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Move alignment into chunk.c
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@siana
siana committed Sep 8, 2012
1 parent 17d8486 commit 6409155
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Showing 6 changed files with 135 additions and 289 deletions.
224 changes: 118 additions & 106 deletions chunk.c
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Original file line number Diff line number Diff line change
Expand Up @@ -158,6 +158,7 @@ static unsigned long func_calloc_c = 0; /* # callocs, done in alloc */
static unsigned long func_realloc_c = 0; /* count the reallocs */
static unsigned long func_recalloc_c = 0; /* count the reallocs */
static unsigned long func_memalign_c = 0; /* count the memaligns */
static unsigned long func_posix_memalign_c = 0; /* count the posix_memaligns */
static unsigned long func_valloc_c = 0; /* count the veallocs */
static unsigned long func_new_c = 0; /* count the news */
static unsigned long func_free_c = 0; /* count the frees */
Expand Down Expand Up @@ -741,6 +742,69 @@ static skip_alloc_t *insert_address(void *address, const int free_b,

return new_p;
}
/************************** alignment utility functions *************************/

/*
currently(5.5.2-3) alignment looks like this:
|FENCE|???|offs|USER|G|FENCE|
what I want alignment to look like is:
|???|offs|FENCE|USER|FENCE|G|
^u_p
...the fences should be right besides the user portion...
addresses increasing from left to right
??? is variable size depending on required alignment.
in the worst case
offs is the size of the ??? portion.
FENCE are the fence posts. they may not always be there.
G is a variable-sized gap caused by alignment.
USER is the user area. users get a u_p pointer pointing.
to USER's base. this is also what free() etc get back
from user space.
USER should be aligned to some alignment
to find the base pointer for dmalloc (to free etc..)
we have to go downward, skip the lower FENCE bytes(conditionally)
skip sizeof offs, read the offs, skip the offs.
Now to find out if the fence bytes are there and should be skipped,
we fetch the slot pointer and examine the
BIT_SET(slot_p->sa_flags, ALLOC_FLAG_FENCE);
removed the offs altogether. alignment is stored in the lot
and offset generated on-the-fly.
*/

/*calculate alignment overhead*/
static unsigned int get_align_overhead(unsigned int align,int fence_b)
{
unsigned int rv=0;

if(align==0)
align=1;
if(fence_b)
rv=FENCE_OVERHEAD_SIZE;

return rv+align-1;//sizes of fence + alignment overhead
}

/*just tests if the remainder is zero*/
static int is_aligned_to(char * p, unsigned int alignment)
{
return 0==(((unsigned int)p)%alignment);//alignment must not be zero
}

/*advance the pointer bytewise until it is aligned. returns result*/
static char * align_to(char * p, unsigned int alignment)
{
/*byte addressable?*/
while(! is_aligned_to(p,(alignment==0)?1:alignment))
{
p++;
}
return p;
}

/******************************* misc routines *******************************/

Expand Down Expand Up @@ -847,36 +911,30 @@ static int expand_chars(const void *buf, const int buf_size,
static void get_pnt_info(const skip_alloc_t *slot_p, pnt_info_t *info_p)
{
info_p->pi_fence_b = BIT_IS_SET(slot_p->sa_flags, ALLOC_FLAG_FENCE);
info_p->pi_valloc_b = BIT_IS_SET(slot_p->sa_flags, ALLOC_FLAG_VALLOC);
info_p->pi_blanked_b = BIT_IS_SET(slot_p->sa_flags, ALLOC_FLAG_BLANK);

info_p->pi_alloc_start = slot_p->sa_mem;

if (info_p->pi_fence_b) {
if (info_p->pi_valloc_b) {
info_p->pi_user_start = (char *)info_p->pi_alloc_start + BLOCK_SIZE;
info_p->pi_fence_bottom = (char *)info_p->pi_user_start -
FENCE_BOTTOM_SIZE;
}
else {
info_p->pi_fence_bottom = info_p->pi_alloc_start;
info_p->pi_user_start = (char *)info_p->pi_alloc_start +
FENCE_BOTTOM_SIZE;
}
char * a_p;
a_p=align_to((char *)info_p->pi_alloc_start +FENCE_BOTTOM_SIZE,slot_p->sa_align);
info_p->pi_fence_bottom = a_p-FENCE_BOTTOM_SIZE;//the fence is directly before user_start
info_p->pi_user_start = a_p;
}
else {
info_p->pi_fence_bottom = NULL;
info_p->pi_user_start = info_p->pi_alloc_start;
info_p->pi_user_start = align_to((char *)info_p->pi_alloc_start,slot_p->sa_align);
}

