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- /* Native-dependent code for GNU/Linux RISC-V.
- Copyright (C) 2018-2022 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 "inferior.h"
- #include "elf/common.h"
- #include "nat/riscv-linux-tdesc.h"
- #include <sys/ptrace.h>
- /* Work around glibc header breakage causing ELF_NFPREG not to be usable. */
- #ifndef NFPREG
- # define NFPREG 33
- #endif
- /* 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;
- /* Read suitable target description. */
- const struct target_desc *read_description () 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 flen = register_size (regcache->arch (), RISCV_FIRST_FP_REGNUM);
- union
- {
- const prfpregset_t *fpregs;
- const gdb_byte *buf;
- }
- fpbuf = { .fpregs = fpregs };
- 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++, fpbuf.buf += flen)
- regcache->raw_supply (i, fpbuf.buf);
- regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, fpbuf.buf);
- }
- else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM)
- {
- fpbuf.buf += flen * (regnum - RISCV_FIRST_FP_REGNUM);
- regcache->raw_supply (regnum, fpbuf.buf);
- }
- else if (regnum == RISCV_CSR_FCSR_REGNUM)
- {
- fpbuf.buf += flen * (RISCV_LAST_FP_REGNUM - RISCV_FIRST_FP_REGNUM + 1);
- regcache->raw_supply (RISCV_CSR_FCSR_REGNUM, fpbuf.buf);
- }
- }
- /* 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)
- {
- int flen = register_size (regcache->arch (), RISCV_FIRST_FP_REGNUM);
- union
- {
- prfpregset_t *fpregs;
- gdb_byte *buf;
- }
- fpbuf = { .fpregs = fpregs };
- 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++, fpbuf.buf += flen)
- regcache->raw_collect (i, fpbuf.buf);
- regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, fpbuf.buf);
- }
- else if (regnum >= RISCV_FIRST_FP_REGNUM && regnum <= RISCV_LAST_FP_REGNUM)
- {
- fpbuf.buf += flen * (regnum - RISCV_FIRST_FP_REGNUM);
- regcache->raw_collect (regnum, fpbuf.buf);
- }
- else if (regnum == RISCV_CSR_FCSR_REGNUM)
- {
- fpbuf.buf += flen * (RISCV_LAST_FP_REGNUM - RISCV_FIRST_FP_REGNUM + 1);
- regcache->raw_collect (RISCV_CSR_FCSR_REGNUM, fpbuf.buf);
- }
- }
- /* Return a target description for the current target. */
- const struct target_desc *
- riscv_linux_nat_target::read_description ()
- {
- const struct riscv_gdbarch_features features
- = riscv_linux_read_features (inferior_ptid.pid ());
- return riscv_lookup_target_description (features);
- }
- /* 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 = ELF_NFPREG * register_size (regcache->arch (),
- RISCV_FIRST_FP_REGNUM);
- gdb_assert (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 = ELF_NFPREG * register_size (regcache->arch (),
- RISCV_FIRST_FP_REGNUM);
- gdb_assert (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
- _initialize_riscv_linux_nat ()
- {
- /* Register the target. */
- linux_target = &the_riscv_linux_nat_target;
- add_inf_child_target (&the_riscv_linux_nat_target);
- }
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