503 lines
12 KiB
C
503 lines
12 KiB
C
/* Kernel core dump functions below target vector, for GDB.
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Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995
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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, Boston, MA 02111-1307, USA.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* This works like "remote" but, you use it like this:
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* target kcore /dev/mem
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* or
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* target kcore /var/crash/host/core.0
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*
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* This way makes it easy to short-circut the whole bfd monster,
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* and direct the inferior stuff to our libkvm implementation.
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*
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*/
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#include <sys/param.h>
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#include <sys/user.h>
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#include <ctype.h>
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#include <fcntl.h>
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#include <kvm.h>
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#include <sys/sysctl.h>
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#include <paths.h>
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#include "defs.h"
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#include <readline/tilde.h>
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#include "gdb_string.h"
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#include "frame.h" /* required by inferior.h */
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#include "inferior.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "command.h"
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#include "bfd.h"
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#include "gdbcore.h"
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#include "solist.h"
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#include "kvm-fbsd-machine.h"
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static void
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kcore_files_info (struct target_ops *);
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static void
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kcore_close (int);
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static void
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get_kcore_registers (int);
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static int
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xfer_umem (CORE_ADDR, char *, int, int);
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#ifdef SOLIB_ADD
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static int kcore_solib_add_stub (PTR);
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#endif
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static char *core_file;
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static kvm_t *core_kd;
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static struct pcb cur_pcb;
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static struct kinfo_proc *cur_proc;
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static struct target_ops kcore_ops;
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int kernel_debugging;
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int kernel_writablecore;
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/* Read the "thing" at kernel address 'addr' into the space pointed to
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by point. The length of the "thing" is determined by the type of p.
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Result is non-zero if transfer fails. */
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#define kvread(addr, p) \
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(target_read_memory ((CORE_ADDR) (addr), (char *) (p), sizeof (*(p))))
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static CORE_ADDR
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ksym_kernbase (void)
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{
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static CORE_ADDR kernbase;
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struct minimal_symbol *sym;
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if (kernbase == 0)
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{
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sym = lookup_minimal_symbol ("kernbase", NULL, NULL);
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if (sym == NULL) {
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kernbase = KERNBASE;
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} else {
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kernbase = SYMBOL_VALUE_ADDRESS (sym);
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}
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}
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return kernbase;
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}
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#define KERNOFF (ksym_kernbase ())
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#define INKERNEL(x) ((x) >= KERNOFF)
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static CORE_ADDR
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ksym_lookup(const char *name)
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{
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struct minimal_symbol *sym;
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sym = lookup_minimal_symbol (name, NULL, NULL);
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if (sym == NULL)
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error ("kernel symbol `%s' not found.", name);
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return SYMBOL_VALUE_ADDRESS (sym);
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}
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/* Provide the address of an initial PCB to use.
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If this is a crash dump, try for "dumppcb".
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If no "dumppcb" or it's /dev/mem, use proc0.
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Return the core address of the PCB we found. */
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static CORE_ADDR
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initial_pcb (void)
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{
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struct minimal_symbol *sym;
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CORE_ADDR addr;
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void *val;
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/* Make sure things are open... */
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if (!core_kd || !core_file)
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return (0);
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/* If this is NOT /dev/mem try for dumppcb. */
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if (strncmp (core_file, _PATH_DEV, sizeof _PATH_DEV - 1))
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{
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sym = lookup_minimal_symbol ("dumppcb", NULL, NULL);
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if (sym != NULL)
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{
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addr = SYMBOL_VALUE_ADDRESS (sym);
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return (addr);
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}
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}
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/* OK, just use thread0's pcb. Note that curproc might
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not exist, and if it does, it will point to gdb.
