freebsd-skq/sys/kern/kern_malloc.c
Mateusz Guzik 9aa6d792b5 malloc: retire malloc_last_fail
The routine does not serve any practical purpose.

Memory can be allocated in many other ways and most consumers pass the
M_WAITOK flag, making malloc not fail in the first place.

Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D27143
2020-11-12 20:22:58 +00:00

1547 lines
38 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1987, 1991, 1993
* The Regents of the University of California.
* Copyright (c) 2005-2009 Robert N. M. Watson
* Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> (mallocarray)
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)kern_malloc.c 8.3 (Berkeley) 1/4/94
*/
/*
* Kernel malloc(9) implementation -- general purpose kernel memory allocator
* based on memory types. Back end is implemented using the UMA(9) zone
* allocator. A set of fixed-size buckets are used for smaller allocations,
* and a special UMA allocation interface is used for larger allocations.
* Callers declare memory types, and statistics are maintained independently
* for each memory type. Statistics are maintained per-CPU for performance
* reasons. See malloc(9) and comments in malloc.h for a detailed
* description.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/vmmeter.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/sbuf.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/vmem.h>
#ifdef EPOCH_TRACE
#include <sys/epoch.h>
#endif
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_domainset.h>
#include <vm/vm_pageout.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
#include <vm/vm_pagequeue.h>
#include <vm/uma.h>
#include <vm/uma_int.h>
#include <vm/uma_dbg.h>
#ifdef DEBUG_MEMGUARD
#include <vm/memguard.h>
#endif
#ifdef DEBUG_REDZONE
#include <vm/redzone.h>
#endif
#if defined(INVARIANTS) && defined(__i386__)
#include <machine/cpu.h>
#endif
#include <ddb/ddb.h>
#ifdef KDTRACE_HOOKS
#include <sys/dtrace_bsd.h>
bool __read_frequently dtrace_malloc_enabled;
dtrace_malloc_probe_func_t __read_mostly dtrace_malloc_probe;
#endif
#if defined(INVARIANTS) || defined(MALLOC_MAKE_FAILURES) || \
defined(DEBUG_MEMGUARD) || defined(DEBUG_REDZONE)
#define MALLOC_DEBUG 1
#endif
/*
* When realloc() is called, if the new size is sufficiently smaller than
* the old size, realloc() will allocate a new, smaller block to avoid
* wasting memory. 'Sufficiently smaller' is defined as: newsize <=
* oldsize / 2^n, where REALLOC_FRACTION defines the value of 'n'.
*/
#ifndef REALLOC_FRACTION
#define REALLOC_FRACTION 1 /* new block if <= half the size */
#endif
/*
* Centrally define some common malloc types.
*/
MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
static struct malloc_type *kmemstatistics;
static int kmemcount;
#define KMEM_ZSHIFT 4
#define KMEM_ZBASE 16
#define KMEM_ZMASK (KMEM_ZBASE - 1)
#define KMEM_ZMAX 65536
#define KMEM_ZSIZE (KMEM_ZMAX >> KMEM_ZSHIFT)
static uint8_t kmemsize[KMEM_ZSIZE + 1];
#ifndef MALLOC_DEBUG_MAXZONES
#define MALLOC_DEBUG_MAXZONES 1
#endif
static int numzones = MALLOC_DEBUG_MAXZONES;
/*
* Small malloc(9) memory allocations are allocated from a set of UMA buckets
* of various sizes.
*
* Warning: the layout of the struct is duplicated in libmemstat for KVM support.
*
* XXX: The comment here used to read "These won't be powers of two for
* long." It's possible that a significant amount of wasted memory could be
* recovered by tuning the sizes of these buckets.
*/
struct {
int kz_size;
const char *kz_name;
uma_zone_t kz_zone[MALLOC_DEBUG_MAXZONES];
} kmemzones[] = {
{16, "malloc-16", },
{32, "malloc-32", },
{64, "malloc-64", },
{128, "malloc-128", },
{256, "malloc-256", },
{384, "malloc-384", },
{512, "malloc-512", },
{1024, "malloc-1024", },
{2048, "malloc-2048", },
{4096, "malloc-4096", },
{8192, "malloc-8192", },
{16384, "malloc-16384", },
{32768, "malloc-32768", },
{65536, "malloc-65536", },
{0, NULL},
};
u_long vm_kmem_size;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RDTUN, &vm_kmem_size, 0,
"Size of kernel memory");
static u_long kmem_zmax = KMEM_ZMAX;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_zmax, CTLFLAG_RDTUN, &kmem_zmax, 0,
"Maximum allocation size that malloc(9) would use UMA as backend");
static u_long vm_kmem_size_min;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RDTUN, &vm_kmem_size_min, 0,
"Minimum size of kernel memory");
static u_long vm_kmem_size_max;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RDTUN, &vm_kmem_size_max, 0,
"Maximum size of kernel memory");
static u_int vm_kmem_size_scale;
SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RDTUN, &vm_kmem_size_scale, 0,
"Scale factor for kernel memory size");
static int sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_vm, OID_AUTO, kmem_map_size,
CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
sysctl_kmem_map_size, "LU", "Current kmem allocation size");
static int sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_vm, OID_AUTO, kmem_map_free,
CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
sysctl_kmem_map_free, "LU", "Free space in kmem");
static SYSCTL_NODE(_vm, OID_AUTO, malloc, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"Malloc information");
static u_int vm_malloc_zone_count = nitems(kmemzones);
SYSCTL_UINT(_vm_malloc, OID_AUTO, zone_count,
CTLFLAG_RD, &vm_malloc_zone_count, 0,
"Number of malloc zones");
static int sysctl_vm_malloc_zone_sizes(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_vm_malloc, OID_AUTO, zone_sizes,
CTLFLAG_RD | CTLTYPE_OPAQUE | CTLFLAG_MPSAFE, NULL, 0,
sysctl_vm_malloc_zone_sizes, "S", "Zone sizes used by malloc");
/*
* The malloc_mtx protects the kmemstatistics linked list.
