/*
* This is the memory allocator. When asked to allocate a buffer, allocate
* it in such a way that the end of the buffer is followed by an inaccessable
* memory page. If software overruns that buffer, it will touch the bad page
* and get an immediate segmentation fault. It's then easy to zero in on the
* offending code with a debugger.
*
* There are a few complications. If the user asks for an odd-sized buffer,
* we would have to have that buffer start on an odd address if the byte after
* the end of the buffer was to be on the inaccessable page. Unfortunately,
* there is lots of software that asks for odd-sized buffers and then
* requires that the returned address be word-aligned, or the size of the
* buffer be a multiple of the word size. An example are the string-processing
* functions on Sun systems, which do word references to the string memory
* and may refer to memory up to three bytes beyond the end of the string.
* For this reason, I take the alignment requests to memalign() and valloc()
* seriously, and
*
* Electric Fence wastes lots of memory. I do a best-fit allocator here
* so that it won't waste even more. It's slow, but thrashing because your
* working set is too big for a system's RAM is even slower.
*/
static void * _DpsMemalign(size_t alignment, size_t userSize, const char *filename, size_t fileline) {
register Slot *slot, *slot2;
register size_t count;
Slot * fullSlot = 0;
Slot * emptySlots[2];
size_t internalSize;
size_t slack;
char * address;
if ( allocationList == 0 )
initialize();
lock();
if ( userSize == 0 && !EF_ALLOW_MALLOC_0 && strcmp(filename, "efence.c"))
EF_Abort("Allocating 0 bytes, probably a bug at %s:%d.", filename, fileline);
/*
* If EF_PROTECT_BELOW is set, all addresses returned by malloc()
* and company will be page-aligned.
*/
if ( !EF_PROTECT_BELOW && alignment > 1 ) {
if ( (slack = userSize % alignment) != 0 )
userSize += alignment - slack;
}
/*
* The internal size of the buffer is rounded up to the next page-size
* boudary, and then we add another page's worth of memory for the
* dead page.
*/
internalSize = userSize + bytesPerPage;
if ( (slack = internalSize % bytesPerPage) != 0 )
internalSize += bytesPerPage - slack;
/*
* These will hold the addresses of two empty Slot structures, that
* can be used to hold information for any memory I create, and any
* memory that I mark free.
*/
emptySlots[0] = 0;
emptySlots[1] = 0;
/*
* The internal memory used by the allocator is currently
* inaccessable, so that errant programs won't scrawl on the
* allocator's arena. I'll un-protect it here so that I can make
* a new allocation. I'll re-protect it before I return.
*/
if ( !noAllocationListProtection )
Page_AllowAccess(allocationList, allocationListSize);
/*
* If I'm running out of empty slots, create some more before
* I don't have enough slots left to make an allocation.
*/
if ( !internalUse && unUsedSlots < 7 ) {
allocateMoreSlots();
}
/*
* Iterate through all of the slot structures. Attempt to find a slot
* containing free memory of the exact right size. Accept a slot with
* more memory than we want, if the exact right size is not available.
* Find two slot structures that are not in use. We will need one if
* we split a buffer into free and allocated parts, and the second if
* we have to create new memory and mark it as free.
*
*/
slot = allocationList;
slot2 = &slot[slotCount - 1];
while (slot <= slot2) {
if ( slot->mode == FREE
&& slot->internalSize >= internalSize ) {
if ( !fullSlot
||slot->internalSize < fullSlot->internalSize) {
fullSlot = slot;
if ( slot->internalSize == internalSize
&& emptySlots[0] )
break; /* All done, */
}
}
else if ( slot->mode == NOT_IN_USE ) {
if ( !emptySlots[0] )
emptySlots[0] = slot;
else if ( !emptySlots[1] )
emptySlots[1] = slot;
else if ( fullSlot
&& fullSlot->internalSize == internalSize )
break; /* All done. */
}
if ( slot2->mode == FREE
&& slot2->internalSize >= internalSize ) {
if ( !fullSlot
||slot2->internalSize < fullSlot->internalSize) {
fullSlot = slot2;
if ( slot2->internalSize == internalSize
&& emptySlots[0] )
break; /* All done, */
}
}
else if ( slot2->mode == NOT_IN_USE ) {
if ( !emptySlots[0] )
emptySlots[0] = slot2;
else if ( !emptySlots[1] )
emptySlots[1] = slot2;
else if ( fullSlot
&& fullSlot->internalSize == internalSize )
break; /* All done. */
}
slot++;
slot2--;
}
/*
for ( slot = allocationList, count = slotCount ; count > 0; count-- ) {
if ( slot->mode == FREE
&& slot->internalSize >= internalSize ) {
if ( !fullSlot
||slot->internalSize < fullSlot->internalSize){
fullSlot = slot;
if ( slot->internalSize == internalSize
&& emptySlots[0] )
break; *//* All done, *//*
}
}
else if ( slot->mode == NOT_IN_USE ) {
if ( !emptySlots[0] )
emptySlots[0] = slot;
else if ( !emptySlots[1] )
emptySlots[1] = slot;
else if ( fullSlot
&& fullSlot->internalSize == internalSize )
break; *//* All done. *//*
}
slot++;
}
*/
if ( !emptySlots[0] )
EF_InternalError("No empty slot 0.");
if ( !fullSlot ) {
/*
* I get here if I haven't been able to find a free buffer
* with all of the memory I need. I'll have to create more
* memory. I'll mark it all as free, and then split it into
* free and allocated portions later.
