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/* Native-dependent code for GNU/Linux RISC-V.
Copyright (C) 2018 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 "defs.h"
#include "regcache.h"
#include "gregset.h"
#include "linux-nat.h"
#include "riscv-tdep.h"
#include "elf/common.h"
#include <sys/ptrace.h>
/* RISC-V Linux native additions to the default linux support. */
class riscv_linux_nat_target final : public linux_nat_target
{
public:
/* Add our register access methods. */
void fetch_registers (struct regcache *regcache, int regnum) override;
void store_registers (struct regcache *regcache, int regnum) override;
};
static riscv_linux_nat_target the_riscv_linux_nat_target;
/* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1)
from regset GREGS into REGCACHE. */
static void
supply_gregset_regnum (struct regcache *regcache, const prgregset_t *gregs,
int regnum)
{
int i;
const elf_greg_t *regp = *gregs;
if (regnum == -1)
{
/* We only support the integer registers and PC here. */
for (i = RISCV_ZERO_REGNUM + 1; i < RISCV_PC_REGNUM; i++)
regcache->raw_supply (i, regp + i);
/* GDB stores PC in reg 32. Linux kernel stores it in reg 0. */
regcache->raw_supply (32, regp + 0);
/* Fill the inaccessible zero register with zero. */
regcache->raw_supply_zeroed (0);
}
else if (regnum == RISCV_ZERO_REGNUM)
regcache->raw_supply_zeroed (0);
else if (regnum > RISCV_ZERO_REGNUM && regnum < RISCV_PC_REGNUM)
regcache->raw_supply (regnum, regp + regnum);
else if (regnum == RISCV_PC_REGNUM)
regcache->raw_supply (32, regp + 0);
}
/* Copy all general purpose registers from regset GREGS into REGCACHE. */
void
supply_gregset (struct regcache *regcache, const prgregset_t *gregs)
{
supply_gregset_regnum (regcache, gregs, -1);
}
/* Copy floating point register REGNUM (or all fp regs if REGNUM == -1)
from regset FPREGS into REGCACHE. */
static void
supply_fpregset_regnum (struct regcache *regcache, const prfpregset_t *fpregs,
int regnum)
{
int i;
if (regnum == -1)
{
/* We only support the FP registers and FCSR here. */
for (i = RISCV_FIRST_FP_REGNUM; i <= RISCV_LAST_FP_REGNUM; i++)
regcache->raw_supply (i, &fpregs->__d.__f[i - RISCV_FIRST_FP_REGNUM]);
regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr);
}
else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM)
regcache->raw_supply (regnum,
&fpregs->__d.__f[regnum - RISCV_FIRST_FP_REGNUM]);
else if (regnum == RISCV_CSR_FCSR_REGNUM)
regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr);
}
/* Copy all floating point registers from regset FPREGS into REGCACHE. */
void
supply_fpregset (struct regcache *regcache, const prfpregset_t *fpregs)
{
supply_fpregset_regnum (regcache, fpregs, -1);
}
/* Copy general purpose register REGNUM (or all gp regs if REGNUM == -1)
from REGCACHE into regset GREGS. */
void
fill_gregset (const struct regcache *regcache, prgregset_t *gregs, int regnum)
{
elf_greg_t *regp = *gregs;
if (regnum == -1)
{
/* We only support the integer registers and PC here. */
for (int i = RISCV_ZERO_REGNUM + 1; i < RISCV_PC_REGNUM; i++)
regcache->raw_collect (i, regp + i);
regcache->raw_collect (32, regp + 0);
}
else if (regnum == RISCV_ZERO_REGNUM)
/* Nothing to do here. */
;
else if (regnum > RISCV_ZERO_REGNUM && regnum < RISCV_PC_REGNUM)
regcache->raw_collect (regnum, regp + regnum);
else if (regnum == RISCV_PC_REGNUM)
regcache->raw_collect (32, regp + 0);
}
/* Copy floating point register REGNUM (or all fp regs if REGNUM == -1)
from REGCACHE into regset FPREGS. */
void
