binutils-gdb/gdb/aarch64-tdep.h
Luis Machado ba60b96371 [aarch64] Add TPIDR2 register support for Linux
With the AArch64 Scalable Matrix Extension we have a new TPIDR2 register, and
it will be added to the existing NT_ARM_TLS register set. Kernel patches are
being reviewed here:

https://lore.kernel.org/linux-arm-kernel/20220818170111.351889-1-broonie@kernel.org/

From GDB's perspective, we handle it in a similar way to the existing TPIDR
register. But we need to consider cases of systems that only have TPIDR and
systems that have both TPIDR and TPIDR2.

With that in mind, the following patch adds the required code to support
TPIDR2 and turns the org.gnu.gdb.aarch64.tls feature into a
dynamically-generated target description as opposed to a static target
description containing only TPIDR.

That means we can remove the gdb/features/aarch64-tls.xml file and replace the
existing gdb/features/aarch64-tls.c auto-generated file with a new file that
dynamically generates the target description containing either TPIDR alone or
TPIDR and TPIDR2.

In the future, when *BSD's start to support this register, they can just
enable it as is being done for the AArch64 Linux target.

The core file read/write code has been updated to support TPIDR2 as well.

On GDBserver's side, there is a small change to the find_regno function to
expose a non-throwing version of it.

It always seemed strange to me how find_regno causes the whole operation to
abort if it doesn't find a particular register name. The patch moves code
from find_regno into find_regno_no_throw and makes find_regno call
find_regno_no_throw instead.

This allows us to do register name lookups to find a particular register
number without risking erroring out if nothing is found.

The patch also adjusts the feature detection code for aarch64-fbsd, since
the infrastructure is shared amongst all aarch64 targets. I haven't added
code to support TPIDR2 in aarch64-fbsd though, as I'm not sure when/if
that will happen.
2022-12-09 13:41:15 +00:00

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C

/* Common target dependent code for GDB on AArch64 systems.
Copyright (C) 2009-2022 Free Software Foundation, Inc.
Contributed by ARM Ltd.
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/>. */
#ifndef AARCH64_TDEP_H
#define AARCH64_TDEP_H
#include "arch/aarch64.h"
#include "displaced-stepping.h"
#include "infrun.h"
#include "gdbarch.h"
/* Forward declarations. */
struct gdbarch;
struct regset;
/* AArch64 Dwarf register numbering. */
#define AARCH64_DWARF_X0 0
#define AARCH64_DWARF_SP 31
#define AARCH64_DWARF_PC 32
#define AARCH64_DWARF_RA_SIGN_STATE 34
#define AARCH64_DWARF_V0 64
#define AARCH64_DWARF_SVE_VG 46
#define AARCH64_DWARF_SVE_FFR 47
#define AARCH64_DWARF_SVE_P0 48
#define AARCH64_DWARF_SVE_Z0 96
/* Size of integer registers. */
#define X_REGISTER_SIZE 8
#define B_REGISTER_SIZE 1
#define H_REGISTER_SIZE 2
#define S_REGISTER_SIZE 4
#define D_REGISTER_SIZE 8
#define Q_REGISTER_SIZE 16
/* Total number of general (X) registers. */
#define AARCH64_X_REGISTER_COUNT 32
/* Total number of D registers. */
#define AARCH64_D_REGISTER_COUNT 32
/* The maximum number of modified instructions generated for one
single-stepped instruction. */
#define AARCH64_DISPLACED_MODIFIED_INSNS 1
/* Target-dependent structure in gdbarch. */
struct aarch64_gdbarch_tdep : gdbarch_tdep_base
{
/* Lowest address at which instructions will appear. */
CORE_ADDR lowest_pc = 0;
/* Offset to PC value in jump buffer. If this is negative, longjmp
support will be disabled. */
int jb_pc = 0;
/* And the size of each entry in the buf. */
size_t jb_elt_size = 0;
/* Types for AdvSISD registers. */
struct type *vnq_type = nullptr;
struct type *vnd_type = nullptr;
struct type *vns_type = nullptr;
struct type *vnh_type = nullptr;
struct type *vnb_type = nullptr;
struct type *vnv_type = nullptr;
/* syscall record. */
int (*aarch64_syscall_record) (struct regcache *regcache,
unsigned long svc_number) = nullptr;
/* The VQ value for SVE targets, or zero if SVE is not supported. */
uint64_t vq = 0;
/* Returns true if the target supports SVE. */
bool has_sve () const
{
return vq != 0;
}
int pauth_reg_base = 0;
int ra_sign_state_regnum = 0;
/* Returns true if the target supports pauth. */
bool has_pauth () const
{
return pauth_reg_base != -1;
}
/* First MTE register. This is -1 if no MTE registers are available. */
int mte_reg_base = 0;
/* Returns true if the target supports MTE. */
bool has_mte () const
{
return mte_reg_base != -1;
}
/* TLS registers. This is -1 if the TLS registers are not available. */
int tls_regnum_base = 0;
int tls_register_count = 0;
bool has_tls() const
{
return tls_regnum_base != -1;
}
/* The W pseudo-registers. */
int w_pseudo_base = 0;
int w_pseudo_count = 0;
};
const target_desc *aarch64_read_description (const aarch64_features &features);
aarch64_features
aarch64_features_from_target_desc (const struct target_desc *tdesc);
extern int aarch64_process_record (struct gdbarch *gdbarch,
struct regcache *regcache, CORE_ADDR addr);
displaced_step_copy_insn_closure_up
aarch64_displaced_step_copy_insn (struct gdbarch *gdbarch,
CORE_ADDR from, CORE_ADDR to,
struct regcache *regs);
void aarch64_displaced_step_fixup (struct gdbarch *gdbarch,
displaced_step_copy_insn_closure *dsc,
CORE_ADDR from, CORE_ADDR to,
struct regcache *regs);
bool aarch64_displaced_step_hw_singlestep (struct gdbarch *gdbarch);
#endif /* aarch64-tdep.h */