1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-25 11:37:56 +00:00
freebsd/gnu/usr.bin/binutils/gdb/kvm-fbsd.c
2002-02-08 04:17:33 +00:00

1046 lines
26 KiB
C

/* Live and postmortem kernel debugging functions for FreeBSD.
Copyright 1996 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* $FreeBSD$ */
#include "defs.h"
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <paths.h>
#include <sys/sysctl.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/user.h>
#include "frame.h" /* required by inferior.h */
#include "inferior.h"
#include "symtab.h"
#include "symfile.h"
#include "objfiles.h"
#include "command.h"
#include "bfd.h"
#include "target.h"
#include "gdbcore.h"
#include <sys/stat.h>
#include <unistd.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <machine/vmparam.h>
#include <machine/pcb.h>
#include <machine/tss.h>
#include <machine/frame.h>
#define _KERNEL
#include <sys/pcpu.h>
#undef _KERNEL
static void kcore_files_info PARAMS ((struct target_ops *));
static void kcore_close PARAMS ((int));
static void get_kcore_registers PARAMS ((int));
static int kcore_xfer_kmem PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
static int xfer_umem PARAMS ((CORE_ADDR, char *, int, int));
static CORE_ADDR ksym_lookup PARAMS ((const char *));
static int read_pcb PARAMS ((int, CORE_ADDR));
static struct proc * curProc PARAMS ((void));
static int set_proc_context PARAMS ((CORE_ADDR paddr));
static void kcore_open PARAMS ((char *filename, int from_tty));
static void kcore_detach PARAMS ((char *args, int from_tty));
static void set_proc_cmd PARAMS ((char *arg, int from_tty));
static void set_cpu_cmd PARAMS ((char *arg, int from_tty));
static CORE_ADDR kvtophys PARAMS ((int, CORE_ADDR));
static int physrd PARAMS ((int, u_int, char*, int));
static int kvm_open PARAMS ((const char *efile, char *cfile, char *sfile,
int perm, char *errout));
static int kvm_close PARAMS ((int fd));
static int kvm_write PARAMS ((int core_kd, CORE_ADDR memaddr,
char *myaddr, int len));
static int kvm_read PARAMS ((int core_kd, CORE_ADDR memaddr,
char *myaddr, int len));
static int kvm_uread PARAMS ((int core_kd, struct proc *p,
CORE_ADDR memaddr, char *myaddr,
int len));
static int kernel_core_file_hook PARAMS ((int fd, CORE_ADDR addr,
char *buf, int len));
static CORE_ADDR kvm_getpcpu PARAMS ((int cfd, int cpuid));
static struct kinfo_proc * kvm_getprocs PARAMS ((int cfd, int op,
CORE_ADDR proc, int *cnt));
extern struct target_ops kcore_ops; /* Forward decl */
/* Non-zero means we are debugging a kernel core file */
int kernel_debugging = 0;
int kernel_writablecore = 0;
static char *core_file;
static int core_kd = -1;
static struct proc *cur_proc;
static CORE_ADDR kernel_start;
static CORE_ADDR pcpu;
#define PCPU_OFFSET(name) \
offsetof(struct pcpu, pc_ ## name)
/*
* Symbol names of kernel entry points. Use special frames.
*/
#define KSYM_TRAP "calltrap"
#define KSYM_INTR "Xintr"
#define KSYM_FASTINTR "Xfastintr"
#define KSYM_SYSCALL "Xsyscall"
/*
* Read the "thing" at kernel address 'addr' into the space pointed to
* by point. The length of the "thing" is determined by the type of p.
* Result is non-zero if transfer fails.
*/
#define kvread(addr, p) \
(target_read_memory ((CORE_ADDR)(addr), (char *)(p), sizeof(*(p))))
/*
* The following is FreeBSD-specific hackery to decode special frames
* and elide the assembly-language stub. This could be made faster by
* defining a frame_type field in the machine-dependent frame information,
* but we don't think that's too important right now.
