1 /* Target-dependent code for OpenBSD/amd64.
3 Copyright 2003, 2004, 2005 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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. */
31 #include "gdb_assert.h"
32 #include "gdb_string.h"
34 #include "amd64-tdep.h"
35 #include "i387-tdep.h"
36 #include "solib-svr4.h"
38 /* Support for core dumps. */
41 amd64obsd_supply_regset (const struct regset *regset,
42 struct regcache *regcache, int regnum,
43 const void *regs, size_t len)
45 const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
47 gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE);
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);
54 static const struct regset *
55 amd64obsd_regset_from_core_section (struct gdbarch *gdbarch,
56 const char *sect_name, size_t sect_size)
58 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
60 /* OpenBSD core dumps don't use seperate register sets for the
61 general-purpose and floating-point registers. */
63 if (strcmp (sect_name, ".reg") == 0
64 && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE)
66 if (tdep->gregset == NULL)
67 tdep->gregset = regset_alloc (gdbarch, amd64obsd_supply_regset, NULL);
75 /* Support for signal handlers. */
77 /* Default page size. */
78 static const int amd64obsd_page_size = 4096;
80 /* Return whether the frame preceding NEXT_FRAME corresponds to an
81 OpenBSD sigtramp routine. */
84 amd64obsd_sigtramp_p (struct frame_info *next_frame)
86 CORE_ADDR pc = frame_pc_unwind (next_frame);
87 CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
88 const gdb_byte sigreturn[] =
91 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
92 0xcd, 0x80 /* int $0x80 */
94 size_t buflen = (sizeof sigreturn) + 1;
98 /* If the function has a valid symbol name, it isn't a
100 find_pc_partial_function (pc, &name, NULL, NULL);
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)
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))
114 /* Check for sigreturn(2). Depending on how the assembler encoded
115 the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
117 if (memcmp (buf, sigreturn, sizeof sigreturn)
118 && memcpy (buf + 1, sigreturn, sizeof sigreturn))
124 /* Assuming NEXT_FRAME is for a frame following a BSD sigtramp
125 routine, return the address of the associated sigcontext structure. */
128 amd64obsd_sigcontext_addr (struct frame_info *next_frame)
130 CORE_ADDR pc = frame_pc_unwind (next_frame);
131 ULONGEST offset = (pc & (amd64obsd_page_size - 1));
133 /* The %rsp register points at `struct sigcontext' upon entry of a
134 signal trampoline. The relevant part of the trampoline is
139 movq $SYS_sigreturn,%rax
142 (see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
143 instruction clobbers %rsp, but its value is saved in `%rdi'. */
146 return frame_unwind_register_unsigned (next_frame, AMD64_RDI_REGNUM);
148 return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
151 /* OpenBSD 3.5 or later. */
153 /* Mapping between the general-purpose registers in `struct reg'
154 format and GDB's register cache layout. */
156 /* From <machine/reg.h>. */
157 int amd64obsd_r_reg_offset[] =
174 11 * 8, /* ... %r15 */
176 17 * 8, /* %eflags */
185 /* From <machine/signal.h>. */
186 static int amd64obsd_sc_reg_offset[] =
203 11 * 8, /* ... %r15 */
205 23 * 8, /* %eflags */
215 amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
217 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
219 amd64_init_abi (info, gdbarch);
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;
226 set_gdbarch_regset_from_core_section (gdbarch,
227 amd64obsd_regset_from_core_section);
229 tdep->jb_pc_offset = 7 * 8;
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);
236 /* OpenBSD uses SVR4-style shared libraries. */
237 set_solib_svr4_fetch_link_map_offsets
238 (gdbarch, svr4_lp64_fetch_link_map_offsets);
242 /* Provide a prototype to silence -Wmissing-prototypes. */
243 void _initialize_amd64obsd_tdep (void);
246 _initialize_amd64obsd_tdep (void)
248 /* The OpenBSD/amd64 native dependent code makes this assumption. */
249 gdb_assert (ARRAY_SIZE (amd64obsd_r_reg_offset) == AMD64_NUM_GREGS);
251 gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
252 GDB_OSABI_OPENBSD_ELF, amd64obsd_init_abi);
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);