908 lines
24 KiB
C
908 lines
24 KiB
C
/* Native-dependent code for Linux/x86.
|
||
Copyright 1999, 2000 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 "inferior.h"
|
||
#include "gdbcore.h"
|
||
|
||
/* For i386_linux_skip_solib_resolver. */
|
||
#include "symtab.h"
|
||
#include "symfile.h"
|
||
#include "objfiles.h"
|
||
|
||
#include <sys/ptrace.h>
|
||
#include <sys/user.h>
|
||
#include <sys/procfs.h>
|
||
|
||
#ifdef HAVE_SYS_REG_H
|
||
#include <sys/reg.h>
|
||
#endif
|
||
|
||
/* Prototypes for supply_gregset etc. */
|
||
#include "gregset.h"
|
||
|
||
/* Prototypes for i387_supply_fsave etc. */
|
||
#include "i387-nat.h"
|
||
|
||
/* Prototypes for local functions. */
|
||
static void dummy_sse_values (void);
|
||
|
||
/* On Linux, threads are implemented as pseudo-processes, in which
|
||
case we may be tracing more than one process at a time. In that
|
||
case, inferior_pid will contain the main process ID and the
|
||
individual thread (process) ID mashed together. These macros are
|
||
used to separate them out. These definitions should be overridden
|
||
if thread support is included. */
|
||
|
||
#if !defined (PIDGET) /* Default definition for PIDGET/TIDGET. */
|
||
#define PIDGET(PID) PID
|
||
#define TIDGET(PID) 0
|
||
#endif
|
||
|
||
|
||
/* The register sets used in Linux ELF core-dumps are identical to the
|
||
register sets in `struct user' that is used for a.out core-dumps,
|
||
and is also used by `ptrace'. The corresponding types are
|
||
`elf_gregset_t' for the general-purpose registers (with
|
||
`elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
|
||
for the floating-point registers.
|
||
|
||
Those types used to be available under the names `gregset_t' and
|
||
`fpregset_t' too, and this file used those names in the past. But
|
||
those names are now used for the register sets used in the
|
||
`mcontext_t' type, and have a different size and layout. */
|
||
|
||
/* Mapping between the general-purpose registers in `struct user'
|
||
format and GDB's register array layout. */
|
||
static int regmap[] =
|
||
{
|
||
EAX, ECX, EDX, EBX,
|
||
UESP, EBP, ESI, EDI,
|
||
EIP, EFL, CS, SS,
|
||
DS, ES, FS, GS
|
||
};
|
||
|
||
/* Which ptrace request retrieves which registers?
|
||
These apply to the corresponding SET requests as well. */
|
||
#define GETREGS_SUPPLIES(regno) \
|
||
(0 <= (regno) && (regno) <= 15)
|
||
#define GETFPREGS_SUPPLIES(regno) \
|
||
(FP0_REGNUM <= (regno) && (regno) <= LAST_FPU_CTRL_REGNUM)
|
||
#define GETFPXREGS_SUPPLIES(regno) \
|
||
(FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM)
|
||
|
||
/* Does the current host support the GETREGS request? */
|
||
int have_ptrace_getregs =
|
||
#ifdef HAVE_PTRACE_GETREGS
|
||
1
|
||
#else
|
||
0
|
||
#endif
|
||
;
|
||
|
||
/* Does the current host support the GETFPXREGS request? The header
|
||
file may or may not define it, and even if it is defined, the
|
||
kernel will return EIO if it's running on a pre-SSE processor.
