binutils-gdb/gdb/rs6000-nat.c

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/* IBM RS/6000 native-dependent code for GDB, the GNU debugger.
Copyright (C) 1986-2017 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 "inferior.h"
#include "target.h"
#include "gdbcore.h"
#include "symfile.h"
#include "objfiles.h"
#include "bfd.h"
#include "gdb-stabs.h"
#include "regcache.h"
#include "arch-utils.h"
#include "inf-child.h"
#include "inf-ptrace.h"
#include "ppc-tdep.h"
#include "rs6000-tdep.h"
#include "rs6000-aix-tdep.h"
#include "exec.h"
#include "observer.h"
#include "xcoffread.h"
#include <sys/ptrace.h>
#include <sys/reg.h>
#include <sys/dir.h>
#include <sys/user.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <a.out.h>
#include <sys/file.h>
#include <sys/stat.h>
#include "gdb_bfd.h"
#include <sys/core.h>
#define __LDINFO_PTRACE32__ /* for __ld_info32 */
#define __LDINFO_PTRACE64__ /* for __ld_info64 */
#include <sys/ldr.h>
#include <sys/systemcfg.h>
/* On AIX4.3+, sys/ldr.h provides different versions of struct ld_info for
debugging 32-bit and 64-bit processes. Define a typedef and macros for
accessing fields in the appropriate structures. */
/* In 32-bit compilation mode (which is the only mode from which ptrace()
works on 4.3), __ld_info32 is #defined as equivalent to ld_info. */
#if defined (__ld_info32) || defined (__ld_info64)
# define ARCH3264
#endif
/* Return whether the current architecture is 64-bit. */
#ifndef ARCH3264
# define ARCH64() 0
#else
# define ARCH64() (register_size (target_gdbarch (), 0) == 8)
#endif
static target_xfer_partial_ftype rs6000_xfer_shared_libraries;
/* Given REGNO, a gdb register number, return the corresponding
number suitable for use as a ptrace() parameter. Return -1 if
there's no suitable mapping. Also, set the int pointed to by
ISFLOAT to indicate whether REGNO is a floating point register. */
static int
regmap (struct gdbarch *gdbarch, int regno, int *isfloat)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
*isfloat = 0;
if (tdep->ppc_gp0_regnum <= regno
&& regno < tdep->ppc_gp0_regnum + ppc_num_gprs)
return regno;
else if (tdep->ppc_fp0_regnum >= 0
&& tdep->ppc_fp0_regnum <= regno
&& regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
{
*isfloat = 1;
return regno - tdep->ppc_fp0_regnum + FPR0;
}
else if (regno == gdbarch_pc_regnum (gdbarch))
return IAR;
else if (regno == tdep->ppc_ps_regnum)
return MSR;
else if (regno == tdep->ppc_cr_regnum)
return CR;
else if (regno == tdep->ppc_lr_regnum)
return LR;
else if (regno == tdep->ppc_ctr_regnum)
return CTR;
else if (regno == tdep->ppc_xer_regnum)
return XER;
else if (tdep->ppc_fpscr_regnum >= 0
&& regno == tdep->ppc_fpscr_regnum)
return FPSCR;
else if (tdep->ppc_mq_regnum >= 0 && regno == tdep->ppc_mq_regnum)
return MQ;
else
return -1;
}
/* Call ptrace(REQ, ID, ADDR, DATA, BUF). */
static int
rs6000_ptrace32 (int req, int id, int *addr, int data, int *buf)
{
#ifdef HAVE_PTRACE64
int ret = ptrace64 (req, id, (uintptr_t) addr, data, buf);
#else
int ret = ptrace (req, id, (int *)addr, data, buf);
#endif
#if 0
printf ("rs6000_ptrace32 (%d, %d, 0x%x, %08x, 0x%x) = 0x%x\n",
req, id, (unsigned int)addr, data, (unsigned int)buf, ret);
#endif
return ret;
}
/* Call ptracex(REQ, ID, ADDR, DATA, BUF). */
static int
rs6000_ptrace64 (int req, int id, long long addr, int data, void *buf)
{
#ifdef ARCH3264
# ifdef HAVE_PTRACE64
int ret = ptrace64 (req, id, addr, data, (PTRACE_TYPE_ARG5) buf);
# else
int ret = ptracex (req, id, addr, data, (PTRACE_TYPE_ARG5) buf);
# endif
#else
int ret = 0;
#endif
#if 0
printf ("rs6000_ptrace64 (%d, %d, %s, %08x, 0x%x) = 0x%x\n",
req, id, hex_string (addr), data, (unsigned int)buf, ret);
#endif
return ret;
}
/* Fetch register REGNO from the inferior. */
static void
