merge from dev-win (padding)

This commit is contained in:
daan 2020-02-01 12:32:59 -08:00
commit edff9d4fbb
14 changed files with 321 additions and 127 deletions

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@ -248,4 +248,4 @@
<Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
<ImportGroup Label="ExtensionTargets">
</ImportGroup>
</Project>
</Project>

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@ -314,8 +314,10 @@ static inline uintptr_t _mi_ptr_cookie(const void* p) {
----------------------------------------------------------- */
static inline mi_page_t* _mi_heap_get_free_small_page(mi_heap_t* heap, size_t size) {
mi_assert_internal(size <= MI_SMALL_SIZE_MAX);
return heap->pages_free_direct[_mi_wsize_from_size(size)];
mi_assert_internal(size <= (MI_SMALL_SIZE_MAX + MI_PADDING_SIZE));
const size_t idx = _mi_wsize_from_size(size);
mi_assert_internal(idx < MI_PAGES_DIRECT);
return heap->pages_free_direct[idx];
}
// Get the page belonging to a certain size class
@ -379,6 +381,13 @@ static inline size_t mi_page_block_size(const mi_page_t* page) {
}
}
// Get the usable block size of a page without fixed padding.
// This may still include internal padding due to alignment and rounding up size classes.
static inline size_t mi_page_usable_block_size(const mi_page_t* page) {
return mi_page_block_size(page) - MI_PADDING_SIZE;
}
// Thread free access
static inline mi_block_t* mi_page_thread_free(const mi_page_t* page) {
return (mi_block_t*)(mi_atomic_read_relaxed(&page->xthread_free) & ~3);
@ -514,30 +523,37 @@ static inline uintptr_t mi_rotr(uintptr_t x, uintptr_t shift) {
return ((x >> shift) | (x << (MI_INTPTR_BITS - shift)));
}
static inline mi_block_t* mi_block_nextx( const void* null, const mi_block_t* block, uintptr_t key1, uintptr_t key2 ) {
static inline void* mi_ptr_decode(const void* null, const mi_encoded_t x, const uintptr_t* keys) {
void* p = (void*)(mi_rotr(x - keys[0], keys[0]) ^ keys[1]);
return (mi_unlikely(p==null) ? NULL : p);
}
static inline mi_encoded_t mi_ptr_encode(const void* null, const void* p, const uintptr_t* keys) {
uintptr_t x = (uintptr_t)(mi_unlikely(p==NULL) ? null : p);
return mi_rotl(x ^ keys[1], keys[0]) + keys[0];
}
static inline mi_block_t* mi_block_nextx( const void* null, const mi_block_t* block, const uintptr_t* keys ) {
#ifdef MI_ENCODE_FREELIST
mi_block_t* b = (mi_block_t*)(mi_rotr(block->next - key1, key1) ^ key2);
if (mi_unlikely((void*)b==null)) { b = NULL; }
return b;
return (mi_block_t*)mi_ptr_decode(null, block->next, keys);
#else
UNUSED(key1); UNUSED(key2); UNUSED(null);
UNUSED(keys); UNUSED(null);
return (mi_block_t*)block->next;
#endif
}
static inline void mi_block_set_nextx(const void* null, mi_block_t* block, const mi_block_t* next, uintptr_t key1, uintptr_t key2) {
static inline void mi_block_set_nextx(const void* null, mi_block_t* block, const mi_block_t* next, const uintptr_t* keys) {
#ifdef MI_ENCODE_FREELIST
if (mi_unlikely(next==NULL)) { next = (mi_block_t*)null; }
block->next = mi_rotl((uintptr_t)next ^ key2, key1) + key1;
block->next = mi_ptr_encode(null, next, keys);
#else
UNUSED(key1); UNUSED(key2); UNUSED(null);
UNUSED(keys); UNUSED(null);
block->next = (mi_encoded_t)next;
#endif
}
static inline mi_block_t* mi_block_next(const mi_page_t* page, const mi_block_t* block) {
#ifdef MI_ENCODE_FREELIST
mi_block_t* next = mi_block_nextx(page,block,page->key[0],page->key[1]);
mi_block_t* next = mi_block_nextx(page,block,page->keys);
// check for free list corruption: is `next` at least in the same page?
// TODO: check if `next` is `page->block_size` aligned?
if (mi_unlikely(next!=NULL && !mi_is_in_same_page(block, next))) {
@ -547,16 +563,16 @@ static inline mi_block_t* mi_block_next(const mi_page_t* page, const mi_block_t*
return next;
#else
UNUSED(page);
return mi_block_nextx(page,block,0,0);
return mi_block_nextx(page,block,NULL);
#endif
}
static inline void mi_block_set_next(const mi_page_t* page, mi_block_t* block, const mi_block_t* next) {
#ifdef MI_ENCODE_FREELIST
mi_block_set_nextx(page,block,next, page->key[0], page->key[1]);
mi_block_set_nextx(page,block,next, page->keys);
#else
UNUSED(page);
mi_block_set_nextx(page,block, next,0,0);
mi_block_set_nextx(page,block,next,NULL);
#endif
}