|
||
|
||
My instinct is to attach this to some architecture- or
|
||
target-specific data structure, but really, a particular GDB
|
||
process can only run on top of one kernel at a time. So it's okay
|
||
for this to be a simple variable. */
|
||
int have_ptrace_getfpxregs =
|
||
#ifdef HAVE_PTRACE_GETFPXREGS
|
||
1
|
||
#else
|
||
0
|
||
#endif
|
||
;
|
||
|
||
|
||
/* Fetching registers directly from the U area, one at a time. */
|
||
|
||
/* FIXME: kettenis/2000-03-05: 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. I want to avoid changing `infptrace.c' right
|
||
now. */
|
||
|
||
#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
|
||
|
||
/* Registers we shouldn't try to fetch. */
|
||
#if !defined (CANNOT_FETCH_REGISTER)
|
||
#define CANNOT_FETCH_REGISTER(regno) 0
|
||
#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_pid)) == 0)
|
||
tid = inferior_pid; /* 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 < ARCH_NUM_REGS; regno++)
|
||
{
|
||
fetch_register (regno);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Registers we shouldn't try to store. */
|
||
#if !defined (CANNOT_STORE_REGISTER)
|
||
#define CANNOT_STORE_REGISTER(regno) 0
|
||
#endif
|
||
|
||
/* 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;
|
||
|
||
if (CANNOT_STORE_REGISTER (regno))
|
||
{
|
||
return;
|
||
}
|
||
|
||
/* Overload thread id onto process id */
|
||
if ((tid = TIDGET (inferior_pid)) == 0)
|
||
tid = inferior_pid; /* 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 (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr,
|
||
*(PTRACE_XFER_TYPE *) & registers[REGISTER_BYTE (regno) + 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 < ARCH_NUM_REGS; regno++)
|
||
{
|
||
store_register (regno);
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
/* Transfering the general-purpose registers between GDB, inferiors
|
||
and core files. */
|
||
|
||
/* Fill GDB's register array with the genereal-purpose register values
|
||
in *GREGSETP. */
|
||
|
||
void
|
||
supply_gregset (elf_gregset_t *gregsetp)
|
||
{
|
||
elf_greg_t *regp = (elf_greg_t *) gregsetp;
|
||
int i;
|
||
|
||
for (i = 0; i < NUM_GREGS; i++)
|
||
supply_register (i, (char *) (regp + regmap[i]));
|
||
}
|
||
|
||
/* 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))
|
||
*(regp + regmap[i]) = *(elf_greg_t *) ®isters[REGISTER_BYTE (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) ®s) < 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 (®s);
|
||
}
|
||
|
||
/* 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) ®s) < 0)
|
||
perror_with_name ("Couldn't get registers");
|
||
|
||
fill_gregset (®s, regno);
|
||
|
||
if (ptrace (PTRACE_SETREGS, tid, 0, (int) ®s) < 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. */
|
||
|
||
/* Fill GDB's register array with the floating-point register values in
|
||
*FPREGSETP. */
|
||
|
||
void
|
||
supply_fpregset (elf_fpregset_t *fpregsetp)
|
||
{
|
||
i387_supply_fsave ((char *) fpregsetp);
|
||
dummy_sse_values ();
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
i387_fill_fsave ((char *) fpregsetp, regno);
|
||
}
|
||
|
||
#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
|
||
|
||
|
||
/* Transfering floating-point and SSE registers to and from GDB. */
|
||
|
||
#ifdef HAVE_PTRACE_GETFPXREGS
|
||
|
||
/* Fill GDB's register array with the floating-point and SSE register
|
||
values in *FPXREGSETP. */
|
||
|
||
static void
|
||
supply_fpxregset (elf_fpxregset_t *fpxregsetp)
|
||
{
|
||
i387_supply_fxsave ((char *) fpxregsetp);
|
||
}
|
||
|
||
/* Fill register REGNO (if it is a floating-point or SSE register) in
|
||
*FPXREGSETP with the value in GDB's register array. If REGNO is
|
||
-1, do this for all registers. */
|
||
|
||
static void
|
||
fill_fpxregset (elf_fpxregset_t *fpxregsetp, int regno)
|
||
{
|
||
i387_fill_fxsave ((char *) fpxregsetp, regno);
|
||
}
|
||
|
||
/* Fetch all registers covered by the PTRACE_GETFPXREGS request from
|
||
process/thread TID and store their values in GDB's register array.
|
||
Return non-zero if successful, zero otherwise. */
|
||
|
||
static int
|
||
fetch_fpxregs (int tid)
|
||
{
|
||
elf_fpxregset_t fpxregs;
|
||
|
||
if (! have_ptrace_getfpxregs)
|
||
return 0;
|
||
|
||
if (ptrace (PTRACE_GETFPXREGS, tid, 0, (int) &fpxregs) < 0)
|
||
{
|
||
if (errno == EIO)
|
||
{
|
||
have_ptrace_getfpxregs = 0;
|
||
return 0;
|
||
}
|
||
|
||
perror_with_name ("Couldn't read floating-point and SSE registers");
|
||
}
|
||
|
||
supply_fpxregset (&fpxregs);
|
||
return 1;
|
||
}
|
||
|
||
/* Store all valid registers in GDB's register array covered by the
|
||
PTRACE_SETFPXREGS request into the process/thread specified by TID.