info_p->pi_align=slot_p->sa_align;
info_p->pi_user_bounds = (char *)info_p->pi_user_start +
slot_p->sa_user_size;

info_p->pi_alloc_bounds = (char *)slot_p->sa_mem + slot_p->sa_total_size;

if (info_p->pi_fence_b) {
info_p->pi_fence_top = info_p->pi_user_bounds;
info_p->pi_upper_bounds = (char *)info_p->pi_alloc_bounds - FENCE_TOP_SIZE;
info_p->pi_upper_bounds = (char *)info_p->pi_fence_top;
}
else {
info_p->pi_fence_top = NULL;
Expand Down Expand Up @@ -1125,9 +1183,13 @@ static void log_error_info(const char *now_file,
}

/* find the previous pointer in case it ran over */
if (dmalloc_errno == ERROR_UNDER_FENCE && start_user != NULL) {
other_p = find_address((char *)start_user - FENCE_BOTTOM_SIZE - 1,
0 /* used list */, 1 /* not exact pointer */,
if (dmalloc_errno == ERROR_UNDER_FENCE && start_user != NULL
&& slot_p != NULL) {
/* argh.. without slot_p I cannot find the prev ptr precisely. this is now wrong. */
other_p = find_address((char *)slot_p->sa_mem-1,
//(char *)start_user - FENCE_BOTTOM_SIZE - 1, how can this have worked? It points to the last byte of prev block, but he's looking for exact base ptr match.
// 0 /* used list */, 1 /* exact pointer */,
0 /* used list */, 0 /* not exact pointer */,
skip_update);
if (other_p != NULL) {
dmalloc_message(" prev pointer '%#lx' (size %u) may have run over from '%s'",
Expand All @@ -1142,7 +1204,7 @@ static void log_error_info(const char *now_file,
&& start_user != NULL
&& slot_p != NULL) {
other_p = find_address((char *)slot_p->sa_mem + slot_p->sa_total_size,
0 /* used list */, 1 /* not exact pointer */,
0 /* used list */, 1 /* exact pointer */,
skip_update);
if (other_p != NULL) {
dmalloc_message(" next pointer '%#lx' (size %u) may have run under from '%s'",
Expand Down Expand Up @@ -1650,36 +1712,22 @@ static int check_used_slot(const skip_alloc_t *slot_p,
}

/*
* If we have a valloc allocation then the _user_ pnt should be
* block aligned otherwise the chunk_pnt should be.
*/
if (pnt_info.pi_valloc_b) {

if ((long)pnt_info.pi_user_start % BLOCK_SIZE != 0) {
dmalloc_errno = ERROR_NOT_ON_BLOCK;
check that the contents does not exceed allocated size
*/

if (pnt_info.pi_fence_b) {
if((pnt_info.pi_fence_top+FENCE_TOP_SIZE)>pnt_info.pi_alloc_bounds) {
dmalloc_errno = ERROR_SLOT_CORRUPT;
return 0;
}
if (slot_p->sa_total_size < BLOCK_SIZE) {
}
else {
if(pnt_info.pi_user_bounds>pnt_info.pi_alloc_bounds) {
dmalloc_errno = ERROR_SLOT_CORRUPT;
return 0;
}

/* now check the below space to make sure it is still clear */
if (pnt_info.pi_fence_b && pnt_info.pi_blanked_b) {
num = (char *)pnt_info.pi_fence_bottom - (char *)pnt_info.pi_alloc_start;
if (num > 0) {
for (mem_p = pnt_info.pi_alloc_start;
mem_p < (char *)pnt_info.pi_fence_bottom;
mem_p++) {
if (*mem_p != ALLOC_BLANK_CHAR) {
dmalloc_errno = ERROR_FREE_OVERWRITTEN;
return 0;
}
}
}
}
}

