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-rw-r--r--src/malloc/oldmalloc/malloc.c550
1 files changed, 550 insertions, 0 deletions
diff --git a/src/malloc/oldmalloc/malloc.c b/src/malloc/oldmalloc/malloc.c
new file mode 100644
index 00000000..df3ea1be
--- /dev/null
+++ b/src/malloc/oldmalloc/malloc.c
@@ -0,0 +1,550 @@
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <stdint.h>
+#include <errno.h>
+#include <sys/mman.h>
+#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
+
+static struct {
+ volatile uint64_t binmap;
+ struct bin bins[64];
+ volatile int split_merge_lock[2];
+} mal;
+
+int __malloc_replaced;
+
+/* Synchronization tools */
+
+static inline void lock(volatile int *lk)
+{
+ 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)
+{
+ if (lk[0]) {
+ a_store(lk, 0);
+ if (lk[1]) __wake(lk, 1, 1);
+ }
+}
+
+static inline void lock_bin(int i)
+{
+ lock(mal.bins[i].lock);
+ if (!mal.bins[i].head)
+ mal.bins[i].head = mal.bins[i].tail = BIN_TO_CHUNK(i);
+}
+
+static inline void unlock_bin(int i)
+{
+ unlock(mal.bins[i].lock);
+}
+
+static int first_set(uint64_t x)
+{
+#if 1
+ return a_ctz_64(x);
+#else
+ static const char debruijn64[64] = {
+ 0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
+ 62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
+ 63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
+ 51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
+ };
+ static const char debruijn32[32] = {
+ 0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
+ 31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
+ };
+ if (sizeof(long) < 8) {
+ uint32_t y = x;
+ if (!y) {
+ y = x>>32;
+ return 32 + debruijn32[(y&-y)*0x076be629 >> 27];
+ }
+ return debruijn32[(y&-y)*0x076be629 >> 27];
+ }
+ return debruijn64[(x&-x)*0x022fdd63cc95386dull >> 58];
+#endif
+}
+
+static const unsigned char bin_tab[60] = {
+ 32,33,34,35,36,36,37,37,38,38,39,39,
+ 40,40,40,40,41,41,41,41,42,42,42,42,43,43,43,43,
+ 44,44,44,44,44,44,44,44,45,45,45,45,45,45,45,45,
+ 46,46,46,46,46,46,46,46,47,47,47,47,47,47,47,47,
+};
+
+static int bin_index(size_t x)
+{
+ x = x / SIZE_ALIGN - 1;
+ if (x <= 32) return x;
+ if (x < 512) return bin_tab[x/8-4];
+ if (x > 0x1c00) return 63;
+ return bin_tab[x/128-4] + 16;
+}
+
+static int bin_index_up(size_t x)
+{
+ x = x / SIZE_ALIGN - 1;
+ if (x <= 32) return x;
+ x--;
+ if (x < 512) return bin_tab[x/8-4] + 1;
+ return bin_tab[x/128-4] + 17;
+}
+
+#if 0
+void __dump_heap(int x)
+{
+ struct chunk *c;
+ int i;
+ for (c = (void *)mal.heap; CHUNK_SIZE(c); c = NEXT_CHUNK(c))
+ fprintf(stderr, "base %p size %zu (%d) flags %d/%d\n",
+ c, CHUNK_SIZE(c), bin_index(CHUNK_SIZE(c)),
+ c->csize & 15,
+ NEXT_CHUNK(c)->psize & 15);
+ for (i=0; i<64; i++) {
+ if (mal.bins[i].head != BIN_TO_CHUNK(i) && mal.bins[i].head) {
+ fprintf(stderr, "bin %d: %p\n", i, mal.bins[i].head);
+ if (!(mal.binmap & 1ULL<<i))
+ fprintf(stderr, "missing from binmap!\n");
+ } else if (mal.binmap & 1ULL<<i)
+ fprintf(stderr, "binmap wrongly contains %d!\n", i);
+ }
+}
+#endif
+
+/* This function returns true if the interval [old,new]
+ * intersects the 'len'-sized interval below &libc.auxv
+ * (interpreted as the main-thread stack) or below &b
+ * (the current stack). It is used to defend against
+ * buggy brk implementations that can cross the stack. */
+
+static int traverses_stack_p(uintptr_t old, uintptr_t new)
+{
+ const uintptr_t len = 8<<20;
+ uintptr_t a, b;
+
+ b = (uintptr_t)libc.auxv;
+ a = b > len ? b-len : 0;
+ if (new>a && old<b) return 1;
+
+ b = (uintptr_t)&b;
+ a = b > len ? b-len : 0;
+ if (new>a && old<b) return 1;
+
+ return 0;
+}
+
+/* Expand the heap in-place if brk can be used, or otherwise via mmap,
+ * using an exponential lower bound on growth by mmap to make
