| 1 | /* Intel 386 native support for System V systems (pre-SVR4). |
| 2 | |
| 3 | Copyright (C) 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., 51 Franklin Street, Fifth Floor, |
| 21 | Boston, MA 02110-1301, 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 | #include <sys/param.h> |
| 39 | #include <sys/dir.h> |
| 40 | #include <signal.h> |
| 41 | #include <sys/user.h> |
| 42 | #include <sys/ioctl.h> |
| 43 | #include <fcntl.h> |
| 44 | |
| 45 | #ifdef TARGET_HAS_HARDWARE_WATCHPOINTS |
| 46 | #include <sys/debugreg.h> |
| 47 | #endif |
| 48 | |
| 49 | #include <sys/file.h> |
| 50 | #include "gdb_stat.h" |
| 51 | |
| 52 | #ifdef HAVE_SYS_REG_H |
| 53 | #include <sys/reg.h> |
| 54 | #endif |
| 55 | |
| 56 | #include "floatformat.h" |
| 57 | |
| 58 | #include "target.h" |
| 59 | |
| 60 | #include "i386-tdep.h" |
| 61 | \f |
| 62 | |
| 63 | /* Mapping between the general-purpose registers in `struct user' |
| 64 | format and GDB's register array layout. */ |
| 65 | static int regmap[] = |
| 66 | { |
| 67 | EAX, ECX, EDX, EBX, |
| 68 | UESP, EBP, ESI, EDI, |
| 69 | EIP, EFL, CS, SS, |
| 70 | DS, ES, FS, GS, |
| 71 | }; |
| 72 | |
| 73 | /* Support for the user struct. */ |
| 74 | |
| 75 | /* Return the address of register REGNUM. BLOCKEND is the value of |
| 76 | u.u_ar0, and points to the place where GS is stored. */ |
| 77 | |
| 78 | CORE_ADDR |
| 79 | register_u_addr (CORE_ADDR blockend, int regnum) |
| 80 | { |
| 81 | struct user u; |
| 82 | CORE_ADDR fpstate; |
| 83 | |
| 84 | if (i386_fp_regnum_p (regnum)) |
| 85 | { |
| 86 | #ifdef KSTKSZ /* SCO, and others? */ |
| 87 | blockend += 4 * (SS + 1) - KSTKSZ; |
| 88 | fpstate = blockend + ((char *) &u.u_fps.u_fpstate - (char *) &u); |
| 89 | return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM)); |
| 90 | #else |
| 91 | fpstate = blockend + ((char *) &u.i387.st_space - (char *) &u); |
| 92 | return (fpstate + 10 * (regnum - FP0_REGNUM)); |
| 93 | #endif |
| 94 | } |
| 95 | |
| 96 | return (blockend + 4 * regmap[regnum]); |
| 97 | } |
| 98 | |
| 99 | /* Return the size of the user struct. */ |
| 100 | |
| 101 | int |
| 102 | kernel_u_size (void) |
| 103 | { |
| 104 | return (sizeof (struct user)); |
| 105 | } |
| 106 | \f |
| 107 | #ifdef TARGET_HAS_HARDWARE_WATCHPOINTS |
| 108 | |
| 109 | #if !defined (offsetof) |
| 110 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) |
| 111 | #endif |
| 112 | |
| 113 | /* Record the value of the debug control register. */ |
| 114 | static int debug_control_mirror; |
| 115 | |
| 116 | /* Record which address associates with which register. */ |
| 117 | static CORE_ADDR address_lookup[DR_LASTADDR - DR_FIRSTADDR + 1]; |
| 118 | |
| 119 | static int i386_insert_aligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int, |
| 120 | int); |
| 121 | |
| 122 | static int i386_insert_nonaligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int, |
| 123 | int); |
| 124 | |
| 125 | /* Insert a watchpoint. */ |
| 126 | |
| 127 | int |
| 128 | i386_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw) |
| 129 | { |
| 130 | return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw); |
| 131 | } |
| 132 | |
| 133 | static int |
| 134 | i386_insert_aligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr, |
| 135 | int len, int rw) |
| 136 | { |
| 137 | int i; |
| 138 | int read_write_bits, len_bits; |
| 139 | int free_debug_register; |
| 140 | int register_number; |
| 141 | |
| 142 | /* Look for a free debug register. */ |
| 143 | for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) |
| 144 | { |
| 145 | if (address_lookup[i - DR_FIRSTADDR] == 0) |
| 146 | break; |
| 147 | } |
| 148 | |
| 149 | /* No more debug registers! */ |
| 150 | if (i > DR_LASTADDR) |
| 151 | return -1; |
| 152 | |
