1154 lines
31 KiB
C
1154 lines
31 KiB
C
/* Native-dependent code for Linux running on i386's, for GDB.
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Copyright (C) 1999, 2000 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "inferior.h"
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#include "gdbcore.h"
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/* For i386_linux_skip_solib_resolver. */
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#include "symtab.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include <sys/ptrace.h>
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#include <sys/user.h>
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#include <sys/procfs.h>
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#ifdef HAVE_SYS_REG_H
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#include <sys/reg.h>
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#endif
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/* Prototypes for supply_gregset etc. */
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#include "gregset.h"
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/* On Linux, threads are implemented as pseudo-processes, in which
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case we may be tracing more than one process at a time. In that
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case, inferior_pid will contain the main process ID and the
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individual thread (process) ID mashed together. These macros are
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used to separate them out. These definitions should be overridden
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if thread support is included. */
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#if !defined (PIDGET) /* Default definition for PIDGET/TIDGET. */
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#define PIDGET(PID) PID
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#define TIDGET(PID) 0
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#endif
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/* The register sets used in Linux ELF core-dumps are identical to the
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register sets in `struct user' that is used for a.out core-dumps,
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and is also used by `ptrace'. The corresponding types are
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`elf_gregset_t' for the general-purpose registers (with
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`elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
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for the floating-point registers.
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Those types used to be available under the names `gregset_t' and
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`fpregset_t' too, and this file used those names in the past. But
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those names are now used for the register sets used in the
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`mcontext_t' type, and have a different size and layout. */
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/* Mapping between the general-purpose registers in `struct user'
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format and GDB's register array layout. */
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static int regmap[] =
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{
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EAX, ECX, EDX, EBX,
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UESP, EBP, ESI, EDI,
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EIP, EFL, CS, SS,
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DS, ES, FS, GS
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};
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/* Which ptrace request retrieves which registers?
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These apply to the corresponding SET requests as well. */
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#define GETREGS_SUPPLIES(regno) \
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(0 <= (regno) && (regno) <= 15)
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#define GETFPREGS_SUPPLIES(regno) \
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(FP0_REGNUM <= (regno) && (regno) <= LAST_FPU_CTRL_REGNUM)
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#define GETXFPREGS_SUPPLIES(regno) \
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(FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM)
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/* Does the current host support the GETREGS request? */
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int have_ptrace_getregs =
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#ifdef HAVE_PTRACE_GETREGS
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1
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#else
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0
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#endif
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;
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/* Does the current host support the GETXFPREGS request? The header
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file may or may not define it, and even if it is defined, the
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kernel will return EIO if it's running on a pre-SSE processor.
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PTRACE_GETXFPREGS is a Cygnus invention, since we wrote our own
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Linux kernel patch for SSE support. That patch may or may not
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actually make it into the official distribution. If you find that
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years have gone by since this stuff was added, and Linux isn't
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using PTRACE_GETXFPREGS, that means that our patch didn't make it,
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and you can delete this, and the related code.
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My instinct is to attach this to some architecture- or
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target-specific data structure, but really, a particular GDB
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process can only run on top of one kernel at a time. So it's okay
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for this to be a simple variable. */
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int have_ptrace_getxfpregs =
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#ifdef HAVE_PTRACE_GETXFPREGS
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1
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#else
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0
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#endif
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;
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/* Fetching registers directly from the U area, one at a time. */
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/* FIXME: kettenis/2000-03-05: This duplicates code from `inptrace.c'.