/* check out the fence-posts */
if (pnt_info.pi_fence_b && (! fence_read(&pnt_info))) {
/* errno set in fence_read */
Expand Down Expand Up @@ -1916,36 +1964,23 @@ int _dmalloc_chunk_startup(void)
*
* user_pnt -> Address we are looking for.
*
* exact_b -> Set to 1 to find the exact pointer. If 0 then the
* address could be inside a block.
*
* file -> should typically point to filename of source file. String is _not_
* copied.
*
* line -> source file line number
*
*/
int _dmalloc_chunk_tag_pnt(const void * user_pnt,int exact_b,char *file,int line)
int _dmalloc_chunk_tag_pnt(const void * user_pnt,char *file,int line)
{
skip_alloc_t *slot_p;
char * u_p=user_pnt;
skip_alloc_t *slot_p;

if (BIT_IS_SET(_dmalloc_flags, DEBUG_LOG_TRANS)) {
dmalloc_message("tagging pointer '%#lx'",
(unsigned long)user_pnt);
}

if(exact_b) {
/*
of course this may fail, if _dmalloc_flags is changed at certain points
*/
if (BIT_IS_SET(_dmalloc_flags, DEBUG_CHECK_FENCE)) {
u_p-=FENCE_BOTTOM_SIZE;
}
}

/* find the pointer with loose checking for fence */
slot_p = find_address(u_p, 0 /* used list */, exact_b,
slot_p = find_address(user_pnt, 0 /* used list */, 0/* it would not work.. */,
skip_update);
if (slot_p == NULL) {
dmalloc_errno = ERROR_NOT_FOUND;
Expand Down Expand Up @@ -2102,7 +2137,7 @@ int _dmalloc_chunk_read_info(const void *user_pnt, const char *where,
SET_POINTER(seen_cp, NULL);
#endif
SET_POINTER(used_p, slot_p->sa_use_iter);
SET_POINTER(valloc_bp, BIT_IS_SET(slot_p->sa_flags, ALLOC_FLAG_VALLOC));
SET_POINTER(valloc_bp, 0);//BIT_IS_SET(slot_p->sa_flags, ALLOC_FLAG_VALLOC));
SET_POINTER(fence_bp, BIT_IS_SET(slot_p->sa_flags, ALLOC_FLAG_FENCE));

return 1;
Expand Down Expand Up @@ -2367,6 +2402,7 @@ int _dmalloc_chunk_pnt_check(const char *func, const void *user_pnt,
return 1;
}


/************************** low-level user functions *************************/

/*
Expand Down Expand Up @@ -2400,23 +2436,27 @@ void *_dmalloc_chunk_malloc(const char *file, const unsigned int line,
const unsigned int alignment)
{
unsigned long needed_size;
int valloc_b = 0, memalign_b = 0, fence_b = 0;
int fence_b = 0;
char where_buf[MAX_FILE_LENGTH + 64], disp_buf[64];
skip_alloc_t *slot_p;
pnt_info_t pnt_info;
const char *trans_log;
unsigned int align=alignment;
if(0==alignment)
align=1;

/* counts calls to malloc */
if (func_id == DMALLOC_FUNC_CALLOC) {
func_calloc_c++;
}
else if (alignment == BLOCK_SIZE) {
else if (func_id == DMALLOC_FUNC_POSIX_MEMALIGN) {
func_posix_memalign_c++;
}
else if (func_id == DMALLOC_FUNC_VALLOC) {
func_valloc_c++;
valloc_b = 1;
}
else if (alignment > 0) {
else if (func_id == DMALLOC_FUNC_MEMALIGN) {
func_memalign_c++;
memalign_b = 1;
}
else if (func_id == DMALLOC_FUNC_NEW) {
func_new_c++;
Expand Down Expand Up @@ -2444,30 +2484,7 @@ void *_dmalloc_chunk_malloc(const char *file, const unsigned int line,
}
#endif

needed_size = size;