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@ -12,6 +12,10 @@ terms of the MIT license. A copy of the license can be found in the file
#include <stdint.h> // uintptr_t, uint16_t, etc
#include <mimalloc-atomic.h> // _Atomic
// Minimal alignment necessary. On most platforms 16 bytes are needed
// due to SSE registers for example. This must be at least `MI_INTPTR_SIZE`
#define MI_MAX_ALIGN_SIZE 16 // sizeof(max_align_t)
// ------------------------------------------------------
// Variants
// ------------------------------------------------------
@ -44,17 +48,24 @@ terms of the MIT license. A copy of the license can be found in the file
#endif
#endif
// Reserve extra padding at the end of each block to be more resilient against heap block overflows.
// The padding can detect byte-precise buffer overflow on free.
#if !defined(MI_PADDING) && (MI_DEBUG>=1)
#define MI_PADDING 1
#endif
// Encoded free lists allow detection of corrupted free lists
// and can detect buffer overflows and double `free`s.
#if (MI_SECURE>=3 || MI_DEBUG>=1)
// and can detect buffer overflows, modify after free, and double `free`s.
#if (MI_SECURE>=3 || MI_DEBUG>=1 || defined(MI_PADDING))
#define MI_ENCODE_FREELIST 1
#endif
// ------------------------------------------------------
// Platform specific values
// ------------------------------------------------------
// ------------------------------------------------------
// Size of a pointer.
// We assume that `sizeof(void*)==sizeof(intptr_t)`
@ -82,6 +93,7 @@ terms of the MIT license. A copy of the license can be found in the file
#define MiB (KiB*KiB)
#define GiB (MiB*KiB)
// ------------------------------------------------------
// Main internal data-structures
// ------------------------------------------------------
@ -113,10 +125,6 @@ terms of the MIT license. A copy of the license can be found in the file
#define MI_LARGE_OBJ_WSIZE_MAX (MI_LARGE_OBJ_SIZE_MAX/MI_INTPTR_SIZE)
#define MI_HUGE_OBJ_SIZE_MAX (2*MI_INTPTR_SIZE*MI_SEGMENT_SIZE) // (must match MI_REGION_MAX_ALLOC_SIZE in memory.c)
// Minimal alignment necessary. On most platforms 16 bytes are needed
// due to SSE registers for example. This must be at least `MI_INTPTR_SIZE`
#define MI_MAX_ALIGN_SIZE 16 // sizeof(max_align_t)
// Maximum number of size classes. (spaced exponentially in 12.5% increments)
#define MI_BIN_HUGE (73U)
@ -209,7 +217,7 @@ typedef struct mi_page_s {
mi_block_t* free; // list of available free blocks (`malloc` allocates from this list)
#ifdef MI_ENCODE_FREELIST
uintptr_t key[2]; // two random keys to encode the free lists (see `_mi_block_next`)
uintptr_t keys[2]; // two random keys to encode the free lists (see `_mi_block_next`)
#endif
uint32_t used; // number of blocks in use (including blocks in `local_free` and `thread_free`)
uint32_t xblock_size; // size available in each block (always `>0`)
@ -294,18 +302,34 @@ typedef struct mi_random_cxt_s {
} mi_random_ctx_t;
// In debug mode there is a padding stucture at the end of the blocks to check for buffer overflows
#if defined(MI_PADDING)
typedef struct mi_padding_s {
uint32_t canary; // encoded block value to check validity of the padding (in case of overflow)
uint32_t delta; // padding bytes before the block. (mi_usable_size(p) - delta == exact allocated bytes)
} mi_padding_t;
#define MI_PADDING_SIZE (sizeof(mi_padding_t))
#define MI_PADDING_WSIZE ((MI_PADDING_SIZE + MI_INTPTR_SIZE - 1) / MI_INTPTR_SIZE)
#else
#define MI_PADDING_SIZE 0
#define MI_PADDING_WSIZE 0
#endif
#define MI_PAGES_DIRECT (MI_SMALL_WSIZE_MAX + MI_PADDING_WSIZE + 1)
// A heap owns a set of pages.
struct mi_heap_s {
mi_tld_t* tld;
mi_page_t* pages_free_direct[MI_SMALL_WSIZE_MAX + 2]; // optimize: array where every entry points a page with possibly free blocks in the corresponding queue for that size.
mi_page_queue_t pages[MI_BIN_FULL + 1]; // queue of pages for each size class (or "bin")
mi_page_t* pages_free_direct[MI_PAGES_DIRECT]; // optimize: array where every entry points a page with possibly free blocks in the corresponding queue for that size.
mi_page_queue_t pages[MI_BIN_FULL + 1]; // queue of pages for each size class (or "bin")
volatile _Atomic(mi_block_t*) thread_delayed_free;
uintptr_t thread_id; // thread this heap belongs too
uintptr_t cookie; // random cookie to verify pointers (see `_mi_ptr_cookie`)
uintptr_t key[2]; // twb random keys used to encode the `thread_delayed_free` list
mi_random_ctx_t random; // random number context used for secure allocation
size_t page_count; // total number of pages in the `pages` queues.
bool no_reclaim; // `true` if this heap should not reclaim abandoned pages
uintptr_t thread_id; // thread this heap belongs too
uintptr_t cookie; // random cookie to verify pointers (see `_mi_ptr_cookie`)
uintptr_t keys[2]; // two random keys used to encode the `thread_delayed_free` list
mi_random_ctx_t random; // random number context used for secure allocation
size_t page_count; // total number of pages in the `pages` queues.
bool no_reclaim; // `true` if this heap should not reclaim abandoned pages
};
@ -316,7 +340,7 @@ struct mi_heap_s {
#define MI_DEBUG_UNINIT (0xD0)
#define MI_DEBUG_FREED (0xDF)
#define MI_DEBUG_PADDING (0xDE)
#if (MI_DEBUG)
// use our own assertion to print without memory allocation

