| 1 | /* Motorola m68k target-dependent support for GNU/Linux. |
| 2 | |
| 3 | Copyright 1996, 1998, 2000, 2001, 2002, 2003, 2004 |
| 4 | 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 | #include "gdbcore.h" |
| 25 | #include "doublest.h" |
| 26 | #include "floatformat.h" |
| 27 | #include "frame.h" |
| 28 | #include "target.h" |
| 29 | #include "gdb_string.h" |
| 30 | #include "gdbtypes.h" |
| 31 | #include "osabi.h" |
| 32 | #include "regcache.h" |
| 33 | #include "objfiles.h" |
| 34 | #include "symtab.h" |
| 35 | #include "m68k-tdep.h" |
| 36 | #include "trad-frame.h" |
| 37 | #include "frame-unwind.h" |
| 38 | #include "glibc-tdep.h" |
| 39 | #include "solib-svr4.h" |
| 40 | \f |
| 41 | /* Offsets (in target ints) into jmp_buf. */ |
| 42 | |
| 43 | #define M68K_LINUX_JB_ELEMENT_SIZE 4 |
| 44 | #define M68K_LINUX_JB_PC 7 |
| 45 | |
| 46 | /* Check whether insn1 and insn2 are parts of a signal trampoline. */ |
| 47 | |
| 48 | #define IS_SIGTRAMP(insn1, insn2) \ |
| 49 | (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ |
| 50 | (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ |
| 51 | /* moveq #119,d0; trap #0 */ \ |
| 52 | || insn1 == 0x70774e40) |
| 53 | |
| 54 | #define IS_RT_SIGTRAMP(insn1, insn2) \ |
| 55 | (/* movel #173,d0; trap #0 */ \ |
| 56 | (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ |
| 57 | /* moveq #82,d0; notb d0; trap #0 */ \ |
| 58 | || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) |
| 59 | |
| 60 | /* Return non-zero if PC points into the signal trampoline. For the |
| 61 | sake of m68k_linux_get_sigtramp_info we also distinguish between |
| 62 | non-RT and RT signal trampolines. */ |
| 63 | |
| 64 | static int |
| 65 | m68k_linux_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 66 | { |
| 67 | CORE_ADDR sp; |
| 68 | char buf[12]; |
| 69 | unsigned long insn0, insn1, insn2; |
| 70 | |
| 71 | if (deprecated_read_memory_nobpt (pc - 4, buf, sizeof (buf))) |
| 72 | return 0; |
| 73 | insn1 = extract_unsigned_integer (buf + 4, 4); |
| 74 | insn2 = extract_unsigned_integer (buf + 8, 4); |
| 75 | if (IS_SIGTRAMP (insn1, insn2)) |
| 76 | return 1; |
| 77 | if (IS_RT_SIGTRAMP (insn1, insn2)) |
| 78 | return 2; |
| 79 | |
| 80 | insn0 = extract_unsigned_integer (buf, 4); |
| 81 | if (IS_SIGTRAMP (insn0, insn1)) |
| 82 | return 1; |
| 83 | if (IS_RT_SIGTRAMP (insn0, insn1)) |
| 84 | return 2; |
| 85 | |
| 86 | insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16); |
| 87 | insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16); |
| 88 | if (IS_SIGTRAMP (insn0, insn1)) |
| 89 | return 1; |
| 90 | if (IS_RT_SIGTRAMP (insn0, insn1)) |
| 91 | return 2; |
| 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | /* From <asm/sigcontext.h>. */ |
| 97 | static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] = |
| 98 | { |
| 99 | 2 * 4, /* %d0 */ |
| 100 | 3 * 4, /* %d1 */ |
| 101 | -1, /* %d2 */ |
| 102 | -1, /* %d3 */ |
| 103 | -1, /* %d4 */ |
| 104 | -1, /* %d5 */ |
| 105 | -1, /* %d6 */ |
| 106 | -1, /* %d7 */ |
| 107 | 4 * 4, /* %a0 */ |
| 108 | 5 * 4, /* %a1 */ |
| 109 | -1, /* %a2 */ |
| 110 | -1, /* %a3 */ |
| 111 | -1, /* %a4 */ |
| 112 | -1, /* %a5 */ |
| 113 | -1, /* %fp */ |
| 114 | 1 * 4, /* %sp */ |
| 115 | 5 * 4 + 2, /* %sr */ |
| 116 | 6 * 4 + 2, /* %pc */ |
| 117 | 8 * 4, /* %fp0 */ |
| 118 | 11 * 4, /* %fp1 */ |
| 119 | -1, /* %fp2 */ |
| 120 | -1, /* %fp3 */ |
| 121 | -1, /* %fp4 */ |
| 122 | -1, /* %fp5 */ |