*/
struct mtx malloc_mtx;
#ifdef MALLOC_PROFILE
uint64_t krequests[KMEM_ZSIZE + 1];
static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
#endif
static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
#if defined(MALLOC_MAKE_FAILURES) || (MALLOC_DEBUG_MAXZONES > 1)
static SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"Kernel malloc debugging options");
#endif
/*
* malloc(9) fault injection -- cause malloc failures every (n) mallocs when
* the caller specifies M_NOWAIT. If set to 0, no failures are caused.
*/
#ifdef MALLOC_MAKE_FAILURES
static int malloc_failure_rate;
static int malloc_nowait_count;
static int malloc_failure_count;
SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RWTUN,
&malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
&malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
#endif
static int
sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS)
{
u_long size;
size = uma_size();
return (sysctl_handle_long(oidp, &size, 0, req));
}
static int
sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS)
{
u_long size, limit;
/* The sysctl is unsigned, implement as a saturation value. */
size = uma_size();
limit = uma_limit();
if (size > limit)
size = 0;
else
size = limit - size;
return (sysctl_handle_long(oidp, &size, 0, req));
}
static int
sysctl_vm_malloc_zone_sizes(SYSCTL_HANDLER_ARGS)
{
int sizes[nitems(kmemzones)];
int i;
for (i = 0; i < nitems(kmemzones); i++) {
sizes[i] = kmemzones[i].kz_size;
}
return (SYSCTL_OUT(req, &sizes, sizeof(sizes)));
}
/*
* malloc(9) uma zone separation -- sub-page buffer overruns in one
* malloc type will affect only a subset of other malloc types.
*/
#if MALLOC_DEBUG_MAXZONES > 1
static void
tunable_set_numzones(void)
{
TUNABLE_INT_FETCH("debug.malloc.numzones",
&numzones);
/* Sanity check the number of malloc uma zones. */
if (numzones <= 0)
numzones = 1;
if (numzones > MALLOC_DEBUG_MAXZONES)
numzones = MALLOC_DEBUG_MAXZONES;
}
SYSINIT(numzones, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_set_numzones, NULL);
SYSCTL_INT(_debug_malloc, OID_AUTO, numzones, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
&numzones, 0, "Number of malloc uma subzones");
/*
* Any number that changes regularly is an okay choice for the
* offset. Build numbers are pretty good of you have them.
*/
static u_int zone_offset = __FreeBSD_version;
TUNABLE_INT("debug.malloc.zone_offset", &zone_offset);
SYSCTL_UINT(_debug_malloc, OID_AUTO, zone_offset, CTLFLAG_RDTUN,
&zone_offset, 0, "Separate malloc types by examining the "
"Nth character in the malloc type short description.");
static void
mtp_set_subzone(struct malloc_type *mtp)
{
struct malloc_type_internal *mtip;
const char *desc;
size_t len;
u_int val;
mtip = &mtp->ks_mti;
desc = mtp->ks_shortdesc;
if (desc == NULL || (len = strlen(desc)) == 0)
val = 0;
else
val = desc[zone_offset % len];
mtip->mti_zone = (val % numzones);
}
static inline u_int
mtp_get_subzone(struct malloc_type *mtp)
{
struct malloc_type_internal *mtip;
mtip = &mtp->ks_mti;
KASSERT(mtip->mti_zone < numzones,
("mti_zone %u out of range %d",
mtip->mti_zone, numzones));
return (mtip->mti_zone);
}
#elif MALLOC_DEBUG_MAXZONES == 0
#error "MALLOC_DEBUG_MAXZONES must be positive."
#else
static void
mtp_set_subzone(struct malloc_type *mtp)
{
struct malloc_type_internal *mtip;
mtip = &mtp->ks_mti;
mtip->mti_zone = 0;
}
static inline u_int
mtp_get_subzone(struct malloc_type *mtp)
{
return (0);
}
#endif /* MALLOC_DEBUG_MAXZONES > 1 */
/*
* An allocation has succeeded -- update malloc type statistics for the
* amount of bucket size. Occurs within a critical section so that the
* thread isn't preempted and doesn't migrate while updating per-PCU
* statistics.
