hyung-hwan/hawk
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fixed strict aliasing issues in xma.c

Browse Source
This commit is contained in:
hyung-hwan
2025-07-14 22:55:48 +09:00
parent febcaa8708
commit 07cbbfa02a
4 changed files with 246 additions and 102 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
lib/hawk-xma.h
View File

@ -87,7 +87,7 @@ typedef struct hawk_xma_t hawk_xma_t;
typedef struct hawk_xma_fblk_t hawk_xma_fblk_t;
typedef struct hawk_xma_mblk_t hawk_xma_mblk_t;
#define HAWK_XMA_FIXED 32
#define HAWK_XMA_FIXED (32)
#define HAWK_XMA_SIZE_BITS ((HAWK_SIZEOF_OOW_T*8)-1)
struct hawk_xma_t

187
lib/xma.c
View File

@ -62,15 +62,29 @@ $1 = (hawk_int_t *) 0x7fffea722f78
#define FIXED HAWK_XMA_FIXED
#define XFIMAX(xma) (HAWK_COUNTOF(xma->xfree)-1)
#define fblk_free(b) (((hawk_xma_fblk_t*)(b))->free)
#define fblk_size(b) (((hawk_xma_fblk_t*)(b))->size)
#define fblk_prev_size(b) (((hawk_xma_fblk_t*)(b))->prev_size)
#if 0
#define mblk_free(b) (((hawk_xma_mblk_t*)(b))->free)
#define mblk_size(b) (((hawk_xma_mblk_t*)(b))->size)
#define mblk_prev_size(b) (((hawk_xma_mblk_t*)(b))->prev_size)
#else
/* Let mblk_free(), mblk_size(), mblk_prev_size() be an alias to
* fblk_free(), fblk_size(), fblk_prev_size() to follow strict aliasing rule.
* if gcc/clang is used, specifying __attribute__((__may_alias__)) to hawk_xma_mblk_t
* and hawk_xma_fblk_t would also work. */
#define mblk_free(b) fblk_free(b)
#define mblk_size(b) fblk_size(b)
#define mblk_prev_size(b) fblk_prev_size(b)
#endif
#define next_mblk(b) ((hawk_xma_mblk_t*)((hawk_uint8_t*)b + MBLKHDRSIZE + mblk_size(b)))
#define prev_mblk(b) ((hawk_xma_mblk_t*)((hawk_uint8_t*)b - (MBLKHDRSIZE + mblk_prev_size(b))))
struct hawk_xma_mblk_t
{
hawk_oow_t prev_size;
/* the block size is shifted by 1 bit and the maximum value is
* offset by 1 bit because of the 'free' bit-field.
* i could keep 'size' without shifting with bit manipulation
@ -84,11 +98,12 @@ struct hawk_xma_mblk_t
struct hawk_xma_fblk_t
{
hawk_oow_t prev_size;
hawk_oow_t prev_size; /**< size of the previous block */
hawk_oow_t free: 1;
hawk_oow_t size: HAWK_XMA_SIZE_BITS;/**< block size */
/* these two fields are used only if the block is free */
/* the fields are must be identical to the fields of hawk_xma_mblk_t */
/* the two fields below are used only if the block is free */
hawk_xma_fblk_t* free_prev; /**< link to the previous free block */
hawk_xma_fblk_t* free_next; /**< link to the next free block */
};
@ -187,7 +202,6 @@ static HAWK_INLINE hawk_oow_t getxfi (hawk_xma_t* xma, hawk_oow_t size)
return xfi;
}
hawk_xma_t* hawk_xma_open (hawk_mmgr_t* mmgr, hawk_oow_t xtnsize, void* zoneptr, hawk_oow_t zonesize)
{
hawk_xma_t* xma;
@ -326,7 +340,6 @@ static HAWK_INLINE void detach_from_freelist (hawk_xma_t* xma, hawk_xma_fblk_t*
{
/* the previous item does not exist. the block is the first
* item in the free list. */
hawk_oow_t xfi = getxfi(xma, b->size);
HAWK_ASSERT(b == xma->xfree[xfi]);
/* let's update the free list head */
@ -412,7 +425,7 @@ static hawk_xma_fblk_t* alloc_from_freelist (hawk_xma_t* xma, hawk_oow_t xfi, ha