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The problem is that we define FETCH_INFERIOR_REGISTERS since we
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want to use our own versions of {fetch,store}_inferior_registers
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that use the GETREGS request. This means that the code in
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`infptrace.c' is #ifdef'd out. But we need to fall back on that
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code when GDB is running on top of a kernel that doesn't support
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the GETREGS request. I want to avoid changing `infptrace.c' right
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now. */
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#ifndef PT_READ_U
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#define PT_READ_U PTRACE_PEEKUSR
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#endif
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#ifndef PT_WRITE_U
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#define PT_WRITE_U PTRACE_POKEUSR
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#endif
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/* Default the type of the ptrace transfer to int. */
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#ifndef PTRACE_XFER_TYPE
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#define PTRACE_XFER_TYPE int
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#endif
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/* Registers we shouldn't try to fetch. */
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#if !defined (CANNOT_FETCH_REGISTER)
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#define CANNOT_FETCH_REGISTER(regno) 0
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#endif
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/* Fetch one register. */
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static void
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fetch_register (int regno)
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{
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/* This isn't really an address. But ptrace thinks of it as one. */
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CORE_ADDR regaddr;
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char mess[128]; /* For messages */
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register int i;
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unsigned int offset; /* Offset of registers within the u area. */
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char buf[MAX_REGISTER_RAW_SIZE];
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int tid;
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if (CANNOT_FETCH_REGISTER (regno))
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{
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memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */
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supply_register (regno, buf);
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return;
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}
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/* Overload thread id onto process id */
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if ((tid = TIDGET (inferior_pid)) == 0)
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tid = inferior_pid; /* no thread id, just use process id */
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offset = U_REGS_OFFSET;
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regaddr = register_addr (regno, offset);
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))
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{
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errno = 0;
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*(PTRACE_XFER_TYPE *) & buf[i] = ptrace (PT_READ_U, tid,
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(PTRACE_ARG3_TYPE) regaddr, 0);
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regaddr += sizeof (PTRACE_XFER_TYPE);
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if (errno != 0)
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{
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sprintf (mess, "reading register %s (#%d)",
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REGISTER_NAME (regno), regno);
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perror_with_name (mess);
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}
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}
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supply_register (regno, buf);
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}
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/* Fetch register values from the inferior.
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If REGNO is negative, do this for all registers.
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Otherwise, REGNO specifies which register (so we can save time). */
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void
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old_fetch_inferior_registers (int regno)
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{
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if (regno >= 0)
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{
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fetch_register (regno);
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}
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else
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{
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for (regno = 0; regno < ARCH_NUM_REGS; regno++)
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{
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fetch_register (regno);
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}
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}
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}
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/* Registers we shouldn't try to store. */
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#if !defined (CANNOT_STORE_REGISTER)
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#define CANNOT_STORE_REGISTER(regno) 0
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#endif
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/* Store one register. */
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static void
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store_register (int regno)
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{
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/* This isn't really an address. But ptrace thinks of it as one. */
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CORE_ADDR regaddr;
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char mess[128]; /* For messages */
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register int i;
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unsigned int offset; /* Offset of registers within the u area. */
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int tid;
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if (CANNOT_STORE_REGISTER (regno))
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{
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return;
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}
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/* Overload thread id onto process id */
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if ((tid = TIDGET (inferior_pid)) == 0)
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tid = inferior_pid; /* no thread id, just use process id */
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offset = U_REGS_OFFSET;
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regaddr = register_addr (regno, offset);
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for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))
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{
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errno = 0;
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ptrace (PT_WRITE_U, tid, (PTRACE_ARG3_TYPE) regaddr,
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*(PTRACE_XFER_TYPE *) & registers[REGISTER_BYTE (regno) + i]);
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regaddr += sizeof (PTRACE_XFER_TYPE);
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if (errno != 0)
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{
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sprintf (mess, "writing register %s (#%d)",
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REGISTER_NAME (regno), regno);
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perror_with_name (mess);
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}
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}
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}
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/* Store our register values back into the inferior.
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If REGNO is negative, do this for all registers.
