  80
  81         lock_kernel();
  82         filename = getname(file);
  83         error = PTR_ERR(filename);
  84         if (IS_ERR(filename)) goto out;
  85         error = execve1(filename, argv, env);
  86         putname(filename);
  87  out:
  88         unlock_kernel();
  89         return error;
  90 }