void* hawk_xma_alloc (hawk_xma_t* xma, hawk_oow_t size)
{
hawk_xma_fblk_t* cand;
hawk_oow_t xfi;
hawk_oow_t xfi, native_xfi;
DBG_VERIFY(xma, "alloc start");
@ -425,6 +438,7 @@ void* hawk_xma_alloc (hawk_xma_t* xma, hawk_oow_t size)
HAWK_ASSERT(size >= ALIGN);
xfi = getxfi(xma, size);
native_xfi = xfi;
/*if (xfi < XFIMAX(xma) && xma->xfree[xfi])*/
if (xfi < FIXED && xma->xfree[xfi])
@ -487,10 +501,20 @@ void* hawk_xma_alloc (hawk_xma_t* xma, hawk_oow_t size)
}
if (!cand)
{
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.nallocbadops++;
#endif
return HAWK_NULL;
/* try fixed-sized free chains */
for (xfi = native_xfi + 1; xfi < FIXED; xfi++)
{
cand = alloc_from_freelist(xma, xfi, size);
if (cand) break;
}
if (!cand)
{
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.nallocbadops++;
#endif
return HAWK_NULL;
}
}
}
}
@ -504,52 +528,51 @@ void* hawk_xma_alloc (hawk_xma_t* xma, hawk_oow_t size)
static void* _realloc_merge (hawk_xma_t* xma, void* b, hawk_oow_t size)
{
hawk_xma_mblk_t* blk = (hawk_xma_mblk_t*)USR_TO_SYS(b);
hawk_uint8_t* blk = (hawk_uint8_t*)USR_TO_SYS(b);
DBG_VERIFY(xma, "realloc merge start");
/* rounds up 'size' to be multiples of ALIGN */
if (size < MINALLOCSIZE) size = MINALLOCSIZE;
size = HAWK_ALIGN_POW2(size, ALIGN);
if (size > blk->size)
if (size > mblk_size(blk))
{
/* grow the current block */
hawk_oow_t req;
hawk_xma_mblk_t* n;
hawk_uint8_t* n;
hawk_oow_t rem;
req = size - blk->size; /* required size additionally */
req = size - mblk_size(blk); /* required size additionally */
n = next_mblk(blk);
n = (hawk_uint8_t*)next_mblk(blk);
/* check if the next adjacent block is available */
if ((hawk_uint8_t*)n >= xma->end || !n->free || req > n->size) return HAWK_NULL; /* no! */
if (n >= xma->end || !mblk_free(n) || req > mblk_size(n)) return HAWK_NULL; /* no! */
/* TODO: check more blocks if the next block is free but small in size.
* check the previous adjacent blocks also */
HAWK_ASSERT(blk->size == n->prev_size);
HAWK_ASSERT(mblk_size(blk) == mblk_prev_size(n));
/* let's merge the current block with the next block */
detach_from_freelist(xma, (hawk_xma_fblk_t*)n);
rem = (MBLKHDRSIZE + n->size) - req;
rem = (MBLKHDRSIZE + mblk_size(n)) - req;
if (rem >= FBLKMINSIZE)
{
/*
* the remaining part of the next block is large enough
* to hold a block. break the next block.
*/
hawk_uint8_t* y, * z;
hawk_xma_mblk_t* y, * z;
blk->size += req;
y = next_mblk(blk);
y->free = 1;
y->size = rem - MBLKHDRSIZE;
y->prev_size = blk->size;
mblk_size(blk) += req;
y = (hawk_uint8_t*)next_mblk(blk);
mblk_free(y) = 1;
mblk_size(y) = rem - MBLKHDRSIZE;
mblk_prev_size(y) = mblk_size(blk);
attach_to_freelist(xma, (hawk_xma_fblk_t*)y);
z = next_mblk(y);
if ((hawk_uint8_t*)z < xma->end) z->prev_size = y->size;
z = (hawk_uint8_t*)next_mblk(y);
if (z < xma->end) mblk_prev_size(z) = mblk_size(y);
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.alloc += req;
@ -559,54 +582,54 @@ static void* _realloc_merge (hawk_xma_t* xma, void* b, hawk_oow_t size)
}
else
{
hawk_xma_mblk_t* z;
hawk_uint8_t* z;
/* the remaining part of the next block is too small to form an indepent block.