| 123 | -1, /* %fp6 */ |
| 124 | -1, /* %fp7 */ |
| 125 | 14 * 4, /* %fpcr */ |
| 126 | 15 * 4, /* %fpsr */ |
| 127 | 16 * 4 /* %fpiaddr */ |
| 128 | }; |
| 129 | |
| 130 | /* From <asm/ucontext.h>. */ |
| 131 | static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] = |
| 132 | { |
| 133 | 6 * 4, /* %d0 */ |
| 134 | 7 * 4, /* %d1 */ |
| 135 | 8 * 4, /* %d2 */ |
| 136 | 9 * 4, /* %d3 */ |
| 137 | 10 * 4, /* %d4 */ |
| 138 | 11 * 4, /* %d5 */ |
| 139 | 12 * 4, /* %d6 */ |
| 140 | 13 * 4, /* %d7 */ |
| 141 | 14 * 4, /* %a0 */ |
| 142 | 15 * 4, /* %a1 */ |
| 143 | 16 * 4, /* %a2 */ |
| 144 | 17 * 4, /* %a3 */ |
| 145 | 18 * 4, /* %a4 */ |
| 146 | 19 * 4, /* %a5 */ |
| 147 | 20 * 4, /* %fp */ |
| 148 | 21 * 4, /* %sp */ |
| 149 | 23 * 4, /* %sr */ |
| 150 | 22 * 4, /* %pc */ |
| 151 | 27 * 4, /* %fp0 */ |
| 152 | 30 * 4, /* %fp1 */ |
| 153 | 33 * 4, /* %fp2 */ |
| 154 | 36 * 4, /* %fp3 */ |
| 155 | 39 * 4, /* %fp4 */ |
| 156 | 42 * 4, /* %fp5 */ |
| 157 | 45 * 4, /* %fp6 */ |
| 158 | 48 * 4, /* %fp7 */ |
| 159 | 24 * 4, /* %fpcr */ |
| 160 | 25 * 4, /* %fpsr */ |
| 161 | 26 * 4 /* %fpiaddr */ |
| 162 | }; |
| 163 | |
| 164 | |
| 165 | /* Get info about saved registers in sigtramp. */ |
| 166 | |
| 167 | struct m68k_linux_sigtramp_info |
| 168 | { |
| 169 | /* Address of sigcontext. */ |
| 170 | CORE_ADDR sigcontext_addr; |
| 171 | |
| 172 | /* Offset of registers in `struct sigcontext'. */ |
| 173 | int *sc_reg_offset; |
| 174 | }; |
| 175 | |
| 176 | static struct m68k_linux_sigtramp_info |
| 177 | m68k_linux_get_sigtramp_info (struct frame_info *next_frame) |
| 178 | { |
| 179 | CORE_ADDR sp; |
| 180 | char buf[4]; |
| 181 | struct m68k_linux_sigtramp_info info; |
| 182 | |
| 183 | frame_unwind_register (next_frame, M68K_SP_REGNUM, buf); |
| 184 | sp = extract_unsigned_integer (buf, 4); |
| 185 | |
| 186 | /* Get sigcontext address, it is the third parameter on the stack. */ |
| 187 | info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4); |
| 188 | |
| 189 | if (m68k_linux_pc_in_sigtramp (frame_pc_unwind (next_frame), 0) == 2) |
| 190 | info.sc_reg_offset = m68k_linux_ucontext_reg_offset; |
| 191 | else |
| 192 | info.sc_reg_offset = m68k_linux_sigcontext_reg_offset; |
| 193 | return info; |
| 194 | } |
| 195 | |
| 196 | /* Signal trampolines. */ |
| 197 | |
| 198 | static struct trad_frame_cache * |
| 199 | m68k_linux_sigtramp_frame_cache (struct frame_info *next_frame, |
| 200 | void **this_cache) |
| 201 | { |
| 202 | struct frame_id this_id; |
| 203 | struct trad_frame_cache *cache; |
| 204 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| 205 | struct m68k_linux_sigtramp_info info; |
| 206 | char buf[4]; |
| 207 | int i; |
| 208 | |
| 209 | if (*this_cache) |
| 210 | return *this_cache; |
| 211 | |
| 212 | cache = trad_frame_cache_zalloc (next_frame); |
| 213 | |
| 214 | /* FIXME: cagney/2004-05-01: This is is long standing broken code. |
| 215 | The frame ID's code address should be the start-address of the |
| 216 | signal trampoline and not the current PC within that |
| 217 | trampoline. */ |
| 218 | frame_unwind_register (next_frame, M68K_SP_REGNUM, buf); |
| 219 | /* See the end of m68k_push_dummy_call. */ |
| 220 | this_id = frame_id_build (extract_unsigned_integer (buf, 4) - 4 + 8, |
| 221 | frame_pc_unwind (next_frame)); |
| 222 | trad_frame_set_id (cache, this_id); |
| 223 | |
| 224 | info = m68k_linux_get_sigtramp_info (next_frame); |