*/
enum frametype { tf_normal, tf_trap, tf_interrupt, tf_syscall };
CORE_ADDR
fbsd_kern_frame_saved_pc (fr)
struct frame_info *fr;
{
struct minimal_symbol *sym;
CORE_ADDR this_saved_pc;
enum frametype frametype;
this_saved_pc = read_memory_integer (fr->frame + 4, 4);
sym = lookup_minimal_symbol_by_pc (this_saved_pc);
frametype = tf_normal;
if (sym != NULL) {
if (strcmp (SYMBOL_NAME(sym), KSYM_TRAP) == 0)
frametype = tf_trap;
else if (strncmp (SYMBOL_NAME(sym), KSYM_INTR,
strlen(KSYM_INTR)) == 0 || strncmp (SYMBOL_NAME(sym),
KSYM_FASTINTR, strlen(KSYM_FASTINTR)) == 0)
frametype = tf_interrupt;
else if (strcmp (SYMBOL_NAME(sym), KSYM_SYSCALL) == 0)
frametype = tf_syscall;
}
switch (frametype) {
case tf_normal:
return (this_saved_pc);
#define oEIP offsetof(struct trapframe, tf_eip)
case tf_trap:
return (read_memory_integer (fr->frame + 8 + oEIP, 4));
case tf_interrupt:
return (read_memory_integer (fr->frame + 12 + oEIP, 4));
case tf_syscall:
return (read_memory_integer (fr->frame + 8 + oEIP, 4));
#undef oEIP
}
}
static CORE_ADDR
ksym_lookup (name)
const char *name;
{
struct minimal_symbol *sym;
sym = lookup_minimal_symbol (name, NULL, NULL);
if (sym == NULL)
error ("kernel symbol `%s' not found.", name);
return SYMBOL_VALUE_ADDRESS (sym);
}
static struct proc *
curProc ()
{
struct proc *p;
struct thread *td;
CORE_ADDR addr = pcpu + PCPU_OFFSET (curthread);
if (kvread (addr, &td))
error ("cannot read thread pointer at %x\n", addr);
addr = (CORE_ADDR)td + offsetof(struct thread, td_proc);
if (kvread (addr, &p))
error ("cannot read proc pointer at %x\n", addr);
return p;
}
/*
* Set the process context to that of the proc structure at
* system address paddr.
*/
static int
set_proc_context (paddr)
CORE_ADDR paddr;
{
struct proc p;
if (paddr < kernel_start)
return (1);
cur_proc = (struct proc *)paddr;
#ifdef notyet
set_kernel_boundaries (cur_proc);
#endif
/* Fetch all registers from core file */
target_fetch_registers (-1);
/* Now, set up the frame cache, and print the top of stack */
flush_cached_frames ();
set_current_frame (create_new_frame (read_fp (), read_pc ()));
select_frame (get_current_frame (), 0);
return (0);
}
/* Discard all vestiges of any previous core file
and mark data and stack spaces as empty. */
/* ARGSUSED */
static void
kcore_close (quitting)
int quitting;
{
inferior_pid = 0; /* Avoid confusion from thread stuff */
if (core_kd)
{
kvm_close (core_kd);
free (core_file);
core_file = NULL;
core_kd = -1;
}
}
/* This routine opens and sets up the core file bfd */
static void
kcore_open (filename, from_tty)
char *filename;
int from_tty;
{
const char *p;
struct cleanup *old_chain;
char buf[256], *cp;
int ontop;
CORE_ADDR addr;
struct pcb pcb;
target_preopen (from_tty);
unpush_target (&kcore_ops);
if (!filename)
{
/*error (core_kd?*/
error ( (core_kd >= 0)?
"No core file specified. (Use `detach' to stop debugging a core file.)"
: "No core file specified.");
}
filename = tilde_expand (filename);
if (filename[0] != '/')
{
cp = concat (current_directory, "/", filename, NULL);
free (filename);
filename = cp;
}
old_chain = make_cleanup (free, filename);
/*
* gdb doesn't really do anything if the exec-file couldn't
* be opened (in that case exec_bfd is NULL). Usually that's
* no big deal, but kvm_open needs the exec-file's name,
* which results in dereferencing a NULL pointer, a real NO-NO !
* So, check here if the open of the exec-file succeeded.
