| 1 | /* Target-dependent code for OpenBSD/amd64. |
| 2 | |
| 3 | Copyright 2003, 2004, 2005 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 "gdbcore.h" |
| 25 | #include "symtab.h" |
| 26 | #include "objfiles.h" |
| 27 | #include "osabi.h" |
| 28 | #include "regset.h" |
| 29 | #include "target.h" |
| 30 | |
| 31 | #include "gdb_assert.h" |
| 32 | #include "gdb_string.h" |
| 33 | |
| 34 | #include "amd64-tdep.h" |
| 35 | #include "i387-tdep.h" |
| 36 | #include "solib-svr4.h" |
| 37 | |
| 38 | /* Support for core dumps. */ |
| 39 | |
| 40 | static void |
| 41 | amd64obsd_supply_regset (const struct regset *regset, |
| 42 | struct regcache *regcache, int regnum, |
| 43 | const void *regs, size_t len) |
| 44 | { |
| 45 | const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
| 46 | |
| 47 | gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE); |
| 48 | |
| 49 | i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset); |
| 50 | amd64_supply_fxsave (regcache, regnum, |
| 51 | ((const gdb_byte *)regs) + tdep->sizeof_gregset); |
| 52 | } |
| 53 | |
| 54 | static const struct regset * |
| 55 | amd64obsd_regset_from_core_section (struct gdbarch *gdbarch, |
| 56 | const char *sect_name, size_t sect_size) |
| 57 | { |
| 58 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 59 | |
| 60 | /* OpenBSD core dumps don't use seperate register sets for the |
| 61 | general-purpose and floating-point registers. */ |
| 62 | |
| 63 | if (strcmp (sect_name, ".reg") == 0 |
| 64 | && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE) |
| 65 | { |
| 66 | if (tdep->gregset == NULL) |
| 67 | tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL); |
| 68 | return tdep->gregset; |
| 69 | } |
| 70 | |
| 71 | return NULL; |
| 72 | } |
| 73 | \f |
| 74 | |
| 75 | /* Support for signal handlers. */ |
| 76 | |
| 77 | /* Default page size. */ |
| 78 | static const int amd64obsd_page_size = 4096; |
| 79 | |
| 80 | /* Return whether the frame preceding NEXT_FRAME corresponds to an |
| 81 | OpenBSD sigtramp routine. */ |
| 82 | |
| 83 | static int |
| 84 | amd64obsd_sigtramp_p (struct frame_info *next_frame) |
| 85 | { |
| 86 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 87 | CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1)); |
| 88 | const gdb_byte sigreturn[] = |
| 89 | { |
| 90 | 0x48, 0xc7, 0xc0, |
| 91 | 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */ |
| 92 | 0xcd, 0x80 /* int $0x80 */ |
| 93 | }; |
| 94 | size_t buflen = (sizeof sigreturn) + 1; |
| 95 | gdb_byte *buf; |
| 96 | char *name; |
| 97 | |
| 98 | /* If the function has a valid symbol name, it isn't a |
| 99 | trampoline. */ |
| 100 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 101 | if (name != NULL) |
| 102 | return 0; |
| 103 | |
| 104 | /* If the function lives in a valid section (even without a starting |
| 105 | point) it isn't a trampoline. */ |
| 106 | if (find_pc_section (pc) != NULL) |
| 107 | return 0; |
| 108 | |
| 109 | /* If we can't read the instructions at START_PC, return zero. */ |
| 110 | buf = alloca ((sizeof sigreturn) + 1); |
| 111 | if (!safe_frame_unwind_memory (next_frame, start_pc + 6, buf, buflen)) |
| 112 | return 0; |
| 113 | |
| 114 | /* Check for sigreturn(2). Depending on how the assembler encoded |
| 115 | the `movq %rsp, %rdi' instruction, the code starts at offset 6 or |
| 116 | 7. */ |
| 117 | if (memcmp (buf, sigreturn, sizeof sigreturn) |
| 118 | && memcpy (buf + 1, sigreturn, sizeof sigreturn)) |
| 119 | return 0; |
| 120 | |
| 121 | return 1; |
| 122 | } |
| 123 | |
| 124 | /* Assuming NEXT_FRAME is for a frame following a BSD sigtramp |
| 125 | routine, return the address of the associated sigcontext structure. */ |
| 126 | |
| 127 | static CORE_ADDR |
| 128 | amd64obsd_sigcontext_addr (struct frame_info *next_frame) |
| 129 | { |
| 130 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 131 | ULONGEST offset = (pc & (amd64obsd_page_size - 1)); |
| 132 | |
| 133 | /* The %rsp register points at `struct sigcontext' upon entry of a |