*/
static void
malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
int zindx)
{
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp;
critical_enter();
mtip = &mtp->ks_mti;
mtsp = zpcpu_get(mtip->mti_stats);
if (size > 0) {
mtsp->mts_memalloced += size;
mtsp->mts_numallocs++;
}
if (zindx != -1)
mtsp->mts_size |= 1 << zindx;
#ifdef KDTRACE_HOOKS
if (__predict_false(dtrace_malloc_enabled)) {
uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
if (probe_id != 0)
(dtrace_malloc_probe)(probe_id,
(uintptr_t) mtp, (uintptr_t) mtip,
(uintptr_t) mtsp, size, zindx);
}
#endif
critical_exit();
}
void
malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
{
if (size > 0)
malloc_type_zone_allocated(mtp, size, -1);
}
/*
* A free operation has occurred -- update malloc type statistics for the
* amount of the bucket size. Occurs within a critical section so that the
* thread isn't preempted and doesn't migrate while updating per-CPU
* statistics.
*/
void
malloc_type_freed(struct malloc_type *mtp, unsigned long size)
{
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp;
critical_enter();
mtip = &mtp->ks_mti;
mtsp = zpcpu_get(mtip->mti_stats);
mtsp->mts_memfreed += size;
mtsp->mts_numfrees++;
#ifdef KDTRACE_HOOKS
if (__predict_false(dtrace_malloc_enabled)) {
uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
if (probe_id != 0)
(dtrace_malloc_probe)(probe_id,
(uintptr_t) mtp, (uintptr_t) mtip,
(uintptr_t) mtsp, size, 0);
}
#endif
critical_exit();
}
/*
* contigmalloc:
*
* Allocate a block of physically contiguous memory.
*
* If M_NOWAIT is set, this routine will not block and return NULL if
* the allocation fails.
*/
void *
contigmalloc(unsigned long size, struct malloc_type *type, int flags,
vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
vm_paddr_t boundary)
{
void *ret;
ret = (void *)kmem_alloc_contig(size, flags, low, high, alignment,
boundary, VM_MEMATTR_DEFAULT);
if (ret != NULL)
malloc_type_allocated(type, round_page(size));
return (ret);
}
void *
contigmalloc_domainset(unsigned long size, struct malloc_type *type,
struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high,
unsigned long alignment, vm_paddr_t boundary)
{
void *ret;
ret = (void *)kmem_alloc_contig_domainset(ds, size, flags, low, high,
alignment, boundary, VM_MEMATTR_DEFAULT);
if (ret != NULL)
malloc_type_allocated(type, round_page(size));
return (ret);
}
/*
* contigfree:
*
* Free a block of memory allocated by contigmalloc.
*
* This routine may not block.
*/
void
contigfree(void *addr, unsigned long size, struct malloc_type *type)
{
kmem_free((vm_offset_t)addr, size);
malloc_type_freed(type, round_page(size));
}
#ifdef MALLOC_DEBUG
static int
malloc_dbg(caddr_t *vap, size_t *sizep, struct malloc_type *mtp,
int flags)
{
#ifdef INVARIANTS
int indx;
KASSERT(mtp->ks_version == M_VERSION, ("malloc: bad malloc type version"));
/*
* Check that exactly one of M_WAITOK or M_NOWAIT is specified.
*/
indx = flags & (M_WAITOK | M_NOWAIT);
if (indx != M_NOWAIT && indx != M_WAITOK) {
static struct timeval lasterr;
static int curerr, once;
if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
printf("Bad malloc flags: %x\n", indx);
kdb_backtrace();
flags |= M_WAITOK;
once++;
}
}
#endif
#ifdef MALLOC_MAKE_FAILURES
if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
atomic_add_int(&malloc_nowait_count, 1);
if ((malloc_nowait_count % malloc_failure_rate) == 0) {
atomic_add_int(&malloc_failure_count, 1);
*vap = NULL;
return (EJUSTRETURN);
}
}
#endif
if (flags & M_WAITOK) {
KASSERT(curthread->td_intr_nesting_level == 0,
("malloc(M_WAITOK) in interrupt context"));
if (__predict_false(!THREAD_CAN_SLEEP())) {
#ifdef EPOCH_TRACE
epoch_trace_list(curthread);
#endif
KASSERT(1,
("malloc(M_WAITOK) with sleeping prohibited"));
}
}
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("malloc: called with spinlock or critical section held"));
#ifdef DEBUG_MEMGUARD
if (memguard_cmp_mtp(mtp, *sizep)) {
*vap = memguard_alloc(*sizep, flags);
if (*vap != NULL)
return (EJUSTRETURN);
/* This is unfortunate but should not be fatal. */
}
#endif
#ifdef DEBUG_REDZONE
*sizep = redzone_size_ntor(*sizep);
#endif
return (0);
}
#endif
/*
* Handle large allocations and frees by using kmem_malloc directly.