*/
if (exec_bfd == NULL) /* the open failed */
error ("kgdb could not open the exec-file, please check the name you used !");
core_kd = kvm_open (exec_bfd->filename, filename, NULL,
kernel_writablecore? O_RDWR : O_RDONLY, "kgdb: ");
if (core_kd < 0)
perror_with_name (filename);
/* Looks semi-reasonable. Toss the old core file and work on the new. */
discard_cleanups (old_chain); /* Don't free filename any more */
core_file = filename;
ontop = !push_target (&kcore_ops);
kernel_start = bfd_get_start_address (exec_bfd); /* XXX */
/* print out the panic string if there is one */
if (kvread (ksym_lookup ("panicstr"), &addr) == 0
&& addr != 0
&& target_read_memory (addr, buf, sizeof (buf)) == 0)
{
for (cp = buf; cp < &buf[sizeof (buf)] && *cp; cp++)
if (!isascii (*cp) || (!isprint (*cp) && !isspace (*cp)))
*cp = '?';
*cp = '\0';
if (buf[0] != '\0')
printf ("panicstr: %s\n", buf);
}
/* Print all the panic messages if possible. */
if (symfile_objfile != NULL)
{
printf ("panic messages:\n---\n");
snprintf (buf, sizeof buf,
"/sbin/dmesg -N %s -M %s | \
/usr/bin/awk '/^(panic:|Fatal trap) / { printing = 1 } \
{ if (printing) print $0 }'",
symfile_objfile->name, filename);
fflush(stdout);
system (buf);
printf ("---\n");
}
if (!ontop)
{
warning ("you won't be able to access this core file until you terminate\n\
your %s; do ``info files''", target_longname);
return;
}
/* we may need this later */
cur_proc = (struct proc *)curProc ();
/* Now, set up the frame cache, and print the top of stack */
flush_cached_frames ();
set_current_frame (create_new_frame (read_fp (), read_pc ()));
select_frame (get_current_frame (), 0);
print_stack_frame (selected_frame, selected_frame_level, 1);
}
static void
kcore_detach (args, from_tty)
char *args;
int from_tty;
{
if (args)
error ("Too many arguments");
unpush_target (&kcore_ops);
reinit_frame_cache ();
if (from_tty)
printf_filtered ("No kernel core file now.\n");
}
/* Get the registers out of a core file. This is the machine-
independent part. Fetch_core_registers is the machine-dependent
part, typically implemented in the xm-file for each architecture. */
/* We just get all the registers, so we don't use regno. */
/* ARGSUSED */
static void
get_kcore_registers (regno)
int regno;
{
struct pcb *pcbaddr;
struct thread *mainthread;
/* find the pcb for the current process */
if (cur_proc == NULL)
error ("get_kcore_registers no proc");
if (kvread (&TAILQ_FIRST(&cur_proc->p_threads), &mainthread)) /* XXXKSE */
error ("cannot read main thread for proc at %#x", cur_proc);
if (kvread (&mainthread->td_pcb, &pcbaddr)) /* XXXKSE */
error ("cannot read pcb pointer for proc at %#x", cur_proc);
if (read_pcb (core_kd, (CORE_ADDR)pcbaddr) < 0)
error ("cannot read pcb at %#x", pcbaddr);
}
static void
kcore_files_info (t)
struct target_ops *t;
{
printf ("\t`%s'\n", core_file);
}
static CORE_ADDR
ksym_maxuseraddr()
{
static CORE_ADDR maxuseraddr;
struct minimal_symbol *sym;
if (maxuseraddr == 0)
{
sym = lookup_minimal_symbol ("PTmap", NULL, NULL);
if (sym == NULL) {
maxuseraddr = VM_MAXUSER_ADDRESS;
} else {
maxuseraddr = SYMBOL_VALUE_ADDRESS (sym);
}
}
return maxuseraddr;
}
static int
kcore_xfer_kmem (memaddr, myaddr, len, write, target)
