Expand PMF_FN_* macros.

[netbsd-mini2440.git] / sys / kern / kern_malloc_debug.c

/*      $NetBSD: kern_malloc_debug.c,v 1.21 2009/09/13 18:45:11 pooka Exp $     */

/*
 * Copyright (c) 1999, 2000 Artur Grabowski <art@openbsd.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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``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 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.
 *
 * OpenBSD: kern_malloc_debug.c,v 1.10 2001/07/26 13:33:52 art Exp
 */

/*
 * This really belongs in kern/kern_malloc.c, but it was too much pollution.
 */

/*
 * It's only possible to debug one type/size at a time. The question is
 * if this is a limitation or a feature. We never want to run this as the
 * default malloc because we'll run out of memory really fast. Adding
 * more types will also add to the complexity of the code.
 *
 * This is really simple. Every malloc() allocates two virtual pages,
 * the second page is left unmapped, and the value returned is aligned
 * so that it ends at (or very close to) the page boundary to catch overflows.
 * Every free() changes the protection of the first page to VM_PROT_NONE so
 * that we can catch any dangling writes to it.
 * To minimize the risk of writes to recycled chunks we keep an LRU of latest
 * freed chunks. The length of it is controlled by MALLOC_DEBUG_CHUNKS.
 *
 * Don't expect any performance.
 *
 * TODO:
 *  - support for size >= PAGE_SIZE
 *  - add support to the fault handler to give better diagnostics if we fail.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_malloc_debug.c,v 1.21 2009/09/13 18:45:11 pooka Exp $");

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/pool.h>

#include <uvm/uvm.h>

/*
 * debug_malloc_type and debug_malloc_size define the type and size of
 * memory to be debugged. Use 0 for a wildcard. debug_malloc_size_lo
 * is the lower limit and debug_malloc_size_hi the upper limit of sizes
 * being debugged; 0 will not work as a wildcard for the upper limit.
 * For any debugging to take place, type must be != NULL, size must be >= 0,
 * and if the limits are being used, size must be set to 0.
 * See /usr/src/sys/sys/malloc.h and malloc(9) for a list of types.
 *
 * Although those are variables, it's a really bad idea to change the type
 * if any memory chunks of this type are used. It's ok to change the size
 * in runtime.
 */
struct malloc_type *debug_malloc_type = NULL;
int debug_malloc_size = -1;
int debug_malloc_size_lo = -1;
int debug_malloc_size_hi = -1;

/*
 * MALLOC_DEBUG_CHUNKS is the number of memory chunks we require on the
 * freelist before we reuse them.
 */
#define MALLOC_DEBUG_CHUNKS 16

void debug_malloc_allocate_free(int);

struct debug_malloc_entry {
        TAILQ_ENTRY(debug_malloc_entry) md_list;
        vaddr_t md_va;
        paddr_t md_pa;
        size_t md_size;
        struct malloc_type *md_type;
};

TAILQ_HEAD(,debug_malloc_entry) debug_malloc_freelist =
        TAILQ_HEAD_INITIALIZER(debug_malloc_freelist);
TAILQ_HEAD(,debug_malloc_entry) debug_malloc_usedlist =
        TAILQ_HEAD_INITIALIZER(debug_malloc_usedlist);

int debug_malloc_allocs;
int debug_malloc_frees;
int debug_malloc_pages;
int debug_malloc_chunks_on_freelist;

static struct pool debug_malloc_pool;

void
debug_malloc_init(void)
{

        pool_init(&debug_malloc_pool, sizeof(struct debug_malloc_entry),
            0, 0, 0, "mdbepl", NULL, IPL_VM);
}

int
debug_malloc(unsigned long size, struct malloc_type *type, int flags,
    void **addr)
{
        struct debug_malloc_entry *md = NULL;
        int s, wait = !(flags & M_NOWAIT);

        /* Careful not to compare unsigned long to int -1 */
        if ((type != debug_malloc_type && debug_malloc_type != 0) ||
            (size != debug_malloc_size && debug_malloc_size != 0) ||
            (debug_malloc_size_lo != -1 && size < debug_malloc_size_lo) ||
            (debug_malloc_size_hi != -1 && size > debug_malloc_size_hi))
                return (0);

        /* XXX - fix later */
        if (size > PAGE_SIZE)
                return (0);

        s = splvm();
        if (debug_malloc_chunks_on_freelist < MALLOC_DEBUG_CHUNKS)
                debug_malloc_allocate_free(wait);

        md = TAILQ_FIRST(&debug_malloc_freelist);
        if (md == NULL) {
                splx(s);
                return (0);
        }
        TAILQ_REMOVE(&debug_malloc_freelist, md, md_list);
        debug_malloc_chunks_on_freelist--;

        TAILQ_INSERT_HEAD(&debug_malloc_usedlist, md, md_list);
        debug_malloc_allocs++;
        splx(s);

        pmap_kenter_pa(md->md_va, md->md_pa,
            VM_PROT_READ|VM_PROT_WRITE|PMAP_KMPAGE, 0);
        pmap_update(pmap_kernel());

        md->md_size = size;
        md->md_type = type;

