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 "objfiles.h" 29#include "solib-svr4.h" 30#include "trad-frame.h" 31 32#include "gdb_assert.h" 33 34#include "sparc64-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 (&sparc64obsd_core_gregset, 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. The offset where we can find the code that 78 makes this system call varies from release to release. For OpenBSD 79 3.6 and later releases we can find the code at offset 0xec. For 80 OpenBSD 3.5 and earlier releases, we find it at offset 0xe8. */ 81 82static const int sparc64obsd_page_size = 8192; 83static const int sparc64obsd_sigreturn_offset[] = { 0xec, 0xe8, -1 }; 84 85static int 86sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) 87{ 88 CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); 89 unsigned long insn; 90 const int *offset; 91 92 if (name) 93 return 0; 94 95 for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++) 96 { 97 /* Check for "restore %g0, SYS_sigreturn, %g1". */ 98 insn = sparc_fetch_instruction (start_pc + *offset); 99 if (insn != 0x83e82067) 100 continue; 101 102 /* Check for "t ST_SYSCALL". */ 103 insn = sparc_fetch_instruction (start_pc + *offset + 8); 104 if (insn != 0x91d02000) 105 continue; 106 107 return 1; 108 } 109 110 return 0; 111} 112 113static struct sparc_frame_cache * 114sparc64obsd_frame_cache (struct frame_info *next_frame, void **this_cache) 115{ 116 struct sparc_frame_cache *cache; 117 CORE_ADDR addr; 118 119 if (*this_cache) 120 return *this_cache; 121 122 cache = sparc_frame_cache (next_frame, this_cache); 123 gdb_assert (cache == *this_cache); 124 125 /* If we couldn't find the frame's function, we're probably dealing 126 with an on-stack signal trampoline. */ 127 if (cache->pc == 0) 128 { 129 cache->pc = frame_pc_unwind (next_frame); 130 cache->pc &= ~(sparc64obsd_page_size - 1); 131 132 /* Since we couldn't find the frame's function, the cache was 133 initialized under the assumption that we're frameless. */ 134 cache->frameless_p = 0; 135 addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM); 136 cache->base = addr; 137 } 138 139 /* We find the appropriate instance of `struct sigcontext' at a 140 fixed offset in the signal frame. */ 141 addr = cache->base + BIAS + 128 + 16; 142 cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, next_frame); 143 144 return cache; 145} 146 147static void 148sparc64obsd_frame_this_id (struct frame_info *next_frame, void **this_cache, 149 struct frame_id *this_id) 150{ 151 struct sparc_frame_cache *cache = 152 sparc64obsd_frame_cache (next_frame, this_cache); 153 154 (*this_id) = frame_id_build (cache->base, cache->pc); 155} 156 157static void 158sparc64obsd_frame_prev_register (struct frame_info *next_frame, 159 void **this_cache, 160 int regnum, int *optimizedp, 161 enum lval_type *lvalp, CORE_ADDR *addrp, 162 int *realnump, void *valuep) 163{ 164 struct sparc_frame_cache *cache = 165 sparc64obsd_frame_cache (next_frame, this_cache); 166 167 trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum, 168 optimizedp, lvalp, addrp, realnump, valuep); 169} 170 171static const struct frame_unwind sparc64obsd_frame_unwind = 172{ 173 SIGTRAMP_FRAME, 174 sparc64obsd_frame_this_id, 175 sparc64obsd_frame_prev_register 176}; 177 178static const struct frame_unwind * 179sparc64obsd_sigtramp_frame_sniffer (struct frame_info *next_frame) 180{ 181 CORE_ADDR pc = frame_pc_unwind (next_frame); 182 char *name; 183 184 find_pc_partial_function (pc, &name, NULL, NULL); 185 if (sparc64obsd_pc_in_sigtramp (pc, name)) 186 return &sparc64obsd_frame_unwind; 187 188 return NULL; 189} 190 191 192static void 193sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 194{ 195 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 196 197 tdep->gregset = regset_alloc (gdbarch, sparc64obsd_supply_gregset, NULL); 198 tdep->sizeof_gregset = 832; 199 200 frame_unwind_append_sniffer (gdbarch, sparc64obsd_sigtramp_frame_sniffer); 201 202 sparc64_init_abi (info, gdbarch); 203 204 /* OpenBSD/sparc64 has SVR4-style shared libraries... */ 205 set_gdbarch_in_solib_call_trampoline (gdbarch, in_plt_section); 206 set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); 207 set_solib_svr4_fetch_link_map_offsets 208 (gdbarch, svr4_lp64_fetch_link_map_offsets); 209} 210 211 212/* Provide a prototype to silence -Wmissing-prototypes. */ 213void _initialize_sparc64obsd_tdep (void); 214 215void 216_initialize_sparc64obsd_tdep (void) 217{ 218 gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, 219 GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi); 220} 221