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/* Copyright (C) 1995-2021 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 "arch/arm.h"
#include "arch/arm-linux.h"
#include "linux-low.h"
#include "linux-aarch32-low.h"
#include <sys/ptrace.h>
/* Don't include elf.h if linux/elf.h got included by gdb_proc_service.h.
On Bionic elf.h and linux/elf.h have conflicting definitions. */
#ifndef ELFMAG0
#include <elf.h>
#endif
/* Correct in either endianness. */
#define arm_abi_breakpoint 0xef9f0001UL
/* For new EABI binaries. We recognize it regardless of which ABI
is used for gdbserver, so single threaded debugging should work
OK, but for multi-threaded debugging we only insert the current
ABI's breakpoint instruction. For now at least. */
#define arm_eabi_breakpoint 0xe7f001f0UL
#if (defined __ARM_EABI__ || defined __aarch64__)
static const unsigned long arm_breakpoint = arm_eabi_breakpoint;
#else
static const unsigned long arm_breakpoint = arm_abi_breakpoint;
#endif
#define arm_breakpoint_len 4
static const unsigned short thumb_breakpoint = 0xde01;
#define thumb_breakpoint_len 2
static const unsigned short thumb2_breakpoint[] = { 0xf7f0, 0xa000 };
#define thumb2_breakpoint_len 4
/* Some older versions of GNU/Linux and Android do not define
the following macros. */
#ifndef NT_ARM_VFP
#define NT_ARM_VFP 0x400
#endif
/* Collect GP registers from REGCACHE to buffer BUF. */
void
arm_fill_gregset (struct regcache *regcache, void *buf)
{
int i;
uint32_t *regs = (uint32_t *) buf;
uint32_t cpsr = regs[ARM_CPSR_GREGNUM];
for (i = ARM_A1_REGNUM; i <= ARM_PC_REGNUM; i++)
collect_register (regcache, i, &regs[i]);
collect_register (regcache, ARM_PS_REGNUM, &regs[ARM_CPSR_GREGNUM]);
/* Keep reserved bits bit 20 to bit 23. */
regs[ARM_CPSR_GREGNUM] = ((regs[ARM_CPSR_GREGNUM] & 0xff0fffff)
| (cpsr & 0x00f00000));
}
/* Supply GP registers contents, stored in BUF, to REGCACHE. */
void
arm_store_gregset (struct regcache *regcache, const void *buf)
{
int i;
char zerobuf[8];
const uint32_t *regs = (const uint32_t *) buf;
uint32_t cpsr = regs[ARM_CPSR_GREGNUM];
memset (zerobuf, 0, 8);
for (i = ARM_A1_REGNUM; i <= ARM_PC_REGNUM; i++)
supply_register (regcache, i, &regs[i]);
for (; i < ARM_PS_REGNUM; i++)
supply_register (regcache, i, zerobuf);
/* Clear reserved bits bit 20 to bit 23. */
cpsr &= 0xff0fffff;
supply_register (regcache, ARM_PS_REGNUM, &cpsr);
}
/* Collect NUM number of VFP registers from REGCACHE to buffer BUF. */
void
arm_fill_vfpregset_num (struct regcache *regcache, void *buf, int num)
{
int i, base;
gdb_assert (num == 16 || num == 32);
base = find_regno (regcache->tdesc, "d0");
for (i = 0; i < num; i++)
collect_register (regcache, base + i, (char *) buf + i * 8);
collect_register_by_name (regcache, "fpscr", (char *) buf + 32 * 8);
}
/* Supply NUM number of VFP registers contents, stored in BUF, to
REGCACHE. */
void
arm_store_vfpregset_num (struct regcache *regcache, const void *buf, int num)
{
int i, base;
gdb_assert (num == 16 || num == 32);
base = find_regno (regcache->tdesc, "d0");
for (i = 0; i < num; i++)
supply_register (regcache, base + i, (char *) buf + i * 8);
supply_register_by_name (regcache, "fpscr", (char *) buf + 32 * 8);
}
static void
arm_fill_vfpregset (struct regcache *regcache, void *buf)
{
arm_fill_vfpregset_num (regcache, buf, 32);
}
static void
arm_store_vfpregset (struct regcache *regcache, const void *buf)
{
arm_store_vfpregset_num (regcache, buf, 32);
}
/* Register sets with using PTRACE_GETREGSET. */
static struct regset_info aarch32_regsets[] = {