+ * fragmentation asymptotically irrelevant. The size argument is both
+ * an input and an output, since the caller needs to know the size
+ * allocated, which will be larger than requested due to page alignment
+ * and mmap minimum size rules. The caller is responsible for locking
+ * to prevent concurrent calls. */
+
+static void *__expand_heap(size_t *pn)
+{
+ static uintptr_t brk;
+ static unsigned mmap_step;
+ size_t n = *pn;
+
+ if (n > SIZE_MAX/2 - PAGE_SIZE) {
+ errno = ENOMEM;
+ return 0;
+ }
+ n += -n & PAGE_SIZE-1;
+
+ if (!brk) {
+ brk = __syscall(SYS_brk, 0);
+ brk += -brk & PAGE_SIZE-1;
+ }
+
+ if (n < SIZE_MAX-brk && !traverses_stack_p(brk, brk+n)
+ && __syscall(SYS_brk, brk+n)==brk+n) {
+ *pn = n;
+ brk += n;
+ return (void *)(brk-n);
+ }
+
+ size_t min = (size_t)PAGE_SIZE << mmap_step/2;
+ if (n < min) n = min;
+ void *area = __mmap(0, n, PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (area == MAP_FAILED) return 0;
+ *pn = n;
+ mmap_step++;
+ return area;
+}
+
+static struct chunk *expand_heap(size_t n)
+{
+ static void *end;
+ void *p;
+ struct chunk *w;
+
+ /* The argument n already accounts for the caller's chunk
+ * overhead needs, but if the heap can't be extended in-place,
+ * we need room for an extra zero-sized sentinel chunk. */
+ n += SIZE_ALIGN;
+
+ p = __expand_heap(&n);
+ if (!p) return 0;
+
+ /* If not just expanding existing space, we need to make a
+ * new sentinel chunk below the allocated space. */
+ if (p != end) {
+ /* Valid/safe because of the prologue increment. */
+ n -= SIZE_ALIGN;
+ p = (char *)p + SIZE_ALIGN;
+ w = MEM_TO_CHUNK(p);
+ w->psize = 0 | C_INUSE;
+ }
+
+ /* Record new heap end and fill in footer. */
+ end = (char *)p + n;
+ w = MEM_TO_CHUNK(end);
+ w->psize = n | C_INUSE;
+ w->csize = 0 | C_INUSE;
+
+ /* Fill in header, which may be new or may be replacing a
+ * zero-size sentinel header at the old end-of-heap. */
+ w = MEM_TO_CHUNK(p);
+ w->csize = n | C_INUSE;
+
+ return w;
+}
+
+static int adjust_size(size_t *n)
+{
+ /* Result of pointer difference must fit in ptrdiff_t. */
+ if (*n-1 > PTRDIFF_MAX - SIZE_ALIGN - PAGE_SIZE) {
+ if (*n) {
+ errno = ENOMEM;
+ return -1;
+ } else {
+ *n = SIZE_ALIGN;
+ return 0;
+ }
+ }
+ *n = (*n + OVERHEAD + SIZE_ALIGN - 1) & SIZE_MASK;
+ return 0;
+}
+
+static void unbin(struct chunk *c, int i)
+{
+ if (c->prev == c->next)
+ a_and_64(&mal.binmap, ~(1ULL<<i));
+ c->prev->next = c->next;
+ c->next->prev = c->prev;
+ c->csize |= C_INUSE;
+ NEXT_CHUNK(c)->psize |= C_INUSE;
+}
+
+static void bin_chunk(struct chunk *self, int i)
+{
+ self->next = BIN_TO_CHUNK(i);
+ self->prev = mal.bins[i].tail;
+ self->next->prev = self;
+ self->prev->next = self;
+ if (self->prev == BIN_TO_CHUNK(i))
+ a_or_64(&mal.binmap, 1ULL<<i);
+}
+
+static void trim(struct chunk *self, size_t n)
+{
+ size_t n1 = CHUNK_SIZE(self);
+ struct chunk *next, *split;
+
+ if (n >= n1 - DONTCARE) return;
+
+ next = NEXT_CHUNK(self);
+ split = (void *)((char *)self + n);
+
+ split->psize = n | C_INUSE;
+ split->csize = n1-n;
+ next->psize = n1-n;
+ self->csize = n | C_INUSE;
+
+ int i = bin_index(n1-n);
+ lock_bin(i);
+
+ bin_chunk(split, i);
+
+ unlock_bin(i);
+}
+
+void *malloc(size_t n)
+{
+ struct chunk *c;
+ int i, j;
+ uint64_t mask;
+
+ if (adjust_size(&n) < 0) return 0;
+
+ if (n > MMAP_THRESHOLD) {
+ size_t len = n + OVERHEAD + PAGE_SIZE - 1 & -PAGE_SIZE;
+ char *base = __mmap(0, len, PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (base == (void *)-1) return 0;
+ c = (void *)(base + SIZE_ALIGN - OVERHEAD);
+ c->csize = len - (SIZE_ALIGN - OVERHEAD);
+ c->psize = SIZE_ALIGN - OVERHEAD;
+ return CHUNK_TO_MEM(c);
+ }
+
+ i = bin_index_up(n);
+ if (i<63 && (mal.binmap & (1ULL<<i))) {
+ lock_bin(i);
