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freebsd/sys/kern/subr_busdma_bufalloc.c
Ryan Stone f2c2231e0c Fix integer truncation bug in malloc(9)
A couple of internal functions used by malloc(9) and uma truncated
a size_t down to an int.  This could cause any number of issues
(e.g. indefinite sleeps, memory corruption) if any kernel
subsystem tried to allocate 2GB or more through malloc.  zfs would
attempt such an allocation when run on a system with 2TB or more
of RAM.

Note to self: When this is MFCed, sparc64 needs the same fix.

Differential revision:	https://reviews.freebsd.org/D2106
Reviewed by:	kib
Reported by:	Michael Fuckner <michael@fuckner.net>
Tested by:	Michael Fuckner <michael@fuckner.net>
MFC after:	2 weeks
2015-04-01 12:42:26 +00:00

175 lines
5.1 KiB
C

/*-
* Copyright (c) 2012 Ian Lepore
* 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("$FreeBSD$");
/*
* Buffer allocation support routines for bus_dmamem_alloc implementations.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/busdma_bufalloc.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/uma.h>
/*
* We manage buffer zones up to a page in size. Buffers larger than a page can
* be managed by one of the kernel's page-oriented memory allocation routines as
* efficiently as what we can do here. Also, a page is the largest size for
* which we can g'tee contiguity when using uma, and contiguity is one of the
* requirements we have to fulfill.
*/
#define MIN_ZONE_BUFSIZE 32
#define MAX_ZONE_BUFSIZE PAGE_SIZE
/*
* The static array of 12 bufzones is big enough to handle all the zones for the
* smallest supported allocation size of 32 through the largest supported page
* size of 64K. If you up the biggest page size number, up the array size too.
* Basically the size of the array needs to be log2(maxsize)-log2(minsize)+1,
* but I don't know of an easy way to express that as a compile-time constant.
*/
#if PAGE_SIZE > 65536
#error Unsupported page size
#endif
struct busdma_bufalloc {
bus_size_t min_size;
size_t num_zones;
struct busdma_bufzone buf_zones[12];
};
busdma_bufalloc_t
busdma_bufalloc_create(const char *name, bus_size_t minimum_alignment,
uma_alloc alloc_func, uma_free free_func, u_int32_t zcreate_flags)
{
struct busdma_bufalloc *ba;
struct busdma_bufzone *bz;
int i;
bus_size_t cursize;
ba = malloc(sizeof(struct busdma_bufalloc), M_DEVBUF,
M_ZERO | M_WAITOK);
ba->min_size = MAX(MIN_ZONE_BUFSIZE, minimum_alignment);
/*
* Each uma zone is created with an alignment of size-1, meaning that
* the alignment is equal to the size (I.E., 64 byte buffers are aligned
* to 64 byte boundaries, etc). This allows for a fast efficient test
* when deciding whether a pool buffer meets the constraints of a given
* tag used for allocation: the buffer is usable if tag->alignment <=
* bufzone->size.
*/
for (i = 0, bz = ba->buf_zones, cursize = ba->min_size;
i < nitems(ba->buf_zones) && cursize <= MAX_ZONE_BUFSIZE;
++i, ++bz, cursize <<= 1) {
snprintf(bz->name, sizeof(bz->name), "dma %.10s %lu",
name, cursize);
bz->size = cursize;
bz->umazone = uma_zcreate(bz->name, bz->size,
NULL, NULL, NULL, NULL, bz->size - 1, zcreate_flags);
if (bz->umazone == NULL) {
busdma_bufalloc_destroy(ba);
return (NULL);
}
if (alloc_func != NULL)
uma_zone_set_allocf(bz->umazone, alloc_func);
if (free_func != NULL)
uma_zone_set_freef(bz->umazone, free_func);
++ba->num_zones;
}
return (ba);
}
void
busdma_bufalloc_destroy(busdma_bufalloc_t ba)
{
struct busdma_bufzone *bz;
int i;
if (ba == NULL)
return;
for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
uma_zdestroy(bz->umazone);
}
free(ba, M_DEVBUF);
}
struct busdma_bufzone *
busdma_bufalloc_findzone(busdma_bufalloc_t ba, bus_size_t size)
{
struct busdma_bufzone *bz;
int i;
if (size > MAX_ZONE_BUFSIZE)
return (NULL);
for (i = 0, bz = ba->buf_zones; i < ba->num_zones; ++i, ++bz) {
if (bz->size >= size)
return (bz);
}
panic("Didn't find a buffer zone of the right size");
}
void *
busdma_bufalloc_alloc_uncacheable(uma_zone_t zone, vm_size_t size,
uint8_t *pflag, int wait)
{
#ifdef VM_MEMATTR_UNCACHEABLE
/* Inform UMA that this allocator uses kernel_arena/object. */
*pflag = UMA_SLAB_KERNEL;
return ((void *)kmem_alloc_attr(kernel_arena, size, wait, 0,
BUS_SPACE_MAXADDR, VM_MEMATTR_UNCACHEABLE));
#else
panic("VM_MEMATTR_UNCACHEABLE unavailable");
#endif /* VM_MEMATTR_UNCACHEABLE */
}
void
busdma_bufalloc_free_uncacheable(void *item, vm_size_t size, uint8_t pflag)
{
kmem_free(kernel_arena, (vm_offset_t)item, size);
}