439 lines
10 KiB
C
439 lines
10 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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/* $FreeBSD$ */
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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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#include <sys/param.h>
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#include <sys/time.h>
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#include <sys/proc.h>
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#include <sys/user.h>
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#include <errno.h>
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#include <signal.h>
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#include <fcntl.h>
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#include <kvm.h>
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#include <paths.h>
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#include "defs.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 "symtab.h"
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#include "command.h"
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#include "bfd.h"
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#include "target.h"
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#include "gdbcore.h"
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static void
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kcore_files_info PARAMS ((struct target_ops *));
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static void
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kcore_close PARAMS ((int));
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static void
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get_kcore_registers PARAMS ((int));
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static int
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xfer_mem PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
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static int
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xfer_umem PARAMS ((CORE_ADDR, char *, int, int));
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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 target_ops kcore_ops;
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int kernel_writablecore;
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/*
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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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*/
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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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CORE_ADDR
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ksym_lookup(name)
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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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/*
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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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*/
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static CORE_ADDR
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initial_pcb()
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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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sym = lookup_minimal_symbol("dumppcb", NULL, NULL);
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if (sym != NULL) {
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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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/*
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* OK, just use proc0pcb. 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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*/
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addr = ksym_lookup("proc0paddr");
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if (kvread(addr, &val)) {
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error("cannot read proc0paddr pointer at %x\n", addr);
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val = 0;
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}
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return ((CORE_ADDR)val);
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}
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/*
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* Set the current context to that of the PCB struct
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* at the system address passed.
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*/
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static int
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set_context(addr)
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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 (quitting)
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int quitting;
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{
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inferior_pid = 0; /* Avoid confusion from thread stuff */
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if (core_kd) {
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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 (filename, from_tty)
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char *filename; /* the core file */
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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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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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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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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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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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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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if (!ontop) {
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warning (
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"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 (args, from_tty)
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char *args;
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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 (regno)
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int regno;
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{
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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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*/
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/*
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* Zero out register set then fill in the ones we know about.
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*/
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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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/* If mourn is being called in all the right places, this could be say
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`gdb internal error' (since generic_mourn calls breakpoint_init_inferior). */
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static int
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ignore (addr, contents)
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CORE_ADDR addr;
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char *contents;
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{
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return 0;
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}
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static int
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xfer_kmem (memaddr, myaddr, len, write, target)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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int write;
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struct target_ops *target;
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{
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int n;
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#if 0 /* XXX */
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if (it is a user address)
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return xfer_umem(memaddr, myaddr, len, write);
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#endif
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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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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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#if 0 /* XXX */
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static int
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xfer_umem (memaddr, myaddr, len, write)
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CORE_ADDR memaddr;
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char *myaddr;
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int len;
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int write; /* ignored */
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{
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int n;
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struct proc proc;
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if (kvread(cur_proc, &proc))
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error("cannot read proc at %#x", cur_proc);
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n = kvm_uread(core_kd, &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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#endif
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static void
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set_proc_cmd(arg)
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char *arg;
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{
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CORE_ADDR addr;
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void *val;
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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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/* Read the PCB address in proc structure. */
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addr += (int) &((struct proc *)0)->p_addr;
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if (kvread(addr, &val))
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error("cannot read u area ptr");
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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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static void
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set_pcb_cmd(arg)
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char *arg;
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{
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CORE_ADDR addr;
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void *val;
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if (!arg)
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error_no_arg("pcb 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 (set_context(addr))
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error("invalid pcb address");
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}
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void
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_initialize_kcorelow()
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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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