{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS,
ARM_CORE_REGS_SIZE + ARM_INT_REGISTER_SIZE, GENERAL_REGS,
arm_fill_gregset, arm_store_gregset },
{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_ARM_VFP, ARM_VFP3_REGS_SIZE,
EXTENDED_REGS,
arm_fill_vfpregset, arm_store_vfpregset },
NULL_REGSET
};
static struct regsets_info aarch32_regsets_info =
{
aarch32_regsets, /* regsets */
0, /* num_regsets */
NULL, /* disabled_regsets */
};
struct regs_info regs_info_aarch32 =
{
NULL, /* regset_bitmap */
NULL, /* usrregs */
&aarch32_regsets_info
};
/* Returns 1 if the current instruction set is thumb, 0 otherwise. */
int
arm_is_thumb_mode (void)
{
struct regcache *regcache = get_thread_regcache (current_thread, 1);
unsigned long cpsr;
collect_register_by_name (regcache, "cpsr", &cpsr);
if (cpsr & 0x20)
return 1;
else
return 0;
}
/* Returns 1 if there is a software breakpoint at location. */
int
arm_breakpoint_at (CORE_ADDR where)
{
if (arm_is_thumb_mode ())
{
/* Thumb mode. */
unsigned short insn;
the_target->read_memory (where, (unsigned char *) &insn, 2);
if (insn == thumb_breakpoint)
return 1;
if (insn == thumb2_breakpoint[0])
{
the_target->read_memory (where + 2, (unsigned char *) &insn, 2);
if (insn == thumb2_breakpoint[1])
return 1;
}
}
else
{
/* ARM mode. */
unsigned long insn;
the_target->read_memory (where, (unsigned char *) &insn, 4);
if (insn == arm_abi_breakpoint)
return 1;
if (insn == arm_eabi_breakpoint)
return 1;
}
return 0;
}
/* Implementation of linux_target_ops method "breakpoint_kind_from_pc".
Determine the type and size of breakpoint to insert at PCPTR. Uses the
program counter value to determine whether a 16-bit or 32-bit breakpoint
should be used. It returns the breakpoint's kind, and adjusts the program
counter (if necessary) to point to the actual memory location where the
breakpoint should be inserted. */
int
arm_breakpoint_kind_from_pc (CORE_ADDR *pcptr)
{
if (IS_THUMB_ADDR (*pcptr))
{
gdb_byte buf[2];
*pcptr = UNMAKE_THUMB_ADDR (*pcptr);
/* Check whether we are replacing a thumb2 32-bit instruction. */
if (target_read_memory (*pcptr, buf, 2) == 0)
{
unsigned short inst1 = 0;
target_read_memory (*pcptr, (gdb_byte *) &inst1, 2);
if (thumb_insn_size (inst1) == 4)
return ARM_BP_KIND_THUMB2;
}
return ARM_BP_KIND_THUMB;
}
else
return ARM_BP_KIND_ARM;
}
/* Implementation of the linux_target_ops method "sw_breakpoint_from_kind". */
const gdb_byte *
arm_sw_breakpoint_from_kind (int kind , int *size)
{
*size = arm_breakpoint_len;
/* Define an ARM-mode breakpoint; we only set breakpoints in the C
library, which is most likely to be ARM. If the kernel supports
clone events, we will never insert a breakpoint, so even a Thumb
C library will work; so will mixing EABI/non-EABI gdbserver and
application. */
switch (kind)
{
case ARM_BP_KIND_THUMB:
*size = thumb_breakpoint_len;
return (gdb_byte *) &thumb_breakpoint;
case ARM_BP_KIND_THUMB2:
*size = thumb2_breakpoint_len;
return (gdb_byte *) &thumb2_breakpoint;
case ARM_BP_KIND_ARM:
*size = arm_breakpoint_len;
return (const gdb_byte *) &arm_breakpoint;
default:
return NULL;
}
return NULL;
}
/* Implementation of the linux_target_ops method
"breakpoint_kind_from_current_state". */
int
arm_breakpoint_kind_from_current_state (CORE_ADDR *pcptr)
{
if (arm_is_thumb_mode ())
{
*pcptr = MAKE_THUMB_ADDR (*pcptr);
return arm_breakpoint_kind_from_pc (pcptr);
}
else
{
return arm_breakpoint_kind_from_pc (pcptr);
}
}
void
initialize_low_arch_aarch32 (void)
{
initialize_regsets_info (&aarch32_regsets_info);
}