/* adjust the size */
if (BIT_IS_SET(_dmalloc_flags, DEBUG_CHECK_FENCE)) {
needed_size += FENCE_OVERHEAD_SIZE;
fence_b = 1;

/*
* If the user is requesting a page-aligned block of data then we
* will need another block below the allocation just for the fence
* information. Ugh.
*/
if (valloc_b) {
needed_size += BLOCK_SIZE;
}
}
else if (valloc_b && needed_size <= BLOCK_SIZE / 2) {
/*
* If we are valloc-ing, make sure that we get a blocksized chunk
* because they are always block aligned. We know here that fence
* posting is not on otherwise it would have been set above.
*/
needed_size = BLOCK_SIZE;
}
needed_size=get_align_overhead(align,fence_b=BIT_IS_SET(_dmalloc_flags, DEBUG_CHECK_FENCE))+size;

/* get some space for our memory */
slot_p = get_memory(needed_size);
Expand All @@ -2478,10 +2495,8 @@ void *_dmalloc_chunk_malloc(const char *file, const unsigned int line,
if (fence_b) {
BIT_SET(slot_p->sa_flags, ALLOC_FLAG_FENCE);
}
if (valloc_b) {
BIT_SET(slot_p->sa_flags, ALLOC_FLAG_VALLOC);
}
slot_p->sa_user_size = size;
slot_p->sa_user_size = size;//this is different... just the user size. excludes alignment overhead. where is it used.. do I need additional info?
slot_p->sa_align = align;//that should do...

/* initialize the bblocks */
alloc_cur_given += slot_p->sa_total_size;
Expand Down Expand Up @@ -2807,7 +2822,9 @@ void *_dmalloc_chunk_realloc(const char *file, const unsigned int line,
pnt_info_t pnt_info;
void *new_user_pnt;
unsigned int old_size, old_line;

char where_buf[MAX_FILE_LENGTH + 64];
char where_buf2[MAX_FILE_LENGTH + 64];

/* counts calls to realloc */
if (func_id == DMALLOC_FUNC_RECALLOC) {
func_recalloc_c++;
Expand Down Expand Up @@ -2843,6 +2860,13 @@ void *_dmalloc_chunk_realloc(const char *file, const unsigned int line,
return 0;
}

if(slot_p->sa_align!=1)
dmalloc_message("WARNING: reallocating aligned ptr from '%s' at '%s'",
_dmalloc_chunk_desc_pnt(where_buf, sizeof(where_buf),
slot_p->sa_file, slot_p->sa_line),
_dmalloc_chunk_desc_pnt(where_buf2, sizeof(where_buf),
file, line));

/* get info about the pointer */
get_pnt_info(slot_p, &pnt_info);
old_file = slot_p->sa_file;
Expand Down Expand Up @@ -3000,8 +3024,8 @@ void _dmalloc_chunk_log_stats(void)
/* log user allocation information */
dmalloc_message("alloc calls: malloc %lu, calloc %lu, realloc %lu, free %lu",
func_malloc_c, func_calloc_c, func_realloc_c, func_free_c);
dmalloc_message("alloc calls: recalloc %lu, memalign %lu, valloc %lu",
func_recalloc_c, func_memalign_c, func_valloc_c);
dmalloc_message("alloc calls: recalloc %lu, memalign %lu, posix_memalign %lu, valloc %lu",
func_recalloc_c, func_memalign_c, func_posix_memalign_c, func_valloc_c);
dmalloc_message("alloc calls: new %lu, delete %lu",
func_new_c, func_delete_c);
dmalloc_message(" current memory in use: %lu bytes (%lu pnts)",
Expand Down Expand Up @@ -3195,18 +3219,6 @@ void _dmalloc_chunk_log_changed(const unsigned long mark,
}
}

DMALLOC_PNT _dmalloc_chunk_get_baseptr(DMALLOC_PNT p)
{
char * rv=p;
DMALLOC_SIZE offset=0;
if(NULL==p)
return NULL;
rv-=sizeof(offset);
memmove(&offset,rv,sizeof(offset));
rv-=offset;
return rv;
}


/*
* unsigned long _dmalloc_chunk_count_changed
Expand Down

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