| 134 | signal trampoline. The relevant part of the trampoline is |
| 135 | |
| 136 | call *%rax |
| 137 | movq %rsp, %rdi |
| 138 | pushq %rdi |
| 139 | movq $SYS_sigreturn,%rax |
| 140 | int $0x80 |
| 141 | |
| 142 | (see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq' |
| 143 | instruction clobbers %rsp, but its value is saved in `%rdi'. */ |
| 144 | |
| 145 | if (offset > 5) |
| 146 | return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM); |
| 147 | else |
| 148 | return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM); |
| 149 | } |
| 150 | \f |
| 151 | /* OpenBSD 3.5 or later. */ |
| 152 | |
| 153 | /* Mapping between the general-purpose registers in `struct reg' |
| 154 | format and GDB's register cache layout. */ |
| 155 | |
| 156 | /* From <machine/reg.h>. */ |
| 157 | int amd64obsd_r_reg_offset[] = |
| 158 | { |
| 159 | 14 * 8, /* %rax */ |
| 160 | 13 * 8, /* %rbx */ |
| 161 | 3 * 8, /* %rcx */ |
| 162 | 2 * 8, /* %rdx */ |
| 163 | 1 * 8, /* %rsi */ |
| 164 | 0 * 8, /* %rdi */ |
| 165 | 12 * 8, /* %rbp */ |
| 166 | 15 * 8, /* %rsp */ |
| 167 | 4 * 8, /* %r8 .. */ |
| 168 | 5 * 8, |
| 169 | 6 * 8, |
| 170 | 7 * 8, |
| 171 | 8 * 8, |
| 172 | 9 * 8, |
| 173 | 10 * 8, |
| 174 | 11 * 8, /* ... %r15 */ |
| 175 | 16 * 8, /* %rip */ |
| 176 | 17 * 8, /* %eflags */ |
| 177 | 18 * 8, /* %cs */ |
| 178 | 19 * 8, /* %ss */ |
| 179 | 20 * 8, /* %ds */ |
| 180 | 21 * 8, /* %es */ |
| 181 | 22 * 8, /* %fs */ |
| 182 | 23 * 8 /* %gs */ |
| 183 | }; |
| 184 | |
| 185 | /* From <machine/signal.h>. */ |
| 186 | static int amd64obsd_sc_reg_offset[] = |
| 187 | { |
| 188 | 14 * 8, /* %rax */ |
| 189 | 13 * 8, /* %rbx */ |
| 190 | 3 * 8, /* %rcx */ |
| 191 | 2 * 8, /* %rdx */ |
| 192 | 1 * 8, /* %rsi */ |
| 193 | 0 * 8, /* %rdi */ |
| 194 | 12 * 8, /* %rbp */ |
| 195 | 24 * 8, /* %rsp */ |
| 196 | 4 * 8, /* %r8 ... */ |
| 197 | 5 * 8, |
| 198 | 6 * 8, |
| 199 | 7 * 8, |
| 200 | 8 * 8, |
| 201 | 9 * 8, |
| 202 | 10 * 8, |
| 203 | 11 * 8, /* ... %r15 */ |
| 204 | 21 * 8, /* %rip */ |
| 205 | 23 * 8, /* %eflags */ |
| 206 | 22 * 8, /* %cs */ |
| 207 | 25 * 8, /* %ss */ |
| 208 | 18 * 8, /* %ds */ |
| 209 | 17 * 8, /* %es */ |
| 210 | 16 * 8, /* %fs */ |
| 211 | 15 * 8 /* %gs */ |
| 212 | }; |
| 213 | |
| 214 | static void |
| 215 | amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 216 | { |
| 217 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 218 | |
| 219 | amd64_init_abi (info, gdbarch); |
| 220 | |
| 221 | /* Initialize general-purpose register set details. */ |
| 222 | tdep->gregset_reg_offset = amd64obsd_r_reg_offset; |
| 223 | tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset); |
| 224 | tdep->sizeof_gregset = 24 * 8; |
| 225 | |
| 226 | set_gdbarch_regset_from_core_section (gdbarch, |
| 227 | amd64obsd_regset_from_core_section); |
| 228 | |
| 229 | tdep->jb_pc_offset = 7 * 8; |
| 230 | |
| 231 | tdep->sigtramp_p = amd64obsd_sigtramp_p; |
| 232 | tdep->sigcontext_addr = amd64obsd_sigcontext_addr; |
| 233 | tdep->sc_reg_offset = amd64obsd_sc_reg_offset; |
| 234 | tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset); |
| 235 | |
| 236 | /* OpenBSD uses SVR4-style shared libraries. */ |
| 237 | set_solib_svr4_fetch_link_map_offsets |
| 238 | (gdbarch, svr4_lp64_fetch_link_map_offsets); |
| 239 | } |
| 240 | \f |
| 241 | |
| 242 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 243 | void _initialize_amd64obsd_tdep (void); |
| 244 | |
| 245 | void |
| 246 | _initialize_amd64obsd_tdep (void) |
| 247 | { |
| 248 | /* The OpenBSD/amd64 native dependent code makes this assumption. */ |
| 249 | gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS); |
| 250 | |
| 251 | gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, |
| 252 | GDB_OSABI_OPENBSD_ELF, amd64obsd_init_abi); |
| 253 | |
| 254 | /* OpenBSD uses traditional (a.out) NetBSD-style core dumps. */ |
| 255 | gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, |
| 256 | GDB_OSABI_NETBSD_AOUT, amd64obsd_init_abi); |
| 257 | } |