netsurf/utils/memdebug.c

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/** \file
* Heap debugging functions (implementation).
*
* Based on memdebug.c from curl (see below), with the following modifications:
*
* - renamed functions from curl_ to memdebug_
* - added memdebug_strndup
* - added guard bytes before and after each block to help detect overflows
* - if a guard byte is corrupted during free, dumps the DA to file
*/
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* $Id: memdebug.c,v 1.1 2004/07/28 22:35:02 bursa Exp $
***************************************************************************/
#include <assert.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#ifdef riscos
#include <unixlib/local.h>
#include "oslib/os.h"
#include "oslib/osfile.h"
#endif
#include "memdebug.h"
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#define MAGIC 0x34343434
#define GUARD 0x34
#if defined(riscos) && !defined(__ELF__)
extern int __dynamic_num;
#endif
struct memdebug {
size_t size;
unsigned int magic;
double mem[1];
/* I'm hoping this is the thing with the strictest alignment
* requirements. That also means we waste some space :-( */
};
/*
* Note that these debug functions are very simple and they are meant to
* remain so. For advanced analysis, record a log file and write perl scripts
* to analyze them!
*
* Don't use these with multithreaded test programs!
*/
#define logfile memdebug_debuglogfile
FILE *memdebug_debuglogfile;
static bool memlimit; /* enable memory limit */
static long memsize; /* set number of mallocs allowed */
/* this sets the log file name */
void memdebug_memdebug(const char *logname)
{
if(logname)
logfile = fopen(logname, "w");
else
logfile = stderr;
}
/* This function sets the number of malloc() calls that should return
successfully! */
void memdebug_memlimit(long limit)
{
memlimit = true;
memsize = limit;
}
/* returns true if this isn't allowed! */
static bool countcheck(const char *func, int line, const char *source)
{
/* if source is NULL, then the call is made internally and this check
should not be made */
if(memlimit && source) {
if(!memsize) {
if(logfile && source)
fprintf(logfile, "LIMIT %s:%d %s reached memlimit\n",
source, line, func);
if(source)
fprintf(stderr, "LIMIT %s:%d %s reached memlimit\n",
source, line, func);
return true; /* RETURN ERROR! */
}
else
memsize--; /* countdown */
/* log the countdown */
if(logfile && source)
fprintf(logfile, "LIMIT %s:%d %ld ALLOCS left\n",
source, line, memsize);
}
return false; /* allow this */
}
void *memdebug_malloc(size_t wantedsize, int line, const char *source)
{
struct memdebug *mem;
size_t size;
if(countcheck("malloc", line, source))
return NULL;
/* alloc at least 64 bytes */
size = sizeof(struct memdebug)+wantedsize + 8;
mem=(struct memdebug *)(malloc)(size);
if(mem) {
unsigned int i;
/* fill memory with junk */
memset(mem->mem, 0xA5, wantedsize);
mem->size = wantedsize;
mem->magic = MAGIC;
for (i = 0; i != 8; i++)
((char *) mem->mem)[wantedsize + i] = GUARD;
}
if(logfile && source)
fprintf(logfile, "MEM %s:%d malloc(%zu) = %p\n",
source, line, wantedsize, mem ? mem->mem : 0);
return (mem ? mem->mem : NULL);
}
void *memdebug_calloc(size_t wanted_elements, size_t wanted_size,
int line, const char *source)
{
struct memdebug *mem;
size_t size, user_size;
if(countcheck("calloc", line, source))
return NULL;
/* alloc at least 64 bytes */
user_size = wanted_size * wanted_elements;
size = sizeof(struct memdebug) + user_size + 8;
mem = (struct memdebug *)(malloc)(size);
if(mem) {
unsigned int i;
/* fill memory with zeroes */
memset(mem->mem, 0, user_size);
mem->size = user_size;
mem->magic = MAGIC;
for (i = 0; i != 8; i++)
((char *) mem->mem)[mem->size + i] = GUARD;
}
if(logfile && source)
fprintf(logfile, "MEM %s:%d calloc(%zu,%zu) = %p\n",
source, line, wanted_elements, wanted_size, mem ? mem->mem : 0);
return (mem ? mem->mem : NULL);
}
char *memdebug_strdup(const char *str, int line, const char *source)
{
char *mem;
size_t len;
assert(str != NULL);
if(countcheck("strdup", line, source))
return NULL;
