freebsd-dev/lib/libkvm/kvm_cptime.c
John Baldwin 7f911abe54 Add support to libkvm for reading vmcores from other architectures.
- Add a kvaddr_type to represent kernel virtual addresses instead of
  unsigned long.
- Add a struct kvm_nlist which is a stripped down version of struct nlist
  that uses kvaddr_t for n_value.
- Add a kvm_native() routine that returns true if an open kvm descriptor
  is for a native kernel and memory image.
- Add a kvm_open2() function similar to kvm_openfiles().  It drops the
  unused 'swapfile' argument and adds a new function pointer argument for
  a symbol resolving function.  Native kernels still use _fdnlist() from
  libc to resolve symbols if a resolver function is not supplied, but cross
  kernels require a resolver.
- Add a kvm_nlist2() function similar to kvm_nlist() except that it uses
  struct kvm_nlist instead of struct nlist.
- Add a kvm_read2() function similar to kvm_read() except that it uses
  kvaddr_t instead of unsigned long for the kernel virtual address.
- Add a new kvm_arch switch of routines needed by a vmcore backend.
  Each backend is responsible for implementing kvm_read2() for a given
  vmcore format.
- Use libelf to read headers from ELF kernels and cores (except for
  powerpc cores).
- Add internal helper routines for the common page offset hash table used
  by the minidump backends.
- Port all of the existing kvm backends to implement a kvm_arch switch and
  to be cross-friendly by using private constants instead of ones that
  vary by platform (e.g. PAGE_SIZE).  Static assertions are present when
  a given backend is compiled natively to ensure the private constants
  match the real ones.
- Enable all of the existing vmcore backends on all platforms.  This means
  that libkvm on any platform should be able to perform KVA translation
  and read data from a vmcore of any platform.

Tested on:	amd64, i386, sparc64 (marius)
Differential Revision:	https://reviews.freebsd.org/D3341
2015-11-27 18:58:26 +00:00

141 lines
3.7 KiB
C

/*-
* Copyright (c) 2008 Yahoo!, Inc.
* All rights reserved.
* Written by: John Baldwin <jhb@FreeBSD.org>
*
* 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.
* 3. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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>
#include <sys/pcpu.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <kvm.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include "kvm_private.h"
static struct nlist kvm_cp_time_nl[] = {
{ .n_name = "_cp_time" }, /* (deprecated) */
{ .n_name = NULL },
};
#define NL_CP_TIME 0
static int kvm_cp_time_cached;
static int
_kvm_cp_time_init(kvm_t *kd)
{
if (kvm_nlist(kd, kvm_cp_time_nl) < 0)
return (-1);
kvm_cp_time_cached = 1;
return (0);
}
static int
getsysctl(kvm_t *kd, const char *name, void *buf, size_t len)
{
size_t nlen;
nlen = len;
if (sysctlbyname(name, buf, &nlen, NULL, 0) < 0) {
_kvm_err(kd, kd->program, "cannot read sysctl %s:%s", name,
strerror(errno));
return (-1);
}
if (nlen != len) {
_kvm_err(kd, kd->program, "sysctl %s has unexpected size",
name);
return (-1);
}
return (0);
}
int
kvm_getcptime(kvm_t *kd, long *cp_time)
{
struct pcpu *pc;
int i, j, maxcpu;
if (kd == NULL) {
kvm_cp_time_cached = 0;
return (0);
}
if (ISALIVE(kd))
return (getsysctl(kd, "kern.cp_time", cp_time, sizeof(long) *
CPUSTATES));
if (!kd->arch->ka_native(kd)) {
_kvm_err(kd, kd->program,
"cannot read cp_time from non-native core");
return (-1);
}
if (kvm_cp_time_cached == 0) {
if (_kvm_cp_time_init(kd) < 0)
return (-1);
}
/* If this kernel has a "cp_time[]" symbol, then just read that. */
if (kvm_cp_time_nl[NL_CP_TIME].n_value != 0) {
if (kvm_read(kd, kvm_cp_time_nl[NL_CP_TIME].n_value, cp_time,
sizeof(long) * CPUSTATES) != sizeof(long) * CPUSTATES) {
_kvm_err(kd, kd->program, "cannot read cp_time array");
return (-1);
}
return (0);
}
/*
* If we don't have that symbol, then we have to simulate
* "cp_time[]" by adding up the individual times for each CPU.
*/
maxcpu = kvm_getmaxcpu(kd);
if (maxcpu < 0)
return (-1);
for (i = 0; i < CPUSTATES; i++)
cp_time[i] = 0;
for (i = 0; i < maxcpu; i++) {
pc = kvm_getpcpu(kd, i);
if (pc == NULL)
continue;
if (pc == (void *)-1)
return (-1);
for (j = 0; j < CPUSTATES; j++)
cp_time[j] += pc->pc_cp_time[j];
free(pc);
}
return (0);
}