fetch_register (struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
int addr[MAX_REGISTER_SIZE];
int nr, isfloat;
pid_t pid = ptid_get_pid (regcache_get_ptid (regcache));
/* Retrieved values may be -1, so infer errors from errno. */
errno = 0;
nr = regmap (gdbarch, regno, &isfloat);
/* Floating-point registers. */
if (isfloat)
rs6000_ptrace32 (PT_READ_FPR, pid, addr, nr, 0);
/* Bogus register number. */
else if (nr < 0)
{
if (regno >= gdbarch_num_regs (gdbarch))
fprintf_unfiltered (gdb_stderr,
"gdb error: register no %d not implemented.\n",
regno);
return;
}
/* Fixed-point registers. */
else
{
if (!ARCH64 ())
*addr = rs6000_ptrace32 (PT_READ_GPR, pid, (int *) nr, 0, 0);
else
{
/* PT_READ_GPR requires the buffer parameter to point to long long,
even if the register is really only 32 bits. */
long long buf;
rs6000_ptrace64 (PT_READ_GPR, pid, nr, 0, &buf);
if (register_size (gdbarch, regno) == 8)
memcpy (addr, &buf, 8);
else
*addr = buf;
}
}
if (!errno)
regcache_raw_supply (regcache, regno, (char *) addr);
else
{
#if 0
/* FIXME: this happens 3 times at the start of each 64-bit program. */
perror (_("ptrace read"));
#endif
errno = 0;
}
}
/* Store register REGNO back into the inferior. */
static void
store_register (struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
int addr[MAX_REGISTER_SIZE];
int nr, isfloat;
pid_t pid = ptid_get_pid (regcache_get_ptid (regcache));
/* Fetch the register's value from the register cache. */
regcache_raw_collect (regcache, regno, addr);
/* -1 can be a successful return value, so infer errors from errno. */
errno = 0;
nr = regmap (gdbarch, regno, &isfloat);
/* Floating-point registers. */
if (isfloat)
rs6000_ptrace32 (PT_WRITE_FPR, pid, addr, nr, 0);
/* Bogus register number. */
else if (nr < 0)
{
if (regno >= gdbarch_num_regs (gdbarch))
fprintf_unfiltered (gdb_stderr,
"gdb error: register no %d not implemented.\n",
regno);
}
/* Fixed-point registers. */
else
{
/* The PT_WRITE_GPR operation is rather odd. For 32-bit inferiors,
the register's value is passed by value, but for 64-bit inferiors,
the address of a buffer containing the value is passed. */
if (!ARCH64 ())
rs6000_ptrace32 (PT_WRITE_GPR, pid, (int *) nr, *addr, 0);
else
{
/* PT_WRITE_GPR requires the buffer parameter to point to an 8-byte
area, even if the register is really only 32 bits. */
long long buf;
if (register_size (gdbarch, regno) == 8)
memcpy (&buf, addr, 8);
else
buf = *addr;
rs6000_ptrace64 (PT_WRITE_GPR, pid, nr, 0, &buf);
}
}
if (errno)
{
perror (_("ptrace write"));
errno = 0;
}
}
/* Read from the inferior all registers if REGNO == -1 and just register
REGNO otherwise. */
static void
rs6000_fetch_inferior_registers (struct target_ops *ops,
struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
if (regno != -1)
fetch_register (regcache, regno);
else
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Read 32 general purpose registers. */
for (regno = tdep->ppc_gp0_regnum;
regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
regno++)
{
fetch_register (regcache, regno);
}
/* Read general purpose floating point registers. */
if (tdep->ppc_fp0_regnum >= 0)
for (regno = 0; regno < ppc_num_fprs; regno++)
fetch_register (regcache, tdep->ppc_fp0_regnum + regno);
/* Read special registers. */
fetch_register (regcache, gdbarch_pc_regnum (gdbarch));
fetch_register (regcache, tdep->ppc_ps_regnum);
fetch_register (regcache, tdep->ppc_cr_regnum);
fetch_register (regcache, tdep->ppc_lr_regnum);
fetch_register (regcache, tdep->ppc_ctr_regnum);
fetch_register (regcache, tdep->ppc_xer_regnum);
if (tdep->ppc_fpscr_regnum >= 0)
fetch_register (regcache, tdep->ppc_fpscr_regnum);
if (tdep->ppc_mq_regnum >= 0)
fetch_register (regcache, tdep->ppc_mq_regnum);
}
}
/* Store our register values back into the inferior.
If REGNO is -1, do this for all registers.
