mirror of
https://github.com/bminor/binutils-gdb.git
synced 2025-11-16 12:34:43 +00:00
1d5f884e50
I spotted this while reviewing a patch adding a new gdbarch_software_single_step implementation. I find the name "software_single_step" a bit misleading or unclear. It makes it sounds as if the function executed a single step. In reality, this function returns the possible next PCs for current instructions. We have a similar concept in GDBserver: linux_process_target::low_get_next_pcs. I like that name, it's clear and straight to the point. Rename gdbarch_software_single_step to gdbarch_get_next_pcs. I find this name more indicative of what happens. There is some code for ARM shared between GDB and GDBserver to implement both sides, also called "get next pcs", so I think it all fits well together. Tested by rebuilding. Change-Id: Ide74011a5034ba11117b7e7c865a093ef0b1dece Approved-by: Kevin Buettner <kevinb@redhat.com> Acked-by: Luis Machado <luis.machado.foss@gmail.com>
132 lines
3.9 KiB
C
132 lines
3.9 KiB
C
/* Target-dependent code for OpenBSD/alpha.
|
||
|
||
Copyright (C) 2006-2025 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 "frame.h"
|
||
#include "gdbcore.h"
|
||
#include "osabi.h"
|
||
|
||
#include "obsd-tdep.h"
|
||
#include "alpha-tdep.h"
|
||
#include "alpha-bsd-tdep.h"
|
||
#include "solib-svr4.h"
|
||
|
||
/* Signal trampolines. */
|
||
|
||
/* The OpenBSD kernel maps the signal trampoline at some random
|
||
location in user space, which means that the traditional BSD way of
|
||
detecting it won't work.
|
||
|
||
The signal trampoline will be mapped at an address that is page
|
||
aligned. We recognize the signal trampoline by looking for the
|
||
sigreturn system call. */
|
||
|
||
static const int alphaobsd_page_size = 8192;
|
||
|
||
static LONGEST
|
||
alphaobsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
return (pc & (alphaobsd_page_size - 1));
|
||
}
|
||
|
||
static int
|
||
alphaobsd_pc_in_sigtramp (struct gdbarch *gdbarch,
|
||
CORE_ADDR pc, const char *name)
|
||
{
|
||
CORE_ADDR start_pc = (pc & ~(alphaobsd_page_size - 1));
|
||
unsigned insn;
|
||
|
||
if (name)
|
||
return 0;
|
||
|
||
/* Check for "". */
|
||
insn = alpha_read_insn (gdbarch, start_pc + 5 * ALPHA_INSN_SIZE);
|
||
if (insn != 0x201f0067)
|
||
return 0;
|
||
|
||
/* Check for "". */
|
||
insn = alpha_read_insn (gdbarch, start_pc + 6 * ALPHA_INSN_SIZE);
|
||
if (insn != 0x00000083)
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
alphaobsd_sigcontext_addr (const frame_info_ptr &this_frame)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (this_frame);
|
||
CORE_ADDR pc = get_frame_pc (this_frame);
|
||
|
||
if (alphaobsd_sigtramp_offset (gdbarch, pc) < 3 * ALPHA_INSN_SIZE)
|
||
{
|
||
/* On entry, a pointer the `struct sigcontext' is passed in %a2. */
|
||
return get_frame_register_unsigned (this_frame, ALPHA_A0_REGNUM + 2);
|
||
}
|
||
else if (alphaobsd_sigtramp_offset (gdbarch, pc) < 4 * ALPHA_INSN_SIZE)
|
||
{
|
||
/* It is stored on the stack Before calling the signal handler. */
|
||
CORE_ADDR sp;
|
||
sp = get_frame_register_unsigned (this_frame, ALPHA_SP_REGNUM);
|
||
return get_frame_memory_unsigned (this_frame, sp, 8);
|
||
}
|
||
else
|
||
{
|
||
/* It is reloaded into %a0 for the sigreturn(2) call. */
|
||
return get_frame_register_unsigned (this_frame, ALPHA_A0_REGNUM);
|
||
}
|
||
}
|
||
|
||
|
||
static void
|
||
alphaobsd_init_abi(struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
alpha_gdbarch_tdep *tdep = gdbarch_tdep<alpha_gdbarch_tdep> (gdbarch);
|
||
|
||
/* Hook into the DWARF CFI frame unwinder. */
|
||
alpha_dwarf2_init_abi (info, gdbarch);
|
||
|
||
/* Hook into the MDEBUG frame unwinder. */
|
||
alpha_mdebug_init_abi (info, gdbarch);
|
||
|
||
/* OpenBSD/alpha 3.0 and earlier does not provide single step
|
||
support via ptrace(2); use software single-stepping for now. */
|
||
set_gdbarch_get_next_pcs (gdbarch, alpha_software_single_step);
|
||
|
||
/* OpenBSD/alpha has SVR4-style shared libraries. */
|
||
set_solib_svr4_ops (gdbarch, make_svr4_lp64_solib_ops);
|
||
set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver);
|
||
|
||
tdep->dynamic_sigtramp_offset = alphaobsd_sigtramp_offset;
|
||
tdep->pc_in_sigtramp = alphaobsd_pc_in_sigtramp;
|
||
tdep->sigcontext_addr = alphaobsd_sigcontext_addr;
|
||
|
||
tdep->jb_pc = 2;
|
||
tdep->jb_elt_size = 8;
|
||
|
||
set_gdbarch_iterate_over_regset_sections
|
||
(gdbarch, alphanbsd_iterate_over_regset_sections);
|
||
}
|
||
|
||
|
||
INIT_GDB_FILE (alphaobsd_tdep)
|
||
{
|
||
gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_OPENBSD,
|
||
alphaobsd_init_abi);
|
||
}
|