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@ -18,20 +18,22 @@ static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t
// note: we don't require `size > offset`, we just guarantee that
// the address at offset is aligned regardless of the allocated size.
mi_assert(alignment > 0 && alignment % sizeof(void*) == 0);
if (alignment <= MI_MAX_ALIGN_SIZE && offset==0) return _mi_heap_malloc_zero(heap, size, zero);
if (mi_unlikely(size > PTRDIFF_MAX)) return NULL; // we don't allocate more than PTRDIFF_MAX (see <https://sourceware.org/ml/libc-announce/2019/msg00001.html>)
if (mi_unlikely(alignment==0 || !_mi_is_power_of_two(alignment))) return NULL; // require power-of-two (see <https://en.cppreference.com/w/c/memory/aligned_alloc>)
const uintptr_t align_mask = alignment-1; // for any x, `(x & align_mask) == (x % alignment)`
// try if there is a small block available with just the right alignment
if (mi_likely(size <= MI_SMALL_SIZE_MAX)) {
mi_page_t* page = _mi_heap_get_free_small_page(heap,size);
mi_page_t* page = _mi_heap_get_free_small_page(heap,size + MI_PADDING_SIZE);
const bool is_aligned = (((uintptr_t)page->free+offset) & align_mask)==0;
if (mi_likely(page->free != NULL && is_aligned))
{
#if MI_STAT>1
mi_heap_stat_increase( heap, malloc, size);
#endif
void* p = _mi_page_malloc(heap,page,size); // TODO: inline _mi_page_malloc
void* p = _mi_page_malloc(heap,page,size + MI_PADDING_SIZE); // TODO: inline _mi_page_malloc
mi_assert_internal(p != NULL);
mi_assert_internal(((uintptr_t)p + offset) % alignment == 0);
if (zero) _mi_block_zero_init(page,p,size);

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@ -47,16 +47,19 @@ int mi_posix_memalign(void** p, size_t alignment, size_t size) mi_attr_noexcept
// Note: The spec dictates we should not modify `*p` on an error. (issue#27)
// <http://man7.org/linux/man-pages/man3/posix_memalign.3.html>
if (p == NULL) return EINVAL;
if (alignment % sizeof(void*) != 0) return EINVAL; // natural alignment
if (alignment % sizeof(void*) != 0) return EINVAL; // natural alignment
if (!_mi_is_power_of_two(alignment)) return EINVAL; // not a power of 2
void* q = mi_malloc_aligned(size, alignment);
void* q = (alignment <= MI_MAX_ALIGN_SIZE ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
if (q==NULL && size != 0) return ENOMEM;
mi_assert_internal(((uintptr_t)q % alignment) == 0);
*p = q;
return 0;
}
void* mi_memalign(size_t alignment, size_t size) mi_attr_noexcept {
return mi_malloc_aligned(size, alignment);
void* p = (alignment <= MI_MAX_ALIGN_SIZE ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
mi_assert_internal(((uintptr_t)p % alignment) == 0);
return p;
}
void* mi_valloc(size_t size) mi_attr_noexcept {
@ -73,7 +76,9 @@ void* mi_pvalloc(size_t size) mi_attr_noexcept {
void* mi_aligned_alloc(size_t alignment, size_t size) mi_attr_noexcept {
if (alignment==0 || !_mi_is_power_of_two(alignment)) return NULL;
if ((size&(alignment-1)) != 0) return NULL; // C11 requires integral multiple, see <https://en.cppreference.com/w/c/memory/aligned_alloc>
return mi_malloc_aligned(size, alignment);
void* p = (alignment <= MI_MAX_ALIGN_SIZE ? mi_malloc(size) : mi_malloc_aligned(size, alignment));
mi_assert_internal(((uintptr_t)p % alignment) == 0);
return p;
}
void* mi_reallocarray( void* p, size_t count, size_t size ) mi_attr_noexcept { // BSD

