| 1 | /* Native-dependent code for Lynx running on i386's, for GDB. |
| 2 | Copyright 1988, 1989, 1991, 1992, 1993 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "gdbcore.h" |
| 24 | #include "target.h" |
| 25 | |
| 26 | #include <sys/ptrace.h> |
| 27 | #include "/usr/include/sys/wait.h" |
| 28 | |
| 29 | /* these values indicate the offset of the named register in the econtext |
| 30 | structure */ |
| 31 | |
| 32 | #define EAX 10 |
| 33 | #define ECX 9 |
| 34 | #define EDX 8 |
| 35 | #define EBX 7 |
| 36 | #define ESP 16 |
| 37 | #define EBP 5 |
| 38 | #define ESI 4 |
| 39 | #define EDI 3 |
| 40 | #define EIP 13 |
| 41 | #define EFL 15 |
| 42 | #define CS 14 |
| 43 | #define SS 17 |
| 44 | #define DS 2 |
| 45 | #define ES 1 |
| 46 | |
| 47 | /* Currently these are not being used. So set them to 0 */ |
| 48 | |
| 49 | #define FS 0 |
| 50 | #define GS 0 |
| 51 | |
| 52 | /* this table must line up with REGISTER_NAMES in m-i386.h */ |
| 53 | static unsigned int regmap[] = |
| 54 | { |
| 55 | EAX, ECX, EDX, EBX, |
| 56 | ESP, EBP, ESI, EDI, |
| 57 | EIP, EFL, CS, SS, |
| 58 | DS, ES, FS, GS, |
| 59 | }; |
| 60 | |
| 61 | /* Return the address in the core dump or inferior of register REGNO. |
| 62 | BLOCKEND is the address of the econtext structure */ |
| 63 | |
| 64 | static unsigned int |
| 65 | register_addr (regno, blockend) |
| 66 | int regno, blockend; |
| 67 | { |
| 68 | if (regno < 0 || regno >= NUM_REGS) |
| 69 | error ("Invalid register number %d.", regno); |
| 70 | |
| 71 | return (blockend + regmap[regno] * sizeof (long)); |
| 72 | } |
| 73 | |
| 74 | /* Fetch one register. */ |
| 75 | |
| 76 | static void |
| 77 | fetch_register (regno, offset, bpid) |
| 78 | int regno, bpid; |
| 79 | unsigned int offset; |
| 80 | { |
| 81 | unsigned int regaddr; |
| 82 | char buf[MAX_REGISTER_RAW_SIZE]; |
| 83 | char mess[128]; /* For messages */ |
| 84 | int i; |
| 85 | |
| 86 | regaddr = register_addr (regno, offset); |
| 87 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) |
| 88 | { |
| 89 | errno = 0; |
| 90 | *(int *) &buf[i] = ptrace (PTRACE_PEEKTHREAD, bpid, |
| 91 | (PTRACE_ARG3_TYPE) regaddr, 0); |
| 92 | regaddr += sizeof (int); |
| 93 | if (errno != 0) |
| 94 | { |
| 95 | sprintf (mess, "reading register %s (#%d)", reg_names[regno], regno); |
| 96 | perror_with_name (mess); |
| 97 | } |
| 98 | } |
| 99 | supply_register (regno, buf); |
| 100 | } |
| 101 | |
| 102 | /* Store our register values back into the inferior. |
| 103 | If REGNO is -1, do this for all registers. |
| 104 | Otherwise, REGNO specifies which register (so we can save time). */ |
| 105 | |
| 106 | static void |
| 107 | store_register (regno, offset, bpid) |
| 108 | int regno, bpid; |
| 109 | unsigned int offset; |
| 110 | { |
| 111 | unsigned int regaddr; |
| 112 | char mess[128]; |
| 113 | extern char registers[]; |
| 114 | int i; |
| 115 | |
| 116 | regaddr = register_addr (regno, offset); |
| 117 | for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int)) |
| 118 | { |
| 119 | errno = 0; |
| 120 | ptrace (PTRACE_POKEUSER, bpid, (PTRACE_ARG3_TYPE) regaddr, |
| 121 | *(int *) ®isters[REGISTER_BYTE (regno) + i]); |
| 122 | if (errno != 0) |
| 123 | { |
| 124 | sprintf (mess, "writing register number %d(%d)", regno, i); |
| 125 | perror_with_name (mess); |
| 126 | } |
| 127 | regaddr += sizeof(int); |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | /* return an offset for use with register_addr() */ |
| 132 | |
| 133 | static unsigned int |
| 134 | fetch_offset (pid) |
| 135 | int pid; |
| 136 | { |
| 137 | struct st_entry s; |
| 138 | unsigned int specpage_off, offset = (char *) &s.ecp - (char *) &s; |
| 139 | |
| 140 | errno = 0; |
| 141 | specpage_off = ptrace (PTRACE_THREADUSER, pid, (PTRACE_ARG3_TYPE) 0, 0); |
| 142 | if (errno != 0) |
| 143 | perror_with_name ("ptrace"); |
| 144 | errno = 0; |
| 145 | offset = ptrace (PTRACE_PEEKTHREAD, pid, (PTRACE_ARG3_TYPE) offset, 0) |
| 146 | - specpage_off; |
| 147 | if (errno != 0) |
| 148 | perror_with_name ("ptrace"); |
| 149 | return offset; |
| 150 | } |
| 151 | |
| 152 | /* Fetch all registers, or just one, from the child process. */ |
| 153 | |
| 154 | void |
| 155 | fetch_inferior_registers (regno) |
| 156 | int regno; |
| 157 | { |
| 158 | unsigned int offset = fetch_offset (inferior_pid); |
| 159 | |
| 160 | if (regno == -1) |
| 161 | { |
| 162 | for (regno = 0; regno < NUM_REGS; regno++) |
| 163 | fetch_register (regno, offset, inferior_pid); |
| 164 | } |
| 165 | else |
| 166 | fetch_register (regno, offset, inferior_pid); |
| 167 | } |
| 168 | |