|
||
Return non-zero if successful, zero otherwise. */
|
||
|
||
static int
|
||
store_fpxregs (int tid, int regno)
|
||
{
|
||
elf_fpxregset_t fpxregs;
|
||
|
||
if (! have_ptrace_getfpxregs)
|
||
return 0;
|
||
|
||
if (ptrace (PTRACE_GETFPXREGS, tid, 0, &fpxregs) == -1)
|
||
perror_with_name ("Couldn't read floating-point and SSE registers");
|
||
|
||
fill_fpxregset (&fpxregs, regno);
|
||
|
||
if (ptrace (PTRACE_SETFPXREGS, tid, 0, &fpxregs) == -1)
|
||
perror_with_name ("Couldn't write floating-point and SSE registers");
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Fill the XMM registers in the register array with dummy values. For
|
||
cases where we don't have access to the XMM registers. I think
|
||
this is cleaner than printing a warning. For a cleaner solution,
|
||
we should gdbarchify the i386 family. */
|
||
|
||
static void
|
||
dummy_sse_values (void)
|
||
{
|
||
/* C doesn't have a syntax for NaN's, so write it out as an array of
|
||
longs. */
|
||
static long dummy[4] = { 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff };
|
||
static long mxcsr = 0x1f80;
|
||
int reg;
|
||
|
||
for (reg = 0; reg < 8; reg++)
|
||
supply_register (XMM0_REGNUM + reg, (char *) dummy);
|
||
supply_register (MXCSR_REGNUM, (char *) &mxcsr);
|
||
}
|
||
|
||
#else
|
||
|
||
static int fetch_fpxregs (int tid) { return 0; }
|
||
static int store_fpxregs (int tid, int regno) { return 0; }
|
||
static void dummy_sse_values (void) {}
|
||
|
||
#endif /* HAVE_PTRACE_GETFPXREGS */
|
||
|
||
|
||
/* 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;
|
||
}
|
||
|
||
/* Linux LWP ID's are process ID's. */
|
||
if ((tid = TIDGET (inferior_pid)) == 0)
|
||
tid = inferior_pid; /* 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;
|
||
}
|
||
|
||
if (fetch_fpxregs (tid))
|
||
return;
|
||
fetch_fpregs (tid);
|
||
return;
|
||
}
|
||
|
||
if (GETREGS_SUPPLIES (regno))
|
||
{
|
||
fetch_regs (tid);
|
||
return;
|
||
}
|
||
|
||
if (GETFPXREGS_SUPPLIES (regno))
|
||
{
|
||
if (fetch_fpxregs (tid))
|
||
return;
|
||
|
||
/* Either our processor or our kernel doesn't support the SSE
|
||
registers, so read the FP registers in the traditional way,
|
||
and fill the SSE registers with dummy values. It would be
|
||
more graceful to handle differences in the register set using
|
||
gdbarch. Until then, this will at least make things work
|
||
plausibly. */
|
||
fetch_fpregs (tid);
|
||
return;
|
||
}
|
||
|
||
internal_error ("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;
|
||
}
|
||
|
||
/* Linux LWP ID's are process ID's. */
|
||
if ((tid = TIDGET (inferior_pid)) == 0)
|
||
tid = inferior_pid; /* Not a threaded program. */
|
||
|
||
/* Use the PTRACE_SETFPXREGS requests whenever possible, since it
|
||
transfers more registers in one system call. But remember that
|
||
store_fpxregs can fail, and return zero. */
|
||
if (regno == -1)
|
||
{
|
||
store_regs (tid, regno);
|
||
if (store_fpxregs (tid, regno))
|
||
return;
|
||
store_fpregs (tid, regno);
|
||
return;
|
||
}
|
||
|
||
if (GETREGS_SUPPLIES (regno))
|
||
{
|
||
store_regs (tid, regno);
|
||
return;
|
||
}
|
||
|
||
if (GETFPXREGS_SUPPLIES (regno))
|
||
{
|
||
if (store_fpxregs (tid, regno))
|
||
return;
|
||
|
||
/* Either our processor or our kernel doesn't support the SSE
|
||
registers, so just write the FP registers in the traditional
|
||
way. */
|
||
store_fpregs (tid, regno);
|
||
return;
|
||
}
|
||
|
||
internal_error ("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 Linux has *three* different kinds of
|
||
register set notes. core-regset.c would have to call
|
||
supply_fpxregset, which most platforms don't have.)