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@ -21,7 +21,7 @@ terms of the MIT license. A copy of the license can be found in the file
// Fast allocation in a page: just pop from the free list.
// Fall back to generic allocation only if the list is empty.
extern inline void* _mi_page_malloc(mi_heap_t* heap, mi_page_t* page, size_t size) mi_attr_noexcept {
extern inline void* _mi_page_malloc(mi_heap_t* heap, mi_page_t* page, size_t size) mi_attr_noexcept {
mi_assert_internal(page->xblock_size==0||mi_page_block_size(page) >= size);
mi_block_t* block = page->free;
if (mi_unlikely(block == NULL)) {
@ -29,84 +29,107 @@ extern inline void* _mi_page_malloc(mi_heap_t* heap, mi_page_t* page, size_t siz
}
mi_assert_internal(block != NULL && _mi_ptr_page(block) == page);
// pop from the free list
page->free = mi_block_next(page,block);
page->free = mi_block_next(page, block);
page->used++;
mi_assert_internal(page->free == NULL || _mi_ptr_page(page->free) == page);
#if (MI_DEBUG!=0)
#if (MI_DEBUG>0)
if (!page->is_zero) { memset(block, MI_DEBUG_UNINIT, size); }
#elif (MI_SECURE!=0)
block->next = 0; // don't leak internal data
#endif
#if (MI_STAT>1)
if(size <= MI_LARGE_OBJ_SIZE_MAX) {
size_t bin = _mi_bin(size);
mi_heap_stat_increase(heap,normal[bin], 1);
const size_t bsize = mi_page_usable_block_size(page);
if (bsize <= MI_LARGE_OBJ_SIZE_MAX) {
const size_t bin = _mi_bin(bsize);
mi_heap_stat_increase(heap, normal[bin], 1);
}
#endif
#if defined(MI_PADDING) && defined(MI_ENCODE_FREELIST)
mi_padding_t* const padding = (mi_padding_t*)((uint8_t*)block + mi_page_usable_block_size(page));
ptrdiff_t delta = ((uint8_t*)padding - (uint8_t*)block - (size - MI_PADDING_SIZE));
mi_assert_internal(delta >= 0 && mi_page_usable_block_size(page) >= (size - MI_PADDING_SIZE + delta));
padding->canary = (uint32_t)(mi_ptr_encode(page,block,page->keys));
padding->delta = (uint32_t)(delta);
uint8_t* fill = (uint8_t*)padding - delta;
const size_t maxpad = (delta > MI_MAX_ALIGN_SIZE ? MI_MAX_ALIGN_SIZE : delta); // set at most N initial padding bytes
for (size_t i = 0; i < maxpad; i++) { fill[i] = MI_DEBUG_PADDING; }
#endif
return block;
}
// allocate a small block
extern inline mi_decl_allocator void* mi_heap_malloc_small(mi_heap_t* heap, size_t size) mi_attr_noexcept {
mi_assert(heap!=NULL);
mi_assert(heap->thread_id == 0 || heap->thread_id == _mi_thread_id()); // heaps are thread local
mi_assert(size <= MI_SMALL_SIZE_MAX);
mi_page_t* page = _mi_heap_get_free_small_page(heap,size);
return _mi_page_malloc(heap, page, size);
mi_page_t* page = _mi_heap_get_free_small_page(heap,size + MI_PADDING_SIZE);
void* p = _mi_page_malloc(heap, page, size + MI_PADDING_SIZE);
mi_assert_internal(p==NULL || mi_usable_size(p) >= size);
#if MI_STAT>1
if (p != NULL) {
if (!mi_heap_is_initialized(heap)) { heap = mi_get_default_heap(); }
mi_heap_stat_increase(heap, malloc, mi_usable_size(p));
}
#endif
return p;
}
extern inline mi_decl_allocator void* mi_malloc_small(size_t size) mi_attr_noexcept {
return mi_heap_malloc_small(mi_get_default_heap(), size);
}
// zero initialized small block
mi_decl_allocator void* mi_zalloc_small(size_t size) mi_attr_noexcept {
void* p = mi_malloc_small(size);
if (p != NULL) { memset(p, 0, size); }
return p;
}
// The main allocation function
extern inline mi_decl_allocator void* mi_heap_malloc(mi_heap_t* heap, size_t size) mi_attr_noexcept {
mi_assert(heap!=NULL);
mi_assert(heap->thread_id == 0 || heap->thread_id == _mi_thread_id()); // heaps are thread local
void* p;
if (mi_likely(size <= MI_SMALL_SIZE_MAX)) {
p = mi_heap_malloc_small(heap, size);
return mi_heap_malloc_small(heap, size);
}
else {
p = _mi_malloc_generic(heap, size);
mi_assert(heap!=NULL);
mi_assert(heap->thread_id == 0 || heap->thread_id == _mi_thread_id()); // heaps are thread local
void* const p = _mi_malloc_generic(heap, size + MI_PADDING_SIZE);
mi_assert_internal(p == NULL || mi_usable_size(p) >= size);
#if MI_STAT>1
if (p != NULL) {
if (!mi_heap_is_initialized(heap)) { heap = mi_get_default_heap(); }
mi_heap_stat_increase(heap, malloc, mi_usable_size(p));
}
#endif
return p;
}
#if MI_STAT>1
if (p != NULL) {
if (!mi_heap_is_initialized(heap)) { heap = mi_get_default_heap(); }
mi_heap_stat_increase( heap, malloc, mi_good_size(size) ); // overestimate for aligned sizes
}
#endif
return p;
}
extern inline mi_decl_allocator void* mi_malloc(size_t size) mi_attr_noexcept {
return mi_heap_malloc(mi_get_default_heap(), size);
}
void _mi_block_zero_init(const mi_page_t* page, void* p, size_t size) {
// note: we need to initialize the whole block to zero, not just size
// note: we need to initialize the whole usable block size to zero, not just the requested size,
// or the recalloc/rezalloc functions cannot safely expand in place (see issue #63)
UNUSED_RELEASE(size);
UNUSED(size);
mi_assert_internal(p != NULL);
mi_assert_internal(mi_page_block_size(page) >= size); // size can be zero
mi_assert_internal(mi_usable_size(p) >= size); // size can be zero
mi_assert_internal(_mi_ptr_page(p)==page);
if (page->is_zero) {
// already zero initialized memory?
((mi_block_t*)p)->next = 0; // clear the free list pointer
mi_assert_expensive(mi_mem_is_zero(p, mi_page_block_size(page)));
mi_assert_expensive(mi_mem_is_zero(p, mi_usable_size(p)));
}
else {
// otherwise memset
memset(p, 0, mi_page_block_size(page));
memset(p, 0, mi_usable_size(p));
}
}
// zero initialized small block
mi_decl_allocator void* mi_zalloc_small(size_t size) mi_attr_noexcept {
void* p = mi_malloc_small(size);
