367 lines
11 KiB
C
367 lines
11 KiB
C
/* Low level Pyramid interface to ptrace, for GDB when running under Unix.
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Copyright (C) 1988, 1989, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include <stdio.h>
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#include "defs.h"
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#include "param.h"
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#include "frame.h"
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#include "inferior.h"
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#include <sys/param.h>
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#include <sys/dir.h>
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#include <signal.h>
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#include <sys/ioctl.h>
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/* #include <fcntl.h> Can we live without this? */
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#include "gdbcore.h"
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#include <sys/user.h> /* After a.out.h */
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#include <sys/file.h>
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#include <sys/stat.h>
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void
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fetch_inferior_registers ()
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{
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register int regno, datum;
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register unsigned int regaddr;
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int reg_buf[NUM_REGS+1];
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struct user u;
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register int skipped_frames = 0;
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registers_fetched ();
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for (regno = 0; regno < 64; regno++) {
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reg_buf[regno] = ptrace (3, inferior_pid, regno, 0);
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#if defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
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printf ("Fetching %s from inferior, got %0x\n",
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reg_names[regno],
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reg_buf[regno]);
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#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
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if (reg_buf[regno] == -1 && errno == EIO) {
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printf("fetch_interior_registers: fetching %s from inferior\n",
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reg_names[regno]);
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errno = 0;
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}
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supply_register (regno, reg_buf+regno);
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}
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/* that leaves regs 64, 65, and 66 */
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datum = ptrace (3, inferior_pid,
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((char *)&u.u_pcb.pcb_csp) -
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((char *)&u), 0);
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/* FIXME: Find the Current Frame Pointer (CFP). CFP is a global
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register (ie, NOT windowed), that gets saved in a frame iff
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the code for that frame has a prologue (ie, "adsf N"). If
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there is a prologue, the adsf insn saves the old cfp in
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pr13, cfp is set to sp, and N bytes of locals are allocated
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(sp is decremented by n).
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This makes finding CFP hard. I guess the right way to do it
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is:
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- If this is the innermost frame, believe ptrace() or
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the core area.
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- Otherwise:
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Find the first insn of the current frame.
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- find the saved pc;
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- find the call insn that saved it;
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- figure out where the call is to;
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- if the first insn is an adsf, we got a frame
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pointer. */
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/* Normal processors have separate stack pointers for user and
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kernel mode. Getting the last user mode frame on such
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machines is easy: the kernel context of the ptrace()'d
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process is on the kernel stack, and the USP points to what
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we want. But Pyramids only have a single cfp for both user and
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kernel mode. And processes being ptrace()'d have some
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kernel-context control frames on their stack.
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To avoid tracing back into the kernel context of an inferior,
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we skip 0 or more contiguous control frames where the pc is
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in the kernel. */
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while (1) {
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register int inferior_saved_pc;
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inferior_saved_pc = ptrace (1, inferior_pid, datum+((32+15)*4), 0);
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if (inferior_saved_pc > 0) break;
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#if defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
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printf("skipping kernel frame %08x, pc=%08x\n", datum,
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inferior_saved_pc);
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#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
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skipped_frames++;
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datum -= CONTROL_STACK_FRAME_SIZE;
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}
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reg_buf[CSP_REGNUM] = datum;
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supply_register(CSP_REGNUM, reg_buf+CSP_REGNUM);
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#ifdef PYRAMID_CONTROL_FRAME_DEBUGGING
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if (skipped_frames) {
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fprintf (stderr,
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"skipped %d frames from %x to %x; cfp was %x, now %x\n",
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skipped_frames, reg_buf[CSP_REGNUM]);
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}
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#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
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}
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/* Store our register values back into the inferior.
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If REGNO is -1, do this for all registers.
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Otherwise, REGNO specifies which register (so we can save time). */
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store_inferior_registers (regno)
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int regno;
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{
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register unsigned int regaddr;
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char buf[80];
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if (regno >= 0)
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{
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if ((0 <= regno) && (regno < 64)) {
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/*regaddr = register_addr (regno, offset);*/
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regaddr = regno;
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errno = 0;
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ptrace (6, inferior_pid, regaddr, read_register (regno));
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if (errno != 0)
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{
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sprintf (buf, "writing register number %d", regno);
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perror_with_name (buf);
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}
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}
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}
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else
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{
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for (regno = 0; regno < NUM_REGS; regno++)
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{
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/*regaddr = register_addr (regno, offset);*/
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regaddr = regno;
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errno = 0;
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ptrace (6, inferior_pid, regaddr, read_register (regno));
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if (errno != 0)
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{
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sprintf (buf, "writing all regs, number %d", regno);
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perror_with_name (buf);
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}
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}
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}
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/*** Extensions to core and dump files, for GDB. */
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extern unsigned int last_frame_offset;
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#ifdef PYRAMID_CORE
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/* Can't make definitions here static, since core.c needs them
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to do bounds checking on the core-file areas. O well. */
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/* have two stacks: one for data, one for register windows. */
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extern CORE_ADDR reg_stack_start;
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extern CORE_ADDR reg_stack_end;
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/* need this so we can find the global registers: they never get saved. */
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CORE_ADDR global_reg_offset;
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static CORE_ADDR last_frame_address;
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CORE_ADDR last_frame_offset;
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/* Address in core file of start of register window stack area.
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Don't know if is this any of meaningful, useful or necessary. */
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extern int reg_stack_offset;
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#endif /* PYRAMID_CORE */
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/* Work with core dump and executable files, for GDB.