*/
size_t chunkSize = MEMORY_CREATION_SIZE;
if ( !emptySlots[1] )
EF_InternalError("No empty slot 1.");
if ( chunkSize < internalSize )
chunkSize = internalSize;
if ( (slack = chunkSize % bytesPerPage) != 0 )
chunkSize += bytesPerPage - slack;
/* Use up one of the empty slots to make the full slot. */
fullSlot = emptySlots[0];
emptySlots[0] = emptySlots[1];
fullSlot->internalAddress = Page_Create(chunkSize);
fullSlot->internalSize = chunkSize;
fullSlot->mode = FREE;
unUsedSlots--;
/* Fill the slot if it was specified to do so. */
if ( EF_FILL != -1 )
memset(
(char *)fullSlot->internalAddress
,EF_FILL
,chunkSize);
}
/*
* If I'm allocating memory for the allocator's own data structures,
* mark it INTERNAL_USE so that no errant software will be able to
* free it.
*/
if ( internalUse )
fullSlot->mode = INTERNAL_USE;
else
fullSlot->mode = ALLOCATED;
/*
* If the buffer I've found is larger than I need, split it into
* an allocated buffer with the exact amount of memory I need, and
* a free buffer containing the surplus memory.
*/
if ( fullSlot->internalSize > internalSize ) {
emptySlots[0]->internalSize
= fullSlot->internalSize - internalSize;
emptySlots[0]->internalAddress
= ((char *)fullSlot->internalAddress) + internalSize;
emptySlots[0]->mode = FREE;
fullSlot->internalSize = internalSize;
unUsedSlots--;
}
if ( !EF_PROTECT_BELOW ) {
/*
* Arrange the buffer so that it is followed by an inaccessable
* memory page. A buffer overrun that touches that page will
* cause a segmentation fault.
*/
address = (char *)fullSlot->internalAddress;
/* Set up the "live" page. */
if ( internalSize - bytesPerPage > 0 )
Page_AllowAccess(
fullSlot->internalAddress
,internalSize - bytesPerPage);
address += internalSize - bytesPerPage;
/* Set up the "dead" page. */
if ( EF_PROTECT_FREE )
Page_Delete(address, bytesPerPage);
else
Page_DenyAccess(address, bytesPerPage);
/* Figure out what address to give the user. */
address -= userSize;
}
else { /* EF_PROTECT_BELOW != 0 */
/*
* Arrange the buffer so that it is preceded by an inaccessable
* memory page. A buffer underrun that touches that page will
* cause a segmentation fault.
*/
address = (char *)fullSlot->internalAddress;
/* Set up the "dead" page. */
if ( EF_PROTECT_FREE )
Page_Delete(address, bytesPerPage);
else
Page_DenyAccess(address, bytesPerPage);
address += bytesPerPage;
/* Set up the "live" page. */
if ( internalSize - bytesPerPage > 0 )
Page_AllowAccess(address, internalSize - bytesPerPage);
}
fullSlot->userAddress = address;
fullSlot->userSize = userSize;
fullSlot->fileline = fileline;
dps_strncpy(fullSlot->filename, filename, DPS_FILENAMELEN);
/* if (slotCount > 1) DpsSort(allocationList, slotCount, sizeof(Slot), (qsort_cmp)cmp_Slot);*/
/*
* Make the pool's internal memory inaccessable, so that the program
* being debugged can't stomp on it.
*/
if ( !internalUse )
Page_DenyAccess(allocationList, allocationListSize);
release();
/* if (address == 0x292d3000) {
int r = 1 / 0;
printf("Error r:%d\n");
}*/
/*
fprintf(stderr, " -- allocated: %p @ %s:%d\n", address, filename, fileline);
*/
return address;
}
// load in an image from the filename, and store it in IPAGE.
