1 /* $NetBSD: db_access.c,v 1.22 2015/06/06 22:06:05 matt Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: David B. Golub, Carnegie Mellon University 29 * Date: 7/90 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: db_access.c,v 1.22 2015/06/06 22:06:05 matt Exp $"); 34 35 #if defined(_KERNEL_OPT) 36 #include "opt_kgdb.h" 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/proc.h> 41 #include <sys/endian.h> 42 43 #include <ddb/ddb.h> 44 45 /* 46 * Access unaligned data items on aligned (longword) 47 * boundaries. 48 * 49 * This file is shared by ddb, kgdb and crash(8). 50 */ 51 52 #if defined(DDB) || !defined(DDB) && !defined(KGDB) 53 #define _COMPILE_THIS 54 #endif 55 56 #if defined(_COMPILE_THIS) || defined(KGDB) && defined(SOFTWARE_SSTEP) 57 58 db_expr_t 59 db_get_value(db_addr_t addr, size_t size, bool is_signed) 60 { 61 char data[sizeof(db_expr_t)] __aligned(sizeof(db_expr_t)); 62 db_expr_t value; 63 size_t i; 64 65 db_read_bytes(addr, size, data); 66 67 value = 0; 68 #if BYTE_ORDER == LITTLE_ENDIAN 69 for (i = size; i-- > 0;) 70 #else /* BYTE_ORDER == BIG_ENDIAN */ 71 for (i = 0; i < size; i++) 72 #endif /* BYTE_ORDER */ 73 value = (value << 8) + (data[i] & 0xFF); 74 75 if (size < sizeof(db_expr_t) && is_signed 76 && (value & ((db_expr_t)1 << (8*size - 1)))) { 77 value |= ~(db_expr_t)0 << (8*size - 1); 78 } 79 return (value); 80 } 81 82 void 83 db_put_value(db_addr_t addr, size_t size, db_expr_t value) 84 { 85 char data[sizeof(db_expr_t)] __aligned(sizeof(db_expr_t)); 86 size_t i; 87 88 #if BYTE_ORDER == LITTLE_ENDIAN 89 for (i = 0; i < size; i++) 90 #else /* BYTE_ORDER == BIG_ENDIAN */ 91 for (i = size; i-- > 0;) 92 #endif /* BYTE_ORDER */ 93 { 94 data[i] = value & 0xFF; 95 value >>= 8; 96 } 97 98 db_write_bytes(addr, size, data); 99 } 100 101 #endif /* _COMPILE_THIS || KGDB && SOFTWARE_SSTEP */ 102 103 #ifdef _COMPILE_THIS 104 105 void * 106 db_read_ptr(const char *name) 107 { 108 db_expr_t val; 109 void *p; 110 111 if (!db_value_of_name(name, &val)) { 112 db_printf("db_read_ptr: cannot find `%s'\n", name); 113 db_error(NULL); 114 /* NOTREACHED */ 115 } 116 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p); 117 return p; 118 } 119 120 int 121 db_read_int(const char *name) 122 { 123 db_expr_t val; 124 int p; 125 126 if (!db_value_of_name(name, &val)) { 127 db_printf("db_read_int: cannot find `%s'\n", name); 128 db_error(NULL); 129 /* NOTREACHED */ 130 } 131 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p); 132 return p; 133 } 134 135 #endif /* _COMPILE_THIS */ 136