* utilize the whole block by merging to the resizing block */
blk->size += MBLKHDRSIZE + n->size;
mblk_size(blk) += MBLKHDRSIZE + mblk_size(n);
z = next_mblk(blk);
if ((hawk_uint8_t*)z < xma->end) z->prev_size = blk->size;
z = (hawk_uint8_t*)next_mblk(blk);
if (z < xma->end) mblk_prev_size(z) = mblk_size(blk);
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.nfree--;
xma->stat.alloc += MBLKHDRSIZE + n->size;
xma->stat.avail -= n->size;
xma->stat.alloc += MBLKHDRSIZE + mblk_size(n);
xma->stat.avail -= mblk_size(n);
if (xma->stat.alloc > xma->stat.alloc_hwmark) xma->stat.alloc_hwmark = xma->stat.alloc;
#endif
}
}
else if (size < blk->size)
else if (size < mblk_size(blk))
{
/* shrink the block */
hawk_oow_t rem = blk->size - size;
hawk_oow_t rem = mblk_size(blk) - size;
if (rem >= FBLKMINSIZE)
{
hawk_xma_mblk_t* n;
hawk_uint8_t* n;
n = next_mblk(blk);
n = (hawk_uint8_t*)next_mblk(blk);
/* the leftover is large enough to hold a block of minimum size.split the current block */
if ((hawk_uint8_t*)n < xma->end && n->free)
if (n < xma->end && mblk_free(n))
{
hawk_xma_mblk_t* y, * z;
hawk_uint8_t* y, * z;
/* make the leftover block merge with the next block */
detach_from_freelist(xma, (hawk_xma_fblk_t*)n);
blk->size = size;
mblk_size(blk) = size;
y = next_mblk(blk); /* update y to the leftover block with the new block size set above */
y->free = 1;
y->size = rem + n->size; /* add up the adjust block - (rem + MBLKHDRSIZE(n) + n->size) - MBLKHDRSIZE(y) */
y->prev_size = blk->size;
y = (hawk_uint8_t*)next_mblk(blk); /* update y to the leftover block with the new block size set above */
mblk_free(y) = 1;
mblk_size(y) = rem + mblk_size(n); /* add up the adjust block - (rem + MBLKHDRSIZE(n) + n->size) - MBLKHDRSIZE(y) */
mblk_prev_size(y) = mblk_size(blk);
/* add 'y' to the free list */
attach_to_freelist(xma, (hawk_xma_fblk_t*)y);
z = next_mblk(y); /* get adjacent block to the merged block */
if ((hawk_uint8_t*)z < xma->end) z->prev_size = y->size;
z = (hawk_uint8_t*)next_mblk(y); /* get adjacent block to the merged block */
if (z < xma->end) mblk_prev_size(z) = mblk_size(y);
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.alloc -= rem;
@ -615,24 +638,24 @@ static void* _realloc_merge (hawk_xma_t* xma, void* b, hawk_oow_t size)
}
else
{
hawk_xma_mblk_t* y;
hawk_uint8_t* y;
/* link the leftover block to the free list */
blk->size = size;
mblk_size(blk) = size;
y = next_mblk(blk); /* update y to the leftover block with the new block size set above */
y->free = 1;
y->size = rem - MBLKHDRSIZE;
y->prev_size = blk->size;
mblk_free(y) = 1;
mblk_size(y) = rem - MBLKHDRSIZE;
mblk_prev_size(y) = mblk_size(blk);
attach_to_freelist(xma, (hawk_xma_fblk_t*)y);
/*n = next_mblk(y);
if ((hawk_uint8_t*)n < xma->end)*/ n->prev_size = y->size;
/*n = (hawk_uint8_t*)next_mblk(y);
if (n < xma->end)*/ mblk_prev_size(n) = mblk_size(y);
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.nfree++;
xma->stat.alloc -= rem;
xma->stat.avail += y->size;
xma->stat.avail += mblk_size(y);
#endif
}
}
@ -692,13 +715,13 @@ void* hawk_xma_realloc (hawk_xma_t* xma, void* b, hawk_oow_t size)
void hawk_xma_free (hawk_xma_t* xma, void* b)
{
hawk_xma_mblk_t* blk = (hawk_xma_mblk_t*)USR_TO_SYS(b);
hawk_xma_mblk_t* x, * y;
hawk_uint8_t* blk = (hawk_uint8_t*)USR_TO_SYS(b);
hawk_uint8_t* x, * y;
hawk_oow_t org_blk_size;
DBG_VERIFY(xma, "free start");
org_blk_size = blk->size;
org_blk_size = mblk_size(blk);
#if defined(HAWK_XMA_ENABLE_STAT)
/* update statistical variables */
@ -707,9 +730,9 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