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Therefore, just use proc0 and let the user set
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some other context if they care about it. */
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addr = ksym_lookup ("thread0");
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if (kvread (addr, &val))
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{
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error ("cannot read thread0 pointer at %x\n", addr);
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val = 0;
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}
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else
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{
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/* Read the PCB address in thread structure. */
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addr += offsetof (struct thread, td_pcb);
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if (kvread (addr, &val))
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{
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error ("cannot read thread0->td_pcb pointer at %x\n", addr);
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val = 0;
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}
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}
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/* thread0 is wholly in the kernel and cur_proc is only used for
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reading user mem, so no point in setting this up. */
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cur_proc = 0;
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return ((CORE_ADDR)val);
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}
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/* Set the current context to that of the PCB struct at the system address
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passed. */
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static int
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set_context (CORE_ADDR addr)
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{
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if (kvread (addr, &cur_pcb))
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error ("cannot read pcb at %#x", addr);
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/* Fetch all registers from core file. */
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target_fetch_registers (-1);
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/* Now, set up the frame cache, and print the top of stack. */
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flush_cached_frames ();
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set_current_frame (create_new_frame (read_fp (), read_pc ()));
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select_frame (get_current_frame (), 0);
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return (0);
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}
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/* Discard all vestiges of any previous core file and mark data and stack
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spaces as empty. */
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/* ARGSUSED */
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static void
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kcore_close (int quitting)
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{
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inferior_ptid = null_ptid; /* Avoid confusion from thread stuff. */
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/* Clear out solib state while the bfd is still open. See
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comments in clear_solib in solib.c. */
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#ifdef CLEAR_SOLIB
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CLEAR_SOLIB ();
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#endif
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if (core_kd)
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{
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kvm_close (core_kd);
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free (core_file);
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core_file = NULL;
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core_kd = NULL;
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}
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}
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/* This routine opens and sets up the core file bfd. */
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static void
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kcore_open (char *filename /* the core file */, int from_tty)
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{
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kvm_t *kd;
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const char *p;
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struct cleanup *old_chain;
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char buf[256], *cp;
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int ontop;
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CORE_ADDR addr;
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target_preopen (from_tty);
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/* The exec file is required for symbols. */
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if (exec_bfd == NULL)
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error ("No kernel exec file specified");
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if (core_kd)
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{
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error ("No core file specified."
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" (Use `detach' to stop debugging a core file.)");
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return;
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}
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if (!filename)
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{
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error ("No core file specified.");
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return;
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}
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filename = tilde_expand (filename);
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if (filename[0] != '/')
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{
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cp = concat (current_directory, "/", filename, NULL);
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free (filename);
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filename = cp;
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}
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old_chain = make_cleanup (free, filename);
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kd = kvm_open (bfd_get_filename(exec_bfd), filename, NULL,
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kernel_writablecore ? O_RDWR: O_RDONLY, 0);
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if (kd == NULL)
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{
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perror_with_name (filename);
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return;
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}
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/* Looks semi-reasonable. Toss the old core file and work on the new. */
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discard_cleanups (old_chain); /* Don't free filename any more. */
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core_file = filename;
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unpush_target (&kcore_ops);
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ontop = !push_target (&kcore_ops);
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/* Note unpush_target (above) calls kcore_close. */
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core_kd = kd;
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/* Print out the panic string if there is one. */
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if (kvread (ksym_lookup ("panicstr"), &addr) == 0 &&
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addr != 0 &&
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target_read_memory (addr, buf, sizeof(buf)) == 0)
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{
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for (cp = buf; cp < &buf[sizeof(buf)] && *cp; cp++)
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if (!isascii (*cp) || (!isprint (*cp) && !isspace (*cp)))
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*cp = '?';
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*cp = '\0';
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if (buf[0] != '\0')
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printf_filtered ("panic: %s\n", buf);
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}
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/* Print all the panic messages if possible. */
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if (symfile_objfile != NULL)
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{
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printf ("panic messages:\n---\n");
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snprintf (buf, sizeof buf,
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"/sbin/dmesg -N %s -M %s | \
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/usr/bin/awk '/^(panic:|Fatal trap) / { printing = 1 } \
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{ if (printing) print $0 }'",
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symfile_objfile->name, filename);
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fflush (stdout);
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system (buf);
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printf ("---\n");
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}
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if (ontop)
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{
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/* Add symbols and section mappings for any kernel modules. */
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#ifdef SOLIB_ADD
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current_target_so_ops = &kgdb_so_ops;
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catch_errors (kcore_solib_add_stub, &from_tty, (char *) 0,
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RETURN_MASK_ALL);
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#endif
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}
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else
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{
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warning ("you won't be able to access this core file until you terminate\n"
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"your %s; do ``info files''", target_longname);
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return;
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}
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/* Now, set up process context, and print the top of stack. */
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(void)set_context (initial_pcb());
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print_stack_frame (selected_frame, selected_frame_level, 1);
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}
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static void
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kcore_detach (char *args, int from_tty)
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{
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if (args)
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error ("Too many arguments");
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unpush_target (&kcore_ops);
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reinit_frame_cache ();
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if (from_tty)
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printf_filtered ("No kernel core file now.\n");
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}
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/* Get the registers out of a core file. This is the machine-
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independent part. Fetch_core_registers is the machine-dependent
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part, typically implemented in the xm-file for each architecture. */
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/* We just get all the registers, so we don't use regno. */
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/* ARGSUSED */
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static void
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get_kcore_registers (int regno)
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{
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/* XXX - Only read the pcb when set_context() is called.
