1/* Target-dependent code for OpenBSD/sparc64. 2 3 Copyright 2004 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., 59 Temple Place - Suite 330, 20 Boston, MA 02111-1307, USA. */ 21 22#include "defs.h" 23#include "frame.h" 24#include "frame-unwind.h" 25#include "osabi.h" 26#include "regset.h" 27#include "symtab.h" 28#include "solib-svr4.h" 29#include "trad-frame.h" 30 31#include "gdb_assert.h" 32 33#include "sparc64-tdep.h" 34#include "nbsd-tdep.h" 35 36/* OpenBSD uses the traditional NetBSD core file format, even for 37 ports that use ELF. The core files don't use multiple register 38 sets. Instead, the general-purpose and floating-point registers 39 are lumped together in a single section. Unlike on NetBSD, OpenBSD 40 uses a different layout for its general-purpose registers than the 41 layout used for ptrace(2). */ 42 43/* From <machine/reg.h>. */ 44const struct sparc_gregset sparc64obsd_core_gregset = 45{ 46 0 * 8, /* "tstate" */ 47 1 * 8, /* %pc */ 48 2 * 8, /* %npc */ 49 3 * 8, /* %y */ 50 -1, /* %fprs */ 51 -1, 52 7 * 8, /* %g1 */ 53 22 * 8, /* %l0 */ 54 4 /* sizeof (%y) */ 55}; 56 57static void 58sparc64obsd_supply_gregset (const struct regset *regset, 59 struct regcache *regcache, 60 int regnum, const void *gregs, size_t len) 61{ 62 const char *regs = gregs; 63 64 sparc64_supply_gregset (regset->descr, regcache, regnum, regs); 65 sparc64_supply_fpregset (regcache, regnum, regs + 288); 66} 67 68 69/* Signal trampolines. */ 70 71/* The OpenBSD kernel maps the signal trampoline at some random 72 location in user space, which means that the traditional BSD way of 73 detecting it won't work. 74 75 The signal trampoline will be mapped at an address that is page 76 aligned. We recognize the signal trampoline by the looking for the 77 sigreturn system call. */ 78 79static const int sparc64obsd_page_size = 8192; 80 81static int 82sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) 83{ 84 CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); 85 unsigned long insn; 86 87 if (name) 88 return 0; 89 90 /* Check for "restore %g0, SYS_sigreturn, %g1". */ 91 insn = sparc_fetch_instruction (start_pc + 0xe8); 92 if (insn != 0x83e82067) 93 return 0; 94 95 /* Check for "t ST_SYSCALL". */ 96 insn = sparc_fetch_instruction (start_pc + 0xf0); 97 if (insn != 0x91d02000) 98 return 0; 99 100 return 1; 101} 102 103static struct sparc_frame_cache * 104sparc64obsd_frame_cache (struct frame_info *next_frame, void **this_cache) 105{ 106 struct sparc_frame_cache *cache; 107 CORE_ADDR addr; 108 109 if (*this_cache) 110 return *this_cache; 111 112 cache = sparc_frame_cache (next_frame, this_cache); 113 gdb_assert (cache == *this_cache); 114 115 /* If we couldn't find the frame's function, we're probably dealing 116 with an on-stack signal trampoline. */ 117 if (cache->pc == 0) 118 { 119 cache->pc = frame_pc_unwind (next_frame); 120 cache->pc &= ~(sparc64obsd_page_size - 1); 121 122 /* Since we couldn't find the frame's function, the cache was 123 initialized under the assumption that we're frameless. */ 124 cache->frameless_p = 0; 125 addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM); 126 cache->base = addr; 127 } 128 129 /* We find the appropriate instance of `struct sigcontext' at a 130 fixed offset in the signal frame. */ 131 addr = cache->base + BIAS + 128 + 16; 132 cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, next_frame); 133 134 return cache; 135} 136 137static void 138sparc64obsd_frame_this_id (struct frame_info *next_frame, void **this_cache, 139 struct frame_id *this_id) 140{ 141 struct sparc_frame_cache *cache = 142 sparc64obsd_frame_cache (next_frame, this_cache); 143 144 (*this_id) = frame_id_build (cache->base, cache->pc); 145} 146 147static void 148sparc64obsd_frame_prev_register (struct frame_info *next_frame, 149 void **this_cache, 150 int regnum, int *optimizedp, 151 enum lval_type *lvalp, CORE_ADDR *addrp, 152 int *realnump, void *valuep) 153{ 154 struct sparc_frame_cache *cache = 155 sparc64obsd_frame_cache (next_frame, this_cache); 156 157 trad_frame_prev_register (next_frame, cache->saved_regs, regnum, 158 optimizedp, lvalp, addrp, realnump, valuep); 159} 160 161static const struct frame_unwind sparc64obsd_frame_unwind = 162{ 163 SIGTRAMP_FRAME, 164 sparc64obsd_frame_this_id, 165 sparc64obsd_frame_prev_register 166}; 167 168static const struct frame_unwind * 169sparc64obsd_sigtramp_frame_sniffer (struct frame_info *next_frame) 170{ 171 CORE_ADDR pc = frame_pc_unwind (next_frame); 172 char *name; 173 174 find_pc_partial_function (pc, &name, NULL, NULL); 175 if (sparc64obsd_pc_in_sigtramp (pc, name)) 176 return &sparc64obsd_frame_unwind; 177 178 return NULL; 179} 180 181 182static void 183sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 184{ 185 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 186 187 tdep->gregset = XMALLOC (struct regset); 188 tdep->gregset->descr = &sparc64obsd_core_gregset; 189 tdep->gregset->supply_regset = sparc64obsd_supply_gregset; 190 tdep->sizeof_gregset = 832; 191 192 set_gdbarch_pc_in_sigtramp (gdbarch, sparc64obsd_pc_in_sigtramp); 193 frame_unwind_append_sniffer (gdbarch, sparc64obsd_sigtramp_frame_sniffer); 194 195 sparc64_init_abi (info, gdbarch); 196 197 set_solib_svr4_fetch_link_map_offsets 198 (gdbarch, nbsd_lp64_solib_svr4_fetch_link_map_offsets); 199} 200 201 202/* Provide a prototype to silence -Wmissing-prototypes. */ 203void _initialize_sparc64obsd_tdep (void); 204 205void 206_initialize_sparc64obsd_tdep (void) 207{ 208 gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, 209 GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi); 210} 211