| 225 | |
| 226 | for (i = 0; i < M68K_NUM_REGS; i++) |
| 227 | if (info.sc_reg_offset[i] != -1) |
| 228 | trad_frame_set_reg_addr (cache, i, |
| 229 | info.sigcontext_addr + info.sc_reg_offset[i]); |
| 230 | |
| 231 | *this_cache = cache; |
| 232 | return cache; |
| 233 | } |
| 234 | |
| 235 | static void |
| 236 | m68k_linux_sigtramp_frame_this_id (struct frame_info *next_frame, |
| 237 | void **this_cache, |
| 238 | struct frame_id *this_id) |
| 239 | { |
| 240 | struct trad_frame_cache *cache = |
| 241 | m68k_linux_sigtramp_frame_cache (next_frame, this_cache); |
| 242 | trad_frame_get_id (cache, this_id); |
| 243 | } |
| 244 | |
| 245 | static void |
| 246 | m68k_linux_sigtramp_frame_prev_register (struct frame_info *next_frame, |
| 247 | void **this_cache, |
| 248 | int regnum, int *optimizedp, |
| 249 | enum lval_type *lvalp, |
| 250 | CORE_ADDR *addrp, |
| 251 | int *realnump, void *valuep) |
| 252 | { |
| 253 | /* Make sure we've initialized the cache. */ |
| 254 | struct trad_frame_cache *cache = |
| 255 | m68k_linux_sigtramp_frame_cache (next_frame, this_cache); |
| 256 | trad_frame_get_register (cache, next_frame, regnum, optimizedp, lvalp, |
| 257 | addrp, realnump, valuep); |
| 258 | } |
| 259 | |
| 260 | static const struct frame_unwind m68k_linux_sigtramp_frame_unwind = |
| 261 | { |
| 262 | SIGTRAMP_FRAME, |
| 263 | m68k_linux_sigtramp_frame_this_id, |
| 264 | m68k_linux_sigtramp_frame_prev_register |
| 265 | }; |
| 266 | |
| 267 | static const struct frame_unwind * |
| 268 | m68k_linux_sigtramp_frame_sniffer (struct frame_info *next_frame) |
| 269 | { |
| 270 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 271 | char *name; |
| 272 | |
| 273 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 274 | if (m68k_linux_pc_in_sigtramp (pc, name)) |
| 275 | return &m68k_linux_sigtramp_frame_unwind; |
| 276 | |
| 277 | return NULL; |
| 278 | } |
| 279 | |
| 280 | static void |
| 281 | m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 282 | { |
| 283 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 284 | |
| 285 | tdep->jb_pc = M68K_LINUX_JB_PC; |
| 286 | tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE; |
| 287 | |
| 288 | /* GNU/Linux uses a calling convention that's similar to SVR4. It |
| 289 | returns integer values in %d0/%di, pointer values in %a0 and |
| 290 | floating values in %fp0, just like SVR4, but uses %a1 to pass the |
| 291 | address to store a structure value. It also returns small |
| 292 | structures in registers instead of memory. */ |
| 293 | m68k_svr4_init_abi (info, gdbarch); |
| 294 | tdep->struct_value_regnum = M68K_A1_REGNUM; |
| 295 | tdep->struct_return = reg_struct_return; |
| 296 | |
| 297 | frame_unwind_append_sniffer (gdbarch, m68k_linux_sigtramp_frame_sniffer); |
| 298 | |
| 299 | /* Shared library handling. */ |
| 300 | |
| 301 | /* GNU/Linux uses SVR4-style shared libraries. */ |
| 302 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| 303 | svr4_ilp32_fetch_link_map_offsets); |
| 304 | |
| 305 | /* GNU/Linux uses the dynamic linker included in the GNU C Library. */ |
| 306 | set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); |
| 307 | |
| 308 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 309 | } |
| 310 | |
| 311 | void |
| 312 | _initialize_m68k_linux_tdep (void) |
| 313 | { |
| 314 | gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX, |
| 315 | m68k_linux_init_abi); |
| 316 | } |