if (p != NULL) {
_mi_block_zero_init(_mi_ptr_page(p), p, size); // todo: can we avoid getting the page again?
}
return p;
}
void* _mi_heap_malloc_zero(mi_heap_t* heap, size_t size, bool zero) {
void* p = mi_heap_malloc(heap,size);
if (zero && p != NULL) {
@ -153,7 +176,7 @@ static mi_decl_noinline bool mi_check_is_double_freex(const mi_page_t* page, con
}
static inline bool mi_check_is_double_free(const mi_page_t* page, const mi_block_t* block) {
mi_block_t* n = mi_block_nextx(page, block, page->key[0], page->key[1]); // pretend it is freed, and get the decoded first field
mi_block_t* n = mi_block_nextx(page, block, page->keys); // pretend it is freed, and get the decoded first field
if (((uintptr_t)n & (MI_INTPTR_SIZE-1))==0 && // quick check: aligned pointer?
(n==NULL || mi_is_in_same_page(block, n))) // quick check: in same page or NULL?
{
@ -171,22 +194,112 @@ static inline bool mi_check_is_double_free(const mi_page_t* page, const mi_block
}
#endif
// ---------------------------------------------------------------------------
// Check for heap block overflow by setting up padding at the end of the block
// ---------------------------------------------------------------------------
#if defined(MI_PADDING) && defined(MI_ENCODE_FREELIST)
static bool mi_page_decode_padding(const mi_page_t* page, const mi_block_t* block, size_t* delta, size_t* bsize) {
*bsize = mi_page_usable_block_size(page);
const mi_padding_t* const padding = (mi_padding_t*)((uint8_t*)block + *bsize);
*delta = padding->delta;
return ((uint32_t)mi_ptr_encode(page,block,page->keys) == padding->canary && *delta <= *bsize);
}
// Return the exact usable size of a block.
static size_t mi_page_usable_size_of(const mi_page_t* page, const mi_block_t* block) {
size_t bsize;
size_t delta;
bool ok = mi_page_decode_padding(page, block, &delta, &bsize);
mi_assert_internal(ok); mi_assert_internal(delta <= bsize);
return (ok ? bsize - delta : 0);
}
static bool mi_verify_padding(const mi_page_t* page, const mi_block_t* block, size_t* size, size_t* wrong) {
size_t bsize;
size_t delta;
bool ok = mi_page_decode_padding(page, block, &delta, &bsize);
*size = *wrong = bsize;
if (!ok) return false;
mi_assert_internal(bsize >= delta);
*size = bsize - delta;
uint8_t* fill = (uint8_t*)block + bsize - delta;
const size_t maxpad = (delta > MI_MAX_ALIGN_SIZE ? MI_MAX_ALIGN_SIZE : delta); // check at most the first N padding bytes
for (size_t i = 0; i < maxpad; i++) {
if (fill[i] != MI_DEBUG_PADDING) {
*wrong = bsize - delta + i;
return false;
}
}
return true;
}
static void mi_check_padding(const mi_page_t* page, const mi_block_t* block) {
size_t size;
size_t wrong;
if (!mi_verify_padding(page,block,&size,&wrong)) {
_mi_error_message(EFAULT, "buffer overflow in heap block %p of size %zu: write after %zu bytes\n", block, size, wrong );
}
}
// When a non-thread-local block is freed, it becomes part of the thread delayed free
// list that is freed later by the owning heap. If the exact usable size is too small to
// contain the pointer for the delayed list, then shrink the padding (by decreasing delta)
// so it will later not trigger an overflow error in `mi_free_block`.
static void mi_padding_shrink(const mi_page_t* page, const mi_block_t* block, const size_t min_size) {
size_t bsize;
size_t delta;
bool ok = mi_page_decode_padding(page, block, &delta, &bsize);
mi_assert_internal(ok);
if (!ok || (bsize - delta) >= min_size) return; // usually already enough space
mi_assert_internal(bsize >= min_size);
if (bsize < min_size) return; // should never happen
size_t new_delta = (bsize - min_size);
mi_assert_internal(new_delta < bsize);
mi_padding_t* padding = (mi_padding_t*)((uint8_t*)block + bsize);
padding->delta = (uint32_t)new_delta;
}
#else
static void mi_check_padding(const mi_page_t* page, const mi_block_t* block) {
UNUSED(page);
UNUSED(block);
}
static size_t mi_page_usable_size_of(const mi_page_t* page, const mi_block_t* block) {
UNUSED(block);
return mi_page_usable_block_size(page);
}
static void mi_padding_shrink(const mi_page_t* page, const mi_block_t* block, const size_t min_size) {
UNUSED(page);
UNUSED(block);
UNUSED(min_size);
}
#endif
// ------------------------------------------------------
// Free
// ------------------------------------------------------
// multi-threaded free
static mi_decl_noinline void _mi_free_block_mt(mi_page_t* page, mi_block_t* block)
{
// The padding check may access the non-thread-owned page for the key values.
// that is safe as these are constant and the page won't be freed (as the block is not freed yet).
mi_check_padding(page, block);
mi_padding_shrink(page, block, sizeof(mi_block_t)); // for small size, ensure we can fit the delayed thread pointers without triggering overflow detection
#if (MI_DEBUG!=0)
memset(block, MI_DEBUG_FREED, mi_usable_size(block));
#endif
// huge page segments are always abandoned and can be freed immediately
mi_segment_t* segment = _mi_page_segment(page);
mi_segment_t* const segment = _mi_page_segment(page);
if (segment->page_kind==MI_PAGE_HUGE) {
_mi_segment_huge_page_free(segment, page, block);
return;
}
// Try to put the block on either the page-local thread free list, or the heap delayed free list.
mi_thread_free_t tfree;
mi_thread_free_t tfreex;
bool use_delayed;
@ -206,14 +319,14 @@ static mi_decl_noinline void _mi_free_block_mt(mi_page_t* page, mi_block_t* bloc
if (mi_unlikely(use_delayed)) {
// racy read on `heap`, but ok because MI_DELAYED_FREEING is set (see `mi_heap_delete` and `mi_heap_collect_abandon`)
