binutils-gdb/gdb/m68klinux-nat.c

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/* Motorola m68k native support for GNU/Linux.
Copyright 1996, 1998, 2000, 2001, 2002 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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "language.h"
#include "gdbcore.h"
#include "regcache.h"
#ifdef USG
#include <sys/types.h>
#endif
#include <sys/param.h>
#include <sys/dir.h>
#include <signal.h>
#include <sys/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 "gdb_stat.h"
#include "floatformat.h"
#include "target.h"
/* This table must line up with REGISTER_NAMES in tm-m68k.h */
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)
int
getregs_supplies (int regno)
{
return 0 <= regno && regno < NUM_GREGS;
}
int
getfpregs_supplies (int regno)
{
return FP0_REGNUM <= regno && regno <= FPI_REGNUM;
}
/* Does the current host support the GETREGS request? */
int have_ptrace_getregs =
#ifdef HAVE_PTRACE_GETREGS
1
#else
0
#endif
;
/* BLOCKEND is the value of u.u_ar0, and points to the place where GS
is stored. */
int
m68k_linux_register_u_addr (int blockend, int regnum)
{
return (blockend + 4 * regmap[regnum]);
}
/* Fetching registers directly from the U area, one at a time. */
/* FIXME: This duplicates code from `inptrace.c'. The problem is that we
define FETCH_INFERIOR_REGISTERS since we want to use our own versions
of {fetch,store}_inferior_registers that use the GETREGS request. This
means that the code in `infptrace.c' is #ifdef'd out. But we need to
fall back on that code when GDB is running on top of a kernel that
doesn't support the GETREGS request. */
#ifndef PT_READ_U
#define PT_READ_U PTRACE_PEEKUSR
#endif
#ifndef PT_WRITE_U
#define PT_WRITE_U PTRACE_POKEUSR
#endif
/* Default the type of the ptrace transfer to int. */
#ifndef PTRACE_XFER_TYPE
#define PTRACE_XFER_TYPE int
#endif
/* Fetch one register. */
static void
fetch_register (int regno)
{
/* This isn't really an address. But ptrace thinks of it as one. */
CORE_ADDR regaddr;
char mess[128]; /* For messages */
register int i;
unsigned int offset; /* Offset of registers within the u area. */
char buf[MAX_REGISTER_RAW_SIZE];
int tid;
if (CANNOT_FETCH_REGISTER (regno))
{
memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */
supply_register (regno, buf);
return;
}
/* Overload thread id onto process id */
if ((tid = TIDGET (inferior_ptid)) == 0)
tid = PIDGET (inferior_ptid); /* no thread id, just use process id */
offset = U_REGS_OFFSET;
regaddr = register_addr (regno, offset);
for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
*(PTRACE_XFER_TYPE *) & buf[i] = ptrace (PT_READ_U, tid,
(PTRACE_ARG3_TYPE) regaddr, 0);
regaddr += sizeof (PTRACE_XFER_TYPE);
if (errno != 0)
{
sprintf (mess, "reading register %s (#%d)",
REGISTER_NAME (regno), regno);
perror_with_name (mess);
}
}
supply_register (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). */
void
old_fetch_inferior_registers (int regno)
{
if (regno >= 0)
{
fetch_register (regno);
}
else
{
for (regno = 0; regno < NUM_REGS; regno++)
{
fetch_register (regno);
}
}
}
/* Store one register. */
static void
store_register (int regno)
{
/* This isn't really an address. But ptrace thinks of it as one. */
CORE_ADDR regaddr;
char mess[128]; /* For messages */
register int i;
unsigned int offset; /* Offset of registers within the u area. */
int tid;
char *buf = alloca (MAX_REGISTER_RAW_SIZE);
if (CANNOT_STORE_REGISTER (regno))
{
return;
}
/* Overload thread id onto process id */
if ((tid = TIDGET (inferior_ptid)) == 0)
tid = PIDGET (inferior_ptid); /* no thread id, just use process id */
offset = U_REGS_OFFSET;
regaddr = register_addr (regno, offset);
/* Put the contents of regno into a local buffer */
regcache_collect (regno, buf);
/* Store the local buffer into the inferior a chunk at the time. */
for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
ptrace (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr,
*(PTRACE_XFER_TYPE *) (buf + i));
regaddr += sizeof (PTRACE_XFER_TYPE);
if (errno != 0)
{
sprintf (mess, "writing register %s (#%d)",
REGISTER_NAME (regno), regno);
perror_with_name (mess);
}
}
}
/* 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). */
void
old_store_inferior_registers (int regno)
{
if (regno >= 0)
{
store_register (regno);
}
else
{
for (regno = 0; regno < NUM_REGS; regno++)
{
store_register (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. */
/* Note both m68k-tdep.c and m68klinux-nat.c contain definitions