len=strlen(str)+1;
mem=memdebug_malloc(len, 0, NULL); /* NULL prevents logging */
if (mem)
memcpy(mem, str, len);
if(logfile)
fprintf(logfile, "MEM %s:%d strdup(%p) (%zu) = %p\n",
source, line, str, len, mem);
return mem;
}
char *memdebug_strndup(const char *str, size_t size, int line, const char *source)
{
char *mem;
size_t len;
assert(str != NULL);
if(countcheck("strndup", line, source))
return NULL;
len=strlen(str)+1;
if (size < len - 1)
len = size + 1;
mem=memdebug_malloc(len, 0, NULL); /* NULL prevents logging */
if (mem) {
memcpy(mem, str, len);
mem[len - 1] = 0;
}
if(logfile)
fprintf(logfile, "MEM %s:%d strndup(%p, %zd) (%zu) = %p\n",
source, line, str, size, len, mem);
return mem;
}
/* We provide a realloc() that accepts a NULL as pointer, which then
performs a malloc(). In order to work with ares. */
void *memdebug_realloc(void *ptr, size_t wantedsize,
int line, const char *source)
{
unsigned int i;
struct memdebug *mem=NULL;
size_t size = sizeof(struct memdebug)+wantedsize+8;
if(countcheck("realloc", line, source))
return NULL;
if(ptr) {
mem = (struct memdebug *)(void *)
((char *)ptr - offsetof(struct memdebug, mem));
}
if(logfile) {
if (mem && mem->magic != MAGIC)
fprintf(logfile, "MAGIC match failed!\n");
for (i = 0; mem && i != 8; i++)
if (((char *) mem->mem)[mem->size + i] != GUARD)
fprintf(logfile, "GUARD %u match failed!\n", i);
fprintf(logfile, "MEM %s:%d realloc(%p, %zu) = ",
source, line, ptr, wantedsize);
fflush(logfile);
}
mem=(struct memdebug *)(realloc)(mem, size);
if(logfile)
fprintf(logfile, "%p\n", mem?mem->mem:NULL);
if(mem) {
mem->size = wantedsize;
mem->magic = MAGIC;
for (i = 0; i != 8; i++)
((char *) mem->mem)[wantedsize + i] = GUARD;
return mem->mem;
}
return NULL;
}
void memdebug_free(void *ptr, int line, const char *source)
{
unsigned int i;
struct memdebug *mem;
if (!ptr)
return;
assert(ptr != NULL);
mem = (struct memdebug *)(void *)
((char *)ptr - offsetof(struct memdebug, mem));
if(logfile) {
fprintf(logfile, "MEM %s:%d free(%p)\n", source, line, ptr);
if (mem->magic != MAGIC) {
fprintf(logfile, "MAGIC match failed!\n");
#ifdef riscos
#ifndef __ELF__
if (__dynamic_num != -1) {
int size;
byte *base_address;
xosdynamicarea_read(__dynamic_num, &size, &base_address,
0, 0, 0, 0, 0);
fprintf(logfile, "saving DA %i %p %x\n", __dynamic_num, base_address,
size);
xosfile_save("core", (bits) base_address, 0, base_address,
base_address + size);
}
#else
__unixlib_write_coredump(NULL);
#endif
#endif
}
fflush(logfile);
for (i = 0; i != 8; i++)
if (((char *) mem->mem)[mem->size + i] != GUARD)
fprintf(logfile, "GUARD %u match failed!\n", i);
fflush(logfile);
}
/* destroy */
memset(mem->mem, 0x13, mem->size);
mem->magic = 0x13131313;
for (i = 0; i != 8; i++)
((char *) mem->mem)[mem->size + i] = 0x13;
/* free for real */
(free)(mem);
}
int memdebug_socket(int domain, int type, int protocol, int line,
const char *source)
{
int sockfd=(socket)(domain, type, protocol);
if(logfile && (sockfd!=-1))
fprintf(logfile, "FD %s:%d socket() = %d\n",
source, line, sockfd);
return sockfd;
}
int memdebug_accept(int s, void *saddr, void *saddrlen,
int line, const char *source)
{
struct sockaddr *addr = (struct sockaddr *)saddr;
socklen_t *addrlen = (socklen_t *)saddrlen;
int sockfd=(accept)(s, addr, addrlen);
if(logfile)
fprintf(logfile, "FD %s:%d accept() = %d\n",
source, line, sockfd);
return sockfd;
}
/* this is our own defined way to close sockets on *ALL* platforms */
int memdebug_sclose(int sockfd, int line, const char *source)
{
int res=sclose(sockfd);
if(logfile)
fprintf(logfile, "FD %s:%d sclose(%d)\n",
source, line, sockfd);
return res;
}
FILE *memdebug_fopen(const char *file, const char *mode,
int line, const char *source)
{
FILE *res=(fopen)(file, mode);
if(logfile)
fprintf(logfile, "FILE %s:%d fopen(\"%s\",\"%s\") = %p\n",
source, line, file, mode, res);
return res;
}
int memdebug_fclose(FILE *file, int line, const char *source)
{
int res;
assert(file != NULL);
res=(fclose)(file);
if(logfile)
fprintf(logfile, "FILE %s:%d fclose(%p)\n",
source, line, file);
return res;
}