old-cross-binutils/gdb/gdbserver/linux-sh-low.c
Antoine Tremblay 7d00775ece Refactor queries for hardware and software single stepping support in GDBServer.
Before this patch there was only one call: can_hardware_single_step. Its
implementation was a check on breakpoint_reinsert_addr if NULL it assumed
that the target could hardware single step.

This patch prepares for the case where this is not true anymore.

In order to improve software single stepping in GDBServer the
breakpoint_reinsert_addr operation of targets that had a very simple
software implementation used only for stepping over thread creation events
will be removed.

This will create a case where a target does not support hardware single
step and has the operation breakpoint_reinsert_addr set to NULL, thus
can_hardware_single_step needs to be implemented another way.

A new target operation supports_hardware_single_step is introduced and is
to return true if the target does support such a feature, support for the
feature is manually hardcoded.

Note that the hardware single step support was enabled as per the current
behavior, I did not check if tile for example really has ptrace singlestep
support but since the current implementation assumed it had, I kept it
that way.

No regressions on Ubuntu 14.04 on ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }

Compilation tested on: aarch64,arm,bfind,crisv32,m32r,ppc,s390,tic6x,tile,
xtensa.
Not tested : sh.

gdb/gdbserver/ChangeLog:

	* linux-aarch64-low.c (aarch64_supports_hardware_single_step):
	New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-arm-low.c (arm_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-bfin-low.c (bfin_supports_hardware_single_step): New function.
	(struct linux_target_ops) <bfin_supports_hardware_single_step>:
	Initialize.
	* linux-crisv32-low.c (cris_supports_hardware_single_step):
	New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-low.c (can_hardware_single_step): Use
	supports_hardware_single_step.
	(can_software_single_step): New function.
	(start_step_over): Call can_software_single_step.
	(linux_supports_hardware_single_step): New function.
	(struct target_ops) <supports_software_single_step>: Initialize.
	* linux-low.h (struct linux_target_ops)
	<supports_hardware_single_step>: Initialize.
	* linux-m32r-low.c (m32r_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-ppc-low.c (ppc_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step> Initialize.
	* linux-s390-low.c (s390_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-sh-low.c (sh_supports_hardware_single_step): New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-tic6x-low.c (tic6x_supports_hardware_single_step): New function.
	(struct linux_target_ops) <tic6x_supports_hardware_single_step>:
	Initialize.
	* linux-tile-low.c (tile_supports_hardware_single_step): New function.
	(struct linux_target_ops) <tile_supports_hardware_single_step>:
	Initialize.
	* linux-x86-low.c (x86_supports_hardware_single_step) New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* linux-xtensa-low.c (xtensa_supports_hardware_single_step):
	New function.
	(struct linux_target_ops) <supports_hardware_single_step>: Initialize.
	* target.h (struct target_ops): <supports_software_single_step>:
	New field.
	(target_supports_software_single_step): New macro.
2015-11-30 15:17:36 -05:00