mi_heap_t* heap = mi_page_heap(page);
mi_heap_t* const heap = mi_page_heap(page);
mi_assert_internal(heap != NULL);
if (heap != NULL) {
// add to the delayed free list of this heap. (do this atomically as the lock only protects heap memory validity)
mi_block_t* dfree;
do {
dfree = mi_atomic_read_ptr_relaxed(mi_block_t,&heap->thread_delayed_free);
mi_block_set_nextx(heap,block,dfree, heap->key[0], heap->key[1]);
mi_block_set_nextx(heap,block,dfree, heap->keys);
} while (!mi_atomic_cas_ptr_weak(mi_block_t,&heap->thread_delayed_free, block, dfree));
}
@ -230,14 +343,14 @@ static mi_decl_noinline void _mi_free_block_mt(mi_page_t* page, mi_block_t* bloc
// regular free
static inline void _mi_free_block(mi_page_t* page, bool local, mi_block_t* block)
{
#if (MI_DEBUG)
memset(block, MI_DEBUG_FREED, mi_page_block_size(page));
#endif
// and push it on the free list
if (mi_likely(local)) {
// owning thread can free a block directly
if (mi_unlikely(mi_check_is_double_free(page, block))) return;
mi_check_padding(page, block);
#if (MI_DEBUG!=0)
memset(block, MI_DEBUG_FREED, mi_page_block_size(page));
#endif
mi_block_set_next(page, block, page->local_free);
page->local_free = block;
page->used--;
@ -246,7 +359,7 @@ static inline void _mi_free_block(mi_page_t* page, bool local, mi_block_t* block
}
else if (mi_unlikely(mi_page_is_in_full(page))) {
_mi_page_unfull(page);
}
}
}
else {
_mi_free_block_mt(page,block);
@ -257,15 +370,15 @@ static inline void _mi_free_block(mi_page_t* page, bool local, mi_block_t* block
// Adjust a block that was allocated aligned, to the actual start of the block in the page.
mi_block_t* _mi_page_ptr_unalign(const mi_segment_t* segment, const mi_page_t* page, const void* p) {
mi_assert_internal(page!=NULL && p!=NULL);
size_t diff = (uint8_t*)p - _mi_page_start(segment, page, NULL);
size_t adjust = (diff % mi_page_block_size(page));
const size_t diff = (uint8_t*)p - _mi_page_start(segment, page, NULL);
const size_t adjust = (diff % mi_page_block_size(page));
return (mi_block_t*)((uintptr_t)p - adjust);
}
static void mi_decl_noinline mi_free_generic(const mi_segment_t* segment, bool local, void* p) {
mi_page_t* page = _mi_segment_page_of(segment, p);
mi_block_t* block = (mi_page_has_aligned(page) ? _mi_page_ptr_unalign(segment, page, p) : (mi_block_t*)p);
mi_page_t* const page = _mi_segment_page_of(segment, p);
mi_block_t* const block = (mi_page_has_aligned(page) ? _mi_page_ptr_unalign(segment, page, p) : (mi_block_t*)p);
_mi_free_block(page, local, block);
}
@ -300,26 +413,30 @@ void mi_free(void* p) mi_attr_noexcept
const uintptr_t tid = _mi_thread_id();
mi_page_t* const page = _mi_segment_page_of(segment, p);
mi_block_t* const block = (mi_block_t*)p;
#if (MI_STAT>1)
mi_heap_t* heap = mi_heap_get_default();
mi_heap_stat_decrease(heap, malloc, mi_usable_size(p));
if (page->xblock_size <= MI_LARGE_OBJ_SIZE_MAX) {
mi_heap_stat_decrease(heap, normal[_mi_bin(page->xblock_size)], 1);
}
// huge page stat is accounted for in `_mi_page_retire`
mi_heap_t* const heap = mi_heap_get_default();
const size_t bsize = mi_page_usable_block_size(page);
mi_heap_stat_decrease(heap, malloc, bsize);
if (bsize <= MI_LARGE_OBJ_SIZE_MAX) { // huge page stats are accounted for in `_mi_page_retire`
mi_heap_stat_decrease(heap, normal[_mi_bin(bsize)], 1);
}
#endif
if (mi_likely(tid == segment->thread_id && page->flags.full_aligned == 0)) { // the thread id matches and it is not a full page, nor has aligned blocks
// local, and not full or aligned
mi_block_t* const block = (mi_block_t*)p;
// local, and not full or aligned
if (mi_unlikely(mi_check_is_double_free(page,block))) return;
mi_check_padding(page, block);
#if (MI_DEBUG!=0)
memset(block, MI_DEBUG_FREED, mi_page_block_size(page));
#endif
mi_block_set_next(page, block, page->local_free);
page->local_free = block;
page->used--;
if (mi_unlikely(mi_page_all_free(page))) {
_mi_page_retire(page);
}
}
}
else {
// non-local, aligned blocks, or a full page; use the more generic path
@ -330,10 +447,10 @@ void mi_free(void* p) mi_attr_noexcept
bool _mi_free_delayed_block(mi_block_t* block) {
// get segment and page
const mi_segment_t* segment = _mi_ptr_segment(block);
const mi_segment_t* const segment = _mi_ptr_segment(block);
mi_assert_internal(_mi_ptr_cookie(segment) == segment->cookie);
mi_assert_internal(_mi_thread_id() == segment->thread_id);
mi_page_t* page = _mi_segment_page_of(segment, block);
mi_page_t* const page = _mi_segment_page_of(segment, block);
// Clear the no-delayed flag so delayed freeing is used again for this page.
// This must be done before collecting the free lists on this page -- otherwise
@ -353,11 +470,12 @@ bool _mi_free_delayed_block(mi_block_t* block) {
// Bytes available in a block
size_t mi_usable_size(const void* p) mi_attr_noexcept {
if (p==NULL) return 0;
const mi_segment_t* segment = _mi_ptr_segment(p);
const mi_page_t* page = _mi_segment_page_of(segment,p);
size_t size = mi_page_block_size(page);
const mi_segment_t* const segment = _mi_ptr_segment(p);
const mi_page_t* const page = _mi_segment_page_of(segment, p);
const mi_block_t* const block = (const mi_block_t*)p;
const size_t size = mi_page_usable_size_of(page, block);
if (mi_unlikely(mi_page_has_aligned(page))) {
ptrdiff_t adjust = (uint8_t*)p - (uint8_t*)_mi_page_ptr_unalign(segment,page,p);
ptrdiff_t const adjust = (uint8_t*)p - (uint8_t*)_mi_page_ptr_unalign(segment,page,p);
mi_assert_internal(adjust >= 0 && (size_t)adjust <= size);
return (size - adjust);
}

