gdb/amd64-netbsd-tdep.c

/* Target-dependent code for NetBSD/amd64.

   Copyright (C) 2003-2025 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "arch-utils.h"
#include "frame.h"
#include "gdbcore.h"
#include "osabi.h"
#include "symtab.h"

#include "amd64-tdep.h"
#include "gdbsupport/x86-xstate.h"
#include "netbsd-tdep.h"
#include "solib-svr4.h"

/* Support for signal handlers.  */

/* Return whether THIS_FRAME corresponds to a NetBSD sigtramp
   routine.  */

static int
amd64nbsd_sigtramp_p (const frame_info_ptr &this_frame)
{
  CORE_ADDR pc = get_frame_pc (this_frame);
  const char *name;

  find_pc_partial_function (pc, &name, NULL, NULL);
  return nbsd_pc_in_sigtramp (pc, name);
}

/* Assuming THIS_FRAME corresponds to a NetBSD sigtramp routine,
   return the address of the associated mcontext structure.  */

static CORE_ADDR
amd64nbsd_mcontext_addr (const frame_info_ptr &this_frame)
{
  CORE_ADDR addr;

  /* The register %r15 points at `struct ucontext' upon entry of a
     signal trampoline.  */
  addr = get_frame_register_unsigned (this_frame, AMD64_R15_REGNUM);

  /* The mcontext structure lives as offset 56 in `struct ucontext'.  */
  return addr + 56;
}

/* NetBSD 2.0 or later.  */

/* Mapping between the general-purpose registers in `struct reg'
   format and GDB's register cache layout.  */

/* From <machine/reg.h>.  */
int amd64nbsd_r_reg_offset[] =
{
  14 * 8,			/* %rax */
  13 * 8,			/* %rbx */
  3 * 8,			/* %rcx */
  2 * 8,			/* %rdx */
  1 * 8,			/* %rsi */
  0 * 8,			/* %rdi */
  12 * 8,			/* %rbp */
  24 * 8,			/* %rsp */
  4 * 8,			/* %r8 ..  */
  5 * 8,
  6 * 8,
  7 * 8,
  8 * 8,
  9 * 8,
  10 * 8,
  11 * 8,			/* ... %r15 */
  21 * 8,			/* %rip */
  23 * 8,			/* %eflags */
  22 * 8,			/* %cs */
  25 * 8,			/* %ss */
  18 * 8,			/* %ds */
  17 * 8,			/* %es */
  16 * 8,			/* %fs */
  15 * 8			/* %gs */
};

static void
amd64nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);

  /* Initialize general-purpose register set details first.  */
  tdep->gregset_reg_offset = amd64nbsd_r_reg_offset;
  tdep->gregset_num_regs = ARRAY_SIZE (amd64nbsd_r_reg_offset);
  tdep->sizeof_gregset = 26 * 8;

  amd64_init_abi (info, gdbarch,
		  amd64_target_description (X86_XSTATE_SSE_MASK, true));
  nbsd_init_abi (info, gdbarch);

  tdep->jb_pc_offset = 7 * 8;

  /* NetBSD has its own convention for signal trampolines.  */
  tdep->sigtramp_p = amd64nbsd_sigtramp_p;
  tdep->sigcontext_addr = amd64nbsd_mcontext_addr;
  tdep->sc_reg_offset = amd64nbsd_r_reg_offset;
  tdep->sc_num_regs = ARRAY_SIZE (amd64nbsd_r_reg_offset);

  /* NetBSD uses SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_lp64_fetch_link_map_offsets);
}

void _initialize_amd64nbsd_tdep ();
void
_initialize_amd64nbsd_tdep ()
{
  /* The NetBSD/amd64 native dependent code makes this assumption.  */
  gdb_assert (ARRAY_SIZE (amd64nbsd_r_reg_offset) == AMD64_NUM_GREGS);

  gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
			  GDB_OSABI_NETBSD, amd64nbsd_init_abi);
}