1/* Intel 386 native support for System V systems (pre-SVR4). 2 3 Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 4 1999, 2000, 2002 Free Software Foundation, Inc. 5 6 This file is part of GDB. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 59 Temple Place - Suite 330, 21 Boston, MA 02111-1307, USA. */ 22 23#include "defs.h" 24 25#ifdef HAVE_PTRACE_H 26#include <ptrace.h> 27#else 28#ifdef HAVE_SYS_PTRACE_H 29#include <sys/ptrace.h> 30#endif 31#endif 32 33#include "frame.h" 34#include "inferior.h" 35#include "language.h" 36#include "gdbcore.h" 37 38#ifdef USG 39#include <sys/types.h> 40#endif 41 42#include <sys/param.h> 43#include <sys/dir.h> 44#include <signal.h> 45#include <sys/user.h> 46#include <sys/ioctl.h> 47#include <fcntl.h> 48 49#ifdef TARGET_HAS_HARDWARE_WATCHPOINTS 50#include <sys/debugreg.h> 51#endif 52 53#include <sys/file.h> 54#include "gdb_stat.h" 55 56#ifdef HAVE_SYS_REG_H 57#include <sys/reg.h> 58#endif 59 60#include "floatformat.h" 61 62#include "target.h" 63 64#include "i386-tdep.h" 65 66 67/* Mapping between the general-purpose registers in `struct user' 68 format and GDB's register array layout. */ 69static int regmap[] = 70{ 71 EAX, ECX, EDX, EBX, 72 UESP, EBP, ESI, EDI, 73 EIP, EFL, CS, SS, 74 DS, ES, FS, GS, 75}; 76 77/* Support for the user struct. */ 78 79/* Return the address of register REGNUM. BLOCKEND is the value of 80 u.u_ar0, and points to the place where GS is stored. */ 81 82CORE_ADDR 83register_u_addr (CORE_ADDR blockend, int regnum) 84{ 85 struct user u; 86 CORE_ADDR fpstate; 87 88 if (i386_fp_regnum_p (regnum)) 89 { 90#ifdef KSTKSZ /* SCO, and others? */ 91 blockend += 4 * (SS + 1) - KSTKSZ; 92 fpstate = blockend + ((char *) &u.u_fps.u_fpstate - (char *) &u); 93 return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM)); 94#else 95 fpstate = blockend + ((char *) &u.i387.st_space - (char *) &u); 96 return (fpstate + 10 * (regnum - FP0_REGNUM)); 97#endif 98 } 99 100 return (blockend + 4 * regmap[regnum]); 101} 102 103/* Return the size of the user struct. */ 104 105int 106kernel_u_size (void) 107{ 108 return (sizeof (struct user)); 109} 110 111#ifdef TARGET_HAS_HARDWARE_WATCHPOINTS 112 113#if !defined (offsetof) 114#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) 115#endif 116 117/* Record the value of the debug control register. */ 118static int debug_control_mirror; 119 120/* Record which address associates with which register. */ 121static CORE_ADDR address_lookup[DR_LASTADDR - DR_FIRSTADDR + 1]; 122 123static int i386_insert_aligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int, 124 int); 125 126static int i386_insert_nonaligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int, 127 int); 128 129/* Insert a watchpoint. */ 130 131int 132i386_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw) 133{ 134 return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw); 135} 136 137static int 138i386_insert_aligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr, 139 int len, int rw) 140{ 141 int i; 142 int read_write_bits, len_bits; 143 int free_debug_register; 144 int register_number; 145 146 /* Look for a free debug register. */ 147 for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) 148 { 149 if (address_lookup[i - DR_FIRSTADDR] == 0) 150 break; 151 } 152 153 /* No more debug registers! */ 154 if (i > DR_LASTADDR) 155 return -1; 156 157 read_write_bits = (rw & 1) ? DR_RW_READ : DR_RW_WRITE; 158 159 if (len == 1) 160 len_bits = DR_LEN_1; 161 else if (len == 2) 162 { 163 if (addr % 2) 164 return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); 165 len_bits = DR_LEN_2; 166 } 167 168 else if (len == 4) 169 { 170 if (addr % 4) 171 return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); 172 len_bits = DR_LEN_4; 173 } 174 else 175 return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); 176 177 free_debug_register = i; 178 register_number = free_debug_register - DR_FIRSTADDR; 179 debug_control_mirror |= 180 ((read_write_bits | len_bits) 181 << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number)); 182 debug_control_mirror |= 183 (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); 184 debug_control_mirror |= DR_LOCAL_SLOWDOWN; 185 debug_control_mirror &= ~DR_CONTROL_RESERVED; 186 187 ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), 188 debug_control_mirror); 189 ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]), 190 addr); 191 192 /* Record where we came from. */ 193 address_lookup[register_number] = addr; 194 return 0; 195} 196 197static int 198i386_insert_nonaligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr, 199 int len, int rw) 200{ 201 int align; 202 int size; 203 int rv; 204 205 static int size_try_array[4][4] = 206 { 207 { 1, 1, 1, 1 }, /* trying size one */ 208 { 2, 1, 2, 1 }, /* trying size two */ 209 { 2, 1, 2, 1 }, /* trying size three */ 210 { 4, 1, 2, 1 } /* trying size four */ 211 }; 212 213 rv = 0; 214 while (len > 0) 215 { 216 align = addr % 4; 217 /* Four is the maximum length for 386. */ 218 size = size_try_array[len > 4 ? 3 : len - 1][align]; 219 220 rv = i386_insert_aligned_watchpoint (pid, waddr, addr, size, rw); 221 if (rv) 222 { 223 i386_remove_watchpoint (pid, waddr, size); 224 return rv; 225 } 226 addr += size; 227 len -= size; 228 } 229 return rv; 230} 231 232/* Remove a watchpoint. */ 233 234int 235i386_remove_watchpoint (int pid, CORE_ADDR addr, int len) 236{ 237 int i; 238 int register_number; 239 240 for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) 241 { 242 register_number = i - DR_FIRSTADDR; 243 if (address_lookup[register_number] == addr) 244 { 245 debug_control_mirror &= 246 ~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); 247 address_lookup[register_number] = 0; 248 } 249 } 250 ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), 251 debug_control_mirror); 252 ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); 253 254 return 0; 255} 256 257/* Check if stopped by a watchpoint. */ 258 259CORE_ADDR 260i386_stopped_by_watchpoint (int pid) 261{ 262 int i; 263 int status; 264 265 status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); 266 ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); 267 268 for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) 269 { 270 if (status & (1 << (i - DR_FIRSTADDR))) 271 return address_lookup[i - DR_FIRSTADDR]; 272 } 273 274 return 0; 275} 276 277#endif /* TARGET_HAS_HARDWARE_WATCHPOINTS */ 278