View File

@ -283,7 +283,7 @@ int mi_reserve_huge_os_pages_at(size_t pages, int numa_node, size_t timeout_msec
_mi_warning_message("failed to reserve %zu gb huge pages\n", pages);
return ENOMEM;
}
_mi_verbose_message("reserved %zu gb huge pages on numa node %i (of the %zu gb requested)\n", pages_reserved, numa_node, pages);
_mi_verbose_message("numa node %i: reserved %zu gb huge pages (of the %zu gb requested)\n", numa_node, pages_reserved, pages);
size_t bcount = mi_block_count_of_size(hsize);
size_t fields = _mi_divide_up(bcount, MI_BITMAP_FIELD_BITS);

View File

@ -197,9 +197,9 @@ mi_heap_t* mi_heap_new(void) {
heap->tld = bheap->tld;
heap->thread_id = _mi_thread_id();
_mi_random_split(&bheap->random, &heap->random);
heap->cookie = _mi_heap_random_next(heap) | 1;
heap->key[0] = _mi_heap_random_next(heap);
heap->key[1] = _mi_heap_random_next(heap);
heap->cookie = _mi_heap_random_next(heap) | 1;
heap->keys[0] = _mi_heap_random_next(heap);
heap->keys[1] = _mi_heap_random_next(heap);
heap->no_reclaim = true; // don't reclaim abandoned pages or otherwise destroy is unsafe
return heap;
}

View File

@ -31,8 +31,14 @@ const mi_page_t _mi_page_empty = {
};
#define MI_PAGE_EMPTY() ((mi_page_t*)&_mi_page_empty)
#define MI_SMALL_PAGES_EMPTY \
{ MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY(), MI_PAGE_EMPTY() }
#if defined(MI_PADDING) && (MI_INTPTR_SIZE >= 8)
#define MI_SMALL_PAGES_EMPTY { MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY(), MI_PAGE_EMPTY() }
#elif defined(MI_PADDING)
#define MI_SMALL_PAGES_EMPTY { MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY(), MI_PAGE_EMPTY(), MI_PAGE_EMPTY() }
#else
#define MI_SMALL_PAGES_EMPTY { MI_INIT128(MI_PAGE_EMPTY), MI_PAGE_EMPTY() }
#endif
// Empty page queues for every bin
@ -167,9 +173,9 @@ static bool _mi_heap_init(void) {
memcpy(heap, &_mi_heap_empty, sizeof(*heap));
heap->thread_id = _mi_thread_id();
_mi_random_init(&heap->random);
heap->cookie = _mi_heap_random_next(heap) | 1;
heap->key[0] = _mi_heap_random_next(heap);
heap->key[1] = _mi_heap_random_next(heap);
heap->cookie = _mi_heap_random_next(heap) | 1;
heap->keys[0] = _mi_heap_random_next(heap);
heap->keys[1] = _mi_heap_random_next(heap);
heap->tld = tld;
tld->heap_backing = heap;
tld->segments.stats = &tld->stats;
@ -412,9 +418,9 @@ void mi_process_init(void) mi_attr_noexcept {
_mi_verbose_message("process init: 0x%zx\n", _mi_heap_main.thread_id);
_mi_random_init(&_mi_heap_main.random);
#ifndef __APPLE__ // TODO: fix this? cannot update cookie if allocation already happened..
_mi_heap_main.cookie = _mi_heap_random_next(&_mi_heap_main);
_mi_heap_main.key[0] = _mi_heap_random_next(&_mi_heap_main);
_mi_heap_main.key[1] = _mi_heap_random_next(&_mi_heap_main);
_mi_heap_main.cookie = _mi_heap_random_next(&_mi_heap_main);
_mi_heap_main.keys[0] = _mi_heap_random_next(&_mi_heap_main);
_mi_heap_main.keys[1] = _mi_heap_random_next(&_mi_heap_main);
#endif
mi_process_setup_auto_thread_done();
_mi_os_init();

View File

@ -319,6 +319,14 @@ static volatile _Atomic(void*) mi_error_arg; // = NULL
static void mi_error_default(int err) {
UNUSED(err);
#if (MI_DEBUG>0)
if (err==EFAULT) {
#ifdef _MSC_VER
__debugbreak();
#endif
abort();
}
#endif
#if (MI_SECURE>0)
if (err==EFAULT) { // abort on serious errors in secure mode (corrupted meta-data)
abort();

View File

@ -851,7 +851,7 @@ static void* mi_os_alloc_huge_os_pagesx(void* addr, size_t size, int numa_node)
else {
// fall back to regular large pages
mi_huge_pages_available = false; // don't try further huge pages
_mi_warning_message("unable to allocate using huge (1GiB) pages, trying large (2MiB) pages instead (status 0x%lx)\n", err);
_mi_warning_message("unable to allocate using huge (1gb) pages, trying large (2mb) pages instead (status 0x%lx)\n", err);
}
}
// on modern Windows try use VirtualAlloc2 for numa aware large OS page allocation
@ -892,7 +892,7 @@ static void* mi_os_alloc_huge_os_pagesx(void* addr, size_t size, int numa_node)
// see: <https://lkml.org/lkml/2017/2/9/875>
long err = mi_os_mbind(p, size, MPOL_PREFERRED, &numa_mask, 8*MI_INTPTR_SIZE, 0);
if (err != 0) {
_mi_warning_message("failed to bind huge (1GiB) pages to NUMA node %d: %s\n", numa_node, strerror(errno));
_mi_warning_message("failed to bind huge (1gb) pages to numa node %d: %s\n", numa_node, strerror(errno));
}
}
return p;