for supply_gregset and supply_fpregset. The definitions
in m68k-tdep.c are valid if USE_PROC_FS is defined. Otherwise,
the definitions in m68klinux-nat.c will be used. This is a
bit of a hack. The supply_* routines do not belong in
*_tdep.c files. But, there are several lynx ports that currently
depend on these definitions. */
#ifndef USE_PROC_FS
/* Prototypes for supply_gregset etc. */
#include "gregset.h"
void
supply_gregset (elf_gregset_t *gregsetp)
{
elf_greg_t *regp = (elf_greg_t *) gregsetp;
int regi;
for (regi = D0_REGNUM; regi <= SP_REGNUM; regi++)
supply_register (regi, (char *) &regp[regmap[regi]]);
supply_register (PS_REGNUM, (char *) &regp[PT_SR]);
supply_register (PC_REGNUM, (char *) &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 (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_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 (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 (&regs);
}
/* Store all valid general-purpose registers in GDB's register array
into the process/thread specified by TID. */
static void
store_regs (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 (&regs, regno);
if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
perror_with_name ("Couldn't write registers");
}
#else
static void fetch_regs (int tid) {}
static void store_regs (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) ((char *) &(f)->fpregs[(n) * 3])
/* Fill GDB's register array with the floating-point register values in
*FPREGSETP. */
void
supply_fpregset (elf_fpregset_t *fpregsetp)
{
int regi;
for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++)
supply_register (regi, FPREG_ADDR (fpregsetp, regi - FP0_REGNUM));
supply_register (FPC_REGNUM, (char *) &fpregsetp->fpcntl[0]);
supply_register (FPS_REGNUM, (char *) &fpregsetp->fpcntl[1]);
supply_register (FPI_REGNUM, (char *) &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 (elf_fpregset_t *fpregsetp, int regno)
{
int i;
/* Fill in the floating-point registers. */
for (i = FP0_REGNUM; i < FP0_REGNUM + 8; i++)
if (regno == -1 || regno == i)
regcache_collect (regno, FPREG_ADDR (fpregsetp, regno - FP0_REGNUM));
/* Fill in the floating-point control registers. */
for (i = FPC_REGNUM; i <= FPI_REGNUM; i++)
if (regno == -1 || regno == i)
regcache_collect (regno, (char *) &fpregsetp->fpcntl[regno - 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 (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 (&fpregs);
}
/* Store all valid floating-point registers in GDB's register array
into the process/thread specified by TID. */
static void
store_fpregs (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 (&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 (int tid) {}
static void store_fpregs (int tid, int regno) {}
#endif
#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
fetch_inferior_registers (int regno)
{
int 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 (regno);
return;
}
/* GNU/Linux LWP ID's are process ID's. */
if ((tid = TIDGET (inferior_ptid)) == 0)
tid = PIDGET (inferior_ptid); /* Not a threaded program. */
/* 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 (tid);
/* The call above might reset `have_ptrace_getregs'. */
if (! have_ptrace_getregs)
{
old_fetch_inferior_registers (-1);
return;
}
fetch_fpregs (tid);
return;
}
if (getregs_supplies (regno))
{
fetch_regs (tid);
return;
}
if (getfpregs_supplies (regno))
{
fetch_fpregs (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
store_inferior_registers (int regno)
{
int 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 (regno);
return;
}
/* GNU/Linux LWP ID's are process ID's. */
if ((tid = TIDGET (inferior_ptid)) == 0)
tid = PIDGET (inferior_ptid); /* Not a threaded program. */
/* 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 (tid, regno);
store_fpregs (tid, regno);
return;
}
if (getregs_supplies (regno))
{
store_regs (tid, regno);
return;
}
if (getfpregs_supplies (regno))
{
store_fpregs (tid, regno);
return;
}
internal_error (__FILE__, __LINE__,
"Got request to store bad register number %d.", regno);
}
/* Interpreting register set info found in core files. */
/* Provide registers to GDB from a core file.
(We can't use the generic version of this function in
core-regset.c, because we need to use elf_gregset_t instead of
gregset_t.)
CORE_REG_SECT points to an array of bytes, which are the contents
of a `note' from a core file which BFD thinks might contain
register contents. CORE_REG_SIZE is its size.