// if there were any errors, return a NULL
IPAGE *
iff_file_load_page(
char * filename
)
{
int x,y;
int plane;
int handle_x = 0;
int handle_y = 1;
BLOCKHEADER bh;
IFF_BMHD bmhd;
FILE * fp;
COLEL * palette = NULL;
IPAGE * iff_page = NULL;
fp = fopen(filename, "r");
// skip the container header...
(void)endian_little_read_32(fp);
(void)endian_little_read_32(fp);
(void)endian_little_read_32(fp);
bmhd.width=0;
bmhd.height=0;
// parse the file...
iff_read_header(fp, &bh);
while (bh.size)
{
/*
printf( "%c%c%c%c\n",
(bh.name>>24)&0xff,
(bh.name>>16)&0xff,
(bh.name>>8)&0xff,
(bh.name)&0xff );
*/
switch (bh.name)
{
case(IFF_BLOCK_BMHD):
//printf("Bitmap header\n");
bmhd.width = endian_little_read_16(fp) & 0x00ffff;
bmhd.height = endian_little_read_16(fp) & 0x00ffff;
bmhd.x = endian_little_read_16(fp) & 0x00ffff;
bmhd.y = endian_little_read_16(fp) & 0x00ffff;
bmhd.planes = endian_little_read_8(fp) & 0x0000ff;
bmhd.masking = endian_little_read_8(fp) & 0x0000ff;
bmhd.comp = endian_little_read_8(fp) & 0x0000ff;
(void)endian_little_read_8(fp); // pad. not used. -- store 0
bmhd.xparent = endian_little_read_16(fp) & 0x00ffff;
bmhd.xaspect = endian_little_read_8(fp) & 0x0000ff;
bmhd.yaspect = endian_little_read_8(fp) & 0x0000ff;
bmhd.pwidth = endian_little_read_16(fp) & 0x00ffff;
bmhd.pheight = endian_little_read_16(fp) & 0x00ffff;
/*
printf("image is %d by %d (%d %d) (%d %d)\n",
bmhd.width, bmhd.height,
bmhd.pwidth, bmhd.pheight,
bmhd.xaspect, bmhd.yaspect);
printf("%d planes %d %s\n",
bmhd.planes, bmhd.masking,
(bmhd.comp==1)?"RLE":"?");
*/
break;
case(IFF_BLOCK_GRAB):
handle_x = endian_little_read_16(fp);
handle_y = endian_little_read_16(fp);
break;
case(IFF_BLOCK_CMAP):
palette = (COLEL *) malloc(bh.size*sizeof(COLEL));
for (x=0 ; x<bh.size/3 ; x++)
{
palette[x].r = endian_little_read_8(fp)&0x00ff;
palette[x].g = endian_little_read_8(fp)&0x00ff;
palette[x].b = endian_little_read_8(fp)&0x00ff;
}
break;
case(IFF_BLOCK_CRNG):
// Electronic Arts Deluxe Paint color range
(void)endian_little_read_16(fp); // pad -- store 0
(void)endian_little_read_16(fp); // rate
(void)endian_little_read_16(fp); // active -- 1 means cycle them
(void)endian_little_read_8(fp); // start range
(void)endian_little_read_8(fp); // end range
break;
case(IFF_BLOCK_CCRT):
// Commodore Graphicraft color range
(void)endian_little_read_16(fp); // direction 0=stop 1=forw -1=back
(void)endian_little_read_8(fp); // start range
(void)endian_little_read_8(fp); // end range
(void)endian_little_read_32(fp); // seconds
(void)endian_little_read_32(fp); // microseconds
(void)endian_little_read_16(fp); // pad -- store 0
break;
case(IFF_BLOCK_BODY):
//printf("Image Body %d (%d colors)\n", bh.size, 1<<bmhd.planes);
iff_page = Page_Create(bmhd.width, bmhd.height, 1<<bmhd.planes);
iff_page->handle_x = handle_x;
iff_page->handle_y = handle_y;
// at this point, we should have a palette, but just in case,
// we'll put an if around this anyway...
if (palette)
{
free(iff_page->palette);
iff_page->palette = palette;
}
// now load in the bitmap data...
for (y=0 ; y < iff_page->h ; y++)
{
// decode image data
for ( plane = 0 ; plane < bmhd.planes ; plane++)
{
if (1) //bmhd.comp==1)
{
iff_decode_plane(fp, iff_page->pimage, y,
iff_page->w, plane);
} else {
iff_load_in_plane(fp, iff_page->pimage, y,
iff_page->w, plane);
}
}
// and the mask...
if (bmhd.masking == 1)
{
iff_decode_plane(fp, iff_page->alpha, y, iff_page->w, 1);
}
}
return iff_page;
break;
default:
iff_skip_block(fp, &bh);
}
iff_read_header(fp, &bh);
}
fclose(fp);
return iff_page;
}
/*
* initialize sets up the memory allocation arena and the run-time
* configuration information.