|
||
|
||
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
|
||
3 --- the extended floating-point register set, in elf_fpxregset_t format
|
||
|
||
REG_ADDR isn't used on 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;
|
||
|
||
#ifdef HAVE_PTRACE_GETFPXREGS
|
||
{
|
||
elf_fpxregset_t fpxregset;
|
||
|
||
case 3:
|
||
if (core_reg_size != sizeof (fpxregset))
|
||
warning ("Wrong size fpxregset in core file.");
|
||
else
|
||
{
|
||
memcpy (&fpxregset, core_reg_sect, sizeof (fpxregset));
|
||
supply_fpxregset (&fpxregset);
|
||
}
|
||
break;
|
||
}
|
||
#endif
|
||
|
||
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;
|
||
}
|
||
}
|
||
|
||
|
||
/* The instruction for a Linux system call is:
|
||
int $0x80
|
||
or 0xcd 0x80. */
|
||
|
||
static const unsigned char linux_syscall[] = { 0xcd, 0x80 };
|
||
|
||
#define LINUX_SYSCALL_LEN (sizeof linux_syscall)
|
||
|
||
/* The system call number is stored in the %eax register. */
|
||
#define LINUX_SYSCALL_REGNUM 0 /* %eax */
|
||
|
||
/* We are specifically interested in the sigreturn and rt_sigreturn
|
||
system calls. */
|
||
|
||
#ifndef SYS_sigreturn
|
||
#define SYS_sigreturn 0x77
|
||
#endif
|
||
#ifndef SYS_rt_sigreturn
|
||
#define SYS_rt_sigreturn 0xad
|
||
#endif
|
||
|
||
/* Offset to saved processor flags, from <asm/sigcontext.h>. */
|
||
#define LINUX_SIGCONTEXT_EFLAGS_OFFSET (64)
|
||
|
||
/* Resume execution of the inferior process.
|
||
If STEP is nonzero, single-step it.
|
||
If SIGNAL is nonzero, give it that signal. */
|
||
|
||
void
|
||
child_resume (int pid, int step, enum target_signal signal)
|
||
{
|
||
int request = PTRACE_CONT;
|
||
|
||
if (pid == -1)
|
||
/* Resume all threads. */
|
||
/* I think this only gets used in the non-threaded case, where "resume
|
||
all threads" and "resume inferior_pid" are the same. */
|
||
pid = inferior_pid;
|
||
|
||
if (step)
|
||
{
|
||
CORE_ADDR pc = read_pc_pid (pid);
|
||
unsigned char buf[LINUX_SYSCALL_LEN];
|
||
|
||
request = PTRACE_SINGLESTEP;
|
||
|
||
/* Returning from a signal trampoline is done by calling a
|
||
special system call (sigreturn or rt_sigreturn, see
|
||
i386-linux-tdep.c for more information). This system call
|
||
restores the registers that were saved when the signal was
|
||
raised, including %eflags. That means that single-stepping
|
||
won't work. Instead, we'll have to modify the signal context
|
||
that's about to be restored, and set the trace flag there. */
|
||
|
||
/* First check if PC is at a system call. */
|
||
if (read_memory_nobpt (pc, (char *) buf, LINUX_SYSCALL_LEN) == 0
|
||
&& memcmp (buf, linux_syscall, LINUX_SYSCALL_LEN) == 0)
|
||
{
|
||
int syscall = read_register_pid (LINUX_SYSCALL_REGNUM, pid);
|
||
|
||
/* Then check the system call number. */
|
||
if (syscall == SYS_sigreturn || syscall == SYS_rt_sigreturn)
|
||
{
|
||
CORE_ADDR sp = read_register (SP_REGNUM);
|
||
CORE_ADDR addr = sp;
|
||
unsigned long int eflags;
|
||
|
||
if (syscall == SYS_rt_sigreturn)
|
||
addr = read_memory_integer (sp + 8, 4) + 20;
|
||
|
||
/* Set the trace flag in the context that's about to be
|
||
restored. */
|
||
addr += LINUX_SIGCONTEXT_EFLAGS_OFFSET;
|
||
read_memory (addr, (char *) &eflags, 4);
|
||
eflags |= 0x0100;
|
||
