#include "libc.h"
#include "atomic.h"
#include "pthread_impl.h"
+#include "malloc_impl.h"
#if defined(__GNUC__) && defined(__PIC__)
#define inline inline __attribute__((always_inline))
#endif
-void *__mmap(void *, size_t, int, int, int, off_t);
-int __munmap(void *, size_t);
-void *__mremap(void *, size_t, size_t, int, ...);
-int __madvise(void *, size_t, int);
-
-struct chunk {
- size_t psize, csize;
- struct chunk *next, *prev;
-};
-
-struct bin {
- volatile int lock[2];
- struct chunk *head;
- struct chunk *tail;
-};
-
static struct {
volatile uint64_t binmap;
struct bin bins[64];
volatile int free_lock[2];
} mal;
-
-#define SIZE_ALIGN (4*sizeof(size_t))
-#define SIZE_MASK (-SIZE_ALIGN)
-#define OVERHEAD (2*sizeof(size_t))
-#define MMAP_THRESHOLD (0x1c00*SIZE_ALIGN)
-#define DONTCARE 16
-#define RECLAIM 163840
-
-#define CHUNK_SIZE(c) ((c)->csize & -2)
-#define CHUNK_PSIZE(c) ((c)->psize & -2)
-#define PREV_CHUNK(c) ((struct chunk *)((char *)(c) - CHUNK_PSIZE(c)))
-#define NEXT_CHUNK(c) ((struct chunk *)((char *)(c) + CHUNK_SIZE(c)))
-#define MEM_TO_CHUNK(p) (struct chunk *)((char *)(p) - OVERHEAD)
-#define CHUNK_TO_MEM(c) (void *)((char *)(c) + OVERHEAD)
-#define BIN_TO_CHUNK(i) (MEM_TO_CHUNK(&mal.bins[i].head))
-
-#define C_INUSE ((size_t)1)
-
-#define IS_MMAPPED(c) !((c)->csize & (C_INUSE))
-
+int __malloc_replaced;
/* Synchronization tools */
static inline void lock(volatile int *lk)
{
- if (libc.threads_minus_1)
+ int need_locks = libc.need_locks;
+ if (need_locks) {
while(a_swap(lk, 1)) __wait(lk, lk+1, 1, 1);
+ if (need_locks < 0) libc.need_locks = 0;
+ }
}
static inline void unlock(volatile int *lk)
}
#endif
-void *__expand_heap(size_t *);
-
static struct chunk *expand_heap(size_t n)
{
static int heap_lock[2];
next->psize = n1-n | C_INUSE;
self->csize = n | C_INUSE;
- free(CHUNK_TO_MEM(split));
+ __bin_chunk(split);
}
void *malloc(size_t n)
return CHUNK_TO_MEM(c);
}
-void *__malloc0(size_t n)
+static size_t mal0_clear(char *p, size_t pagesz, size_t n)
+{
+#ifdef __GNUC__
+ typedef uint64_t __attribute__((__may_alias__)) T;
+#else
+ typedef unsigned char T;
+#endif
+ char *pp = p + n;
+ size_t i = (uintptr_t)pp & (pagesz - 1);
+ for (;;) {
+ pp = memset(pp - i, 0, i);
+ if (pp - p < pagesz) return pp - p;
+ for (i = pagesz; i; i -= 2*sizeof(T), pp -= 2*sizeof(T))
+ if (((T *)pp)[-1] | ((T *)pp)[-2])
+ break;
+ }
+}
+
+void *calloc(size_t m, size_t n)
{
+ if (n && m > (size_t)-1/n) {
+ errno = ENOMEM;
+ return 0;
+ }
+ n *= m;
void *p = malloc(n);
- if (p && !IS_MMAPPED(MEM_TO_CHUNK(p))) {
- size_t *z;
- n = (n + sizeof *z - 1)/sizeof *z;
- for (z=p; n; n--, z++) if (*z) *z=0;
+ if (!p) return p;
+ if (!__malloc_replaced) {
+ if (IS_MMAPPED(MEM_TO_CHUNK(p)))
+ return p;
+ if (n >= PAGE_SIZE)
+ n = mal0_clear(p, PAGE_SIZE, n);
}
- return p;
+ return memset(p, 0, n);
}
void *realloc(void *p, size_t n)
size_t newlen = n + extra;
/* Crash on realloc of freed chunk */
if (extra & 1) a_crash();
- if (newlen < PAGE_SIZE && (new = malloc(n))) {
- memcpy(new, p, n-OVERHEAD);
- free(p);
- return new;
+ if (newlen < PAGE_SIZE && (new = malloc(n-OVERHEAD))) {
+ n0 = n;
+ goto copy_free_ret;
}
newlen = (newlen + PAGE_SIZE-1) & -PAGE_SIZE;
if (oldlen == newlen) return p;
/* As a last resort, allocate a new chunk and copy to it. */
new = malloc(n-OVERHEAD);
if (!new) return 0;
+copy_free_ret:
memcpy(new, p, n0-OVERHEAD);
free(CHUNK_TO_MEM(self));
return new;
}
-void free(void *p)
+void __bin_chunk(struct chunk *self)
{
- struct chunk *self, *next;
+ struct chunk *next = NEXT_CHUNK(self);
size_t final_size, new_size, size;
int reclaim=0;
int i;
- if (!p) return;
-
- self = MEM_TO_CHUNK(p);
-
- if (IS_MMAPPED(self)) {
- size_t extra = self->psize;
- char *base = (char *)self - extra;
- size_t len = CHUNK_SIZE(self) + extra;
- /* Crash on double free */
- if (extra & 1) a_crash();
- __munmap(base, len);
- return;
- }
-
final_size = new_size = CHUNK_SIZE(self);
- next = NEXT_CHUNK(self);
/* Crash on corrupted footer (likely from buffer overflow) */
if (next->psize != self->csize) a_crash();
unlock_bin(i);
}
+
+static void unmap_chunk(struct chunk *self)
+{
+ size_t extra = self->psize;
+ char *base = (char *)self - extra;
+ size_t len = CHUNK_SIZE(self) + extra;
+ /* Crash on double free */
+ if (extra & 1) a_crash();
+ __munmap(base, len);
+}
+
+void free(void *p)
+{
+ if (!p) return;
+
+ struct chunk *self = MEM_TO_CHUNK(p);
+
+ if (IS_MMAPPED(self))
+ unmap_chunk(self);
+ else
+ __bin_chunk(self);
+}
+
+void __malloc_donate(char *start, char *end)
+{
+ size_t align_start_up = (SIZE_ALIGN-1) & (-(uintptr_t)start - OVERHEAD);
+ size_t align_end_down = (SIZE_ALIGN-1) & (uintptr_t)end;
+
+ /* Getting past this condition ensures that the padding for alignment
+ * and header overhead will not overflow and will leave a nonzero
+ * multiple of SIZE_ALIGN bytes between start and end. */
+ if (end - start <= OVERHEAD + align_start_up + align_end_down)
+ return;
+ start += align_start_up + OVERHEAD;
+ end -= align_end_down;
+
+ struct chunk *c = MEM_TO_CHUNK(start), *n = MEM_TO_CHUNK(end);
+ c->psize = n->csize = C_INUSE;
+ c->csize = n->psize = C_INUSE | (end-start);
+ __bin_chunk(c);
+}
projects / musl / blobdiff