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When looking at a live kernel this may be a problem,
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but the user can do another "proc" or "pcb" command to
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grab a new copy of the pcb... */
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/* Zero out register set then fill in the ones we know about. */
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fetch_kcore_registers (&cur_pcb);
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}
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static void
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kcore_files_info (t)
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struct target_ops *t;
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{
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printf_filtered ("\t`%s'\n", core_file);
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}
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static int
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xfer_kmem (CORE_ADDR memaddr, char *myaddr, int len, int write,
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struct mem_attrib *attrib, struct target_ops *target)
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{
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int n;
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if (!INKERNEL (memaddr))
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return xfer_umem (memaddr, myaddr, len, write);
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if (core_kd == NULL)
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return 0;
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if (write)
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n = kvm_write (core_kd, memaddr, myaddr, len);
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else
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n = kvm_read (core_kd, memaddr, myaddr, len) ;
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if (n < 0) {
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fprintf_unfiltered (gdb_stderr, "can not access 0x%x, %s\n",
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(unsigned)memaddr, kvm_geterr (core_kd));
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n = 0;
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}
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return n;
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}
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static int
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xfer_umem (CORE_ADDR memaddr, char *myaddr, int len, int write /* ignored */)
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{
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int n = 0;
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if (cur_proc == 0)
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{
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error ("---Can't read userspace from dump, or kernel process---\n");
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return 0;
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}
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if (write)
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error ("kvm_uwrite unimplemented\n");
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else
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n = kvm_uread (core_kd, cur_proc, memaddr, myaddr, len) ;
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if (n < 0)
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return 0;
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return n;
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}
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static void
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set_proc_cmd (char *arg, int from_tty)
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{
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CORE_ADDR addr, pid_addr, first_td;
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void *val;
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struct kinfo_proc *kp;
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int cnt;
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pid_t pid;
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if (!arg)
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error_no_arg ("proc address for the new context");
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if (core_kd == NULL)
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error ("no kernel core file");
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addr = (CORE_ADDR) parse_and_eval_address (arg);
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if (!INKERNEL (addr))
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{
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kp = kvm_getprocs (core_kd, KERN_PROC_PID, addr, &cnt);
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if (!cnt)
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error ("invalid pid");
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addr = (CORE_ADDR)kp->ki_paddr;
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cur_proc = kp;
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}
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else
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{
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/* Update cur_proc. */
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pid_addr = addr + offsetof (struct proc, p_pid);
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if (kvread (pid_addr, &pid))
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error ("cannot read pid ptr");
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cur_proc = kvm_getprocs (core_kd, KERN_PROC_PID, pid, &cnt);
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if (!cnt)
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error("invalid pid");
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}
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/* Find the first thread in the process. XXXKSE */
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addr += offsetof (struct proc, p_threads.tqh_first);
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if (kvread (addr, &first_td))
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error ("cannot read thread ptr");
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/* Read the PCB address in thread structure. */
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addr = first_td + offsetof (struct thread, td_pcb);
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if (kvread (addr, &val))
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error("cannot read pcb ptr");
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/* Read the PCB address in proc structure. */
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if (set_context ((CORE_ADDR) val))
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error ("invalid proc address");
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}
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#ifdef SOLIB_ADD
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static int
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kcore_solib_add_stub (PTR from_ttyp)
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{
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SOLIB_ADD (NULL, *(int *) from_ttyp, ¤t_target, auto_solib_add);
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return 0;
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}
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#endif /* SOLIB_ADD */
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void
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_initialize_kcorelow (void)
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{
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kcore_ops.to_shortname = "kcore";
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kcore_ops.to_longname = "Kernel core dump file";
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kcore_ops.to_doc =
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"Use a core file as a target. Specify the filename of the core file.";
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kcore_ops.to_open = kcore_open;
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kcore_ops.to_close = kcore_close;
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kcore_ops.to_attach = find_default_attach;
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kcore_ops.to_detach = kcore_detach;
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kcore_ops.to_fetch_registers = get_kcore_registers;
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kcore_ops.to_xfer_memory = xfer_kmem;
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kcore_ops.to_files_info = kcore_files_info;
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kcore_ops.to_create_inferior = find_default_create_inferior;
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kcore_ops.to_stratum = kcore_stratum;
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kcore_ops.to_has_memory = 1;
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kcore_ops.to_has_stack = 1;
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kcore_ops.to_has_registers = 1;
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kcore_ops.to_magic = OPS_MAGIC;
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add_target (&kcore_ops);
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add_com ("proc", class_obscure, set_proc_cmd, "Set current process context");
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}
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