CORE_ADDR memaddr;
char *myaddr;
int len;
int write;
struct target_ops *target;
{
int ns;
int nu;
if (memaddr >= ksym_maxuseraddr())
nu = 0;
else
{
nu = xfer_umem (memaddr, myaddr, len, write);
if (nu <= 0)
return (0);
if (nu == len)
return (nu);
memaddr += nu;
if (memaddr != ksym_maxuseraddr())
return (nu);
myaddr += nu;
len -= nu;
}
ns = (write ? kvm_write : kvm_read) (core_kd, memaddr, myaddr, len);
if (ns < 0)
ns = 0;
return (nu + ns);
}
static int
xfer_umem (memaddr, myaddr, len, write)
CORE_ADDR memaddr;
char *myaddr;
int len;
int write; /* ignored */
{
int n;
struct proc proc;
if (cur_proc == NULL || kvread (cur_proc, &proc))
error ("cannot read proc at %#x", cur_proc);
n = kvm_uread (core_kd, &proc, memaddr, myaddr, len) ;
if (n < 0)
return 0;
return n;
}
static CORE_ADDR
ksym_kernbase()
{
static CORE_ADDR kernbase;
struct minimal_symbol *sym;
if (kernbase == 0)
{
sym = lookup_minimal_symbol ("kernbase", NULL, NULL);
if (sym == NULL) {
kernbase = KERNBASE;
} else {
kernbase = SYMBOL_VALUE_ADDRESS (sym);
}
}
return kernbase;
}
#define KERNOFF (ksym_kernbase())
#define INKERNEL(x) ((x) >= KERNOFF)
static CORE_ADDR sbr;
static CORE_ADDR curpcb;
static int found_pcb;
static int devmem;
static int kfd;
static struct pcb pcb;
static void
set_proc_cmd (arg, from_tty)
char *arg;
int from_tty;
{
CORE_ADDR paddr;
struct kinfo_proc *kp;
int cnt = 0;
if (!arg)
error_no_arg ("proc address for new current process");
if (!kernel_debugging)
error ("not debugging kernel");
paddr = (CORE_ADDR)parse_and_eval_address (arg);
/* assume it's a proc pointer if it's in the kernel */
if (paddr >= kernel_start) {
if (set_proc_context(paddr))
error("invalid proc address");
} else {
kp = kvm_getprocs(core_kd, KERN_PROC_PID, paddr, &cnt);
if (!cnt)
error("invalid pid");
if (set_proc_context((CORE_ADDR)kp->ki_paddr))
error("invalid proc address");
}
}
static void
set_cpu_cmd (arg, from_tty)
char *arg;
int from_tty;
{
CORE_ADDR paddr;
CORE_ADDR pcaddr;
struct kinfo_proc *kp;
int cpu, cfd;
if (!arg)
error_no_arg ("cpu number");
if (!kernel_debugging)
error ("not debugging kernel");
cfd = core_kd;
cpu = (int)parse_and_eval_address (arg);
if ((pcaddr = kvm_getpcpu (cfd, cpu)) == NULL)
error ("cpu number out of range");
pcpu = pcaddr;
curpcb = kvtophys(cfd, pcpu + PCPU_OFFSET (curpcb));
physrd (cfd, curpcb, (char*)&curpcb, sizeof curpcb);
if (!devmem)
paddr = ksym_lookup ("dumppcb") - KERNOFF;
else
paddr = kvtophys (cfd, curpcb);
read_pcb (cfd, paddr);
printf ("initial pcb at %lx\n", (unsigned long)paddr);
if ((cur_proc = curProc()))
target_fetch_registers (-1);
/* Now, set up the frame cache, and print the top of stack */
flush_cached_frames ();
set_current_frame (create_new_frame (read_fp (), read_pc ()));
select_frame (get_current_frame (), 0);
print_stack_frame (selected_frame, selected_frame_level, 1);
}
/* substitutes for the stuff in libkvm which doesn't work */
/* most of this was taken from the old kgdb */
/* we don't need all this stuff, but the call should look the same */
static int
kvm_open (efile, cfile, sfile, perm, errout)
const char *efile;
char *cfile;
char *sfile; /* makes this kvm_open more compatible to the one in libkvm */
int perm;