        /*
         * Align the returned addr so that it ends where the first page
         * ends. roundup to get decent alignment.
         */
        *addr = (void *)(md->md_va + PAGE_SIZE - roundup(size, sizeof(long)));
        if (*addr != NULL && (flags & M_ZERO))
                memset(*addr, 0, size);
        return (1);
}

int
debug_free(void *addr, struct malloc_type *type)
{
        struct debug_malloc_entry *md;
        vaddr_t va;
        int s;

        if (type != debug_malloc_type && debug_malloc_type != 0)
                return (0);

        /*
         * trunc_page to get the address of the page.
         */
        va = trunc_page((vaddr_t)addr);

        s = splvm();
        TAILQ_FOREACH(md, &debug_malloc_usedlist, md_list)
                if (md->md_va == va)
                        break;

        /*
         * If we are not responsible for this entry, let the normal free
         * handle it
         */
        if (md == NULL) {
                /*
                 * sanity check. Check for multiple frees.
                 */
                TAILQ_FOREACH(md, &debug_malloc_freelist, md_list)
                        if (md->md_va == va)
                                panic("debug_free: already free");
                splx(s);
                return (0);
        }

        debug_malloc_frees++;
        TAILQ_REMOVE(&debug_malloc_usedlist, md, md_list);

        TAILQ_INSERT_TAIL(&debug_malloc_freelist, md, md_list);
        debug_malloc_chunks_on_freelist++;
        /*
         * unmap the page.
         */
        pmap_kremove(md->md_va, PAGE_SIZE);
        pmap_update(pmap_kernel());
        splx(s);

        return (1);
}

/*
 * Add one chunk to the freelist.
 *
 * called at splvm.
 */
void
debug_malloc_allocate_free(int wait)
{
        vaddr_t va, offset;
        struct vm_page *pg;
        struct debug_malloc_entry *md;

        md = pool_get(&debug_malloc_pool, wait ? PR_WAITOK : PR_NOWAIT);
        if (md == NULL)
                return;

        va = uvm_km_alloc(kmem_map, PAGE_SIZE * 2, 0,
            UVM_KMF_VAONLY | (wait ? UVM_KMF_NOWAIT : 0));
        if (va == 0) {
                pool_put(&debug_malloc_pool, md);
                return;
        }

        offset = va - vm_map_min(kernel_map);
        for (;;) {
                pg = uvm_pagealloc(NULL, offset, NULL, 0);
                if (pg) {
                        pg->flags &= ~PG_BUSY;  /* new page */
                        UVM_PAGE_OWN(pg, NULL);
                }

                if (pg)
                        break;

                if (wait == 0) {
                        uvm_km_free(kmem_map, va, va + PAGE_SIZE * 2,
                            UVM_KMF_VAONLY);
                        pool_put(&debug_malloc_pool, md);
                        return;
                }
                uvm_wait("debug_malloc");
        }

        md->md_va = va;
        md->md_pa = VM_PAGE_TO_PHYS(pg);

        debug_malloc_pages++;
        TAILQ_INSERT_HEAD(&debug_malloc_freelist, md, md_list);
        debug_malloc_chunks_on_freelist++;
}

void
debug_malloc_print(void)
{

        debug_malloc_printit(printf, 0);
}

void
debug_malloc_printit(void (*pr)(const char *, ...), vaddr_t addr)
{
        struct debug_malloc_entry *md;

        if (addr) {
                TAILQ_FOREACH(md, &debug_malloc_freelist, md_list) {
                        if (addr >= md->md_va &&
                            addr < md->md_va + 2 * PAGE_SIZE) {
                                (*pr)("Memory at address 0x%x is in a freed "
                                      "area. type %s, size: %d\n ",
                                      addr, md->md_type->ks_shortdesc,
                                      md->md_size);
                                return;
                        }
                }
                TAILQ_FOREACH(md, &debug_malloc_usedlist, md_list) {
                        if (addr >= md->md_va + PAGE_SIZE &&
                            addr < md->md_va + 2 * PAGE_SIZE) {
                                (*pr)("Memory at address 0x%x is just outside "
                                      "an allocated area. type %s, size: %d\n",
                                      addr, md->md_type->ks_shortdesc,
                                      md->md_size);
                                return;
                        }
                }
                (*pr)("Memory at address 0x%x is outside debugged malloc.\n");
                return;
        }

        (*pr)("allocs: %d\n", debug_malloc_allocs);
        (*pr)("frees: %d\n", debug_malloc_frees);
        (*pr)("pages used: %d\n", debug_malloc_pages);
        (*pr)("chunks on freelist: %d\n", debug_malloc_chunks_on_freelist);

        (*pr)("\taddr:\tsize:\n");
        (*pr)("free chunks:\n");
        TAILQ_FOREACH(md, &debug_malloc_freelist, md_list)
                (*pr)("\t0x%x\t0x%x\t%s\n", md->md_va, md->md_size,
                      md->md_type->ks_shortdesc);
        (*pr)("used chunks:\n");
        TAILQ_FOREACH(md, &debug_malloc_usedlist, md_list)
                (*pr)("\t0x%x\t0x%x\t%s\n", md->md_va, md->md_size,
                      md->md_type->ks_shortdesc);
}