1/* Target-dependent code for NetBSD/amd64. 2 3 Copyright (C) 2003-2020 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 3 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, see <http://www.gnu.org/licenses/>. */ 19 20#include "defs.h" 21#include "arch-utils.h" 22#include "frame.h" 23#include "gdbcore.h" 24#include "osabi.h" 25#include "symtab.h" 26 27#include "amd64-tdep.h" 28#include "gdbsupport/x86-xstate.h" 29#include "nbsd-tdep.h" 30#include "solib-svr4.h" 31#include "trad-frame.h" 32#include "frame-unwind.h" 33 34/* Support for signal handlers. */ 35 36/* Return whether THIS_FRAME corresponds to a NetBSD sigtramp 37 routine. */ 38 39static int 40amd64nbsd_sigtramp_p (struct frame_info *this_frame) 41{ 42 CORE_ADDR pc = get_frame_pc (this_frame); 43 const char *name; 44 45 find_pc_partial_function (pc, &name, NULL, NULL); 46 return nbsd_pc_in_sigtramp (pc, name); 47} 48 49/* Assuming THIS_FRAME corresponds to a NetBSD sigtramp routine, 50 return the address of the associated mcontext structure. */ 51 52static CORE_ADDR 53amd64nbsd_mcontext_addr (struct frame_info *this_frame) 54{ 55 CORE_ADDR addr; 56 57 /* The register %r15 points at `struct ucontext' upon entry of a 58 signal trampoline. */ 59 addr = get_frame_register_unsigned (this_frame, AMD64_R15_REGNUM); 60 61 /* The mcontext structure lives as offset 56 in `struct ucontext'. */ 62 return addr + 56; 63} 64 65/* NetBSD 2.0 or later. */ 66 67/* Mapping between the general-purpose registers in `struct reg' 68 format and GDB's register cache layout. */ 69 70/* From <machine/reg.h>. */ 71int amd64nbsd_r_reg_offset[] = 72{ 73 14 * 8, /* %rax */ 74 13 * 8, /* %rbx */ 75 3 * 8, /* %rcx */ 76 2 * 8, /* %rdx */ 77 1 * 8, /* %rsi */ 78 0 * 8, /* %rdi */ 79 12 * 8, /* %rbp */ 80 24 * 8, /* %rsp */ 81 4 * 8, /* %r8 .. */ 82 5 * 8, 83 6 * 8, 84 7 * 8, 85 8 * 8, 86 9 * 8, 87 10 * 8, 88 11 * 8, /* ... %r15 */ 89 21 * 8, /* %rip */ 90 23 * 8, /* %eflags */ 91 22 * 8, /* %cs */ 92 25 * 8, /* %ss */ 93 18 * 8, /* %ds */ 94 17 * 8, /* %es */ 95 16 * 8, /* %fs */ 96 15 * 8 /* %gs */ 97}; 98 99/* Kernel debugging support */ 100static const int amd64nbsd_tf_reg_offset[] = 101{ 102 18 * 8, /* %rax */ 103 17 * 8, /* %rbx */ 104 10 * 8, /* %rcx */ 105 2 * 8, /* %rdx */ 106 1 * 8, /* %rsi */ 107 0 * 8, /* %rdi */ 108 16 * 8, /* %rbp */ 109 28 * 8, /* %rsp */ 110 4 * 8, /* %r8 .. */ 111 5 * 8, 112 3 * 8, 113 11 * 8, 114 12 * 8, 115 13 * 8, 116 14 * 8, 117 15 * 8, /* ... %r15 */ 118 25 * 8, /* %rip */ 119 27 * 8, /* %eflags */ 120 26 * 8, /* %cs */ 121 29 * 8, /* %ss */ 122 22 * 8, /* %ds */ 123 21 * 8, /* %es */ 124 20 * 8, /* %fs */ 125 19 * 8, /* %gs */ 126}; 127 128static struct trad_frame_cache * 129amd64nbsd_trapframe_cache(struct frame_info *this_frame, void **this_cache) 130{ 131 struct trad_frame_cache *cache; 132 CORE_ADDR func, sp, addr; 133 ULONGEST cs = 0, rip = 0; 134 const char *name; 135 int i; 136 struct gdbarch *gdbarch = get_frame_arch (this_frame); 137 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 138 139 if (*this_cache) 140 return (struct trad_frame_cache *)*this_cache; 141 142 cache = trad_frame_cache_zalloc (this_frame); 143 *this_cache = cache; 144 145 func = get_frame_func (this_frame); 146 sp = get_frame_register_unsigned (this_frame, AMD64_RSP_REGNUM); 147 148 find_pc_partial_function (func, &name, NULL, NULL); 149 150 /* There is an extra 'call' in the interrupt sequence - ignore the extra 151 * return address */ 152 153 addr = sp; 154 if (name) { 155 if (strncmp (name, "Xintr", 5) == 0 156 || strncmp (name, "Xhandle", 7) == 0) { 157 addr += 8; /* It's an interrupt frame. */ 158 } 159 } 160 161#ifdef DEBUG_TRAPFRAME 162 for (i = 0; i < 50; i++) { 163 cs = read_memory_unsigned_integer (addr + i * 8, 8, byte_order); 164 printf("%s i=%d r=%#jx\n", name, i, (intmax_t)cs); 165 } 166#endif 167 168 for (i = 0; i < ARRAY_SIZE (amd64nbsd_tf_reg_offset); i++) 169 if (amd64nbsd_tf_reg_offset[i] != -1) 170 trad_frame_set_reg_addr (cache, i, addr + amd64nbsd_tf_reg_offset[i]); 171 172 /* Read %cs and %rip when we have the addresses to hand */ 173 cs = read_memory_unsigned_integer (addr 174 + amd64nbsd_tf_reg_offset[AMD64_CS_REGNUM], 8, byte_order); 175 rip = read_memory_unsigned_integer (addr 176 + amd64nbsd_tf_reg_offset[AMD64_RIP_REGNUM], 8, byte_order); 177 178#ifdef DEBUG_TRAPFRAME 179 printf("%s cs=%#jx rip=%#jx\n", name, (intmax_t)cs, (intmax_t)rip); 180#endif 181 182 /* The trap frame layout was changed lf the %rip value is less than 2^16 it 183 * is almost certainly the %ss of the old format. */ 184 if (rip < (1 << 16)) 185 { 186 187 for (i = 0; i < ARRAY_SIZE (amd64nbsd_tf_reg_offset); i++) 188 { 189 190 if (amd64nbsd_tf_reg_offset[i] == -1) 191 continue; 192 193 trad_frame_set_reg_addr (cache, i, addr + amd64nbsd_r_reg_offset[i]); 194 195 /* Read %cs when we have the address to hand */ 196 if (i == AMD64_CS_REGNUM) 197 cs = read_memory_unsigned_integer (addr + amd64nbsd_r_reg_offset[i], 198 8, byte_order); 199 } 200 } 201 202 if ((cs & I386_SEL_RPL) == I386_SEL_UPL || 203 (name && strncmp(name, "Xsoft", 5) == 0)) 204 { 205 /* Trap from user space or soft interrupt; terminate backtrace. */ 206 trad_frame_set_id (cache, outer_frame_id); 207 } 208 else 209 { 210 /* Construct the frame ID using the function start. */ 211 trad_frame_set_id (cache, frame_id_build (sp + 16, func)); 212 } 213 214 return cache; 215} 216 217static void 218amd64nbsd_trapframe_this_id (struct frame_info *this_frame, 219 void **this_cache, 220 struct frame_id *this_id) 221{ 222 struct trad_frame_cache *cache = 223 amd64nbsd_trapframe_cache (this_frame, this_cache); 224 225 trad_frame_get_id (cache, this_id); 226} 227 228static struct value * 229amd64nbsd_trapframe_prev_register (struct frame_info *this_frame, 230 void **this_cache, int regnum) 231{ 232 struct trad_frame_cache *cache = 233 amd64nbsd_trapframe_cache (this_frame, this_cache); 234 235 