char *errout; /* makes this kvm_open more compatible to the one in libkvm */
{
struct stat stb;
int cfd;
CORE_ADDR paddr;
if ((cfd = open (cfile, perm, 0)) < 0)
return (cfd);
if ((pcpu = kvm_getpcpu (cfd, 0)) == NULL)
return (-1);
fstat (cfd, &stb);
if ((stb.st_mode & S_IFMT) == S_IFCHR
&& stb.st_rdev == makedev (2, 0))
{
devmem = 1;
kfd = open (_PATH_KMEM, perm, 0);
}
physrd (cfd, ksym_lookup ("IdlePTD") - KERNOFF, (char*)&sbr, sizeof sbr);
printf ("IdlePTD at phsyical address 0x%08lx\n", (unsigned long)sbr);
curpcb = kvtophys(cfd, pcpu + PCPU_OFFSET (curpcb));
physrd (cfd, curpcb, (char*)&curpcb, sizeof curpcb);
found_pcb = 1; /* for vtophys */
if (!devmem)
paddr = ksym_lookup ("dumppcb") - KERNOFF;
else
paddr = kvtophys (cfd, curpcb);
read_pcb (cfd, paddr);
printf ("initial pcb at physical address 0x%08lx\n", (unsigned long)paddr);
return (cfd);
}
static int
kvm_close (fd)
int fd;
{
return (close (fd));
}
static int
kvm_write (core_kd, memaddr, myaddr, len)
int core_kd;
CORE_ADDR memaddr;
char *myaddr;
{
int cc;
if (devmem)
{
if (kfd > 0)
{
/*
* Just like kvm_read, only we write.
*/
errno = 0;
if (lseek (kfd, (off_t)memaddr, 0) < 0
&& errno != 0)
{
error ("kvm_write:invalid address (%x)", memaddr);
return (0);
}
cc = write (kfd, myaddr, len);
if (cc < 0)
{
error ("kvm_write:write failed");
return (0);
}
else if (cc < len)
error ("kvm_write:short write");
return (cc);
}
else
return (0);
}
else
{
printf ("kvm_write not implemented for dead kernels\n");
return (0);
}
/* NOTREACHED */
}
static int
kvm_read (core_kd, memaddr, myaddr, len)
int core_kd;
CORE_ADDR memaddr;
char *myaddr;
{
return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
}
static int
kvm_uread (core_kd, p, memaddr, myaddr, len)
int core_kd;
register struct proc *p;
CORE_ADDR memaddr;
char *myaddr;
int len;
{
register char *cp;
char procfile[MAXPATHLEN];
ssize_t amount;
int fd;
if (devmem)
{
sprintf (procfile, "/proc/%d/mem", p->p_pid);
fd = open (procfile, O_RDONLY, 0);
if (fd < 0)
{
error ("cannot open %s", procfile);
close (fd);
return (0);
}
cp = myaddr;
while (len > 0)
{
errno = 0;
if (lseek (fd, (off_t)memaddr, 0) == -1 && errno != 0)
{
error ("invalid address (%x) in %s", memaddr, procfile);
break;
}
amount = read (fd, cp, len);
if (amount < 0)
{
error ("error reading %s", procfile);
break;
}
if (amount == 0)
{
error ("EOF reading %s", procfile);
break;
}
cp += amount;
memaddr += amount;
len -= amount;
}
close (fd);
return ((ssize_t) (cp - myaddr));
}
else
return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
}
static struct kinfo_proc kp;
/*
* try to do what kvm_proclist in libkvm would do
*/
static int
kvm_proclist (cfd, pid, p, cnt)
int cfd, pid, *cnt;
struct proc *p;
{
struct proc lp;
for (; p != NULL; p = LIST_NEXT(&lp, p_list)) {
if (!kvm_read(cfd, (CORE_ADDR)p, (char *)&lp, sizeof (lp)))
return (0);
if (lp.p_pid != pid)
continue;
kp.ki_paddr = p;
*cnt = 1;
return (1);
}
*cnt = 0;
return (0);
}
/*
* try to do what kvm_deadprocs in libkvm would do
*/
static struct kinfo_proc *
kvm_deadprocs (cfd, pid, cnt)
int cfd, pid, *cnt;
{
CORE_ADDR allproc, zombproc;
struct proc *p;
allproc = ksym_lookup("allproc");
if (kvm_read(cfd, allproc, (char *)&p, sizeof (p)) == 0)
return (NULL);
kvm_proclist (cfd, pid, p, cnt);