| 169 | /* Store all registers, or just one, to the child process. */ |
| 170 | |
| 171 | void |
| 172 | store_inferior_registers (regno) |
| 173 | int regno; |
| 174 | { |
| 175 | unsigned int offset = fetch_offset (inferior_pid); |
| 176 | |
| 177 | if (regno == -1) |
| 178 | { |
| 179 | for (regno = 0; regno < NUM_REGS; regno++) |
| 180 | store_register (regno, offset, inferior_pid); |
| 181 | } |
| 182 | else |
| 183 | store_register (regno, offset, inferior_pid); |
| 184 | } |
| 185 | |
| 186 | /* Extract the register values out of the core file and store |
| 187 | them where `read_register' will find them. |
| 188 | |
| 189 | CORE_REG_SECT points to the register values themselves, read into memory. |
| 190 | CORE_REG_SIZE is the size of that area. |
| 191 | WHICH says which set of registers we are handling (0 = int, 2 = float |
| 192 | on machines where they are discontiguous). |
| 193 | REG_ADDR is the offset from u.u_ar0 to the register values relative to |
| 194 | core_reg_sect. This is used with old-fashioned core files to |
| 195 | locate the registers in a large upage-plus-stack ".reg" section. |
| 196 | Original upage address X is at location core_reg_sect+x+reg_addr. |
| 197 | */ |
| 198 | |
| 199 | void |
| 200 | fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr) |
| 201 | char *core_reg_sect; |
| 202 | unsigned core_reg_size; |
| 203 | int which; |
| 204 | unsigned reg_addr; |
| 205 | { |
| 206 | struct st_entry s; |
| 207 | unsigned int regno, addr; |
| 208 | |
| 209 | for (regno = 0; regno < NUM_REGS; regno++) |
| 210 | { |
| 211 | addr = register_addr (regno, (char *) &s.ec - (char *) &s); |
| 212 | supply_register (regno, core_reg_sect + addr); |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | /* Wait for child to do something. Return pid of child, or -1 in case |
| 217 | of error; store status through argument pointer STATUS. */ |
| 218 | |
| 219 | int |
| 220 | child_wait (status) |
| 221 | int *status; |
| 222 | { |
| 223 | int pid; |
| 224 | int save_errno; |
| 225 | int thread; |
| 226 | |
| 227 | while (1) |
| 228 | { |
| 229 | int sig; |
| 230 | |
| 231 | if (attach_flag) |
| 232 | set_sigint_trap(); /* Causes SIGINT to be passed on to the |
| 233 | attached process. */ |
| 234 | pid = wait (status); |
| 235 | save_errno = errno; |
| 236 | |
| 237 | if (attach_flag) |
| 238 | clear_sigint_trap(); |
| 239 | |
| 240 | if (pid == -1) |
| 241 | { |
| 242 | if (save_errno == EINTR) |
| 243 | continue; |
| 244 | fprintf (stderr, "Child process unexpectedly missing: %s.\n", |
| 245 | safe_strerror (save_errno)); |
| 246 | *status = 42; /* Claim it exited with signal 42 */ |
| 247 | return -1; |
| 248 | } |
| 249 | |
| 250 | if (pid != PIDGET (inferior_pid)) /* Some other process?!? */ |
| 251 | continue; |
| 252 | |
| 253 | /* thread = WIFTID (*status);*/ |
| 254 | thread = *status >> 16; |
| 255 | |
| 256 | /* Initial thread value can only be acquired via wait, so we have to |
| 257 | resort to this hack. */ |
| 258 | |
| 259 | if (TIDGET (inferior_pid) == 0) |
| 260 | { |
| 261 | inferior_pid = BUILDPID (inferior_pid, thread); |
| 262 | add_thread (inferior_pid); |
| 263 | } |
| 264 | |
| 265 | pid = BUILDPID (pid, thread); |
| 266 | |
| 267 | return pid; |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | /* Return the PC of the caller from the call frame. Assumes the subr prologue |
| 272 | has already been executed, and the frame pointer setup. If this is the |
| 273 | outermost frame, we check to see if we are in a system call by examining the |
| 274 | previous instruction. If so, then the return PC is actually at SP+4 because |
| 275 | system calls use a different calling sequence. */ |
| 276 | |
| 277 | CORE_ADDR |
| 278 | i386lynx_saved_pc_after_call (frame) |
| 279 | struct frame_info *frame; |
| 280 | { |
| 281 | char opcode[7]; |
| 282 | static const char call_inst[] = {0x9a, 0, 0, 0, 0, 8, 0}; /* lcall 0x8,0x0 */ |
| 283 | |
| 284 | read_memory (frame->pc - 7, opcode, 7); |
| 285 | if (memcmp (opcode, call_inst, 7) == 0) |
| 286 | return read_memory_integer (read_register (SP_REGNUM) + 4, 4); |
| 287 | |
| 288 | return read_memory_integer (read_register (SP_REGNUM), 4); |
| 289 | } |
| 290 | |
| 291 | /* Convert a Lynx process ID to a string. Returns the string in a static |
| 292 | buffer. */ |
| 293 | |
| 294 | char * |
| 295 | i386lynx_pid_to_str (pid) |
| 296 | int pid; |
| 297 | { |
| 298 | static char buf[40]; |
| 299 | |
| 300 | sprintf (buf, "process %d thread %d", PIDGET (pid), TIDGET (pid)); |
| 301 | |
| 302 | return buf; |
| 303 | } |