write_memory (addr, (char *) &eflags, 4);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (ptrace (request, pid, 0, target_signal_to_host (signal)) == -1)
|
||
perror_with_name ("ptrace");
|
||
}
|
||
|
||
|
||
/* Calling functions in shared libraries. */
|
||
/* FIXME: kettenis/2000-03-05: Doesn't this belong in a
|
||
target-dependent file? The function
|
||
`i386_linux_skip_solib_resolver' is mentioned in
|
||
`config/i386/tm-linux.h'. */
|
||
|
||
/* Find the minimal symbol named NAME, and return both the minsym
|
||
struct and its objfile. This probably ought to be in minsym.c, but
|
||
everything there is trying to deal with things like C++ and
|
||
SOFUN_ADDRESS_MAYBE_TURQUOISE, ... Since this is so simple, it may
|
||
be considered too special-purpose for general consumption. */
|
||
|
||
static struct minimal_symbol *
|
||
find_minsym_and_objfile (char *name, struct objfile **objfile_p)
|
||
{
|
||
struct objfile *objfile;
|
||
|
||
ALL_OBJFILES (objfile)
|
||
{
|
||
struct minimal_symbol *msym;
|
||
|
||
ALL_OBJFILE_MSYMBOLS (objfile, msym)
|
||
{
|
||
if (SYMBOL_NAME (msym)
|
||
&& STREQ (SYMBOL_NAME (msym), name))
|
||
{
|
||
*objfile_p = objfile;
|
||
return msym;
|
||
}
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
skip_hurd_resolver (CORE_ADDR pc)
|
||
{
|
||
/* The HURD dynamic linker is part of the GNU C library, so many
|
||
GNU/Linux distributions use it. (All ELF versions, as far as I
|
||
know.) An unresolved PLT entry points to "_dl_runtime_resolve",
|
||
which calls "fixup" to patch the PLT, and then passes control to
|
||
the function.
|
||
|
||
We look for the symbol `_dl_runtime_resolve', and find `fixup' in
|
||
the same objfile. If we are at the entry point of `fixup', then
|
||
we set a breakpoint at the return address (at the top of the
|
||
stack), and continue.
|
||
|
||
It's kind of gross to do all these checks every time we're
|
||
called, since they don't change once the executable has gotten
|
||
started. But this is only a temporary hack --- upcoming versions
|
||
of Linux will provide a portable, efficient interface for
|
||
debugging programs that use shared libraries. */
|
||
|
||
struct objfile *objfile;
|
||
struct minimal_symbol *resolver
|
||
= find_minsym_and_objfile ("_dl_runtime_resolve", &objfile);
|
||
|
||
if (resolver)
|
||
{
|
||
struct minimal_symbol *fixup
|
||
= lookup_minimal_symbol ("fixup", 0, objfile);
|
||
|
||
if (fixup && SYMBOL_VALUE_ADDRESS (fixup) == pc)
|
||
return (SAVED_PC_AFTER_CALL (get_current_frame ()));
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c.
|
||
This function:
|
||
1) decides whether a PLT has sent us into the linker to resolve
|
||
a function reference, and
|
||
2) if so, tells us where to set a temporary breakpoint that will
|
||
trigger when the dynamic linker is done. */
|
||
|
||
CORE_ADDR
|
||
i386_linux_skip_solib_resolver (CORE_ADDR pc)
|
||
{
|
||
CORE_ADDR result;
|
||
|
||
/* Plug in functions for other kinds of resolvers here. */
|
||
result = skip_hurd_resolver (pc);
|
||
if (result)
|
||
return result;
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Register that we are able to handle 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_i386_linux_nat (void)
|
||
{
|
||
add_core_fns (&linux_elf_core_fns);
|
||
}
|