+ c = mal.bins[i].head;
+ if (c != BIN_TO_CHUNK(i) && CHUNK_SIZE(c)-n <= DONTCARE) {
+ unbin(c, i);
+ unlock_bin(i);
+ return CHUNK_TO_MEM(c);
+ }
+ unlock_bin(i);
+ }
+ lock(mal.split_merge_lock);
+ for (mask = mal.binmap & -(1ULL<<i); mask; mask -= (mask&-mask)) {
+ j = first_set(mask);
+ lock_bin(j);
+ c = mal.bins[j].head;
+ if (c != BIN_TO_CHUNK(j)) {
+ unbin(c, j);
+ unlock_bin(j);
+ break;
+ }
+ unlock_bin(j);
+ }
+ if (!mask) {
+ c = expand_heap(n);
+ if (!c) {
+ unlock(mal.split_merge_lock);
+ return 0;
+ }
+ }
+ trim(c, n);
+ unlock(mal.split_merge_lock);
+ return CHUNK_TO_MEM(c);
+}
+
+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) 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 memset(p, 0, n);
+}
+
+void *realloc(void *p, size_t n)
+{
+ struct chunk *self, *next;
+ size_t n0, n1;
+ void *new;
+
+ if (!p) return malloc(n);
+
+ if (adjust_size(&n) < 0) return 0;
+
+ self = MEM_TO_CHUNK(p);
+ n1 = n0 = CHUNK_SIZE(self);
+
+ if (n<=n0 && n0-n<=DONTCARE) return p;
+
+ if (IS_MMAPPED(self)) {
+ size_t extra = self->psize;
+ char *base = (char *)self - extra;
+ size_t oldlen = n0 + extra;
+ size_t newlen = n + extra;
+ /* Crash on realloc of freed chunk */
+ if (extra & 1) a_crash();
+ 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;
+ base = __mremap(base, oldlen, newlen, MREMAP_MAYMOVE);
+ if (base == (void *)-1)
+ goto copy_realloc;
+ self = (void *)(base + extra);
+ self->csize = newlen - extra;
+ return CHUNK_TO_MEM(self);
+ }
+
+ next = NEXT_CHUNK(self);
+
+ /* Crash on corrupted footer (likely from buffer overflow) */
+ if (next->psize != self->csize) a_crash();
+
+ lock(mal.split_merge_lock);
+
+ size_t nsize = next->csize & C_INUSE ? 0 : CHUNK_SIZE(next);
+ if (n0+nsize >= n) {
+ int i = bin_index(nsize);
+ lock_bin(i);
+ if (!(next->csize & C_INUSE)) {
+ unbin(next, i);
+ unlock_bin(i);
+ next = NEXT_CHUNK(next);
+ self->csize = next->psize = n0+nsize | C_INUSE;
+ trim(self, n);
+ unlock(mal.split_merge_lock);
+ return CHUNK_TO_MEM(self);
+ }
+ unlock_bin(i);
+ }
+ unlock(mal.split_merge_lock);
+
+copy_realloc:
+ /* 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 __bin_chunk(struct chunk *self)
+{
+ struct chunk *next = NEXT_CHUNK(self);
+
+ /* Crash on corrupted footer (likely from buffer overflow) */
+ if (next->psize != self->csize) a_crash();
+
+ lock(mal.split_merge_lock);
+
+ size_t osize = CHUNK_SIZE(self), size = osize;
+
+ /* Since we hold split_merge_lock, only transition from free to
+ * in-use can race; in-use to free is impossible */
+ size_t psize = self->psize & C_INUSE ? 0 : CHUNK_PSIZE(self);
+ size_t nsize = next->csize & C_INUSE ? 0 : CHUNK_SIZE(next);
+
+ if (psize) {
+ int i = bin_index(psize);
+ lock_bin(i);
+ if (!(self->psize & C_INUSE)) {
+ struct chunk *prev = PREV_CHUNK(self);
+ unbin(prev, i);
+ self = prev;
+ size += psize;
+ }
+ unlock_bin(i);
+ }
+ if (nsize) {
+ int i = bin_index(nsize);
+ lock_bin(i);
+ if (!(next->csize & C_INUSE)) {
+ unbin(next, i);
+ next = NEXT_CHUNK(next);
+ size += nsize;
+ }
+ unlock_bin(i);
+ }
+
+ int i = bin_index(size);
+ lock_bin(i);
+
+ self->csize = size;
+ next->psize = size;
+ bin_chunk(self, i);
+ unlock(mal.split_merge_lock);
+
+ /* Replace middle of large chunks with fresh zero pages */
+ if (size > RECLAIM && (size^(size-osize)) > size-osize) {
+ uintptr_t a = (uintptr_t)self + SIZE_ALIGN+PAGE_SIZE-1 & -PAGE_SIZE;
+ uintptr_t b = (uintptr_t)next - SIZE_ALIGN & -PAGE_SIZE;
+#if 1
+ __madvise((void *)a, b-a, MADV_DONTNEED);
+#else
+ __mmap((void *)a, b-a, PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0);
+#endif
+ }
+
+ 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);
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-04-25 19:24:00 +0000