bsd/dev/i386/stubs.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * Copyright (c) 1997 by Apple Computer, Inc., all rights reserved
  30  * Copyright (c) 1993 NeXT Computer, Inc.
  31  *
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/tty.h>
  38 #include <sys/conf.h>
  39 #include <sys/kauth.h>
  40 #include <sys/ucred.h>
  41 #include <sys/proc_internal.h>
  42 #include <sys/user.h>
  43 #include <kern/task.h>
  44 #include <kern/thread.h>
  45 #include <vm/vm_map.h>
  46 #include <machine/machine_routines.h>
  47
  48 /* XXX should be elsewhere (cpeak) */
  49 extern struct proc *i386_current_proc(void);
  50 extern void     *get_bsduthreadarg(thread_t);
  51 extern int      *get_bsduthreadrval(thread_t);
  52 extern void     *find_user_regs(thread_t);
  53
  54 /*
  55  * copy a null terminated string from the kernel address space into
  56  * the user address space.
  57  *   - if the user is denied write access, return EFAULT.
  58  *   - if the end of string isn't found before
  59  *     maxlen bytes are copied,  return ENAMETOOLONG,
  60  *     indicating an incomplete copy.
  61  *   - otherwise, return 0, indicating success.
  62  * the number of bytes copied is always returned in lencopied.
  63  */
  64 int
  65 copyoutstr(const void *from, user_addr_t to, size_t maxlen, size_t *lencopied)
  66 {
  67         size_t  slen;
  68         size_t  len;
  69         int     error = 0;
  70
  71         slen = strlen(from) + 1;
  72         if (slen > maxlen)
  73                 error = ENAMETOOLONG;
  74
  75         len = min(maxlen,slen);
  76         if (copyout(from, to, len))
  77                 error = EFAULT;
  78         *lencopied = len;
  79
  80         return error;
  81 }
  82
  83
  84 /*
  85  * copy a null terminated string from one point to another in
  86  * the kernel address space.
  87  *   - no access checks are performed.
  88  *   - if the end of string isn't found before
  89  *     maxlen bytes are copied,  return ENAMETOOLONG,
  90  *     indicating an incomplete copy.
  91  *   - otherwise, return 0, indicating success.
  92  * the number of bytes copied is always returned in lencopied.
  93  */
  94 /* from ppc/fault_copy.c -Titan1T4 VERSION  */
  95 int
  96 copystr(const void *vfrom, void *vto, size_t maxlen, size_t *lencopied)
  97 {
  98         size_t          l;
  99         char const      *from = (char const *) vfrom;
 100         char            *to = (char *) vto;
 101
 102         for (l = 0; l < maxlen; l++) {
 103                 if ((*to++ = *from++) == '\0') {
 104                         if (lencopied)
 105                                 *lencopied = l + 1;
 106                         return 0;
 107                 }
 108         }
 109         if (lencopied)
 110                 *lencopied = maxlen;
 111         return ENAMETOOLONG;
 112 }
 113
 114 int
 115 copywithin(void *src, void *dst, size_t count)
 116 {
 117         bcopy(src,dst,count);
 118         return 0;
 119 }
 120
 121 /*
 122  * This is just current_proc() from bsd/kern/bsd_stubs.c, but instead of
 123  * returning kernproc in the non-vfork() case, it can return NULL.  This is
 124  * needed because the system call entry point is in osfmk/i386/bsd_i386.c
 125  * instead of bsd/dev/i386, and therefore cannot see some BSD thread
 126  * internals.  We need to distinguish kernproc defaulting in the vfork and
 127  * non-vfork cases vs. actually being the real process context.
 128  */
 129 struct proc *
 130 i386_current_proc(void)
 131 {
 132         struct uthread * ut;
 133         struct proc *p;
 134         thread_t thr_act = current_thread();
 135
 136         ut = (struct uthread *)get_bsdthread_info(thr_act);
 137         if (ut &&  (ut->uu_flag & UT_VFORK)) {
 138                 if (ut->uu_proc) {
 139                         p = ut->uu_proc;
 140                         if ((p->p_flag & P_INVFORK) == 0)
 141                                 panic("returning child proc not under vfork");
 142                         if (p->p_vforkact != (void *)thr_act)
 143                                 panic("returning child proc which is not cur_act");
 144                         return(p);
 145                 } else {
 146                         return (kernproc);
 147                 }
 148         }
 149
 150         /* Not in vfork - may return NULL */
 151         p = (struct proc *)get_bsdtask_info(current_task());
 152
 153         return (p);
 154 }
 155
 156 void *
 157 get_bsduthreadarg(thread_t th)
 158 {
 159         void    *arg_ptr;
 160         struct uthread *ut;
 161
 162         ut = get_bsdthread_info(th);
 163
 164         if (ml_thread_is64bit(th) == TRUE)
 165                 arg_ptr = (void *)saved_state64(find_user_regs(th));
 166         else
 167                 arg_ptr = (void *)(ut->uu_arg);
 168
 169         return(arg_ptr);
 170 }
 171
 172 int *
 173 get_bsduthreadrval(thread_t th)
 174 {
 175         struct uthread *ut;
 176
 177         ut = get_bsdthread_info(th);
 178         return(&ut->uu_rval[0]);
 179 }