202 lines
4.7 KiB
C

/* GNU/Linux/SH specific low level interface, for the remote server for GDB.
Copyright (C) 1995-2015 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 "server.h"
#include "linux-low.h"
/* Defined in auto-generated file reg-sh.c. */
void init_registers_sh (void);
extern const struct target_desc *tdesc_sh;
#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif
#include <asm/ptrace.h>
#define sh_num_regs 41
/* Currently, don't check/send MQ. */
static int sh_regmap[] = {
0, 4, 8, 12, 16, 20, 24, 28,
32, 36, 40, 44, 48, 52, 56, 60,
REG_PC*4, REG_PR*4, REG_GBR*4, -1,
REG_MACH*4, REG_MACL*4, REG_SR*4,
REG_FPUL*4, REG_FPSCR*4,
REG_FPREG0*4+0, REG_FPREG0*4+4, REG_FPREG0*4+8, REG_FPREG0*4+12,
REG_FPREG0*4+16, REG_FPREG0*4+20, REG_FPREG0*4+24, REG_FPREG0*4+28,
REG_FPREG0*4+32, REG_FPREG0*4+36, REG_FPREG0*4+40, REG_FPREG0*4+44,
REG_FPREG0*4+48, REG_FPREG0*4+52, REG_FPREG0*4+56, REG_FPREG0*4+60,
};
static int
sh_cannot_store_register (int regno)
{
return 0;
}
static int
sh_cannot_fetch_register (int regno)
{
return 0;
}
static CORE_ADDR
sh_get_pc (struct regcache *regcache)
{
unsigned long pc;
collect_register_by_name (regcache, "pc", &pc);
return pc;
}
static void
sh_set_pc (struct regcache *regcache, CORE_ADDR pc)
{
unsigned long newpc = pc;
supply_register_by_name (regcache, "pc", &newpc);
}
/* Correct in either endianness, obviously. */
static const unsigned short sh_breakpoint = 0xc3c3;
#define sh_breakpoint_len 2
/* Implementation of linux_target_ops method "sw_breakpoint_from_kind". */
static const gdb_byte *
sh_sw_breakpoint_from_kind (int kind, int *size)
{
*size = sh_breakpoint_len;
return (const gdb_byte *) &sh_breakpoint;
}
static int
sh_breakpoint_at (CORE_ADDR where)
{
unsigned short insn;
(*the_target->read_memory) (where, (unsigned char *) &insn, 2);
if (insn == sh_breakpoint)
return 1;
/* If necessary, recognize more trap instructions here. GDB only uses the
one. */
return 0;
}
/* Support for hardware single step. */
static int
sh_supports_hardware_single_step (void)
{
return 1;
}
/* Provide only a fill function for the general register set. ps_lgetregs
will use this for NPTL support. */
static void sh_fill_gregset (struct regcache *regcache, void *buf)
{
int i;
for (i = 0; i < 23; i++)
if (sh_regmap[i] != -1)
collect_register (regcache, i, (char *) buf + sh_regmap[i]);
}
static struct regset_info sh_regsets[] = {
{ 0, 0, 0, 0, GENERAL_REGS, sh_fill_gregset, NULL },
NULL_REGSET
};
static struct regsets_info sh_regsets_info =
{
sh_regsets, /* regsets */
0, /* num_regsets */
NULL, /* disabled_regsets */
};
static struct usrregs_info sh_usrregs_info =
{
sh_num_regs,
sh_regmap,
};
static struct regs_info regs_info =
{
NULL, /* regset_bitmap */
&sh_usrregs_info,
&sh_regsets_info
};
static const struct regs_info *
sh_regs_info (void)
{
return &regs_info;
}
static void
sh_arch_setup (void)
{
current_process ()->tdesc = tdesc_sh;
}
struct linux_target_ops the_low_target = {
sh_arch_setup,
sh_regs_info,
sh_cannot_fetch_register,
sh_cannot_store_register,
NULL, /* fetch_register */
sh_get_pc,
sh_set_pc,
NULL, /* breakpoint_kind_from_pc */
sh_sw_breakpoint_from_kind,
NULL,
0,
sh_breakpoint_at,
NULL, /* supports_z_point_type */
NULL, /* insert_point */
NULL, /* remove_point */
NULL, /* stopped_by_watchpoint */
NULL, /* stopped_data_address */
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
NULL, /* new_process */
NULL, /* new_thread */
NULL, /* new_fork */
NULL, /* prepare_to_resume */
NULL, /* process_qsupported */
NULL, /* supports_tracepoints */
NULL, /* get_thread_area */
NULL, /* install_fast_tracepoint_jump_pad */
NULL, /* emit_ops */
NULL, /* get_min_fast_tracepoint_insn_len */
NULL, /* supports_range_stepping */
NULL, /* breakpoint_kind_from_current_state */
sh_supports_hardware_single_step,
};
void
initialize_low_arch (void)
{
init_registers_sh ();
initialize_regsets_info (&sh_regsets_info);
}