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freebsd/lib/libmemstat/memstat_malloc.c
Robert Watson 448036945e Make pointer argument to kread_string() const since the kernel structure
field is const, and then employ __DECONST before getting into the kvm
code.  This eliminates a gcc 4.2 warning about losing constification.

__DECONST advice from:	sam
2007-05-21 18:16:04 +00:00

410 lines
11 KiB
C

/*-
* Copyright (c) 2005 Robert N. M. Watson
* 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/sysctl.h>
#include <err.h>
#include <errno.h>
#include <kvm.h>
#include <nlist.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "memstat.h"
#include "memstat_internal.h"
static struct nlist namelist[] = {
#define X_KMEMSTATISTICS 0
{ .n_name = "_kmemstatistics" },
#define X_MP_MAXCPUS 1
{ .n_name = "_mp_maxcpus" },
{ .n_name = "" },
};
/*
* Extract malloc(9) statistics from the running kernel, and store all memory
* type information in the passed list. For each type, check the list for an
* existing entry with the right name/allocator -- if present, update that
* entry. Otherwise, add a new entry. On error, the entire list will be
* cleared, as entries will be in an inconsistent state.
*
* To reduce the level of work for a list that starts empty, we keep around a
* hint as to whether it was empty when we began, so we can avoid searching
* the list for entries to update. Updates are O(n^2) due to searching for
* each entry before adding it.
*/
int
memstat_sysctl_malloc(struct memory_type_list *list, int flags)
{
struct malloc_type_stream_header *mtshp;
struct malloc_type_header *mthp;
struct malloc_type_stats *mtsp;
struct memory_type *mtp;
int count, hint_dontsearch, i, j, maxcpus;
char *buffer, *p;
size_t size;
hint_dontsearch = LIST_EMPTY(&list->mtl_list);
/*
* Query the number of CPUs, number of malloc types so that we can
* guess an initial buffer size. We loop until we succeed or really
* fail. Note that the value of maxcpus we query using sysctl is not
* the version we use when processing the real data -- that is read
* from the header.
*/
retry:
size = sizeof(maxcpus);
if (sysctlbyname("kern.smp.maxcpus", &maxcpus, &size, NULL, 0) < 0) {
if (errno == EACCES || errno == EPERM)
list->mtl_error = MEMSTAT_ERROR_PERMISSION;
else
list->mtl_error = MEMSTAT_ERROR_DATAERROR;
return (-1);
}
if (size != sizeof(maxcpus)) {
list->mtl_error = MEMSTAT_ERROR_DATAERROR;
return (-1);
}
if (maxcpus > MEMSTAT_MAXCPU) {
list->mtl_error = MEMSTAT_ERROR_TOOMANYCPUS;
return (-1);
}
size = sizeof(count);
if (sysctlbyname("kern.malloc_count", &count, &size, NULL, 0) < 0) {
if (errno == EACCES || errno == EPERM)
list->mtl_error = MEMSTAT_ERROR_PERMISSION;
else
list->mtl_error = MEMSTAT_ERROR_VERSION;
return (-1);
}
if (size != sizeof(count)) {
list->mtl_error = MEMSTAT_ERROR_DATAERROR;
return (-1);
}
size = sizeof(*mthp) + count * (sizeof(*mthp) + sizeof(*mtsp) *
maxcpus);
buffer = malloc(size);
if (buffer == NULL) {
list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
return (-1);
}
if (sysctlbyname("kern.malloc_stats", buffer, &size, NULL, 0) < 0) {
/*
* XXXRW: ENOMEM is an ambiguous return, we should bound the
* number of loops, perhaps.