fill_fpregset (const struct regcache *regcache, prfpregset_t *fpregs,
int regnum)
{
if (regnum == -1)
{
/* We only support the FP registers and FCSR here. */
for (int i = RISCV_FIRST_FP_REGNUM; i <= RISCV_LAST_FP_REGNUM; i++)
regcache->raw_collect (i, &fpregs->__d.__f[i - RISCV_FIRST_FP_REGNUM]);
regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr);
}
else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM)
regcache->raw_collect (regnum,
&fpregs->__d.__f[regnum - RISCV_FIRST_FP_REGNUM]);
else if (regnum == RISCV_CSR_FCSR_REGNUM)
regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, &fpregs->__d.__fcsr);
}
/* Fetch REGNUM (or all registers if REGNUM == -1) from the target
into REGCACHE using PTRACE_GETREGSET. */
void
riscv_linux_nat_target::fetch_registers (struct regcache *regcache, int regnum)
{
int tid;
tid = get_ptrace_pid (regcache->ptid());
if ((regnum >= RISCV_ZERO_REGNUM && regnum <= RISCV_PC_REGNUM)
|| (regnum == -1))
{
struct iovec iov;
elf_gregset_t regs;
iov.iov_base = ®s;
iov.iov_len = sizeof (regs);
if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS,
(PTRACE_TYPE_ARG3) &iov) == -1)
perror_with_name (_("Couldn't get registers"));
else
supply_gregset_regnum (regcache, ®s, regnum);
}
if ((regnum >= RISCV_FIRST_FP_REGNUM
&& regnum <= RISCV_LAST_FP_REGNUM)
|| (regnum == RISCV_CSR_FCSR_REGNUM)
|| (regnum == -1))
{
struct iovec iov;
elf_fpregset_t regs;
iov.iov_base = ®s;
iov.iov_len = sizeof (regs);
if (ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET,
(PTRACE_TYPE_ARG3) &iov) == -1)
perror_with_name (_("Couldn't get registers"));
else
supply_fpregset_regnum (regcache, ®s, regnum);
}
if ((regnum == RISCV_CSR_MISA_REGNUM)
|| (regnum == -1))
{
/* TODO: Need to add a ptrace call for this. */
regcache->raw_supply_zeroed (RISCV_CSR_MISA_REGNUM);
}
/* Access to other CSRs has potential security issues, don't support them for
now. */
}
/* Store REGNUM (or all registers if REGNUM == -1) to the target
from REGCACHE using PTRACE_SETREGSET. */
void
riscv_linux_nat_target::store_registers (struct regcache *regcache, int regnum)
{
int tid;
tid = get_ptrace_pid (regcache->ptid ());
if ((regnum >= RISCV_ZERO_REGNUM && regnum <= RISCV_PC_REGNUM)
|| (regnum == -1))
{
struct iovec iov;
elf_gregset_t regs;
iov.iov_base = ®s;
iov.iov_len = sizeof (regs);
if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS,
(PTRACE_TYPE_ARG3) &iov) == -1)
perror_with_name (_("Couldn't get registers"));
else
{
fill_gregset (regcache, ®s, regnum);
if (ptrace (PTRACE_SETREGSET, tid, NT_PRSTATUS,
(PTRACE_TYPE_ARG3) &iov) == -1)
perror_with_name (_("Couldn't set registers"));
}
}
if ((regnum >= RISCV_FIRST_FP_REGNUM
&& regnum <= RISCV_LAST_FP_REGNUM)
|| (regnum == RISCV_CSR_FCSR_REGNUM)
|| (regnum == -1))
{
struct iovec iov;
elf_fpregset_t regs;
iov.iov_base = ®s;
iov.iov_len = sizeof (regs);
if (ptrace (PTRACE_GETREGSET, tid, NT_FPREGSET,
(PTRACE_TYPE_ARG3) &iov) == -1)
perror_with_name (_("Couldn't get registers"));
else
{
fill_fpregset (regcache, ®s, regnum);
if (ptrace (PTRACE_SETREGSET, tid, NT_FPREGSET,
(PTRACE_TYPE_ARG3) &iov) == -1)
perror_with_name (_("Couldn't set registers"));
}
}
/* Access to CSRs has potential security issues, don't support them for
now. */
}
/* Initialize RISC-V Linux native support. */
void
_initialize_riscv_linux_nat (void)
{
/* Register the target. */
linux_target = &the_riscv_linux_nat_target;
add_inf_child_target (&the_riscv_linux_nat_target);
}
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