View File

@ -281,7 +281,7 @@ void _mi_heap_delayed_free(mi_heap_t* heap) {
// and free them all
while(block != NULL) {
mi_block_t* next = mi_block_nextx(heap,block, heap->key[0], heap->key[1]);
mi_block_t* next = mi_block_nextx(heap,block, heap->keys);
// use internal free instead of regular one to keep stats etc correct
if (!_mi_free_delayed_block(block)) {
// we might already start delayed freeing while another thread has not yet
@ -289,7 +289,7 @@ void _mi_heap_delayed_free(mi_heap_t* heap) {
mi_block_t* dfree;
do {
dfree = mi_atomic_read_ptr_relaxed(mi_block_t,&heap->thread_delayed_free);
mi_block_set_nextx(heap, block, dfree, heap->key[0], heap->key[1]);
mi_block_set_nextx(heap, block, dfree, heap->keys);
} while (!mi_atomic_cas_ptr_weak(mi_block_t,&heap->thread_delayed_free, block, dfree));
}
block = next;
@ -348,7 +348,7 @@ void _mi_page_abandon(mi_page_t* page, mi_page_queue_t* pq) {
#if MI_DEBUG>1
// check there are no references left..
for (mi_block_t* block = (mi_block_t*)pheap->thread_delayed_free; block != NULL; block = mi_block_nextx(pheap, block, pheap->key[0], pheap->key[1])) {
for (mi_block_t* block = (mi_block_t*)pheap->thread_delayed_free; block != NULL; block = mi_block_nextx(pheap, block, pheap->keys)) {
mi_assert_internal(_mi_ptr_page(block) != page);
}
#endif
@ -609,8 +609,8 @@ static void mi_page_init(mi_heap_t* heap, mi_page_t* page, size_t block_size, mi
mi_assert_internal(page_size / block_size < (1L<<16));
page->reserved = (uint16_t)(page_size / block_size);
#ifdef MI_ENCODE_FREELIST
page->key[0] = _mi_heap_random_next(heap);
page->key[1] = _mi_heap_random_next(heap);
page->keys[0] = _mi_heap_random_next(heap);
page->keys[1] = _mi_heap_random_next(heap);
#endif
page->is_zero = page->is_zero_init;
@ -623,8 +623,8 @@ static void mi_page_init(mi_heap_t* heap, mi_page_t* page, size_t block_size, mi
mi_assert_internal(page->retire_expire == 0);
mi_assert_internal(!mi_page_has_aligned(page));
#if (MI_ENCODE_FREELIST)
mi_assert_internal(page->key[0] != 0);
mi_assert_internal(page->key[1] != 0);
mi_assert_internal(page->keys[0] != 0);
mi_assert_internal(page->keys[1] != 0);
#endif
mi_assert_expensive(mi_page_is_valid_init(page));
@ -752,7 +752,7 @@ static mi_page_t* mi_huge_page_alloc(mi_heap_t* heap, size_t size) {
mi_assert_internal(_mi_bin(block_size) == MI_BIN_HUGE);
mi_page_t* page = mi_page_fresh_alloc(heap,NULL,block_size);
if (page != NULL) {
const size_t bsize = mi_page_block_size(page);
const size_t bsize = mi_page_usable_block_size(page);
mi_assert_internal(mi_page_immediate_available(page));
mi_assert_internal(bsize >= size);
mi_assert_internal(_mi_page_segment(page)->page_kind==MI_PAGE_HUGE);
@ -761,11 +761,11 @@ static mi_page_t* mi_huge_page_alloc(mi_heap_t* heap, size_t size) {
mi_page_set_heap(page, NULL);
if (bsize > MI_HUGE_OBJ_SIZE_MAX) {
_mi_stat_increase(&heap->tld->stats.giant, block_size);
_mi_stat_increase(&heap->tld->stats.giant, bsize);
_mi_stat_counter_increase(&heap->tld->stats.giant_count, 1);
}
else {
_mi_stat_increase(&heap->tld->stats.huge, block_size);
_mi_stat_increase(&heap->tld->stats.huge, bsize);
_mi_stat_counter_increase(&heap->tld->stats.huge_count, 1);
}
}

View File

@ -247,6 +247,7 @@ static void mi_page_reset(mi_segment_t* segment, mi_page_t* page, size_t size, m
static void mi_page_unreset(mi_segment_t* segment, mi_page_t* page, size_t size, mi_segments_tld_t* tld)
{
mi_assert_internal(page->is_reset);
mi_assert_internal(page->is_committed);
mi_assert_internal(!segment->mem_is_fixed);
page->is_reset = false;
size_t psize;
@ -778,10 +779,14 @@ static void mi_segment_page_clear(mi_segment_t* segment, mi_page_t* page, bool a
// note: must come after setting `segment_in_use` to false but before block_size becomes 0
//mi_page_reset(segment, page, 0 /*used_size*/, tld);
// zero the page data, but not the segment fields and block_size (for page size calculations)
// zero the page data, but not the segment fields and capacity, and block_size (for page size calculations)
uint32_t block_size = page->xblock_size;
uint16_t capacity = page->capacity;
uint16_t reserved = page->reserved;
ptrdiff_t ofs = offsetof(mi_page_t,capacity);
memset((uint8_t*)page + ofs, 0, sizeof(*page) - ofs);
page->capacity = capacity;
page->reserved = reserved;
page->xblock_size = block_size;
segment->used--;
@ -789,6 +794,9 @@ static void mi_segment_page_clear(mi_segment_t* segment, mi_page_t* page, bool a
if (allow_reset) {
mi_pages_reset_add(segment, page, tld);
}
page->capacity = 0; // after reset there can be zero'd now
page->reserved = 0;
}
void _mi_segment_page_free(mi_page_t* page, bool force, mi_segments_tld_t* tld)
@ -1291,7 +1299,7 @@ void _mi_segment_huge_page_free(mi_segment_t* segment, mi_page_t* page, mi_block
page->is_zero = false;
mi_assert(page->used == 0);
mi_segments_tld_t* tld = &heap->tld->segments;
const size_t bsize = mi_page_block_size(page);
const size_t bsize = mi_page_usable_block_size(page);
if (bsize > MI_HUGE_OBJ_SIZE_MAX) {
_mi_stat_decrease(&tld->stats->giant, bsize);
}

View File

@ -10,6 +10,7 @@
static void double_free1();
static void double_free2();
static void corrupt_free();
static void block_overflow1();
int main() {
mi_version();
@ -18,6 +19,7 @@ int main() {
// double_free1();
// double_free2();
// corrupt_free();
// block_overflow1();
void* p1 = malloc(78);
void* p2 = malloc(24);
@ -41,6 +43,11 @@ int main() {
return 0;
}
static void block_overflow1() {
uint8_t* p = (uint8_t*)mi_malloc(17);
p[18] = 0;
free(p);
}
// The double free samples come ArcHeap [1] by Insu Yun (issue #161)
// [1]: https://arxiv.org/pdf/1903.00503.pdf