*/
static inline bool
malloc_large_slab(uma_slab_t slab)
{
uintptr_t va;
va = (uintptr_t)slab;
return ((va & 1) != 0);
}
static inline size_t
malloc_large_size(uma_slab_t slab)
{
uintptr_t va;
va = (uintptr_t)slab;
return (va >> 1);
}
static caddr_t
malloc_large(size_t *size, struct domainset *policy, int flags)
{
vm_offset_t va;
size_t sz;
sz = roundup(*size, PAGE_SIZE);
va = kmem_malloc_domainset(policy, sz, flags);
if (va != 0) {
/* The low bit is unused for slab pointers. */
vsetzoneslab(va, NULL, (void *)((sz << 1) | 1));
uma_total_inc(sz);
*size = sz;
}
return ((caddr_t)va);
}
static void
free_large(void *addr, size_t size)
{
kmem_free((vm_offset_t)addr, size);
uma_total_dec(size);
}
/*
* malloc:
*
* Allocate a block of memory.
*
* If M_NOWAIT is set, this routine will not block and return NULL if
* the allocation fails.
*/
void *
(malloc)(size_t size, struct malloc_type *mtp, int flags)
{
int indx;
caddr_t va;
uma_zone_t zone;
#if defined(DEBUG_REDZONE)
unsigned long osize = size;
#endif
MPASS((flags & M_EXEC) == 0);
#ifdef MALLOC_DEBUG
va = NULL;
if (malloc_dbg(&va, &size, mtp, flags) != 0)
return (va);
#endif
if (size <= kmem_zmax) {
if (size & KMEM_ZMASK)
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
indx = kmemsize[size >> KMEM_ZSHIFT];
zone = kmemzones[indx].kz_zone[mtp_get_subzone(mtp)];
#ifdef MALLOC_PROFILE
krequests[size >> KMEM_ZSHIFT]++;
#endif
va = uma_zalloc(zone, flags);
if (va != NULL)
size = zone->uz_size;
malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
} else {
va = malloc_large(&size, DOMAINSET_RR(), flags);
malloc_type_allocated(mtp, va == NULL ? 0 : size);
}
if (__predict_false(va == NULL)) {
KASSERT((flags & M_WAITOK) == 0,
("malloc(M_WAITOK) returned NULL"));
}
#ifdef DEBUG_REDZONE
if (va != NULL)
va = redzone_setup(va, osize);
#endif
return ((void *) va);
}
static void *
malloc_domain(size_t *sizep, int *indxp, struct malloc_type *mtp, int domain,
int flags)
{
uma_zone_t zone;
caddr_t va;
size_t size;
int indx;
size = *sizep;
KASSERT(size <= kmem_zmax && (flags & M_EXEC) == 0,
("malloc_domain: Called with bad flag / size combination."));
if (size & KMEM_ZMASK)
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
indx = kmemsize[size >> KMEM_ZSHIFT];
zone = kmemzones[indx].kz_zone[mtp_get_subzone(mtp)];
#ifdef MALLOC_PROFILE
krequests[size >> KMEM_ZSHIFT]++;
#endif
va = uma_zalloc_domain(zone, NULL, domain, flags);
if (va != NULL)
*sizep = zone->uz_size;
*indxp = indx;
return ((void *)va);
}
void *
malloc_domainset(size_t size, struct malloc_type *mtp, struct domainset *ds,
int flags)
{
struct vm_domainset_iter di;
caddr_t va;
int domain;
int indx;
#if defined(DEBUG_REDZONE)
unsigned long osize = size;
#endif
MPASS((flags & M_EXEC) == 0);
#ifdef MALLOC_DEBUG
va = NULL;
if (malloc_dbg(&va, &size, mtp, flags) != 0)
return (va);
#endif
if (size <= kmem_zmax) {
vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
do {
va = malloc_domain(&size, &indx, mtp, domain, flags);
} while (va == NULL &&
vm_domainset_iter_policy(&di, &domain) == 0);
malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
} else {
/* Policy is handled by kmem. */
va = malloc_large(&size, ds, flags);
malloc_type_allocated(mtp, va == NULL ? 0 : size);
}
if (__predict_false(va == NULL)) {
KASSERT((flags & M_WAITOK) == 0,
("malloc(M_WAITOK) returned NULL"));
}
#ifdef DEBUG_REDZONE
if (va != NULL)
va = redzone_setup(va, osize);
#endif
return (va);
}
/*
* Allocate an executable area.
*/
void *
malloc_exec(size_t size, struct malloc_type *mtp, int flags)
{
caddr_t va;
#if defined(DEBUG_REDZONE)
unsigned long osize = size;
#endif
flags |= M_EXEC;
#ifdef MALLOC_DEBUG
va = NULL;
if (malloc_dbg(&va, &size, mtp, flags) != 0)
return (va);
#endif
va = malloc_large(&size, DOMAINSET_RR(), flags);
malloc_type_allocated(mtp, va == NULL ? 0 : size);
if (__predict_false(va == NULL)) {
KASSERT((flags & M_WAITOK) == 0,
("malloc(M_WAITOK) returned NULL"));
}
#ifdef DEBUG_REDZONE
if (va != NULL)
va = redzone_setup(va, osize);
#endif
return ((void *) va);
}
void *
malloc_domainset_exec(size_t size, struct malloc_type *mtp, struct domainset *ds,
int flags)
{
caddr_t va;
#if defined(DEBUG_REDZONE)
unsigned long osize = size;
#endif
flags |= M_EXEC;
#ifdef MALLOC_DEBUG
va = NULL;
if (malloc_dbg(&va, &size, mtp, flags) != 0)
return (va);
#endif
/* Policy is handled by kmem. */
va = malloc_large(&size, ds, flags);
malloc_type_allocated(mtp, va == NULL ? 0 : size);
if (__predict_false(va == NULL)) {
KASSERT((flags & M_WAITOK) == 0,
("malloc(M_WAITOK) returned NULL"));
}
#ifdef DEBUG_REDZONE
if (va != NULL)
va = redzone_setup(va, osize);
#endif
return (va);
}
void *
mallocarray(size_t nmemb, size_t size, struct malloc_type *type, int flags)
{
if (WOULD_OVERFLOW(nmemb, size))
panic("mallocarray: %zu * %zu overflowed", nmemb, size);
return (malloc(size * nmemb, type, flags));
}
#ifdef INVARIANTS
static void
free_save_type(void *addr, struct malloc_type *mtp, u_long size)
{
struct malloc_type **mtpp = addr;
/*
* Cache a pointer to the malloc_type that most recently freed
* this memory here. This way we know who is most likely to
* have stepped on it later.
