bsd/dev/i386/stubs.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1997 by Apple Computer, Inc., all rights reserved
  24  * Copyright (c) 1993 NeXT Computer, Inc.
  25  *
  26  */
  27
  28 #include <sys/param.h>
  29 #include <sys/systm.h>
  30 #include <sys/ioctl.h>
  31 #include <sys/tty.h>
  32 #include <sys/conf.h>
  33 #include <sys/kauth.h>
  34 #include <sys/ucred.h>
  35 #include <sys/proc_internal.h>
  36 #include <sys/user.h>
  37 #include <kern/task.h>
  38 #include <kern/thread.h>
  39 #include <vm/vm_map.h>
  40 #include <machine/machine_routines.h>
  41
  42 /* XXX should be elsewhere (cpeak) */
  43 extern struct proc *i386_current_proc(void);
  44 extern void     *get_bsduthreadarg(thread_t);
  45 extern int      *get_bsduthreadrval(thread_t);
  46 extern void     *find_user_regs(thread_t);
  47
  48 /*
  49  * copy a null terminated string from the kernel address space into
  50  * the user address space.
  51  *   - if the user is denied write access, return EFAULT.
  52  *   - if the end of string isn't found before
  53  *     maxlen bytes are copied,  return ENAMETOOLONG,
  54  *     indicating an incomplete copy.
  55  *   - otherwise, return 0, indicating success.
  56  * the number of bytes copied is always returned in lencopied.
  57  */
  58 int
  59 copyoutstr(const void *from, user_addr_t to, size_t maxlen, size_t *lencopied)
  60 {
  61         size_t  slen;
  62         size_t  len;
  63         int     error = 0;
  64
  65         slen = strlen(from) + 1;
  66         if (slen > maxlen)
  67                 error = ENAMETOOLONG;
  68
  69         len = min(maxlen,slen);
  70         if (copyout(from, to, len))
  71                 error = EFAULT;
  72         *lencopied = len;
  73
  74         return error;
  75 }
  76
  77
  78 /*
  79  * copy a null terminated string from one point to another in
  80  * the kernel address space.
  81  *   - no access checks are performed.
  82  *   - if the end of string isn't found before
  83  *     maxlen bytes are copied,  return ENAMETOOLONG,
  84  *     indicating an incomplete copy.
  85  *   - otherwise, return 0, indicating success.
  86  * the number of bytes copied is always returned in lencopied.
  87  */
  88 /* from ppc/fault_copy.c -Titan1T4 VERSION  */
  89 int
  90 copystr(const void *vfrom, void *vto, size_t maxlen, size_t *lencopied)
  91 {
  92         size_t          l;
  93         char const      *from = (char const *) vfrom;
  94         char            *to = (char *) vto;
  95
  96         for (l = 0; l < maxlen; l++) {
  97                 if ((*to++ = *from++) == '\0') {
  98                         if (lencopied)
  99                                 *lencopied = l + 1;
 100                         return 0;
 101                 }
 102         }
 103         if (lencopied)
 104                 *lencopied = maxlen;
 105         return ENAMETOOLONG;
 106 }
 107
 108 int
 109 copywithin(void *src, void *dst, size_t count)
 110 {
 111         bcopy(src,dst,count);
 112         return 0;
 113 }
 114
 115 /*
 116  * This is just current_proc() from bsd/kern/bsd_stubs.c, but instead of
 117  * returning kernproc in the non-vfork() case, it can return NULL.  This is
 118  * needed because the system call entry point is in osfmk/i386/bsd_i386.c
 119  * instead of bsd/dev/i386, and therefore cannot see some BSD thread
 120  * internals.  We need to distinguish kernproc defaulting in the vfork and
 121  * non-vfork cases vs. actually being the real process context.
 122  */
 123 struct proc *
 124 i386_current_proc(void)
 125 {
 126         struct uthread * ut;
 127         struct proc *p;
 128         thread_t thr_act = current_thread();
 129
 130         ut = (struct uthread *)get_bsdthread_info(thr_act);
 131         if (ut &&  (ut->uu_flag & UT_VFORK)) {
 132                 if (ut->uu_proc) {
 133                         p = ut->uu_proc;
 134                         if ((p->p_flag & P_INVFORK) == 0)
 135                                 panic("returning child proc not under vfork");
 136                         if (p->p_vforkact != (void *)thr_act)
 137                                 panic("returning child proc which is not cur_act");
 138                         return(p);
 139                 } else {
 140                         return (kernproc);
 141                 }
 142         }
 143
 144         /* Not in vfork - may return NULL */
 145         p = (struct proc *)get_bsdtask_info(current_task());
 146
 147         return (p);
 148 }
 149
 150 void *
 151 get_bsduthreadarg(thread_t th)
 152 {
 153         void    *arg_ptr;
 154         struct uthread *ut;
 155
 156         ut = get_bsdthread_info(th);
 157
 158         if (ml_thread_is64bit(th) == TRUE)
 159                 arg_ptr = (void *)saved_state64(find_user_regs(th));
 160         else
 161                 arg_ptr = (void *)(ut->uu_arg);
 162
 163         return(arg_ptr);
 164 }
 165
 166 int *
 167 get_bsduthreadrval(thread_t th)
 168 {
 169         struct uthread *ut;
 170
 171         ut = get_bsdthread_info(th);
 172         return(&ut->uu_rval[0]);
 173 }