Otherwise, REGNO specifies which register (so we can save time). */
static void
rs6000_store_inferior_registers (struct target_ops *ops,
struct regcache *regcache, int regno)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
if (regno != -1)
store_register (regcache, regno);
else
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Write general purpose registers first. */
for (regno = tdep->ppc_gp0_regnum;
regno < tdep->ppc_gp0_regnum + ppc_num_gprs;
regno++)
{
store_register (regcache, regno);
}
/* Write floating point registers. */
if (tdep->ppc_fp0_regnum >= 0)
for (regno = 0; regno < ppc_num_fprs; regno++)
store_register (regcache, tdep->ppc_fp0_regnum + regno);
/* Write special registers. */
store_register (regcache, gdbarch_pc_regnum (gdbarch));
store_register (regcache, tdep->ppc_ps_regnum);
store_register (regcache, tdep->ppc_cr_regnum);
store_register (regcache, tdep->ppc_lr_regnum);
store_register (regcache, tdep->ppc_ctr_regnum);
store_register (regcache, tdep->ppc_xer_regnum);
if (tdep->ppc_fpscr_regnum >= 0)
store_register (regcache, tdep->ppc_fpscr_regnum);
if (tdep->ppc_mq_regnum >= 0)
store_register (regcache, tdep->ppc_mq_regnum);
}
}
/* Implement the to_xfer_partial target_ops method. */
static enum target_xfer_status
rs6000_xfer_partial (struct target_ops *ops, enum target_object object,
const char *annex, gdb_byte *readbuf,
const gdb_byte *writebuf,
ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
{
pid_t pid = ptid_get_pid (inferior_ptid);
int arch64 = ARCH64 ();
switch (object)
{
case TARGET_OBJECT_LIBRARIES_AIX:
return rs6000_xfer_shared_libraries (ops, object, annex,
readbuf, writebuf,
offset, len, xfered_len);
case TARGET_OBJECT_MEMORY:
{
union
{
PTRACE_TYPE_RET word;
gdb_byte byte[sizeof (PTRACE_TYPE_RET)];
} buffer;
ULONGEST rounded_offset;
LONGEST partial_len;
/* Round the start offset down to the next long word
boundary. */
rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET);
/* Since ptrace will transfer a single word starting at that
rounded_offset the partial_len needs to be adjusted down to
that (remember this function only does a single transfer).
Should the required length be even less, adjust it down
again. */
partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset;
if (partial_len > len)
partial_len = len;
if (writebuf)
{
/* If OFFSET:PARTIAL_LEN is smaller than
ROUNDED_OFFSET:WORDSIZE then a read/modify write will
be needed. Read in the entire word. */
if (rounded_offset < offset
|| (offset + partial_len
< rounded_offset + sizeof (PTRACE_TYPE_RET)))
{
/* Need part of initial word -- fetch it. */
if (arch64)
buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
rounded_offset, 0, NULL);
else
buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
(int *) (uintptr_t)
rounded_offset,
0, NULL);
}
/* Copy data to be written over corresponding part of
buffer. */
memcpy (buffer.byte + (offset - rounded_offset),
writebuf, partial_len);
errno = 0;
if (arch64)
rs6000_ptrace64 (PT_WRITE_D, pid,
rounded_offset, buffer.word, NULL);
else
rs6000_ptrace32 (PT_WRITE_D, pid,
(int *) (uintptr_t) rounded_offset,
buffer.word, NULL);
if (errno)
return TARGET_XFER_EOF;
}
if (readbuf)
{
errno = 0;
if (arch64)
buffer.word = rs6000_ptrace64 (PT_READ_I, pid,
rounded_offset, 0, NULL);
else
buffer.word = rs6000_ptrace32 (PT_READ_I, pid,
(int *)(uintptr_t)rounded_offset,
0, NULL);
if (errno)
return TARGET_XFER_EOF;
/* Copy appropriate bytes out of the buffer. */
memcpy (readbuf, buffer.byte + (offset - rounded_offset),
partial_len);
}
*xfered_len = (ULONGEST) partial_len;
return TARGET_XFER_OK;
}
default:
return TARGET_XFER_E_IO;
}
}
/* Wait for the child specified by PTID to do something. Return the
process ID of the child, or MINUS_ONE_PTID in case of error; store
the status in *OURSTATUS. */
static ptid_t
rs6000_wait (struct target_ops *ops,
ptid_t ptid, struct target_waitstatus *ourstatus, int options)
{
pid_t pid;
int status, save_errno;
do
{
set_sigint_trap ();
do
{
pid = waitpid (ptid_get_pid (ptid), &status, 0);
save_errno = errno;
}
while (pid == -1 && errno == EINTR);
clear_sigint_trap ();
if (pid == -1)
{
fprintf_unfiltered (gdb_stderr,
_("Child process unexpectedly missing: %s.\n"),
safe_strerror (save_errno));
/* Claim it exited with unknown signal. */
ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
ourstatus->value.sig = GDB_SIGNAL_UNKNOWN;
return inferior_ptid;
}
/* Ignore terminated detached child processes. */
if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
pid = -1;
}
while (pid == -1);
/* AIX has a couple of strange returns from wait(). */
/* stop after load" status. */
if (status == 0x57c)
ourstatus->kind = TARGET_WAITKIND_LOADED;
/* signal 0. I have no idea why wait(2) returns with this status word. */
else if (status == 0x7f)
ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
/* A normal waitstatus. Let the usual macros deal with it. */
else
store_waitstatus (ourstatus, status);
return pid_to_ptid (pid);
}
/* Set the current architecture from the host running GDB. Called when
starting a child process. */
static void (*super_create_inferior) (struct target_ops *,char *exec_file,
char *allargs, char **env, int from_tty);
static void
rs6000_create_inferior (struct target_ops * ops, char *exec_file,
char *allargs, char **env, int from_tty)
{
enum bfd_architecture arch;
unsigned long mach;
bfd abfd;
struct gdbarch_info info;
super_create_inferior (ops, exec_file, allargs, env, from_tty);
if (__power_rs ())
{
arch = bfd_arch_rs6000;
mach = bfd_mach_rs6k;
}
else
{
arch = bfd_arch_powerpc;
mach = bfd_mach_ppc;
}
/* FIXME: schauer/2002-02-25:
We don't know if we are executing a 32 or 64 bit executable,
and have no way to pass the proper word size to rs6000_gdbarch_init.