if (!*cnt) {
zombproc = ksym_lookup("zombproc");
if (kvm_read(cfd, zombproc, (char *)&p, sizeof (p)) == 0)
return (NULL);
kvm_proclist (cfd, pid, p, cnt);
}
return (&kp);
}
static CORE_ADDR
kvm_getpcpu (cfd, cpuid)
int cfd, cpuid;
{
SLIST_HEAD(, pcpu) pcpu_head;
struct pcpu lpc;
struct pcpu *pc;
physrd (cfd, ksym_lookup ("cpuhead") - KERNOFF, (char*)&pcpu_head,
sizeof pcpu_head);
pc = SLIST_FIRST (&pcpu_head);
for (; pc != NULL; pc = SLIST_NEXT (&lpc, pc_allcpu))
{
kvm_read (cfd, (CORE_ADDR)pc, (char*)&lpc, sizeof lpc);
if (lpc.pc_cpuid == cpuid)
break;
}
return ((CORE_ADDR)pc);
}
/*
* try to do what kvm_getprocs in libkvm would do
*/
static struct kinfo_proc *
kvm_getprocs (cfd, op, proc, cnt)
int cfd, op, *cnt;
CORE_ADDR proc;
{
int mib[4], size;
*cnt = 0;
/* assume it's a pid */
if (devmem) { /* "live" kernel, use sysctl */
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PID;
mib[3] = (int)proc;
size = sizeof (kp);
if (sysctl (mib, 4, &kp, &size, NULL, 0) < 0) {
perror("sysctl");
*cnt = 0;
return (NULL);
}
if (!size)
*cnt = 0;
else
*cnt = 1;
return (&kp);
} else
return (kvm_deadprocs (cfd, (int)proc, cnt));
}
static int
physrd (cfd, addr, dat, len)
int cfd;
u_int addr;
char *dat;
int len;
{
if (lseek (cfd, (off_t)addr, L_SET) == -1)
return (-1);
return (read (cfd, dat, len));
}
static CORE_ADDR
kvtophys (fd, addr)
int fd;
CORE_ADDR addr;
{
CORE_ADDR v;
unsigned int pte;
static CORE_ADDR PTD = -1;
CORE_ADDR current_ptd;
/*
* We may no longer have a linear system page table...
*
* Here's the scoop. IdlePTD contains the physical address
* of a page table directory that always maps the kernel.
* IdlePTD is in memory that is mapped 1-to-1, so we can
* find it easily given its 'virtual' address from ksym_lookup().
* For hysterical reasons, the value of IdlePTD is stored in sbr.
*
* To look up a kernel address, we first convert it to a 1st-level
* address and look it up in IdlePTD. This gives us the physical
* address of a page table page; we extract the 2nd-level part of
* VA and read the 2nd-level pte. Finally, we add the offset part
* of the VA into the physical address from the pte and return it.
*
* User addresses are a little more complicated. If we don't have
* a current PCB from read_pcb(), we use PTD, which is the (fixed)
* virtual address of the current ptd. Since it's NOT in 1-to-1
* kernel space, we must look it up using IdlePTD. If we do have
* a pcb, we get the ptd from pcb_ptd.
*/
if (INKERNEL (addr))
current_ptd = sbr;
else if (found_pcb == 0)
{
if (PTD == -1)
PTD = kvtophys (fd, ksym_lookup ("PTD"));
current_ptd = PTD;
}
else
current_ptd = pcb.pcb_cr3;
/*
* Read the first-level page table (ptd).
*/
v = current_ptd + ( (unsigned)addr >> PDRSHIFT) * sizeof pte;
if (physrd (fd, v, (char *)&pte, sizeof pte) < 0 || (pte&PG_V) == 0)
return (~0);
if (pte & PG_PS)
{
/*
* No second-level page table; ptd describes one 4MB page.
* (We assume that the kernel wouldn't set PG_PS without enabling
* it cr0, and that the kernel doesn't support 36-bit physical
* addresses).
*/
#define PAGE4M_MASK (NBPDR - 1)
#define PG_FRAME4M (~PAGE4M_MASK)
addr = (pte & PG_FRAME4M) + (addr & PAGE4M_MASK);
}
else
{
/*
* Read the second-level page table.