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This code would be in core.c if it weren't machine-dependent. */
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void
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core_file_command (filename, from_tty)
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char *filename;
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int from_tty;
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{
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int val;
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extern char registers[];
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/* Discard all vestiges of any previous core file
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and mark data and stack spaces as empty. */
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if (corefile)
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free (corefile);
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corefile = 0;
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if (corechan >= 0)
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close (corechan);
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corechan = -1;
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data_start = 0;
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data_end = 0;
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stack_start = STACK_END_ADDR;
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stack_end = STACK_END_ADDR;
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#ifdef PYRAMID_CORE
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reg_stack_start = CONTROL_STACK_ADDR;
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reg_stack_end = CONTROL_STACK_ADDR; /* this isn't strictly true...*/
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#endif /* PYRAMID_CORE */
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/* Now, if a new core file was specified, open it and digest it. */
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if (filename)
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{
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filename = tilde_expand (filename);
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make_cleanup (free, filename);
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if (have_inferior_p ())
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error ("To look at a core file, you must kill the inferior with \"kill\".");
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corechan = open (filename, O_RDONLY, 0);
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if (corechan < 0)
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perror_with_name (filename);
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/* 4.2-style (and perhaps also sysV-style) core dump file. */
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{
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struct user u;
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unsigned int reg_offset;
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val = myread (corechan, &u, sizeof u);
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if (val < 0)
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perror_with_name ("Not a core file: reading upage");
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if (val != sizeof u)
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error ("Not a core file: could only read %d bytes", val);
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data_start = exec_data_start;
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data_end = data_start + NBPG * u.u_dsize;
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data_offset = NBPG * UPAGES;
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stack_offset = NBPG * (UPAGES + u.u_dsize);
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/* find registers in core file */
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#ifdef PYRAMID_PTRACE
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stack_start = stack_end - NBPG * u.u_ussize;
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reg_stack_offset = stack_offset + (NBPG *u.u_ussize);
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reg_stack_end = reg_stack_start + NBPG * u.u_cssize;
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last_frame_address = ((int) u.u_pcb.pcb_csp);
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last_frame_offset = reg_stack_offset + last_frame_address
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- CONTROL_STACK_ADDR ;
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global_reg_offset = (char *)&u - (char *)&u.u_pcb.pcb_gr0 ;
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/* skip any control-stack frames that were executed in the
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kernel. */
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while (1) {
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char buf[4];
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val = lseek (corechan, last_frame_offset+(47*4), 0);
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if (val < 0)
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perror_with_name (filename);
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val = myread (corechan, buf, sizeof buf);
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if (val < 0)
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perror_with_name (filename);
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if (*(int *)buf >= 0)
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break;
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printf ("skipping frame %s\n", local_hex_string (last_frame_address));
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last_frame_offset -= CONTROL_STACK_FRAME_SIZE;
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last_frame_address -= CONTROL_STACK_FRAME_SIZE;
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}
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reg_offset = last_frame_offset;
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#if 1 || defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
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printf ("Control stack pointer = %s\n",
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local_hex_string (u.u_pcb.pcb_csp));
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printf ("offset to control stack %d outermost frame %d (%s)\n",
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reg_stack_offset, reg_offset, local_hex_string (last_frame_address));
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#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
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#else /* not PYRAMID_CORE */
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stack_start = stack_end - NBPG * u.u_ssize;
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reg_offset = (int) u.u_ar0 - KERNEL_U_ADDR;
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#endif /* not PYRAMID_CORE */
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#ifdef __not_on_pyr_yet
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/* Some machines put an absolute address in here and some put
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the offset in the upage of the regs. */
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reg_offset = (int) u.u_ar0;
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if (reg_offset > NBPG * UPAGES)
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reg_offset -= KERNEL_U_ADDR;
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#endif
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/* I don't know where to find this info.
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So, for now, mark it as not available. */
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N_SET_MAGIC (core_aouthdr, 0);
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/* Read the register values out of the core file and store
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them where `read_register' will find them. */
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{
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register int regno;
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for (regno = 0; regno < 64; regno++)
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{
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char buf[MAX_REGISTER_RAW_SIZE];
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val = lseek (corechan, register_addr (regno, reg_offset), 0);
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if (val < 0
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|| (val = myread (corechan, buf, sizeof buf)) < 0)
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{
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char * buffer = (char *) alloca (strlen (reg_names[regno])
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+ 30);
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strcpy (buffer, "Reading register ");
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strcat (buffer, reg_names[regno]);
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perror_with_name (buffer);
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}
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if (val < 0)
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perror_with_name (filename);
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#ifdef PYRAMID_CONTROL_FRAME_DEBUGGING
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printf ("[reg %s(%d), offset in file %s=0x%0x, addr =0x%0x, =%0x]\n",
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reg_names[regno], regno, filename,
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register_addr(regno, reg_offset),
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regno * 4 + last_frame_address,
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*((int *)buf));
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#endif /* PYRAMID_CONTROL_FRAME_DEBUGGING */
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supply_register (regno, buf);
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}
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}
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}
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if (filename[0] == '/')
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corefile = savestring (filename, strlen (filename));
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else
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{
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corefile = concat (current_directory, "/", filename);
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}
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#if 1 || defined(PYRAMID_CONTROL_FRAME_DEBUGGING)
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printf ("Providing CSP (%s) as nominal address of current frame.\n",
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local_hex_string(last_frame_address));
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#endif PYRAMID_CONTROL_FRAME_DEBUGGING
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/* FIXME: Which of the following is correct? */
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#if 0
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set_current_frame ( create_new_frame (read_register (FP_REGNUM),
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read_pc ()));
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#else
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set_current_frame ( create_new_frame (last_frame_address,
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read_pc ()));
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#endif
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select_frame (get_current_frame (), 0);
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validate_files ();
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}
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else if (from_tty)
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printf ("No core file now.\n");
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}
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