d607f4c3e3
without VIMAGE virtualization in the kernel. If we cannot resolve a symbol try to see if we can find it with prefix of the virtualized subsystem, currently only "vnet_entry" by identifying either the vnet of the current process for a live system or the vnet of proc0 (or of dumptid if compiled in a non-default way). The way this is done currently allows us to only touch libkvm but no single application. Once we are going to virtualize more subsystems we will have to review this decision for better scaling. Submitted by: rwatson (initial version of kvm_vnet.c, lots of ideas) Reviewed by: rwatson Approved by: re (kib)
238 lines
6.4 KiB
C
238 lines
6.4 KiB
C
/*-
|
|
* Copyright (c) 2009 Robert N. M. Watson
|
|
* Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
|
|
#define _WANT_PRISON
|
|
#define _WANT_UCRED
|
|
#define _WANT_VNET
|
|
|
|
#include <sys/_lock.h>
|
|
#include <sys/_mutex.h>
|
|
#include <sys/_task.h>
|
|
#include <sys/jail.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/types.h>
|
|
#include <sys/vimage.h>
|
|
|
|
#include <net/vnet.h>
|
|
|
|
#include <nlist.h>
|
|
#include <kvm.h>
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
#include "kvm_private.h"
|
|
|
|
/*
|
|
* Set up libkvm to handle virtual network stack symbols by selecting a
|
|
* starting pid.
|
|
*/
|
|
int
|
|
_kvm_vnet_selectpid(kvm_t *kd, pid_t pid)
|
|
{
|
|
struct proc proc;
|
|
struct thread td;
|
|
struct ucred cred;
|
|
struct prison prison;
|
|
struct vnet vnet;
|
|
struct nlist nl[] = {
|
|
/*
|
|
* Note: kvm_nlist strips the first '_' so add an extra one
|
|
* here to __{start,stop}_set_vnet.
|
|
*/
|
|
#define NLIST_START_VNET 0
|
|
{ .n_name = "___start_" VNET_SETNAME },
|
|
#define NLIST_STOP_VNET 1
|
|
{ .n_name = "___stop_" VNET_SETNAME },
|
|
#define NLIST_VNET_HEAD 2
|
|
{ .n_name = "vnet_head" },
|
|
#define NLIST_ALLPROC 3
|
|
{ .n_name = "allproc" },
|
|
#define NLIST_DUMPTID 4
|
|
{ .n_name = "dumptid" },
|
|
#define NLIST_PROC0 5
|
|
{ .n_name = "proc0" },
|
|
{ .n_name = NULL },
|
|
};
|
|
uintptr_t procp, tdp, credp;
|
|
lwpid_t dumptid;
|
|
|
|
/*
|
|
* Locate and cache locations of important symbols
|
|
* using the internal version of _kvm_nlist, turning
|
|
* off initialization to avoid recursion in case of
|
|
* unresolveable symbols.
|
|
*/
|
|
if (_kvm_nlist(kd, nl, 0) != 0) {
|
|
/*
|
|
* XXX-BZ: ___start_/___stop_VNET_SETNAME may fail.
|
|
* For now do not report an error here as we are called
|
|
* internally and in `void context' until we merge the
|
|
* functionality to optionally activate this into programs.
|
|
* By that time we can properly fail and let the callers
|
|
* handle the error.
|
|
*/
|
|
/* _kvm_err(kd, kd->program, "%s: no namelist", __func__); */
|
|
return (-1);
|
|
}
|
|
|
|
/*
|
|
* Auto-detect if this is a crashdump by reading dumptid.
|
|
*/
|
|
dumptid = 0;
|
|
if (nl[NLIST_DUMPTID].n_value) {
|
|
if (kvm_read(kd, nl[NLIST_DUMPTID].n_value, &dumptid,
|
|
sizeof(dumptid)) != sizeof(dumptid)) {
|
|
_kvm_err(kd, kd->program, "%s: dumptid", __func__);
|
|
return (-1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* First, find the process for this pid. If we are workig on a dump,
|
|
* either locate the thread dumptid is refering to or proc0.
|
|
* Based on either, take the address of the ucred.
