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/* Motorola m68k native support for GNU/Linux.
Copyright (C) 1996-2021 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 "defs.h"
#include "frame.h"
#include "inferior.h"
#include "language.h"
#include "gdbcore.h"
#include "regcache.h"
#include "target.h"
#include "linux-nat.h"
#include "gdbarch.h"
#include "m68k-tdep.h"
#include <sys/dir.h>
#include <signal.h>
#include "nat/gdb_ptrace.h"
#include <sys/user.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <sys/procfs.h>
#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif
#include <sys/file.h>
#include <sys/stat.h>
#include "floatformat.h"
/* Prototypes for supply_gregset etc. */
#include "gregset.h"
/* Defines ps_err_e, struct ps_prochandle. */
#include "gdb_proc_service.h"
#include "inf-ptrace.h"
#ifndef PTRACE_GET_THREAD_AREA
#define PTRACE_GET_THREAD_AREA 25
#endif
class m68k_linux_nat_target final : public linux_nat_target
{
public:
/* Add our register access methods. */
void fetch_registers (struct regcache *, int) override;
void store_registers (struct regcache *, int) override;
};
static m68k_linux_nat_target the_m68k_linux_nat_target;
/* This table must line up with gdbarch_register_name in "m68k-tdep.c". */
static const int regmap[] =
{
PT_D0, PT_D1, PT_D2, PT_D3, PT_D4, PT_D5, PT_D6, PT_D7,
PT_A0, PT_A1, PT_A2, PT_A3, PT_A4, PT_A5, PT_A6, PT_USP,
PT_SR, PT_PC,
/* PT_FP0, ..., PT_FP7 */
21, 24, 27, 30, 33, 36, 39, 42,
/* PT_FPCR, PT_FPSR, PT_FPIAR */
45, 46, 47
};
/* Which ptrace request retrieves which registers?
These apply to the corresponding SET requests as well. */
#define NUM_GREGS (18)
#define MAX_NUM_REGS (NUM_GREGS + 11)
static int
getregs_supplies (int regno)
{
return 0 <= regno && regno < NUM_GREGS;
}
static int
getfpregs_supplies (int regno)
{
return M68K_FP0_REGNUM <= regno && regno <= M68K_FPI_REGNUM;
}
/* Does the current host support the GETREGS request? */
static int have_ptrace_getregs =
#ifdef HAVE_PTRACE_GETREGS
1
#else
0
#endif
;
/* Fetching registers directly from the U area, one at a time. */
/* Fetch one register. */
static void
fetch_register (struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = regcache->arch ();
long regaddr, val;
int i;
gdb_byte buf[M68K_MAX_REGISTER_SIZE];
pid_t tid = get_ptrace_pid (regcache->ptid ());
regaddr = 4 * regmap[regno];
for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long))
{
errno = 0;
val = ptrace (PTRACE_PEEKUSER, tid, regaddr, 0);
memcpy (&buf[i], &val, sizeof (long));
regaddr += sizeof (long);
if (errno != 0)
error (_("Couldn't read register %s (#%d): %s."),
gdbarch_register_name (gdbarch, regno),
regno, safe_strerror (errno));
}
regcache->raw_supply (regno, buf);
}
/* Fetch register values from the inferior.
If REGNO is negative, do this for all registers.
Otherwise, REGNO specifies which register (so we can save time). */
static void
old_fetch_inferior_registers (struct regcache *regcache, int regno)
{
if (regno >= 0)
{
fetch_register (regcache, regno);
}
else
{
for (regno = 0;
regno < gdbarch_num_regs (regcache->arch ());
regno++)
{
fetch_register (regcache, regno);
}
}
}
/* Store one register. */
static void
store_register (const struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = regcache->arch ();
long regaddr, val;
int i;
gdb_byte buf[M68K_MAX_REGISTER_SIZE];
pid_t tid = get_ptrace_pid (regcache->ptid ());
regaddr = 4 * regmap[regno];
/* Put the contents of regno into a local buffer. */
regcache->raw_collect (regno, buf);
/* Store the local buffer into the inferior a chunk at the time. */
for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long))
{
errno = 0;
memcpy (&val, &buf[i], sizeof (long));
ptrace (PTRACE_POKEUSER, tid, regaddr, val);
regaddr += sizeof (long);
if (errno != 0)
error (_("Couldn't write register %s (#%d): %s."),
gdbarch_register_name (gdbarch, regno),
regno, safe_strerror (errno));
}
}
/* Store our register values back into the inferior.