*/
if (errno == ENOMEM) {
free(buffer);
goto retry;
}
if (errno == EACCES || errno == EPERM)
list->mtl_error = MEMSTAT_ERROR_PERMISSION;
else
list->mtl_error = MEMSTAT_ERROR_VERSION;
free(buffer);
return (-1);
}
if (size == 0) {
free(buffer);
return (0);
}
if (size < sizeof(*mtshp)) {
list->mtl_error = MEMSTAT_ERROR_VERSION;
free(buffer);
return (-1);
}
p = buffer;
mtshp = (struct malloc_type_stream_header *)p;
p += sizeof(*mtshp);
if (mtshp->mtsh_version != MALLOC_TYPE_STREAM_VERSION) {
list->mtl_error = MEMSTAT_ERROR_VERSION;
free(buffer);
return (-1);
}
if (mtshp->mtsh_maxcpus > MEMSTAT_MAXCPU) {
list->mtl_error = MEMSTAT_ERROR_TOOMANYCPUS;
free(buffer);
return (-1);
}
/*
* For the remainder of this function, we are quite trusting about
* the layout of structures and sizes, since we've determined we have
* a matching version and acceptable CPU count.
*/
maxcpus = mtshp->mtsh_maxcpus;
count = mtshp->mtsh_count;
for (i = 0; i < count; i++) {
mthp = (struct malloc_type_header *)p;
p += sizeof(*mthp);
if (hint_dontsearch == 0) {
mtp = memstat_mtl_find(list, ALLOCATOR_MALLOC,
mthp->mth_name);
} else
mtp = NULL;
if (mtp == NULL)
mtp = _memstat_mt_allocate(list, ALLOCATOR_MALLOC,
mthp->mth_name);
if (mtp == NULL) {
_memstat_mtl_empty(list);
free(buffer);
list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
return (-1);
}
/*
* Reset the statistics on a current node.
*/
_memstat_mt_reset_stats(mtp);
for (j = 0; j < maxcpus; j++) {
mtsp = (struct malloc_type_stats *)p;
p += sizeof(*mtsp);
/*
* Sumarize raw statistics across CPUs into coalesced
* statistics.
*/
mtp->mt_memalloced += mtsp->mts_memalloced;
mtp->mt_memfreed += mtsp->mts_memfreed;
mtp->mt_numallocs += mtsp->mts_numallocs;
mtp->mt_numfrees += mtsp->mts_numfrees;
mtp->mt_sizemask |= mtsp->mts_size;
/*
* Copies of per-CPU statistics.
*/
mtp->mt_percpu_alloc[j].mtp_memalloced =
mtsp->mts_memalloced;
mtp->mt_percpu_alloc[j].mtp_memfreed =
mtsp->mts_memfreed;
mtp->mt_percpu_alloc[j].mtp_numallocs =
mtsp->mts_numallocs;
mtp->mt_percpu_alloc[j].mtp_numfrees =
mtsp->mts_numfrees;
mtp->mt_percpu_alloc[j].mtp_sizemask =
mtsp->mts_size;
}
/*
* Derived cross-CPU statistics.
*/
mtp->mt_bytes = mtp->mt_memalloced - mtp->mt_memfreed;
mtp->mt_count = mtp->mt_numallocs - mtp->mt_numfrees;
}
free(buffer);
return (0);
}
static int
kread(kvm_t *kvm, void *kvm_pointer, void *address, size_t size,
size_t offset)
{
ssize_t ret;
ret = kvm_read(kvm, (unsigned long)kvm_pointer + offset, address,
size);
if (ret < 0)
return (MEMSTAT_ERROR_KVM);
if ((size_t)ret != size)
return (MEMSTAT_ERROR_KVM_SHORTREAD);
return (0);
}
static int
kread_string(kvm_t *kvm, const void *kvm_pointer, char *buffer, int buflen)
{
ssize_t ret;
int i;
for (i = 0; i < buflen; i++) {
ret = kvm_read(kvm, __DECONST(unsigned long, kvm_pointer) +
i, &(buffer[i]), sizeof(char));
if (ret < 0)
return (MEMSTAT_ERROR_KVM);
if ((size_t)ret != sizeof(char))
return (MEMSTAT_ERROR_KVM_SHORTREAD);
if (buffer[i] == '\0')
return (0);
}
/* Truncate. */
buffer[i-1] = '\0';
return (0);
}
static int
