| 1 | /* Target-dependent code for OpenBSD/sparc. |
| 2 | |
| 3 | Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 20 | Boston, MA 02110-1301, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "floatformat.h" |
| 24 | #include "frame.h" |
| 25 | #include "frame-unwind.h" |
| 26 | #include "gdbcore.h" |
| 27 | #include "osabi.h" |
| 28 | #include "regcache.h" |
| 29 | #include "symtab.h" |
| 30 | #include "trad-frame.h" |
| 31 | |
| 32 | #include "gdb_assert.h" |
| 33 | |
| 34 | #include "obsd-tdep.h" |
| 35 | #include "sparc-tdep.h" |
| 36 | #include "solib-svr4.h" |
| 37 | #include "bsd-uthread.h" |
| 38 | |
| 39 | /* Signal trampolines. */ |
| 40 | |
| 41 | /* The OpenBSD kernel maps the signal trampoline at some random |
| 42 | location in user space, which means that the traditional BSD way of |
| 43 | detecting it won't work. |
| 44 | |
| 45 | The signal trampoline will be mapped at an address that is page |
| 46 | aligned. We recognize the signal trampoline by looking for the |
| 47 | sigreturn system call. */ |
| 48 | |
| 49 | static const int sparc32obsd_page_size = 4096; |
| 50 | |
| 51 | static int |
| 52 | sparc32obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 53 | { |
| 54 | CORE_ADDR start_pc = (pc & ~(sparc32obsd_page_size - 1)); |
| 55 | unsigned long insn; |
| 56 | |
| 57 | if (name) |
| 58 | return 0; |
| 59 | |
| 60 | /* Check for "restore %g0, SYS_sigreturn, %g1". */ |
| 61 | insn = sparc_fetch_instruction (start_pc + 0xec); |
| 62 | if (insn != 0x83e82067) |
| 63 | return 0; |
| 64 | |
| 65 | /* Check for "t ST_SYSCALL". */ |
| 66 | insn = sparc_fetch_instruction (start_pc + 0xf4); |
| 67 | if (insn != 0x91d02000) |
| 68 | return 0; |
| 69 | |
| 70 | return 1; |
| 71 | } |
| 72 | |
| 73 | static struct sparc_frame_cache * |
| 74 | sparc32obsd_frame_cache (struct frame_info *next_frame, void **this_cache) |
| 75 | { |
| 76 | struct sparc_frame_cache *cache; |
| 77 | CORE_ADDR addr; |
| 78 | |
| 79 | if (*this_cache) |
| 80 | return *this_cache; |
| 81 | |
| 82 | cache = sparc_frame_cache (next_frame, this_cache); |
| 83 | gdb_assert (cache == *this_cache); |
| 84 | |
| 85 | /* If we couldn't find the frame's function, we're probably dealing |
| 86 | with an on-stack signal trampoline. */ |
| 87 | if (cache->pc == 0) |
| 88 | { |
| 89 | cache->pc = frame_pc_unwind (next_frame); |
| 90 | cache->pc &= ~(sparc32obsd_page_size - 1); |
| 91 | |
| 92 | /* Since we couldn't find the frame's function, the cache was |
| 93 | initialized under the assumption that we're frameless. */ |
| 94 | cache->frameless_p = 0; |
| 95 | addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM); |
| 96 | cache->base = addr; |
| 97 | } |
| 98 | |
| 99 | cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (next_frame); |
| 100 | |
| 101 | return cache; |
| 102 | } |
| 103 | |
| 104 | static void |
| 105 | sparc32obsd_frame_this_id (struct frame_info *next_frame, void **this_cache, |
| 106 | struct frame_id *this_id) |
| 107 | { |
| 108 | struct sparc_frame_cache *cache = |
| 109 | sparc32obsd_frame_cache (next_frame, this_cache); |
| 110 | |
| 111 | (*this_id) = frame_id_build (cache->base, cache->pc); |
| 112 | } |
| 113 | |
| 114 | static void |
| 115 | sparc32obsd_frame_prev_register (struct frame_info *next_frame, |
| 116 | void **this_cache, |
| 117 | int regnum, int *optimizedp, |
| 118 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 119 | int *realnump, gdb_byte *valuep) |
| 120 | { |
| 121 | struct sparc_frame_cache *cache = |
| 122 | sparc32obsd_frame_cache (next_frame, this_cache); |
| 123 | |
| 124 | trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum, |
| 125 | optimizedp, lvalp, addrp, realnump, valuep); |
| 126 | } |
| 127 | |
| 128 | static const struct frame_unwind sparc32obsd_frame_unwind = |
| 129 | { |
| 130 | SIGTRAMP_FRAME, |
| 131 | sparc32obsd_frame_this_id, |
| 132 | sparc32obsd_frame_prev_register |
| 133 | }; |
| 134 | |
| 135 | static const struct frame_unwind * |
| 136 | sparc32obsd_sigtramp_frame_sniffer (struct frame_info *next_frame) |
| 137 | { |
| 138 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 139 | char *name; |