*/
v = (pte&PG_FRAME) + ((addr >> PAGE_SHIFT)&(NPTEPG-1)) * sizeof pte;
if (physrd (fd, v, (char *) &pte, sizeof (pte)) < 0 || (pte&PG_V) == 0)
return (~0);
addr = (pte & PG_FRAME) + (addr & PAGE_MASK);
}
#if 0
printf ("vtophys (%x) -> %x\n", oldaddr, addr);
#endif
return (addr);
}
static int
read_pcb (fd, uaddr)
int fd;
CORE_ADDR uaddr;
{
int i;
int noreg;
CORE_ADDR nuaddr = uaddr;
/* need this for the `proc' command to work */
if (INKERNEL(uaddr))
nuaddr = kvtophys(fd, uaddr);
if (physrd (fd, nuaddr, (char *)&pcb, sizeof pcb) < 0)
{
error ("cannot read pcb at %x\n", uaddr);
return (-1);
}
/*
* get the register values out of the sys pcb and
* store them where `read_register' will find them.
*/
/*
* XXX many registers aren't available.
* XXX for the non-core case, the registers are stale - they are for
* the last context switch to the debugger.
* XXX gcc's register numbers aren't all #defined in tm-i386.h.
*/
noreg = 0;
for (i = 0; i < 3; ++i) /* eax,ecx,edx */
supply_register (i, (char *)&noreg);
supply_register (3, (char *)&pcb.pcb_ebx);
supply_register (SP_REGNUM, (char *)&pcb.pcb_esp);
supply_register (FP_REGNUM, (char *)&pcb.pcb_ebp);
supply_register (6, (char *)&pcb.pcb_esi);
supply_register (7, (char *)&pcb.pcb_edi);
supply_register (PC_REGNUM, (char *)&pcb.pcb_eip);
for (i = 9; i < 14; ++i) /* eflags, cs, ss, ds, es, fs */
supply_register (i, (char *)&noreg);
supply_register (15, (char *)&pcb.pcb_gs);
/* XXX 80387 registers? */
}
/*
* read len bytes from kernel virtual address 'addr' into local
* buffer 'buf'. Return numbert of bytes if read ok, 0 otherwise. On read
* errors, portion of buffer not read is zeroed.
*/
static int
kernel_core_file_hook (fd, addr, buf, len)
int fd;
CORE_ADDR addr;
char *buf;
int len;
{
int i;
CORE_ADDR paddr;
register char *cp;
int cc;
cp = buf;
while (len > 0)
{
paddr = kvtophys (fd, addr);
if (paddr == ~0)
{
memset (buf, '\000', len);
break;
}
/* we can't read across a page boundary */
i = min (len, PAGE_SIZE - (addr & PAGE_MASK));
if ( (cc = physrd (fd, paddr, cp, i)) <= 0)
{
memset (cp, '\000', len);
return (cp - buf);
}
cp += cc;
addr += cc;
len -= cc;
}
return (cp - buf);
}
static struct target_ops kcore_ops;
void
_initialize_kcorelow()
{
kcore_ops.to_shortname = "kcore";
kcore_ops.to_longname = "Kernel core dump file";
kcore_ops.to_doc =
"Use a core file as a target. Specify the filename of the core file.";
kcore_ops.to_open = kcore_open;
kcore_ops.to_close = kcore_close;
kcore_ops.to_attach = find_default_attach;
kcore_ops.to_detach = kcore_detach;
kcore_ops.to_fetch_registers = get_kcore_registers;
kcore_ops.to_xfer_memory = kcore_xfer_kmem;
kcore_ops.to_files_info = kcore_files_info;
kcore_ops.to_create_inferior = find_default_create_inferior;
kcore_ops.to_stratum = kcore_stratum;
kcore_ops.to_has_memory = 1;
kcore_ops.to_has_stack = 1;
kcore_ops.to_has_registers = 1;
kcore_ops.to_magic = OPS_MAGIC;
add_target (&kcore_ops);
add_com ("proc", class_obscure, set_proc_cmd, "Set current process context");
add_com ("cpu", class_obscure, set_cpu_cmd, "Set current cpu");
}