*
* This code assumes that size is a multiple of 8 bytes for
* 64 bit machines
*/
mtpp = (struct malloc_type **) ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
mtpp += (size - sizeof(struct malloc_type *)) /
sizeof(struct malloc_type *);
*mtpp = mtp;
}
#endif
#ifdef MALLOC_DEBUG
static int
free_dbg(void **addrp, struct malloc_type *mtp)
{
void *addr;
addr = *addrp;
KASSERT(mtp->ks_version == M_VERSION, ("free: bad malloc type version"));
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("free: called with spinlock or critical section held"));
/* free(NULL, ...) does nothing */
if (addr == NULL)
return (EJUSTRETURN);
#ifdef DEBUG_MEMGUARD
if (is_memguard_addr(addr)) {
memguard_free(addr);
return (EJUSTRETURN);
}
#endif
#ifdef DEBUG_REDZONE
redzone_check(addr);
*addrp = redzone_addr_ntor(addr);
#endif
return (0);
}
#endif
/*
* free:
*
* Free a block of memory allocated by malloc.
*
* This routine may not block.
*/
void
free(void *addr, struct malloc_type *mtp)
{
uma_zone_t zone;
uma_slab_t slab;
u_long size;
#ifdef MALLOC_DEBUG
if (free_dbg(&addr, mtp) != 0)
return;
#endif
/* free(NULL, ...) does nothing */
if (addr == NULL)
return;
vtozoneslab((vm_offset_t)addr & (~UMA_SLAB_MASK), &zone, &slab);
if (slab == NULL)
panic("free: address %p(%p) has not been allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
if (__predict_true(!malloc_large_slab(slab))) {
size = zone->uz_size;
#ifdef INVARIANTS
free_save_type(addr, mtp, size);
#endif
uma_zfree_arg(zone, addr, slab);
} else {
size = malloc_large_size(slab);
free_large(addr, size);
}
malloc_type_freed(mtp, size);
}
/*
* zfree:
*
* Zero then free a block of memory allocated by malloc.
*
* This routine may not block.
*/
void
zfree(void *addr, struct malloc_type *mtp)
{
uma_zone_t zone;
uma_slab_t slab;
u_long size;
#ifdef MALLOC_DEBUG
if (free_dbg(&addr, mtp) != 0)
return;
#endif
/* free(NULL, ...) does nothing */
if (addr == NULL)
return;
vtozoneslab((vm_offset_t)addr & (~UMA_SLAB_MASK), &zone, &slab);
if (slab == NULL)
panic("free: address %p(%p) has not been allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
if (__predict_true(!malloc_large_slab(slab))) {
size = zone->uz_size;
#ifdef INVARIANTS
free_save_type(addr, mtp, size);
#endif
explicit_bzero(addr, size);
uma_zfree_arg(zone, addr, slab);
} else {
size = malloc_large_size(slab);
explicit_bzero(addr, size);
free_large(addr, size);
}
malloc_type_freed(mtp, size);
}
/*
* realloc: change the size of a memory block
*/
void *
realloc(void *addr, size_t size, struct malloc_type *mtp, int flags)
{
uma_zone_t zone;
uma_slab_t slab;
unsigned long alloc;
void *newaddr;
KASSERT(mtp->ks_version == M_VERSION,
("realloc: bad malloc type version"));
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("realloc: called with spinlock or critical section held"));
/* realloc(NULL, ...) is equivalent to malloc(...) */
if (addr == NULL)
return (malloc(size, mtp, flags));
/*
* XXX: Should report free of old memory and alloc of new memory to
* per-CPU stats.