kread_symbol(kvm_t *kvm, int index, void *address, size_t size,
size_t offset)
{
ssize_t ret;
ret = kvm_read(kvm, namelist[index].n_value + offset, address, size);
if (ret < 0)
return (MEMSTAT_ERROR_KVM);
if ((size_t)ret != size)
return (MEMSTAT_ERROR_KVM_SHORTREAD);
return (0);
}
int
memstat_kvm_malloc(struct memory_type_list *list, void *kvm_handle)
{
struct memory_type *mtp;
void *kmemstatistics;
int hint_dontsearch, j, mp_maxcpus, ret;
char name[MEMTYPE_MAXNAME];
struct malloc_type_stats mts[MEMSTAT_MAXCPU], *mtsp;
struct malloc_type type, *typep;
kvm_t *kvm;
kvm = (kvm_t *)kvm_handle;
hint_dontsearch = LIST_EMPTY(&list->mtl_list);
if (kvm_nlist(kvm, namelist) != 0) {
list->mtl_error = MEMSTAT_ERROR_KVM;
return (-1);
}
if (namelist[X_KMEMSTATISTICS].n_type == 0 ||
namelist[X_KMEMSTATISTICS].n_value == 0) {
list->mtl_error = MEMSTAT_ERROR_KVM_NOSYMBOL;
return (-1);
}
ret = kread_symbol(kvm, X_MP_MAXCPUS, &mp_maxcpus,
sizeof(mp_maxcpus), 0);
if (ret != 0) {
list->mtl_error = ret;
return (-1);
}
if (mp_maxcpus > MEMSTAT_MAXCPU) {
list->mtl_error = MEMSTAT_ERROR_TOOMANYCPUS;
return (-1);
}
ret = kread_symbol(kvm, X_KMEMSTATISTICS, &kmemstatistics,
sizeof(kmemstatistics), 0);
if (ret != 0) {
list->mtl_error = ret;
return (-1);
}
for (typep = kmemstatistics; typep != NULL; typep = type.ks_next) {
ret = kread(kvm, typep, &type, sizeof(type), 0);
if (ret != 0) {
_memstat_mtl_empty(list);
list->mtl_error = ret;
return (-1);
}
ret = kread_string(kvm, (void *)type.ks_shortdesc, name,
MEMTYPE_MAXNAME);
if (ret != 0) {
_memstat_mtl_empty(list);
list->mtl_error = ret;
return (-1);
}
/*
* Take advantage of explicit knowledge that
* malloc_type_internal is simply an array of statistics
* structures of number MAXCPU. Since our compile-time
* value for MAXCPU may differ from the kernel's, we
* populate our own array.
*/
ret = kread(kvm, type.ks_handle, mts, mp_maxcpus *
sizeof(struct malloc_type_stats), 0);
if (ret != 0) {
_memstat_mtl_empty(list);
list->mtl_error = ret;
return (-1);
}
if (hint_dontsearch == 0) {
mtp = memstat_mtl_find(list, ALLOCATOR_MALLOC, name);
} else
mtp = NULL;
if (mtp == NULL)
mtp = _memstat_mt_allocate(list, ALLOCATOR_MALLOC,
name);
if (mtp == NULL) {
_memstat_mtl_empty(list);
list->mtl_error = MEMSTAT_ERROR_NOMEMORY;
return (-1);
}
/*
* This logic is replicated from kern_malloc.c, and should
* be kept in sync.
*/
_memstat_mt_reset_stats(mtp);
for (j = 0; j < mp_maxcpus; j++) {
mtsp = &mts[j];
mtp->mt_memalloced += mtsp->mts_memalloced;
mtp->mt_memfreed += mtsp->mts_memfreed;
mtp->mt_numallocs += mtsp->mts_numallocs;
mtp->mt_numfrees += mtsp->mts_numfrees;
mtp->mt_sizemask |= mtsp->mts_size;
mtp->mt_percpu_alloc[j].mtp_memalloced =
mtsp->mts_memalloced;
mtp->mt_percpu_alloc[j].mtp_memfreed =
mtsp->mts_memfreed;
mtp->mt_percpu_alloc[j].mtp_numallocs =
mtsp->mts_numallocs;
mtp->mt_percpu_alloc[j].mtp_numfrees =
mtsp->mts_numfrees;
mtp->mt_percpu_alloc[j].mtp_sizemask =
mtsp->mts_size;
}
mtp->mt_bytes = mtp->mt_memalloced - mtp->mt_memfreed;
mtp->mt_count = mtp->mt_numallocs - mtp->mt_numfrees;
}
return (0);
}