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Otherwise, REGNO specifies which register (so we can save time). */
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void
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old_store_inferior_registers (int regno)
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{
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if (regno >= 0)
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{
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store_register (regno);
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}
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else
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{
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for (regno = 0; regno < ARCH_NUM_REGS; regno++)
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{
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store_register (regno);
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}
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}
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}
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/* Transfering the general-purpose registers between GDB, inferiors
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and core files. */
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/* Fill GDB's register array with the genereal-purpose register values
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in *GREGSETP. */
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void
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supply_gregset (elf_gregset_t *gregsetp)
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{
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elf_greg_t *regp = (elf_greg_t *) gregsetp;
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int regi;
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for (regi = 0; regi < NUM_GREGS; regi++)
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supply_register (regi, (char *) (regp + regmap[regi]));
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}
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/* Convert the valid general-purpose register values in GDB's register
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array to `struct user' format and store them in *GREGSETP. The
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array VALID indicates which register values are valid. If VALID is
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NULL, all registers are assumed to be valid. */
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static void
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convert_to_gregset (elf_gregset_t *gregsetp, signed char *valid)
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{
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elf_greg_t *regp = (elf_greg_t *) gregsetp;
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int regi;
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for (regi = 0; regi < NUM_GREGS; regi++)
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if (! valid || valid[regi])
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*(regp + regmap[regi]) = * (int *) ®isters[REGISTER_BYTE (regi)];
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}
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/* Fill register REGNO (if it is a general-purpose register) in
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*GREGSETPS with the value in GDB's register array. If REGNO is -1,
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do this for all registers. */
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void
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fill_gregset (elf_gregset_t *gregsetp, int regno)
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{
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if (regno == -1)
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{
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convert_to_gregset (gregsetp, NULL);
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return;
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}
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if (GETREGS_SUPPLIES (regno))
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{
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signed char valid[NUM_GREGS];
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memset (valid, 0, sizeof (valid));
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valid[regno] = 1;
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convert_to_gregset (gregsetp, valid);
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}
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}
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#ifdef HAVE_PTRACE_GETREGS
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/* Fetch all general-purpose registers from process/thread TID and
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store their values in GDB's register array. */
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static void
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fetch_regs (int tid)
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{
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elf_gregset_t regs;
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int ret;
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ret = ptrace (PTRACE_GETREGS, tid, 0, (int) ®s);
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if (ret < 0)
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{
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if (errno == EIO)
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{
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/* The kernel we're running on doesn't support the GETREGS
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request. Reset `have_ptrace_getregs'. */