If REGNO is negative, do this for all registers.
Otherwise, REGNO specifies which register (so we can save time). */
static void
old_store_inferior_registers (const struct regcache *regcache, int regno)
{
if (regno >= 0)
{
store_register (regcache, regno);
}
else
{
for (regno = 0;
regno < gdbarch_num_regs (regcache->arch ());
regno++)
{
store_register (regcache, regno);
}
}
}
/* Given a pointer to a general register set in /proc format
(elf_gregset_t *), unpack the register contents and supply
them as gdb's idea of the current register values. */
void
supply_gregset (struct regcache *regcache, const elf_gregset_t *gregsetp)
{
struct gdbarch *gdbarch = regcache->arch ();
const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
int regi;
for (regi = M68K_D0_REGNUM;
regi <= gdbarch_sp_regnum (gdbarch);
regi++)
regcache->raw_supply (regi, &regp[regmap[regi]]);
regcache->raw_supply (gdbarch_ps_regnum (gdbarch), &regp[PT_SR]);
regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &regp[PT_PC]);
}
/* Fill register REGNO (if it is a general-purpose register) in
*GREGSETPS with the value in GDB's register array. If REGNO is -1,
do this for all registers. */
void
fill_gregset (const struct regcache *regcache,
elf_gregset_t *gregsetp, int regno)
{
elf_greg_t *regp = (elf_greg_t *) gregsetp;
int i;
for (i = 0; i < NUM_GREGS; i++)
if (regno == -1 || regno == i)
regcache->raw_collect (i, regp + regmap[i]);
}
#ifdef HAVE_PTRACE_GETREGS
/* Fetch all general-purpose registers from process/thread TID and
store their values in GDB's register array. */
static void
fetch_regs (struct regcache *regcache, int tid)
{
elf_gregset_t regs;
if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
{
if (errno == EIO)
{
/* The kernel we're running on doesn't support the GETREGS
request. Reset `have_ptrace_getregs'. */
have_ptrace_getregs = 0;
return;
}
perror_with_name (_("Couldn't get registers"));
}
supply_gregset (regcache, (const elf_gregset_t *) &regs);
}
/* Store all valid general-purpose registers in GDB's register array
into the process/thread specified by TID. */
static void
store_regs (const struct regcache *regcache, int tid, int regno)
{
elf_gregset_t regs;
if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
perror_with_name (_("Couldn't get registers"));
fill_gregset (regcache, &regs, regno);
if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
perror_with_name (_("Couldn't write registers"));
}
#else
static void fetch_regs (struct regcache *regcache, int tid)
{
}
static void store_regs (const struct regcache *regcache, int tid, int regno)
{
}
#endif
/* Transfering floating-point registers between GDB, inferiors and cores. */
/* What is the address of fpN within the floating-point register set F? */
#define FPREG_ADDR(f, n) (&(f)->fpregs[(n) * 3])
/* Fill GDB's register array with the floating-point register values in
*FPREGSETP. */
void
supply_fpregset (struct regcache *regcache, const elf_fpregset_t *fpregsetp)
{
struct gdbarch *gdbarch = regcache->arch ();
int regi;
for (regi = gdbarch_fp0_regnum (gdbarch);
regi < gdbarch_fp0_regnum (gdbarch) + 8; regi++)
regcache->raw_supply
(regi, FPREG_ADDR (fpregsetp, regi - gdbarch_fp0_regnum (gdbarch)));
regcache->raw_supply (M68K_FPC_REGNUM, &fpregsetp->fpcntl[0]);
regcache->raw_supply (M68K_FPS_REGNUM, &fpregsetp->fpcntl[1]);
regcache->raw_supply (M68K_FPI_REGNUM, &fpregsetp->fpcntl[2]);
}
/* Fill register REGNO (if it is a floating-point register) in
*FPREGSETP with the value in GDB's register array. If REGNO is -1,
do this for all registers. */
void
fill_fpregset (const struct regcache *regcache,
elf_fpregset_t *fpregsetp, int regno)
{
struct gdbarch *gdbarch = regcache->arch ();
int i;
/* Fill in the floating-point registers. */
for (i = gdbarch_fp0_regnum (gdbarch);
i < gdbarch_fp0_regnum (gdbarch) + 8; i++)
if (regno == -1 || regno == i)
regcache->raw_collect
(i, FPREG_ADDR (fpregsetp, i - gdbarch_fp0_regnum (gdbarch)));
/* Fill in the floating-point control registers. */
for (i = M68K_FPC_REGNUM; i <= M68K_FPI_REGNUM; i++)
