osfmk/ddb/db_access.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  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52 /*
  53  *      Author: David B. Golub, Carnegie Mellon University
  54  *      Date:   7/90
  55  */
  56 #include <mach/boolean.h>
  57 #include <machine/db_machdep.h>         /* type definitions */
  58 #include <machine/setjmp.h>
  59 #include <machine/endian.h>
  60 #include <kern/task.h>
  61 #include <ddb/db_access.h>
  62
  63
  64
  65 /*
  66  * Access unaligned data items on aligned (longword)
  67  * boundaries.
  68  */
  69
  70 int db_access_level = DB_ACCESS_LEVEL;
  71
  72 /*
  73  * This table is for sign-extending things.
  74  * Therefore its entries are signed, and yes
  75  * they are in fact negative numbers.
  76  * So don't put Us in it. Or Ls either.
  77  * Otherwise there is no point having it, n'est pas ?
  78  */
  79 static int db_extend[sizeof(long)+1] = { /* table for sign-extending */
  80 #if defined(__arch64__)
  81         0,
  82         0xFFFFFFFFFFFFFF80,
  83         0xFFFFFFFFFFFF8000,
  84         0xFFFFFFFFFF800000,
  85         0xFFFFFFFF80000000,
  86         0xFFFFFF8000000000,
  87         0xFFFF800000000000,
  88         0xFF80000000000000,
  89         0x8000000000000000,
  90 #else /* !defined(__arch64__) */
  91         0,
  92         0xFFFFFF80,
  93         0xFFFF8000,
  94         0xFF800000,
  95         0x80000000
  96 #endif /* defined(__arch64__) */
  97 };
  98
  99 db_expr_t
 100 db_get_task_value(
 101         db_addr_t       addr,
 102         register int    size,
 103         boolean_t       is_signed,
 104         task_t          task)
 105 {
 106         char            data[sizeof(db_expr_t)];
 107         register db_expr_t value;
 108         register int    i;
 109
 110         db_read_bytes((vm_offset_t)addr, size, data, task);
 111
 112         value = 0;
 113 #if     BYTE_MSF
 114         for (i = 0; i < size; i++)
 115 #else   /* BYTE_LSF */
 116         for (i = size - 1; i >= 0; i--)
 117 #endif
 118         {
 119             value = (value << 8) + (data[i] & 0xFF);
 120         }
 121
 122         if (size <= sizeof(int)) {
 123             if (is_signed && (value & db_extend[size]) != 0)
 124                 value |= db_extend[size];
 125         }
 126         return (value);
 127 }
 128
 129 void
 130 db_put_task_value(
 131         db_addr_t       addr,
 132         register int    size,
 133         register db_expr_t value,
 134         task_t          task)
 135 {
 136         char            data[sizeof(db_expr_t)];
 137         register int    i;
 138
 139 #if     BYTE_MSF
 140         for (i = size - 1; i >= 0; i--)
 141 #else   /* BYTE_LSF */
 142         for (i = 0; i < size; i++)
 143 #endif
 144         {
 145             data[i] = value & 0xFF;
 146             value >>= 8;
 147         }
 148
 149         db_write_bytes((vm_offset_t)addr, size, data, task);
 150 }
 151
 152 db_expr_t
 153 db_get_value(
 154         db_addr_t       addr,
 155         int             size,
 156         boolean_t       is_signed)
 157 {
 158         return(db_get_task_value(addr, size, is_signed, TASK_NULL));
 159 }
 160
 161 void
 162 db_put_value(
 163         db_addr_t       addr,
 164         int             size,
 165         db_expr_t       value)
 166 {
 167         db_put_task_value(addr, size, value, TASK_NULL);
 168 }