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have_ptrace_getregs = 0;
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return;
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}
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warning ("Couldn't get registers.");
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return;
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}
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supply_gregset (®s);
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}
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/* Store all valid general-purpose registers in GDB's register array
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into the process/thread specified by TID. */
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static void
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store_regs (int tid)
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{
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elf_gregset_t regs;
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int ret;
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ret = ptrace (PTRACE_GETREGS, tid, 0, (int) ®s);
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if (ret < 0)
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{
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warning ("Couldn't get registers.");
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return;
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}
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convert_to_gregset (®s, register_valid);
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ret = ptrace (PTRACE_SETREGS, tid, 0, (int) ®s);
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if (ret < 0)
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{
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warning ("Couldn't write registers.");
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return;
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}
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}
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#else
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static void fetch_regs (int tid) {}
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static void store_regs (int tid) {}
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#endif
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/* Transfering floating-point registers between GDB, inferiors and cores. */
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/* What is the address of st(N) within the floating-point register set F? */
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#define FPREG_ADDR(f, n) ((char *) &(f)->st_space + (n) * 10)
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/* Fill GDB's register array with the floating-point register values in
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*FPREGSETP. */
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void
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supply_fpregset (elf_fpregset_t *fpregsetp)
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{
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int reg;
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long l;
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||
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/* Supply the floating-point registers. */
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for (reg = 0; reg < 8; reg++)
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supply_register (FP0_REGNUM + reg, FPREG_ADDR (fpregsetp, reg));
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/* We have to mask off the reserved bits in *FPREGSETP before
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storing the values in GDB's register file. */
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#define supply(REGNO, MEMBER) \
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l = fpregsetp->MEMBER & 0xffff; \
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supply_register (REGNO, (char *) &l)
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supply (FCTRL_REGNUM, cwd);
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supply (FSTAT_REGNUM, swd);
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supply (FTAG_REGNUM, twd);
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supply_register (FCOFF_REGNUM, (char *) &fpregsetp->fip);
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supply (FDS_REGNUM, fos);
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supply_register (FDOFF_REGNUM, (char *) &fpregsetp->foo);
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||
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#undef supply
|
||
|
||
/* Extract the code segment and opcode from the "fcs" member. */
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||
l = fpregsetp->fcs & 0xffff;
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||
supply_register (FCS_REGNUM, (char *) &l);
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||
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||
l = (fpregsetp->fcs >> 16) & ((1 << 11) - 1);
|
||
supply_register (FOP_REGNUM, (char *) &l);
|
||
}
|
||
|
||
/* Convert the valid floating-point register values in GDB's register
|
||
array to `struct user' format and store them in *FPREGSETP. The
|
||
array VALID indicates which register values are valid. If VALID is
|
||
NULL, all registers are assumed to be valid. */
|
||
|
||
static void
|
||
convert_to_fpregset (elf_fpregset_t *fpregsetp, signed char *valid)
|
||
{
|
||
int reg;
|
||
|
||
/* Fill in the floating-point registers. */
|
||
for (reg = 0; reg < 8; reg++)
|
||
if (!valid || valid[reg])
|
||
memcpy (FPREG_ADDR (fpregsetp, reg),
|
||
®isters[REGISTER_BYTE (FP0_REGNUM + reg)],
|
||