|
|
*/
|
|
credp = 0;
|
|
|
|
procp = nl[NLIST_ALLPROC].n_value;
|
|
#define VMCORE_VNET_OF_PROC0
|
|
#ifdef VMCORE_VNET_OF_PROC0
|
|
if (dumptid > 0) {
|
|
procp = nl[NLIST_PROC0].n_value;
|
|
pid = 0;
|
|
}
|
|
#endif
|
|
while (procp != 0) {
|
|
if (kvm_read(kd, procp, &proc, sizeof(proc)) != sizeof(proc)) {
|
|
_kvm_err(kd, kd->program, "%s: proc", __func__);
|
|
return (-1);
|
|
}
|
|
#ifndef VMCORE_VNET_OF_PROC0
|
|
if (dumptid > 0) {
|
|
tdp = (uintptr_t)TAILQ_FIRST(&proc.p_threads);
|
|
while (tdp != 0) {
|
|
if (kvm_read(kd, tdp, &td, sizeof(td)) !=
|
|
sizeof(td)) {
|
|
_kvm_err(kd, kd->program, "%s: thread",
|
|
__func__);
|
|
return (-1);
|
|
}
|
|
if (td.td_tid == dumptid) {
|
|
credp = (uintptr_t)td.td_ucred;
|
|
break;
|
|
}
|
|
tdp = (uintptr_t)TAILQ_NEXT(&td, td_plist);
|
|
}
|
|
} else
|
|
#endif
|
|
if (proc.p_pid == pid)
|
|
credp = (uintptr_t)proc.p_ucred;
|
|
if (credp != 0)
|
|
break;
|
|
procp = (uintptr_t)LIST_NEXT(&proc, p_list);
|
|
}
|
|
if (credp == 0) {
|
|
_kvm_err(kd, kd->program, "%s: pid/tid not found", __func__);
|
|
return (-1);
|
|
}
|
|
if (kvm_read(kd, (uintptr_t)credp, &cred, sizeof(cred)) !=
|
|
sizeof(cred)) {
|
|
_kvm_err(kd, kd->program, "%s: cred", __func__);
|
|
return (-1);
|
|
}
|
|
if (cred.cr_prison == NULL) {
|
|
_kvm_err(kd, kd->program, "%s: no jail", __func__);
|
|
return (-1);
|
|
}
|
|
if (kvm_read(kd, (uintptr_t)cred.cr_prison, &prison, sizeof(prison)) !=
|
|
sizeof(prison)) {
|
|
_kvm_err(kd, kd->program, "%s: prison", __func__);
|
|
return (-1);
|
|
}
|
|
if (prison.pr_vnet == NULL) {
|
|
_kvm_err(kd, kd->program, "%s: no vnet", __func__);
|
|
return (-1);
|
|
}
|
|
if (kvm_read(kd, (uintptr_t)prison.pr_vnet, &vnet, sizeof(vnet)) !=
|
|
sizeof(vnet)) {
|
|
_kvm_err(kd, kd->program, "%s: vnet", __func__);
|
|
return (-1);
|
|
}
|
|
if (vnet.vnet_magic_n != VNET_MAGIC_N) {
|
|
_kvm_err(kd, kd->program, "%s: invalid vnet magic#", __func__);
|
|
return (-1);
|
|
}
|
|
kd->vnet_initialized = 1;
|
|
kd->vnet_start = nl[NLIST_START_VNET].n_value;
|
|
kd->vnet_stop = nl[NLIST_STOP_VNET].n_value;
|
|
kd->vnet_current = (uintptr_t)prison.pr_vnet;
|
|
kd->vnet_base = (uintptr_t)vnet.vnet_data_mem - kd->vnet_start;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check whether the vnet module has been initialized sucessfully
|
|
* or not, intialize it if permitted.
|
|
*/
|
|
int
|
|
_kvm_vnet_initialized(kvm_t *kd, int intialize)
|
|
{
|
|
|
|
if (kd->vnet_initialized || !intialize)
|
|
return (kd->vnet_initialized);
|
|
|
|
(void) _kvm_vnet_selectpid(kd, getpid());
|
|
|
|
return (kd->vnet_initialized);
|
|
}
|
|
|
|
/*
|
|
* Check whether the value is within the vnet symbol range and
|
|
* only if so adjust the offset relative to the current base.
|
|
*/
|
|
uintptr_t
|
|
_kvm_vnet_validaddr(kvm_t *kd, uintptr_t value)
|
|
{
|
|
|
|
if (value == 0)
|
|
return (value);
|
|
|
|
if (!kd->vnet_initialized)
|
|
return (value);
|
|
|
|
if (value < kd->vnet_start || value >= kd->vnet_stop)
|
|
return (value);
|
|
|
|
return (kd->vnet_base + value);
|
|
}
|