bsd/dev/i386/stubs.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Copyright (c) 1997 by Apple Computer, Inc., all rights reserved
  32  * Copyright (c) 1993 NeXT Computer, Inc.
  33  *
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/tty.h>
  40 #include <sys/conf.h>
  41 #include <sys/kauth.h>
  42 #include <sys/ucred.h>
  43 #include <sys/proc_internal.h>
  44 #include <sys/user.h>
  45 #include <kern/task.h>
  46 #include <kern/thread.h>
  47 #include <vm/vm_map.h>
  48 #include <machine/machine_routines.h>
  49
  50 /* XXX should be elsewhere (cpeak) */
  51 extern struct proc *i386_current_proc(void);
  52 extern void     *get_bsduthreadarg(thread_t);
  53 extern int      *get_bsduthreadrval(thread_t);
  54 extern void     *find_user_regs(thread_t);
  55
  56 /*
  57  * copy a null terminated string from the kernel address space into
  58  * the user address space.
  59  *   - if the user is denied write access, return EFAULT.
  60  *   - if the end of string isn't found before
  61  *     maxlen bytes are copied,  return ENAMETOOLONG,
  62  *     indicating an incomplete copy.
  63  *   - otherwise, return 0, indicating success.
  64  * the number of bytes copied is always returned in lencopied.
  65  */
  66 int
  67 copyoutstr(const void *from, user_addr_t to, size_t maxlen, size_t *lencopied)
  68 {
  69         size_t  slen;
  70         size_t  len;
  71         int     error = 0;
  72
  73         slen = strlen(from) + 1;
  74         if (slen > maxlen)
  75                 error = ENAMETOOLONG;
  76
  77         len = min(maxlen,slen);
  78         if (copyout(from, to, len))
  79                 error = EFAULT;
  80         *lencopied = len;
  81
  82         return error;
  83 }
  84
  85
  86 /*
  87  * copy a null terminated string from one point to another in
  88  * the kernel address space.
  89  *   - no access checks are performed.
  90  *   - if the end of string isn't found before
  91  *     maxlen bytes are copied,  return ENAMETOOLONG,
  92  *     indicating an incomplete copy.
  93  *   - otherwise, return 0, indicating success.
  94  * the number of bytes copied is always returned in lencopied.
  95  */
  96 /* from ppc/fault_copy.c -Titan1T4 VERSION  */
  97 int
  98 copystr(const void *vfrom, void *vto, size_t maxlen, size_t *lencopied)
  99 {
 100         size_t          l;
 101         char const      *from = (char const *) vfrom;
 102         char            *to = (char *) vto;
 103
 104         for (l = 0; l < maxlen; l++) {
 105                 if ((*to++ = *from++) == '\0') {
 106                         if (lencopied)
 107                                 *lencopied = l + 1;
 108                         return 0;
 109                 }
 110         }
 111         if (lencopied)
 112                 *lencopied = maxlen;
 113         return ENAMETOOLONG;
 114 }
 115
 116 int
 117 copywithin(void *src, void *dst, size_t count)
 118 {
 119         bcopy(src,dst,count);
 120         return 0;
 121 }
 122
 123 /*
 124  * This is just current_proc() from bsd/kern/bsd_stubs.c, but instead of
 125  * returning kernproc in the non-vfork() case, it can return NULL.  This is
 126  * needed because the system call entry point is in osfmk/i386/bsd_i386.c
 127  * instead of bsd/dev/i386, and therefore cannot see some BSD thread
 128  * internals.  We need to distinguish kernproc defaulting in the vfork and
 129  * non-vfork cases vs. actually being the real process context.
 130  */
 131 struct proc *
 132 i386_current_proc(void)
 133 {
 134         struct uthread * ut;
 135         struct proc *p;
 136         thread_t thr_act = current_thread();
 137
 138         ut = (struct uthread *)get_bsdthread_info(thr_act);
 139         if (ut &&  (ut->uu_flag & UT_VFORK)) {
 140                 if (ut->uu_proc) {
 141                         p = ut->uu_proc;
 142                         if ((p->p_flag & P_INVFORK) == 0)
 143                                 panic("returning child proc not under vfork");
 144                         if (p->p_vforkact != (void *)thr_act)
 145                                 panic("returning child proc which is not cur_act");
 146                         return(p);
 147                 } else {
 148                         return (kernproc);
 149                 }
 150         }
 151
 152         /* Not in vfork - may return NULL */
 153         p = (struct proc *)get_bsdtask_info(current_task());
 154
 155         return (p);
 156 }
 157
 158 void *
 159 get_bsduthreadarg(thread_t th)
 160 {
 161         void    *arg_ptr;
 162         struct uthread *ut;
 163
 164         ut = get_bsdthread_info(th);
 165
 166         if (ml_thread_is64bit(th) == TRUE)
 167                 arg_ptr = (void *)saved_state64(find_user_regs(th));
 168         else
 169                 arg_ptr = (void *)(ut->uu_arg);
 170
 171         return(arg_ptr);
 172 }
 173
 174 int *
 175 get_bsduthreadrval(thread_t th)
 176 {
 177         struct uthread *ut;
 178
 179         ut = get_bsdthread_info(th);
 180         return(&ut->uu_rval[0]);
 181 }