So we have to avoid switching to a new architecture, if the architecture
matches already.
Blindly calling rs6000_gdbarch_init used to work in older versions of
GDB, as rs6000_gdbarch_init incorrectly used the previous tdep to
determine the wordsize. */
if (exec_bfd)
{
const struct bfd_arch_info *exec_bfd_arch_info;
exec_bfd_arch_info = bfd_get_arch_info (exec_bfd);
if (arch == exec_bfd_arch_info->arch)
return;
}
bfd_default_set_arch_mach (&abfd, arch, mach);
gdbarch_info_init (&info);
info.bfd_arch_info = bfd_get_arch_info (&abfd);
info.abfd = exec_bfd;
if (!gdbarch_update_p (info))
internal_error (__FILE__, __LINE__,
_("rs6000_create_inferior: failed "
"to select architecture"));
}
/* Shared Object support. */
/* Return the LdInfo data for the given process. Raises an error
if the data could not be obtained.
The returned value must be deallocated after use. */
static gdb_byte *
rs6000_ptrace_ldinfo (ptid_t ptid)
{
const int pid = ptid_get_pid (ptid);
int ldi_size = 1024;
void *ldi = xmalloc (ldi_size);
int rc = -1;
while (1)
{
if (ARCH64 ())
rc = rs6000_ptrace64 (PT_LDINFO, pid, (unsigned long) ldi, ldi_size,
NULL);
else
rc = rs6000_ptrace32 (PT_LDINFO, pid, (int *) ldi, ldi_size, NULL);
if (rc != -1)
break; /* Success, we got the entire ld_info data. */
if (errno != ENOMEM)
perror_with_name (_("ptrace ldinfo"));
/* ldi is not big enough. Double it and try again. */
ldi_size *= 2;
ldi = xrealloc (ldi, ldi_size);
}
return (gdb_byte *) ldi;
}
/* Implement the to_xfer_partial target_ops method for
TARGET_OBJECT_LIBRARIES_AIX objects. */
static enum target_xfer_status
rs6000_xfer_shared_libraries
(struct target_ops *ops, enum target_object object,
const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf,
ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
{
gdb_byte *ldi_buf;
ULONGEST result;
struct cleanup *cleanup;
/* This function assumes that it is being run with a live process.
Core files are handled via gdbarch. */
gdb_assert (target_has_execution);
if (writebuf)
return TARGET_XFER_E_IO;
ldi_buf = rs6000_ptrace_ldinfo (inferior_ptid);
gdb_assert (ldi_buf != NULL);
cleanup = make_cleanup (xfree, ldi_buf);
result = rs6000_aix_ld_info_to_xml (target_gdbarch (), ldi_buf,
readbuf, offset, len, 1);
xfree (ldi_buf);
do_cleanups (cleanup);
if (result == 0)
return TARGET_XFER_EOF;
else
{
*xfered_len = result;
return TARGET_XFER_OK;
}
}
void _initialize_rs6000_nat (void);
void
_initialize_rs6000_nat (void)
{
struct target_ops *t;
t = inf_ptrace_target ();
t->to_fetch_registers = rs6000_fetch_inferior_registers;
t->to_store_registers = rs6000_store_inferior_registers;
t->to_xfer_partial = rs6000_xfer_partial;
super_create_inferior = t->to_create_inferior;
t->to_create_inferior = rs6000_create_inferior;
t->to_wait = rs6000_wait;
add_target (t);
}