return trad_frame_get_register (cache, this_frame, regnum); 236} 237 238static int 239amd64nbsd_trapframe_sniffer (const struct frame_unwind *self, 240 struct frame_info *this_frame, 241 void **this_prologue_cache) 242{ 243 ULONGEST cs; 244 const char *name; 245 246 cs = get_frame_register_unsigned (this_frame, AMD64_CS_REGNUM); 247 if ((cs & I386_SEL_RPL) == I386_SEL_UPL) 248 return 0; 249 250 find_pc_partial_function (get_frame_pc (this_frame), &name, NULL, NULL); 251 return (name && ((strcmp (name, "alltraps") == 0) 252 || (strcmp (name, "calltrap") == 0) 253 || (strcmp (name, "handle_syscall") == 0) 254 || (strcmp (name, "Xdoreti") == 0) 255 || (strcmp (name, "Xspllower") == 0) 256 || (strncmp (name, "Xhandle", 7) == 0) 257 || (strncmp (name, "Xintr", 5) == 0) 258 || (strncmp (name, "Xpreempt", 8) == 0) 259 || (strncmp (name, "Xrecurse", 8) == 0) 260 || (strncmp (name, "Xresume", 7) == 0) 261 || (strncmp (name, "Xsoft", 5) == 0) 262 || (strncmp (name, "Xstray", 6) == 0) 263 || (strncmp (name, "Xsyscall", 8) == 0) 264 || (strncmp (name, "Xtrap", 5) == 0) 265 )); 266} 267 268static const struct frame_unwind amd64nbsd_trapframe_unwind = { 269 /* FIXME: kettenis/20051219: This really is more like an interrupt 270 frame, but SIGTRAMP_FRAME would print <signal handler called>, 271 which really is not what we want here. */ 272 NORMAL_FRAME, 273 default_frame_unwind_stop_reason, 274 amd64nbsd_trapframe_this_id, 275 amd64nbsd_trapframe_prev_register, 276 NULL, 277 amd64nbsd_trapframe_sniffer 278}; 279 280static void 281amd64nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 282{ 283 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 284 285 /* Initialize general-purpose register set details first. */ 286 tdep->gregset_reg_offset = amd64nbsd_r_reg_offset; 287 tdep->gregset_num_regs = ARRAY_SIZE (amd64nbsd_r_reg_offset); 288 tdep->sizeof_gregset = 26 * 8; 289 290 amd64_init_abi (info, gdbarch, 291 amd64_target_description (X86_XSTATE_SSE_MASK, true)); 292 nbsd_init_abi (info, gdbarch); 293 294 tdep->jb_pc_offset = 7 * 8; 295 296 /* NetBSD has its own convention for signal trampolines. */ 297 tdep->sigtramp_p = amd64nbsd_sigtramp_p; 298 tdep->sigcontext_addr = amd64nbsd_mcontext_addr; 299 tdep->sc_reg_offset = amd64nbsd_r_reg_offset; 300 tdep->sc_num_regs = ARRAY_SIZE (amd64nbsd_r_reg_offset); 301 302 /* NetBSD uses SVR4-style shared libraries. */ 303 set_solib_svr4_fetch_link_map_offsets 304 (gdbarch, svr4_lp64_fetch_link_map_offsets); 305 /* Unwind kernel trap frames correctly. */ 306 frame_unwind_prepend_unwinder (gdbarch, &amd64nbsd_trapframe_unwind); 307} 308 309void _initialize_amd64nbsd_tdep (); 310void 311_initialize_amd64nbsd_tdep () 312{ 313 /* The NetBSD/amd64 native dependent code makes this assumption. */ 314 gdb_assert (ARRAY_SIZE (amd64nbsd_r_reg_offset) == AMD64_NUM_GREGS); 315 316 gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, 317 GDB_OSABI_NETBSD, amd64nbsd_init_abi); 318} 319