| 140 | |
| 141 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 142 | if (sparc32obsd_pc_in_sigtramp (pc, name)) |
| 143 | return &sparc32obsd_frame_unwind; |
| 144 | |
| 145 | return NULL; |
| 146 | } |
| 147 | \f |
| 148 | |
| 149 | /* Offset wthin the thread structure where we can find %fp and %i7. */ |
| 150 | #define SPARC32OBSD_UTHREAD_FP_OFFSET 128 |
| 151 | #define SPARC32OBSD_UTHREAD_PC_OFFSET 132 |
| 152 | |
| 153 | static void |
| 154 | sparc32obsd_supply_uthread (struct regcache *regcache, |
| 155 | int regnum, CORE_ADDR addr) |
| 156 | { |
| 157 | CORE_ADDR fp, fp_addr = addr + SPARC32OBSD_UTHREAD_FP_OFFSET; |
| 158 | gdb_byte buf[4]; |
| 159 | |
| 160 | gdb_assert (regnum >= -1); |
| 161 | |
| 162 | fp = read_memory_unsigned_integer (fp_addr, 4); |
| 163 | if (regnum == SPARC_SP_REGNUM || regnum == -1) |
| 164 | { |
| 165 | store_unsigned_integer (buf, 4, fp); |
| 166 | regcache_raw_supply (regcache, SPARC_SP_REGNUM, buf); |
| 167 | |
| 168 | if (regnum == SPARC_SP_REGNUM) |
| 169 | return; |
| 170 | } |
| 171 | |
| 172 | if (regnum == SPARC32_PC_REGNUM || regnum == SPARC32_NPC_REGNUM |
| 173 | || regnum == -1) |
| 174 | { |
| 175 | CORE_ADDR i7, i7_addr = addr + SPARC32OBSD_UTHREAD_PC_OFFSET; |
| 176 | |
| 177 | i7 = read_memory_unsigned_integer (i7_addr, 4); |
| 178 | if (regnum == SPARC32_PC_REGNUM || regnum == -1) |
| 179 | { |
| 180 | store_unsigned_integer (buf, 4, i7 + 8); |
| 181 | regcache_raw_supply (regcache, SPARC32_PC_REGNUM, buf); |
| 182 | } |
| 183 | if (regnum == SPARC32_NPC_REGNUM || regnum == -1) |
| 184 | { |
| 185 | store_unsigned_integer (buf, 4, i7 + 12); |
| 186 | regcache_raw_supply (regcache, SPARC32_NPC_REGNUM, buf); |
| 187 | } |
| 188 | |
| 189 | if (regnum == SPARC32_PC_REGNUM || regnum == SPARC32_NPC_REGNUM) |
| 190 | return; |
| 191 | } |
| 192 | |
| 193 | sparc_supply_rwindow (regcache, fp, regnum); |
| 194 | } |
| 195 | |
| 196 | static void |
| 197 | sparc32obsd_collect_uthread(const struct regcache *regcache, |
| 198 | int regnum, CORE_ADDR addr) |
| 199 | { |
| 200 | CORE_ADDR sp; |
| 201 | gdb_byte buf[4]; |
| 202 | |
| 203 | gdb_assert (regnum >= -1); |
| 204 | |
| 205 | if (regnum == SPARC_SP_REGNUM || regnum == -1) |
| 206 | { |
| 207 | CORE_ADDR fp_addr = addr + SPARC32OBSD_UTHREAD_FP_OFFSET; |
| 208 | |
| 209 | regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf); |
| 210 | write_memory (fp_addr,buf, 4); |
| 211 | } |
| 212 | |
| 213 | if (regnum == SPARC32_PC_REGNUM || regnum == -1) |
| 214 | { |
| 215 | CORE_ADDR i7, i7_addr = addr + SPARC32OBSD_UTHREAD_PC_OFFSET; |
| 216 | |
| 217 | regcache_raw_collect (regcache, SPARC32_PC_REGNUM, buf); |
| 218 | i7 = extract_unsigned_integer (buf, 4) - 8; |
| 219 | write_memory_unsigned_integer (i7_addr, 4, i7); |
| 220 | |
| 221 | if (regnum == SPARC32_PC_REGNUM) |
| 222 | return; |
| 223 | } |
| 224 | |
| 225 | regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf); |
| 226 | sp = extract_unsigned_integer (buf, 4); |
| 227 | sparc_collect_rwindow (regcache, sp, regnum); |
| 228 | } |
| 229 | \f |
| 230 | |
| 231 | static void |
| 232 | sparc32obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 233 | { |
| 234 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 235 | |
| 236 | /* OpenBSD/sparc is very similar to NetBSD/sparc ELF. */ |
| 237 | sparc32nbsd_elf_init_abi (info, gdbarch); |
| 238 | |
| 239 | set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); |
| 240 | |
| 241 | frame_unwind_append_sniffer (gdbarch, sparc32obsd_sigtramp_frame_sniffer); |
| 242 | |
| 243 | /* OpenBSD provides a user-level threads implementation. */ |
| 244 | bsd_uthread_set_supply_uthread (gdbarch, sparc32obsd_supply_uthread); |
| 245 | bsd_uthread_set_collect_uthread (gdbarch, sparc32obsd_collect_uthread); |
| 246 | } |
| 247 | |
| 248 | \f |
| 249 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 250 | void _initialize_sparc32obsd_tdep (void); |
| 251 | |
| 252 | void |
| 253 | _initialize_sparc32obsd_tdep (void) |
| 254 | { |
| 255 | gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_OPENBSD_ELF, |
| 256 | sparc32obsd_init_abi); |
| 257 | } |