*/
static void initialize(void) {
size_t size = MEMORY_CREATION_SIZE;
size_t slack;
char * string;
Slot * slot;
EF_Print(version);
#ifdef __linux__
{
struct rlimit nolimit = { RLIM_INFINITY, RLIM_INFINITY };
int rc = setrlimit( RLIMIT_AS, &nolimit);
}
#endif
lock();
/*
* Import the user's environment specification of the default
* alignment for malloc(). We want that alignment to be under
* user control, since smaller alignment lets us catch more bugs,
* however some software will break if malloc() returns a buffer
* that is not word-aligned.
*
* I would like
* alignment to be zero so that we could catch all one-byte
* overruns, however if malloc() is asked to allocate an odd-size
* buffer and returns an address that is not word-aligned, or whose
* size is not a multiple of the word size, software breaks.
* This was the case with the Sun string-handling routines,
* which can do word fetches up to three bytes beyond the end of a
* string. I handle this problem in part by providing
* byte-reference-only versions of the string library functions, but
* there are other functions that break, too. Some in X Windows, one
* in Sam Leffler's TIFF library, and doubtless many others.
*/
if ( EF_ALIGNMENT == -1 ) {
if ( (string = getenv("EF_ALIGNMENT")) != 0 )
EF_ALIGNMENT = (size_t)atoi(string);
else
EF_ALIGNMENT = sizeof(int);
}
/*
* See if the user wants to protect the address space below a buffer,
* rather than that above a buffer.
*/
if ( EF_PROTECT_BELOW == -1 ) {
if ( (string = getenv("EF_PROTECT_BELOW")) != 0 )
EF_PROTECT_BELOW = (atoi(string) != 0);
else
EF_PROTECT_BELOW = 0;
}
/*
* See if the user wants to protect memory that has been freed until
* the program exits, rather than until it is re-allocated.
*/
if ( EF_PROTECT_FREE == -1 ) {
if ( (string = getenv("EF_PROTECT_FREE")) != 0 )
EF_PROTECT_FREE = (atoi(string) != 0);
else
EF_PROTECT_FREE = 0;
}
/*
* See if the user wants to allow malloc(0).
*/
if ( EF_ALLOW_MALLOC_0 == -1 ) {
if ( (string = getenv("EF_ALLOW_MALLOC_0")) != 0 )
EF_ALLOW_MALLOC_0 = (atoi(string) != 0);
else
EF_ALLOW_MALLOC_0 = 0;
}
/*
* Check if we should be filling new memory with a value.
*/
if ( EF_FILL == -1 ) {
if ( (string = getenv("EF_FILL")) != 0)
EF_FILL = (unsigned char) atoi(string);
}
/*
* Get the run-time configuration of the virtual memory page size.
*/
bytesPerPage = Page_Size();
/*
* Figure out how many Slot structures to allocate at one time.
*/
slotCount = slotsPerPage = bytesPerPage / sizeof(Slot);
allocationListSize = bytesPerPage;
if ( allocationListSize > size )
size = allocationListSize;
if ( (slack = size % bytesPerPage) != 0 )
size += bytesPerPage - slack;
/*
* Allocate memory, and break it up into two malloc buffers. The
* first buffer will be used for Slot structures, the second will
* be marked free.
*/
slot = allocationList = (Slot *)Page_Create(size);
memset((char *)allocationList, 0, allocationListSize);
slot[0].internalSize = slot[0].userSize = allocationListSize;
slot[0].internalAddress = slot[0].userAddress = allocationList;
slot[0].mode = INTERNAL_USE;
if ( size > allocationListSize ) {
slot[1].internalAddress = slot[1].userAddress
= ((char *)slot[0].internalAddress) + slot[0].internalSize;
slot[1].internalSize
= slot[1].userSize = size - slot[0].internalSize;
slot[1].mode = FREE;
}
/*
* Deny access to the free page, so that we will detect any software
* that treads upon free memory.
*/
Page_DenyAccess(slot[1].internalAddress, slot[1].internalSize);
/*
* Account for the two slot structures that we've used.
*/
unUsedSlots = slotCount - 2;
/* if (slotCount > 1) DpsSort(allocationList, slotCount, sizeof(Slot), (qsort_cmp)cmp_Slot);*/
release();
#ifdef HAVE_PTHREAD
if (!semEnabled) {
semEnabled = 1;
#if USE_DPS_MUTEX
InitMutex(&ef_mutex);
#else
if (sem_init(&EF_sem, 0, 1) < 0) {
semEnabled = 0;
}
#endif
}
#endif
}
