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2000-12-28  Wolfram Gloger  <wg@malloc.de>

	* malloc/malloc.c (MALLOC_COPY): Handle case if source and
	destination overlap.  Assume dest is always below source if
	overlapping.
This commit is contained in:
Ulrich Drepper
2000-12-31 07:39:50 +00:00
parent c77a447822
commit 09f5e1635a
5 changed files with 56 additions and 39 deletions
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36
malloc/malloc.c
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@ -423,11 +423,12 @@ Void_t* memmove();
#endif
#endif
#if USE_MEMCPY
/* The following macros are only invoked with (2n+1)-multiples of
INTERNAL_SIZE_T units, with a positive integer n. This is exploited
for fast inline execution when n is small. */
for fast inline execution when n is small. If the regions to be
copied do overlap, the destination lies always _below_ the source. */
#if USE_MEMCPY
#define MALLOC_ZERO(charp, nbytes) \
do { \
@ -446,7 +447,9 @@ do { \
} else memset((charp), 0, mzsz); \
} while(0)
#define MALLOC_COPY(dest,src,nbytes) \
/* If the regions overlap, dest is always _below_ src. */
#define MALLOC_COPY(dest,src,nbytes,overlap) \
do { \
INTERNAL_SIZE_T mcsz = (nbytes); \
if(mcsz <= 9*sizeof(mcsz)) { \
@ -461,12 +464,12 @@ do { \
*mcdst++ = *mcsrc++; \
*mcdst++ = *mcsrc++; \
*mcdst = *mcsrc ; \
} else memcpy(dest, src, mcsz); \
} else if(overlap) \
memmove(dest, src, mcsz); \
else \
memcpy(dest, src, mcsz); \
} while(0)
#define MALLOC_MEMMOVE(dest,src,nbytes) \
memmove(dest, src, mcsz)
#else /* !USE_MEMCPY */
/* Use Duff's device for good zeroing/copying performance. */
@ -488,7 +491,9 @@ do { \
} \
} while(0)
#define MALLOC_COPY(dest,src,nbytes) \
/* If the regions overlap, dest is always _below_ src. */
#define MALLOC_COPY(dest,src,nbytes,overlap) \
do { \
INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src; \
INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest; \
@ -3255,7 +3260,7 @@ Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
/* Must alloc, copy, free. */
newmem = mALLOc(bytes);
if (newmem == 0) return 0; /* propagate failure */
MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ);
MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ, 0);
munmap_chunk(oldp);
return newmem;
}
@ -3370,7 +3375,8 @@ arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb;
unlink(prev, bck, fwd);
newp = prev;
newsize += prevsize + nextsize;
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize);
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize,
1);
top(ar_ptr) = chunk_at_offset(newp, nb);
set_head(top(ar_ptr), (newsize - nb) | PREV_INUSE);
set_head_size(newp, nb);
@ -3385,7 +3391,7 @@ arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb;
unlink(prev, bck, fwd);
newp = prev;
newsize += nextsize + prevsize;
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize);
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 1);
goto split;
}
}
@ -3396,7 +3402,7 @@ arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb;
unlink(prev, bck, fwd);
newp = prev;
newsize += prevsize;
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize);
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 1);
goto split;
}
}
@ -3436,7 +3442,7 @@ arena* ar_ptr; mchunkptr oldp; INTERNAL_SIZE_T oldsize, nb;
}
/* Otherwise copy, free, and exit */
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize);
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), oldsize), oldmem, oldsize, 0);
chunk_free(ar_ptr, oldp);
return newp;
}
@ -4605,7 +4611,7 @@ realloc_check(oldmem, bytes, caller)
newp = (top_check() >= 0) ? chunk_alloc(&main_arena, nb) : NULL;
if (newp) {
MALLOC_COPY(BOUNDED_N(chunk2mem(newp), nb),
oldmem, oldsize - 2*SIZE_SZ);
oldmem, oldsize - 2*SIZE_SZ, 0);
munmap_chunk(oldp);
}
}