*/
#ifdef DEBUG_MEMGUARD
if (is_memguard_addr(addr))
return (memguard_realloc(addr, size, mtp, flags));
#endif
#ifdef DEBUG_REDZONE
slab = NULL;
zone = NULL;
alloc = redzone_get_size(addr);
#else
vtozoneslab((vm_offset_t)addr & (~UMA_SLAB_MASK), &zone, &slab);
/* Sanity check */
KASSERT(slab != NULL,
("realloc: address %p out of range", (void *)addr));
/* Get the size of the original block */
if (!malloc_large_slab(slab))
alloc = zone->uz_size;
else
alloc = malloc_large_size(slab);
/* Reuse the original block if appropriate */
if (size <= alloc
&& (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
return (addr);
#endif /* !DEBUG_REDZONE */
/* Allocate a new, bigger (or smaller) block */
if ((newaddr = malloc(size, mtp, flags)) == NULL)
return (NULL);
/* Copy over original contents */
bcopy(addr, newaddr, min(size, alloc));
free(addr, mtp);
return (newaddr);
}
/*
* reallocf: same as realloc() but free memory on failure.
*/
void *
reallocf(void *addr, size_t size, struct malloc_type *mtp, int flags)
{
void *mem;
if ((mem = realloc(addr, size, mtp, flags)) == NULL)
free(addr, mtp);
return (mem);
}
/*
* malloc_size: returns the number of bytes allocated for a request of the
* specified size
*/
size_t
malloc_size(size_t size)
{
int indx;
if (size > kmem_zmax)
return (0);
if (size & KMEM_ZMASK)
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
indx = kmemsize[size >> KMEM_ZSHIFT];
return (kmemzones[indx].kz_size);
}
/*
* malloc_usable_size: returns the usable size of the allocation.
*/
size_t
malloc_usable_size(const void *addr)
{
#ifndef DEBUG_REDZONE
uma_zone_t zone;
uma_slab_t slab;
#endif
u_long size;
if (addr == NULL)
return (0);
#ifdef DEBUG_MEMGUARD
if (is_memguard_addr(__DECONST(void *, addr)))
return (memguard_get_req_size(addr));
#endif
#ifdef DEBUG_REDZONE
size = redzone_get_size(__DECONST(void *, addr));
#else
vtozoneslab((vm_offset_t)addr & (~UMA_SLAB_MASK), &zone, &slab);
if (slab == NULL)
panic("malloc_usable_size: address %p(%p) is not allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
if (!malloc_large_slab(slab))
size = zone->uz_size;
else
size = malloc_large_size(slab);
#endif
return (size);
}
CTASSERT(VM_KMEM_SIZE_SCALE >= 1);
/*
* Initialize the kernel memory (kmem) arena.
*/
void
kmeminit(void)
{
u_long mem_size;
u_long tmp;
#ifdef VM_KMEM_SIZE
if (vm_kmem_size == 0)
vm_kmem_size = VM_KMEM_SIZE;
#endif
#ifdef VM_KMEM_SIZE_MIN
if (vm_kmem_size_min == 0)
vm_kmem_size_min = VM_KMEM_SIZE_MIN;
#endif
#ifdef VM_KMEM_SIZE_MAX
if (vm_kmem_size_max == 0)
vm_kmem_size_max = VM_KMEM_SIZE_MAX;
#endif
/*
* Calculate the amount of kernel virtual address (KVA) space that is
* preallocated to the kmem arena. In order to support a wide range
* of machines, it is a function of the physical memory size,
* specifically,
*
* min(max(physical memory size / VM_KMEM_SIZE_SCALE,
* VM_KMEM_SIZE_MIN), VM_KMEM_SIZE_MAX)
*
* Every architecture must define an integral value for
* VM_KMEM_SIZE_SCALE. However, the definitions of VM_KMEM_SIZE_MIN
* and VM_KMEM_SIZE_MAX, which represent respectively the floor and
* ceiling on this preallocation, are optional. Typically,
* VM_KMEM_SIZE_MAX is itself a function of the available KVA space on
* a given architecture.
*/
mem_size = vm_cnt.v_page_count;
if (mem_size <= 32768) /* delphij XXX 128MB */
kmem_zmax = PAGE_SIZE;
if (vm_kmem_size_scale < 1)
vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
/*
* Check if we should use defaults for the "vm_kmem_size"
* variable:
*/
if (vm_kmem_size == 0) {
vm_kmem_size = mem_size / vm_kmem_size_scale;
vm_kmem_size = vm_kmem_size * PAGE_SIZE < vm_kmem_size ?
vm_kmem_size_max : vm_kmem_size * PAGE_SIZE;
if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min)
vm_kmem_size = vm_kmem_size_min;
if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
vm_kmem_size = vm_kmem_size_max;
}
if (vm_kmem_size == 0)
panic("Tune VM_KMEM_SIZE_* for the platform");
/*
* The amount of KVA space that is preallocated to the
* kmem arena can be set statically at compile-time or manually
* through the kernel environment. However, it is still limited to
* twice the physical memory size, which has been sufficient to handle
* the most severe cases of external fragmentation in the kmem arena.
*/
if (vm_kmem_size / 2 / PAGE_SIZE > mem_size)
vm_kmem_size = 2 * mem_size * PAGE_SIZE;
vm_kmem_size = round_page(vm_kmem_size);
#ifdef DEBUG_MEMGUARD
tmp = memguard_fudge(vm_kmem_size, kernel_map);
#else
tmp = vm_kmem_size;
#endif
uma_set_limit(tmp);
#ifdef DEBUG_MEMGUARD
/*
* Initialize MemGuard if support compiled in. MemGuard is a
* replacement allocator used for detecting tamper-after-free
* scenarios as they occur. It is only used for debugging.