if (regno == -1 || regno == i)
regcache->raw_collect (i, &fpregsetp->fpcntl[i - M68K_FPC_REGNUM]);
}
#ifdef HAVE_PTRACE_GETREGS
/* Fetch all floating-point registers from process/thread TID and store
thier values in GDB's register array. */
static void
fetch_fpregs (struct regcache *regcache, int tid)
{
elf_fpregset_t fpregs;
if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
perror_with_name (_("Couldn't get floating point status"));
supply_fpregset (regcache, (const elf_fpregset_t *) &fpregs);
}
/* Store all valid floating-point registers in GDB's register array
into the process/thread specified by TID. */
static void
store_fpregs (const struct regcache *regcache, int tid, int regno)
{
elf_fpregset_t fpregs;
if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
perror_with_name (_("Couldn't get floating point status"));
fill_fpregset (regcache, &fpregs, regno);
if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0)
perror_with_name (_("Couldn't write floating point status"));
}
#else
static void fetch_fpregs (struct regcache *regcache, int tid)
{
}
static void store_fpregs (const struct regcache *regcache, int tid, int regno)
{
}
#endif
/* Transferring arbitrary registers between GDB and inferior. */
/* Fetch register REGNO from the child process. If REGNO is -1, do
this for all registers (including the floating point and SSE
registers). */
void
m68k_linux_nat_target::fetch_registers (struct regcache *regcache, int regno)
{
pid_t tid;
/* Use the old method of peeking around in `struct user' if the
GETREGS request isn't available. */
if (! have_ptrace_getregs)
{
old_fetch_inferior_registers (regcache, regno);
return;
}
tid = get_ptrace_pid (regcache->ptid ());
/* Use the PTRACE_GETFPXREGS request whenever possible, since it
transfers more registers in one system call, and we'll cache the
results. But remember that fetch_fpxregs can fail, and return
zero. */
if (regno == -1)
{
fetch_regs (regcache, tid);
/* The call above might reset `have_ptrace_getregs'. */
if (! have_ptrace_getregs)
{
old_fetch_inferior_registers (regcache, -1);
return;
}
fetch_fpregs (regcache, tid);
return;
}
if (getregs_supplies (regno))
{
fetch_regs (regcache, tid);
return;
}
if (getfpregs_supplies (regno))
{
fetch_fpregs (regcache, tid);
return;
}
internal_error (__FILE__, __LINE__,
_("Got request for bad register number %d."), regno);
}
/* Store register REGNO back into the child process. If REGNO is -1,
do this for all registers (including the floating point and SSE
registers). */
void
m68k_linux_nat_target::store_registers (struct regcache *regcache, int regno)
{
pid_t tid;
/* Use the old method of poking around in `struct user' if the
SETREGS request isn't available. */
if (! have_ptrace_getregs)
{
old_store_inferior_registers (regcache, regno);
return;
}
tid = get_ptrace_pid (regcache->ptid ());
/* Use the PTRACE_SETFPREGS requests whenever possible, since it
transfers more registers in one system call. But remember that
store_fpregs can fail, and return zero. */
if (regno == -1)
{
store_regs (regcache, tid, regno);
store_fpregs (regcache, tid, regno);
return;
}
if (getregs_supplies (regno))
{
store_regs (regcache, tid, regno);
return;
}
if (getfpregs_supplies (regno))
{
store_fpregs (regcache, tid, regno);
return;
}
internal_error (__FILE__, __LINE__,
_("Got request to store bad register number %d."), regno);
}
/* Fetch the thread-local storage pointer for libthread_db. */
ps_err_e
ps_get_thread_area (struct ps_prochandle *ph,
lwpid_t lwpid, int idx, void **base)
{
if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) < 0)
return PS_ERR;
/* IDX is the bias from the thread pointer to the beginning of the
thread descriptor. It has to be subtracted due to implementation
quirks in libthread_db. */
*base = (char *) *base - idx;
return PS_OK;
}
void _initialize_m68k_linux_nat ();
void
_initialize_m68k_linux_nat ()
{
/* Register the target. */
linux_target = &the_m68k_linux_nat_target;
add_inf_child_target (&the_m68k_linux_nat_target);
}