| 153 | read_write_bits = (rw & 1) ? DR_RW_READ : DR_RW_WRITE; |
| 154 | |
| 155 | if (len == 1) |
| 156 | len_bits = DR_LEN_1; |
| 157 | else if (len == 2) |
| 158 | { |
| 159 | if (addr % 2) |
| 160 | return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); |
| 161 | len_bits = DR_LEN_2; |
| 162 | } |
| 163 | |
| 164 | else if (len == 4) |
| 165 | { |
| 166 | if (addr % 4) |
| 167 | return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); |
| 168 | len_bits = DR_LEN_4; |
| 169 | } |
| 170 | else |
| 171 | return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw); |
| 172 | |
| 173 | free_debug_register = i; |
| 174 | register_number = free_debug_register - DR_FIRSTADDR; |
| 175 | debug_control_mirror |= |
| 176 | ((read_write_bits | len_bits) |
| 177 | << (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number)); |
| 178 | debug_control_mirror |= |
| 179 | (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); |
| 180 | debug_control_mirror |= DR_LOCAL_SLOWDOWN; |
| 181 | debug_control_mirror &= ~DR_CONTROL_RESERVED; |
| 182 | |
| 183 | ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), |
| 184 | debug_control_mirror); |
| 185 | ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]), |
| 186 | addr); |
| 187 | |
| 188 | /* Record where we came from. */ |
| 189 | address_lookup[register_number] = addr; |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | static int |
| 194 | i386_insert_nonaligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr, |
| 195 | int len, int rw) |
| 196 | { |
| 197 | int align; |
| 198 | int size; |
| 199 | int rv; |
| 200 | |
| 201 | static int size_try_array[4][4] = |
| 202 | { |
| 203 | { 1, 1, 1, 1 }, /* trying size one */ |
| 204 | { 2, 1, 2, 1 }, /* trying size two */ |
| 205 | { 2, 1, 2, 1 }, /* trying size three */ |
| 206 | { 4, 1, 2, 1 } /* trying size four */ |
| 207 | }; |
| 208 | |
| 209 | rv = 0; |
| 210 | while (len > 0) |
| 211 | { |
| 212 | align = addr % 4; |
| 213 | /* Four is the maximum length for 386. */ |
| 214 | size = size_try_array[len > 4 ? 3 : len - 1][align]; |
| 215 | |
| 216 | rv = i386_insert_aligned_watchpoint (pid, waddr, addr, size, rw); |
| 217 | if (rv) |
| 218 | { |
| 219 | i386_remove_watchpoint (pid, waddr, size); |
| 220 | return rv; |
| 221 | } |
| 222 | addr += size; |
| 223 | len -= size; |
| 224 | } |
| 225 | return rv; |
| 226 | } |
| 227 | |
| 228 | /* Remove a watchpoint. */ |
| 229 | |
| 230 | int |
| 231 | i386_remove_watchpoint (int pid, CORE_ADDR addr, int len) |
| 232 | { |
| 233 | int i; |
| 234 | int register_number; |
| 235 | |
| 236 | for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) |
| 237 | { |
| 238 | register_number = i - DR_FIRSTADDR; |
| 239 | if (address_lookup[register_number] == addr) |
| 240 | { |
| 241 | debug_control_mirror &= |
| 242 | ~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number)); |
| 243 | address_lookup[register_number] = 0; |
| 244 | } |
| 245 | } |
| 246 | ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]), |
| 247 | debug_control_mirror); |
| 248 | ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); |
| 249 | |
| 250 | return 0; |
| 251 | } |
| 252 | |
| 253 | /* Check if stopped by a watchpoint. */ |
| 254 | |
| 255 | CORE_ADDR |
| 256 | i386_stopped_by_watchpoint (int pid) |
| 257 | { |
| 258 | int i; |
| 259 | int status; |
| 260 | |
| 261 | status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); |
| 262 | ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0); |
| 263 | |
| 264 | for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) |
| 265 | { |
| 266 | if (status & (1 << (i - DR_FIRSTADDR))) |
| 267 | return address_lookup[i - DR_FIRSTADDR]; |
| 268 | } |
| 269 | |
| 270 | return 0; |
| 271 | } |
| 272 | |
| 273 | #endif /* TARGET_HAS_HARDWARE_WATCHPOINTS */ |