*/
memguard_init(kernel_arena);
#endif
}
/*
* Initialize the kernel memory allocator
*/
/* ARGSUSED*/
static void
mallocinit(void *dummy)
{
int i;
uint8_t indx;
mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
kmeminit();
if (kmem_zmax < PAGE_SIZE || kmem_zmax > KMEM_ZMAX)
kmem_zmax = KMEM_ZMAX;
for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
int size = kmemzones[indx].kz_size;
const char *name = kmemzones[indx].kz_name;
int subzone;
for (subzone = 0; subzone < numzones; subzone++) {
kmemzones[indx].kz_zone[subzone] =
uma_zcreate(name, size,
#ifdef INVARIANTS
mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
#else
NULL, NULL, NULL, NULL,
#endif
UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
}
for (;i <= size; i+= KMEM_ZBASE)
kmemsize[i >> KMEM_ZSHIFT] = indx;
}
}
SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_SECOND, mallocinit, NULL);
void
malloc_init(void *data)
{
struct malloc_type_internal *mtip;
struct malloc_type *mtp;
KASSERT(vm_cnt.v_page_count != 0, ("malloc_register before vm_init"));
mtp = data;
if (mtp->ks_version != M_VERSION)
panic("malloc_init: type %s with unsupported version %lu",
mtp->ks_shortdesc, mtp->ks_version);
mtip = &mtp->ks_mti;
mtip->mti_stats = uma_zalloc_pcpu(pcpu_zone_64, M_WAITOK | M_ZERO);
mtp_set_subzone(mtp);
mtx_lock(&malloc_mtx);
mtp->ks_next = kmemstatistics;
kmemstatistics = mtp;
kmemcount++;
mtx_unlock(&malloc_mtx);
}
void
malloc_uninit(void *data)
{
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp;
struct malloc_type *mtp, *temp;
long temp_allocs, temp_bytes;
int i;
mtp = data;
KASSERT(mtp->ks_version == M_VERSION,
("malloc_uninit: bad malloc type version"));
mtx_lock(&malloc_mtx);
mtip = &mtp->ks_mti;
if (mtp != kmemstatistics) {
for (temp = kmemstatistics; temp != NULL;
temp = temp->ks_next) {
if (temp->ks_next == mtp) {
temp->ks_next = mtp->ks_next;
break;
}
}
KASSERT(temp,
("malloc_uninit: type '%s' not found", mtp->ks_shortdesc));
} else
kmemstatistics = mtp->ks_next;
kmemcount--;
mtx_unlock(&malloc_mtx);
/*
* Look for memory leaks.
*/
temp_allocs = temp_bytes = 0;
for (i = 0; i <= mp_maxid; i++) {
mtsp = zpcpu_get_cpu(mtip->mti_stats, i);
temp_allocs += mtsp->mts_numallocs;
temp_allocs -= mtsp->mts_numfrees;
temp_bytes += mtsp->mts_memalloced;
temp_bytes -= mtsp->mts_memfreed;
}
if (temp_allocs > 0 || temp_bytes > 0) {
printf("Warning: memory type %s leaked memory on destroy "
"(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
temp_allocs, temp_bytes);
}
uma_zfree_pcpu(pcpu_zone_64, mtip->mti_stats);
}
struct malloc_type *
malloc_desc2type(const char *desc)
{
struct malloc_type *mtp;
mtx_assert(&malloc_mtx, MA_OWNED);
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
if (strcmp(mtp->ks_shortdesc, desc) == 0)
return (mtp);
}
return (NULL);
}
static int
sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
{
struct malloc_type_stream_header mtsh;
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp, zeromts;
struct malloc_type_header mth;
struct malloc_type *mtp;
int error, i;
struct sbuf sbuf;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
mtx_lock(&malloc_mtx);
bzero(&zeromts, sizeof(zeromts));
/*
* Insert stream header.
*/
bzero(&mtsh, sizeof(mtsh));
mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
mtsh.mtsh_maxcpus = MAXCPU;
mtsh.mtsh_count = kmemcount;
(void)sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh));
/*
* Insert alternating sequence of type headers and type statistics.
*/
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
mtip = &mtp->ks_mti;
/*
* Insert type header.
*/
bzero(&mth, sizeof(mth));
strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
(void)sbuf_bcat(&sbuf, &mth, sizeof(mth));
/*
* Insert type statistics for each CPU.
*/
for (i = 0; i <= mp_maxid; i++) {
mtsp = zpcpu_get_cpu(mtip->mti_stats, i);
(void)sbuf_bcat(&sbuf, mtsp, sizeof(*mtsp));
}
/*
* Fill in the missing CPUs.