REGISTER_RAW_SIZE(FP0_REGNUM + reg));
|
||
|
||
/* We're not supposed to touch the reserved bits in *FPREGSETP. */
|
||
|
||
#define fill(MEMBER, REGNO) \
|
||
if (! valid || valid[(REGNO)]) \
|
||
fpregsetp->MEMBER \
|
||
= ((fpregsetp->MEMBER & ~0xffff) \
|
||
| (* (int *) ®isters[REGISTER_BYTE (REGNO)] & 0xffff))
|
||
|
||
#define fill_register(MEMBER, REGNO) \
|
||
if (! valid || valid[(REGNO)]) \
|
||
memcpy (&fpregsetp->MEMBER, ®isters[REGISTER_BYTE (REGNO)], \
|
||
sizeof (fpregsetp->MEMBER))
|
||
|
||
fill (cwd, FCTRL_REGNUM);
|
||
fill (swd, FSTAT_REGNUM);
|
||
fill (twd, FTAG_REGNUM);
|
||
fill_register (fip, FCOFF_REGNUM);
|
||
fill (foo, FDOFF_REGNUM);
|
||
fill_register (fos, FDS_REGNUM);
|
||
|
||
#undef fill
|
||
#undef fill_register
|
||
|
||
if (! valid || valid[FCS_REGNUM])
|
||
fpregsetp->fcs
|
||
= ((fpregsetp->fcs & ~0xffff)
|
||
| (* (int *) ®isters[REGISTER_BYTE (FCS_REGNUM)] & 0xffff));
|
||
|
||
if (! valid || valid[FOP_REGNUM])
|
||
fpregsetp->fcs
|
||
= ((fpregsetp->fcs & 0xffff)
|
||
| ((*(int *) ®isters[REGISTER_BYTE (FOP_REGNUM)] & ((1 << 11) - 1))
|
||
<< 16));
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
if (regno == -1)
|
||
{
|
||
convert_to_fpregset (fpregsetp, NULL);
|
||
return;
|
||
}
|
||
|
||
if (GETFPREGS_SUPPLIES(regno))
|
||
{
|
||
signed char valid[MAX_NUM_REGS];
|
||
|
||
memset (valid, 0, sizeof (valid));
|
||
valid[regno] = 1;
|
||
|
||
convert_to_fpregset (fpregsetp, valid);
|
||
}
|
||
}
|
||
|
||
#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;
|
||
int ret;
|
||
|
||
ret = ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs);
|
||
if (ret < 0)
|
||
{
|
||
warning ("Couldn't get floating point status.");
|
||
return;
|
||
}
|
||
|
||
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)
|
||
{
|
||
elf_fpregset_t fpregs;
|
||
int ret;
|
||
|
||
ret = ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs);
|
||
if (ret < 0)
|
||
{
|
||
warning ("Couldn't get floating point status.");
|
||
return;
|
||
}
|
||
|
||
convert_to_fpregset (&fpregs, register_valid);
|
||
|
||
ret = ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs);
|
||
if (ret < 0)
|
||
{
|
||
warning ("Couldn't write floating point status.");
|
||
return;
|
||
}
|
||
}
|
||
|
||
#else
|
||
|
||
static void fetch_fpregs (int tid) {}
|
||
static void store_fpregs (int tid) {}
|
||
|
||
#endif
|
||
|
||
|
||
/* Transfering floating-point and SSE registers to and from GDB. */
|
||
|
||
/* PTRACE_GETXFPREGS is a Cygnus invention, since we wrote our own
|
||
Linux kernel patch for SSE support. That patch may or may not
|
||
actually make it into the official distribution. If you find that
|
||
years have gone by since this code was added, and Linux isn't using
|
||
PTRACE_GETXFPREGS, that means that our patch didn't make it, and
|
||
you can delete this code. */
|
||
|
||
#ifdef HAVE_PTRACE_GETXFPREGS
|
||
|
||
/* Fill GDB's register array with the floating-point and SSE register
|
||
values in *XFPREGS. */
|
||
|
||
static void
|
||
supply_xfpregset (struct user_xfpregs_struct *xfpregs)
|
||
{
|
||
int reg;
|
||
|
||
/* Supply the floating-point registers. */
|
||
for (reg = 0; reg < 8; reg++)
|
||
supply_register (FP0_REGNUM + reg, (char *) &xfpregs->st_space[reg]);
|
||
|
||
{
|
||
supply_register (FCTRL_REGNUM, (char *) &xfpregs->cwd);
|
||
supply_register (FSTAT_REGNUM, (char *) &xfpregs->swd);
|
||
supply_register (FTAG_REGNUM, (char *) &xfpregs->twd);
|
||
supply_register (FCOFF_REGNUM, (char *) &xfpregs->fip);
|
||
supply_register (FDS_REGNUM, (char *) &xfpregs->fos);
|
||
supply_register (FDOFF_REGNUM, (char *) &xfpregs->foo);
|
||
|
||
/* Extract the code segment and opcode from the "fcs" member. */
|
||
{
|
||
long l;
|
||
|
||
l = xfpregs->fcs & 0xffff;
|
||
supply_register (FCS_REGNUM, (char *) &l);
|
||
|
||
l = (xfpregs->fcs >> 16) & ((1 << 11) - 1);
|
||
supply_register (FOP_REGNUM, (char *) &l);
|
||
}
|
||
}
|
||
|
||
/* Supply the SSE registers. */
|
||
for (reg = 0; reg < 8; reg++)
|
||
supply_register (XMM0_REGNUM + reg, (char *) &xfpregs->xmm_space[reg]);
|
||
supply_register (MXCSR_REGNUM, (char *) &xfpregs->mxcsr);
|
||
}
|
||
|
||
/* Convert the valid floating-point and SSE registers in GDB's
|
||
register array to `struct user' format and store them in *XFPREGS.
|
||
The array VALID indicates which registers are valid. If VALID is
|
||
NULL, all registers are assumed to be valid. */
|
||
|
||
static void
|
||
convert_to_xfpregset (struct user_xfpregs_struct *xfpregs,
|
||
signed char *valid)
|
||
{
|
||
int reg;
|
||
|
||
/* Fill in the floating-point registers. */
|
||
for (reg = 0; reg < 8; reg++)
|
||
if (!valid || valid[reg])
|
||
memcpy (&xfpregs->st_space[reg],
|
||
®isters[REGISTER_BYTE (FP0_REGNUM + reg)],
|
||
REGISTER_RAW_SIZE(FP0_REGNUM + reg));
|
||
|
||
#define fill(MEMBER, REGNO) \
|
||
if (! valid || valid[(REGNO)]) \
|
||
memcpy (&xfpregs->MEMBER, ®isters[REGISTER_BYTE (REGNO)], \
|
||
sizeof (xfpregs->MEMBER))
|
||
|
||
fill (cwd, FCTRL_REGNUM);
|
||
fill (swd, FSTAT_REGNUM);
|
||
fill (twd, FTAG_REGNUM);
|
||
fill (fip, FCOFF_REGNUM);
|
||
fill (foo, FDOFF_REGNUM);
|
||
fill (fos, FDS_REGNUM);
|
||
|
||
#undef fill
|
||
|
||
if (! valid || valid[FCS_REGNUM])
|
||
xfpregs->fcs
|
||
= ((xfpregs->fcs & ~0xffff)
|
||
| (* (int *) ®isters[REGISTER_BYTE (FCS_REGNUM)] & 0xffff));
|
||
|
||
if (! valid || valid[FOP_REGNUM])
|
||
xfpregs->fcs
|
||
= ((xfpregs->fcs & 0xffff)
|
||
| ((*(int *) ®isters[REGISTER_BYTE (FOP_REGNUM)] & ((1 << 11) - 1))
|
||
<< 16));
|
||
|
||
/* Fill in the XMM registers. */
|
||
for (reg = 0; reg < 8; reg++)
|
||
if (! valid || valid[reg])
|
||
memcpy (&xfpregs->xmm_space[reg],
|
||
®isters[REGISTER_BYTE (XMM0_REGNUM + reg)],
|
||
REGISTER_RAW_SIZE (XMM0_REGNUM + reg));
|
||
}
|
||
|
||
/* Fetch all registers covered by the PTRACE_SETXFPREGS request from
|
||
process/thread TID and store their values in GDB's register array.