xma->stat.nfreeops++;
#endif
x = prev_mblk(blk);
y = next_mblk(blk);
if (((hawk_uint8_t*)x >= xma->start && x->free) && ((hawk_uint8_t*)y < xma->end && y->free))
x = (hawk_uint8_t*)prev_mblk(blk);
y = (hawk_uint8_t*)next_mblk(blk);
if ((x >= xma->start && mblk_free(x)) && (y < xma->end && mblk_free(y)))
{
/*
* Merge the block with surrounding blocks
@ -728,25 +751,26 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
*
*/
hawk_xma_mblk_t* z = next_mblk(y);
hawk_uint8_t* z;
hawk_oow_t ns = MBLKHDRSIZE + org_blk_size + MBLKHDRSIZE;
hawk_oow_t bs = ns + y->size;
/* blk's header size + blk->size + y's header size */
hawk_oow_t bs = ns + mblk_size(y);
detach_from_freelist(xma, (hawk_xma_fblk_t*)x);
detach_from_freelist(xma, (hawk_xma_fblk_t*)y);
x->size += bs;
mblk_size(x) += bs;
attach_to_freelist(xma, (hawk_xma_fblk_t*)x);
z = next_mblk(x);
if ((hawk_uint8_t*)z < xma->end) z->prev_size = x->size;
z = (hawk_uint8_t*)next_mblk(x);
if ((hawk_uint8_t*)z < xma->end) mblk_prev_size(z) = mblk_size(x);
#if defined(HAWK_XMA_ENABLE_STAT)
xma->stat.nfree--;
xma->stat.avail += ns;
#endif
}
else if ((hawk_uint8_t*)y < xma->end && y->free)
else if (y < xma->end && mblk_free(y))
{
/*
* Merge the block with the next block
@ -769,18 +793,18 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
*
*
*/
hawk_xma_mblk_t* z = next_mblk(y);
hawk_uint8_t* z = (hawk_uint8_t*)next_mblk(y);
/* detach y from the free list */
detach_from_freelist(xma, (hawk_xma_fblk_t*)y);
/* update the block availability */
blk->free = 1;
mblk_free(blk) = 1;
/* update the block size. MBLKHDRSIZE for the header space in x */
blk->size += MBLKHDRSIZE + y->size;
mblk_size(blk) += MBLKHDRSIZE + mblk_size(y);
/* update the backward link of Y */
if ((hawk_uint8_t*)z < xma->end) z->prev_size = blk->size;
if ((hawk_uint8_t*)z < xma->end) mblk_prev_size(z) = mblk_size(blk);
/* attach blk to the free list */
attach_to_freelist(xma, (hawk_xma_fblk_t*)blk);
@ -789,7 +813,7 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
xma->stat.avail += org_blk_size + MBLKHDRSIZE;
#endif
}
else if ((hawk_uint8_t*)x >= xma->start && x->free)
else if (x >= xma->start && mblk_free(x))
{
/*
* Merge the block with the previous block
@ -807,10 +831,10 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
*/
detach_from_freelist(xma, (hawk_xma_fblk_t*)x);
x->size += MBLKHDRSIZE + org_blk_size;
mblk_size(x) += MBLKHDRSIZE + org_blk_size;
HAWK_ASSERT(y == next_mblk(x));
if ((hawk_uint8_t*)y < xma->end) y->prev_size = x->size;
if ((hawk_uint8_t*)y < xma->end) mblk_prev_size(y) = mblk_size(x);
attach_to_freelist(xma, (hawk_xma_fblk_t*)x);
@ -820,7 +844,7 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
}
else
{
blk->free = 1;
mblk_free(blk) = 1;
attach_to_freelist(xma, (hawk_xma_fblk_t*)blk);
#if defined(HAWK_XMA_ENABLE_STAT)
@ -835,7 +859,7 @@ void hawk_xma_free (hawk_xma_t* xma, void* b)
void hawk_xma_dump (hawk_xma_t* xma, hawk_xma_dumper_t dumper, void* ctx)
{
hawk_xma_mblk_t* tmp;
hawk_oow_t fsum, asum;
hawk_oow_t fsum, asum, xfi;
#if defined(HAWK_XMA_ENABLE_STAT)
hawk_oow_t isum;
#endif
@ -859,6 +883,19 @@ void hawk_xma_dump (hawk_xma_t* xma, hawk_xma_dumper_t dumper, void* ctx)
else asum += tmp->size;
}
dumper(ctx, "== free list ==\n");
for (xfi = 0; xfi <= XFIMAX(xma); xfi++)
{
if (xma->xfree[xfi])
{
hawk_xma_fblk_t* f;
for (f = xma->xfree[xfi]; f; f = f->free_next)
{
dumper(ctx, " xfi %d fblk %p size %lu\n", xfi, f, (unsigned long)f->size);
}
}
}
#if defined(HAWK_XMA_ENABLE_STAT)
isum = (xma->stat.nfree + xma->stat.nused) * MBLKHDRSIZE;
#endif