WHICH says which register set corelow suspects this is:
0 --- the general-purpose register set, in elf_gregset_t format
2 --- the floating-point register set, in elf_fpregset_t format
REG_ADDR isn't used on GNU/Linux. */
static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
int which, CORE_ADDR reg_addr)
{
elf_gregset_t gregset;
elf_fpregset_t fpregset;
switch (which)
{
case 0:
if (core_reg_size != sizeof (gregset))
warning ("Wrong size gregset in core file.");
else
{
memcpy (&gregset, core_reg_sect, sizeof (gregset));
supply_gregset (&gregset);
}
break;
case 2:
if (core_reg_size != sizeof (fpregset))
warning ("Wrong size fpregset in core file.");
else
{
memcpy (&fpregset, core_reg_sect, sizeof (fpregset));
supply_fpregset (&fpregset);
}
break;
default:
/* We've covered all the kinds of registers we know about here,
so this must be something we wouldn't know what to do with
anyway. Just ignore it. */
break;
}
}
int
kernel_u_size (void)
{
return (sizeof (struct user));
}
/* Check whether insn1 and insn2 are parts of a signal trampoline. */
#define IS_SIGTRAMP(insn1, insn2) \
(/* addaw #20,sp; moveq #119,d0; trap #0 */ \
(insn1 == 0xdefc0014 && insn2 == 0x70774e40) \
/* moveq #119,d0; trap #0 */ \
|| insn1 == 0x70774e40)
#define IS_RT_SIGTRAMP(insn1, insn2) \
(/* movel #173,d0; trap #0 */ \
(insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \
/* moveq #82,d0; notb d0; trap #0 */ \
|| (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40))
/* Return non-zero if PC points into the signal trampoline. For the sake
of m68k_linux_frame_saved_pc we also distinguish between non-RT and RT
signal trampolines. */
int
m68k_linux_in_sigtramp (CORE_ADDR pc)
{
CORE_ADDR sp;
char buf[12];
unsigned long insn0, insn1, insn2;
if (read_memory_nobpt (pc - 4, buf, sizeof (buf)))
return 0;
insn1 = extract_unsigned_integer (buf + 4, 4);
insn2 = extract_unsigned_integer (buf + 8, 4);
if (IS_SIGTRAMP (insn1, insn2))
return 1;
if (IS_RT_SIGTRAMP (insn1, insn2))
return 2;
insn0 = extract_unsigned_integer (buf, 4);
if (IS_SIGTRAMP (insn0, insn1))
return 1;
if (IS_RT_SIGTRAMP (insn0, insn1))
return 2;
insn0 = (insn0 << 16) | (insn1 >> 16);
insn1 = (insn1 << 16) | (insn2 >> 16);
if (IS_SIGTRAMP (insn0, insn1))
return 1;
if (IS_RT_SIGTRAMP (insn0, insn1))
return 2;
return 0;
}
/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
#define SIGCONTEXT_PC_OFFSET 26
/* Offset to saved PC in ucontext, from <asm/ucontext.h>. */
#define UCONTEXT_PC_OFFSET 88
/* Get saved user PC for sigtramp from sigcontext or ucontext. */
static CORE_ADDR
m68k_linux_sigtramp_saved_pc (struct frame_info *frame)
{
CORE_ADDR sigcontext_addr;
char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
/* Get sigcontext address, it is the third parameter on the stack. */
if (frame->next)
sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
+ FRAME_ARGS_SKIP
+ sigcontext_offs,
ptrbytes);
else
sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
+ sigcontext_offs,
ptrbytes);
/* Don't cause a memory_error when accessing sigcontext in case the
stack layout has changed or the stack is corrupt. */
if (m68k_linux_in_sigtramp (frame->pc) == 2)
target_read_memory (sigcontext_addr + UCONTEXT_PC_OFFSET, buf, ptrbytes);
else
target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
return extract_unsigned_integer (buf, ptrbytes);
}
/* Return the saved program counter for FRAME. */
CORE_ADDR
m68k_linux_frame_saved_pc (struct frame_info *frame)
{
if (frame->signal_handler_caller)
return m68k_linux_sigtramp_saved_pc (frame);
return read_memory_integer (frame->frame + 4, 4);
}
/* Register that we are able to handle GNU/Linux ELF core file
formats. */
static struct core_fns linux_elf_core_fns =
{
bfd_target_elf_flavour, /* core_flavour */
default_check_format, /* check_format */
default_core_sniffer, /* core_sniffer */
fetch_core_registers, /* core_read_registers */
NULL /* next */
};
void
_initialize_m68k_linux_nat (void)
{
add_core_fns (&linux_elf_core_fns);
}