*/
for (; i < MAXCPU; i++) {
(void)sbuf_bcat(&sbuf, &zeromts, sizeof(zeromts));
}
}
mtx_unlock(&malloc_mtx);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, malloc_stats,
CTLFLAG_RD | CTLTYPE_STRUCT | CTLFLAG_MPSAFE, 0, 0,
sysctl_kern_malloc_stats, "s,malloc_type_ustats",
"Return malloc types");
SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
"Count of kernel malloc types");
void
malloc_type_list(malloc_type_list_func_t *func, void *arg)
{
struct malloc_type *mtp, **bufmtp;
int count, i;
size_t buflen;
mtx_lock(&malloc_mtx);
restart:
mtx_assert(&malloc_mtx, MA_OWNED);
count = kmemcount;
mtx_unlock(&malloc_mtx);
buflen = sizeof(struct malloc_type *) * count;
bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
mtx_lock(&malloc_mtx);
if (count < kmemcount) {
free(bufmtp, M_TEMP);
goto restart;
}
for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
bufmtp[i] = mtp;
mtx_unlock(&malloc_mtx);
for (i = 0; i < count; i++)
(func)(bufmtp[i], arg);
free(bufmtp, M_TEMP);
}
#ifdef DDB
static int64_t
get_malloc_stats(const struct malloc_type_internal *mtip, uint64_t *allocs,
uint64_t *inuse)
{
const struct malloc_type_stats *mtsp;
uint64_t frees, alloced, freed;
int i;
*allocs = 0;
frees = 0;
alloced = 0;
freed = 0;
for (i = 0; i <= mp_maxid; i++) {
mtsp = zpcpu_get_cpu(mtip->mti_stats, i);
*allocs += mtsp->mts_numallocs;
frees += mtsp->mts_numfrees;
alloced += mtsp->mts_memalloced;
freed += mtsp->mts_memfreed;
}
*inuse = *allocs - frees;
return (alloced - freed);
}
DB_SHOW_COMMAND(malloc, db_show_malloc)
{
const char *fmt_hdr, *fmt_entry;
struct malloc_type *mtp;
uint64_t allocs, inuse;
int64_t size;
/* variables for sorting */
struct malloc_type *last_mtype, *cur_mtype;
int64_t cur_size, last_size;
int ties;
if (modif[0] == 'i') {
fmt_hdr = "%s,%s,%s,%s\n";
fmt_entry = "\"%s\",%ju,%jdK,%ju\n";
} else {
fmt_hdr = "%18s %12s %12s %12s\n";
fmt_entry = "%18s %12ju %12jdK %12ju\n";
}
db_printf(fmt_hdr, "Type", "InUse", "MemUse", "Requests");
/* Select sort, largest size first. */
last_mtype = NULL;
last_size = INT64_MAX;
for (;;) {
cur_mtype = NULL;
cur_size = -1;
ties = 0;
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
/*
* In the case of size ties, print out mtypes
* in the order they are encountered. That is,
* when we encounter the most recently output
* mtype, we have already printed all preceding
* ties, and we must print all following ties.
*/
if (mtp == last_mtype) {
ties = 1;
continue;
}
size = get_malloc_stats(&mtp->ks_mti, &allocs,
&inuse);
if (size > cur_size && size < last_size + ties) {
cur_size = size;
cur_mtype = mtp;
}
}
if (cur_mtype == NULL)
break;
size = get_malloc_stats(&cur_mtype->ks_mti, &allocs, &inuse);
db_printf(fmt_entry, cur_mtype->ks_shortdesc, inuse,
howmany(size, 1024), allocs);
if (db_pager_quit)
break;
last_mtype = cur_mtype;
last_size = cur_size;
}
}
#if MALLOC_DEBUG_MAXZONES > 1
DB_SHOW_COMMAND(multizone_matches, db_show_multizone_matches)
{
struct malloc_type_internal *mtip;
struct malloc_type *mtp;
u_int subzone;
if (!have_addr) {
db_printf("Usage: show multizone_matches <malloc type/addr>\n");
return;
}
mtp = (void *)addr;
if (mtp->ks_version != M_VERSION) {
db_printf("Version %lx does not match expected %x\n",
mtp->ks_version, M_VERSION);
return;
}
mtip = &mtp->ks_mti;
subzone = mtip->mti_zone;
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
mtip = &mtp->ks_mti;
if (mtip->mti_zone != subzone)
continue;
db_printf("%s\n", mtp->ks_shortdesc);
if (db_pager_quit)
break;
}
}
#endif /* MALLOC_DEBUG_MAXZONES > 1 */
#endif /* DDB */
#ifdef MALLOC_PROFILE
static int
sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
uint64_t count;
uint64_t waste;
uint64_t mem;
int error;
int rsize;
int size;
int i;
waste = 0;
mem = 0;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
sbuf_printf(&sbuf,
"\n Size Requests Real Size\n");
for (i = 0; i < KMEM_ZSIZE; i++) {
size = i << KMEM_ZSHIFT;
rsize = kmemzones[kmemsize[i]].kz_size;
count = (long long unsigned)krequests[i];
sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
(unsigned long long)count, rsize);
if ((rsize * count) > (size * count))
waste += (rsize * count) - (size * count);
mem += (rsize * count);
}
sbuf_printf(&sbuf,
"\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
(unsigned long long)mem, (unsigned long long)waste);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
SYSCTL_OID(_kern, OID_AUTO, mprof,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT, NULL, 0,
sysctl_kern_mprof, "A",
"Malloc Profiling");
#endif /* MALLOC_PROFILE */