|
||
Return non-zero if successful, zero otherwise. */
|
||
|
||
static int
|
||
fetch_xfpregs (int tid)
|
||
{
|
||
struct user_xfpregs_struct xfpregs;
|
||
int ret;
|
||
|
||
if (! have_ptrace_getxfpregs)
|
||
return 0;
|
||
|
||
ret = ptrace (PTRACE_GETXFPREGS, tid, 0, &xfpregs);
|
||
if (ret == -1)
|
||
{
|
||
if (errno == EIO)
|
||
{
|
||
have_ptrace_getxfpregs = 0;
|
||
return 0;
|
||
}
|
||
|
||
warning ("Couldn't read floating-point and SSE registers.");
|
||
return 0;
|
||
}
|
||
|
||
supply_xfpregset (&xfpregs);
|
||
return 1;
|
||
}
|
||
|
||
/* Store all valid registers in GDB's register array covered by the
|
||
PTRACE_SETXFPREGS request into the process/thread specified by TID.
|
||
Return non-zero if successful, zero otherwise. */
|
||
|
||
static int
|
||
store_xfpregs (int tid)
|
||
{
|
||
struct user_xfpregs_struct xfpregs;
|
||
int ret;
|
||
|
||
if (! have_ptrace_getxfpregs)
|
||
return 0;
|
||
|
||
ret = ptrace (PTRACE_GETXFPREGS, tid, 0, &xfpregs);
|
||
if (ret == -1)
|
||
{
|
||
if (errno == EIO)
|
||
{
|
||
have_ptrace_getxfpregs = 0;
|
||
return 0;
|
||
}
|
||
|
||
warning ("Couldn't read floating-point and SSE registers.");
|
||
return 0;
|
||
}
|
||
|
||
convert_to_xfpregset (&xfpregs, register_valid);
|
||
|
||
if (ptrace (PTRACE_SETXFPREGS, tid, 0, &xfpregs) < 0)
|
||
{
|
||
warning ("Couldn't write floating-point and SSE registers.");
|
||
return 0;
|
||
}
|
||
|
||
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
|
||
|
||
/* Stub versions of the above routines, for systems that don't have
|
||
PTRACE_GETXFPREGS. */
|
||
static int store_xfpregs (int tid) { return 0; }
|
||
static int fetch_xfpregs (int tid) { return 0; }
|
||
static void dummy_sse_values (void) {}
|
||
|
||
#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;
|
||
}
|
||
|
||
/* Linux LWP ID's are process ID's. */
|
||
if ((tid = TIDGET (inferior_pid)) == 0)
|
||
tid = inferior_pid; /* Not a threaded program. */
|
||
|
||
/* Use the PTRACE_GETXFPREGS request whenever possible, since it
|
||
transfers more registers in one system call, and we'll cache the
|
||
results. But remember that fetch_xfpregs 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_xfpregs (tid))
|
||
return;
|
||
fetch_fpregs (tid);
|
||
return;
|
||
}
|
||
|
||
if (GETREGS_SUPPLIES (regno))
|
||
{
|
||
fetch_regs (tid);
|
||
return;
|
||
}
|
||
|
||
if (GETXFPREGS_SUPPLIES (regno))
|
||
{
|
||
if (fetch_xfpregs (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);
|
||
dummy_sse_values ();
|
||
return;
|
||
}
|
||
|
||
internal_error ("i386-linux-nat.c (fetch_inferior_registers): "
|
||
"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_SETXFPREGS requests whenever possibl, since it
|
||
transfers more registers in one system call. But remember that
|
||
store_xfpregs can fail, and return zero. */
|
||
if (regno == -1)
|
||
{
|
||
store_regs (tid);
|
||
if (store_xfpregs (tid))
|
||
return;
|
||
store_fpregs (tid);
|
||
return;
|
||
}
|
||
|
||
if (GETREGS_SUPPLIES (regno))
|
||
{
|
||
store_regs (tid);
|
||
return;
|
||
}
|
||
|
||
if (GETXFPREGS_SUPPLIES (regno))
|
||
{
|
||
if (store_xfpregs (tid))
|
||
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);
|
||
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_xfpregset, 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 struct
|
||
user_xfpregs_struct 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_GETXFPREGS
|
||
{
|
||
struct user_xfpregs_struct xfpregset;
|
||
|
||
case 3:
|
||
if (core_reg_size != sizeof (xfpregset))
|
||
warning ("Wrong size user_xfpregs_struct in core file.");
|
||
else
|
||
{
|
||
memcpy (&xfpregset, core_reg_sect, sizeof (xfpregset));
|
||
supply_xfpregset (&xfpregset);
|
||
}
|
||
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);
|
||
}
|