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--- /dev/null
+++ libmalloc/libmalloc-521.120.7/src/magazine_medium.c
@@ -0,0 +1,2933 @@
+/*
+ * Copyright (c) 2018 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include "internal.h"
+
+#if CONFIG_MEDIUM_ALLOCATOR
+
+/********************* MEDIUM FREE LIST UTILITIES ************************/
+
+#pragma mark meta header helpers
+
+static MALLOC_INLINE uint64_t
+medium_sliding_madvise_granularity(magazine_t *magazine)
+{
+ uint64_t granularity = MEDIUM_MADVISE_MIN;
+ // Use a sliding madvise granularity based on how many bytes the region
+ // currently has allocated. This way we will advise at a finer granularity
+ // as the region becomes more and more empty.
+ // region_trailer_t *t = REGION_TRAILER_FOR_MEDIUM_REGION(region);
+ if (magazine->mag_num_bytes_in_objects > 0) {
+ if (magazine_medium_madvise_window_scale_factor == 1) {
+ // NB: This code has a bug causing undefined behavior whenever the result of clzl is > 32
+ // because it's shifting a signed integer. It should be 1ULL << (64 - ...) but
+ // fixing this bug will introduce memory regressions, so for now we've only fixed it on very
+ // large memory configs that are scaling up their window anyways.
+ // See rdar://82128925 for details
+ granularity = MAX(granularity, 1 << (64 -
+ __builtin_clzl(magazine->mag_num_bytes_in_objects >> MEDIUM_MADVISE_SHIFT)));
+ } else {
+ granularity = MAX(granularity, 1ULL << (64 -
+ __builtin_clzl(magazine->mag_num_bytes_in_objects >> MEDIUM_MADVISE_SHIFT)));
+ if (os_mul_overflow(granularity, magazine_medium_madvise_window_scale_factor, &granularity)) {
+ return UINT64_MAX;
+ }
+ }
+ }
+ return granularity;
+}
+
+static MALLOC_INLINE void
+medium_madvise_header_mark_dirty(msize_t *headers, msize_t index,
+ msize_t msize)
+{
+ // MALLOC_ASSERT(index < NUM_MEDIUM_BLOCKS);
+ // MALLOC_ASSERT(index + msize <= NUM_MEDIUM_BLOCKS);
+ headers[index] = msize;
+ headers[index + msize - 1] = msize;
+}
+
+static MALLOC_INLINE void
+medium_madvise_header_mark_clean(msize_t *headers, msize_t index,
+ msize_t msize)
+{
+ // MALLOC_ASSERT(index < NUM_MEDIUM_BLOCKS);
+ // MALLOC_ASSERT(index + msize <= NUM_MEDIUM_BLOCKS);
+ headers[index] = msize | MEDIUM_IS_ADVISED;
+ headers[index + msize - 1] = msize | MEDIUM_IS_ADVISED;
+}
+
+static MALLOC_INLINE void
+medium_madvise_header_mark_middle(msize_t *headers, msize_t index)
+{
+ // MALLOC_ASSERT(index < NUM_MEDIUM_BLOCKS);
+ headers[index] = 0;
+}
+
+static MALLOC_INLINE msize_t
+medium_madvise_header_dirty_len(msize_t *headers, msize_t index)
+{
+ // MALLOC_ASSERT(index < NUM_MEDIUM_BLOCKS);
+ if (headers[index] & MEDIUM_IS_ADVISED) {
+ return 0;
+ }
+ return headers[index] & ~MEDIUM_IS_ADVISED;
+}
+
+/*
+ * Mark a block as free. Only the first quantum of a block is marked thusly,
+ * the remainder are marked "middle".
+ */
+static MALLOC_INLINE void
+medium_meta_header_set_is_free(msize_t *meta_headers, msize_t index, msize_t msize)
+{
+ meta_headers[index] = msize | MEDIUM_IS_FREE;
+}
+
+/*
+ * Mark a block as not free, preserving its size.
+ */
+static MALLOC_INLINE void
+medium_meta_header_set_not_free(msize_t *meta_headers, msize_t index)
+{
+ meta_headers[index] &= ~MEDIUM_IS_FREE;
+}
+
+/*
+ * Mark a block as in use. Only the first quantum of a block is marked thusly,
+ * the remainder are marked "middle".
+ */
+static MALLOC_INLINE void
+medium_meta_header_set_in_use(msize_t *meta_headers, msize_t index, msize_t msize)
+{
+ meta_headers[index] = msize;
+}
+
+/*
+ * Mark a quantum as being the second or later in a block.
+ */
+static MALLOC_INLINE void
+medium_meta_header_set_middle(msize_t *meta_headers, msize_t index)
+{
+ meta_headers[index] = 0;
+}
+
+#pragma mark in-place free list
+
+static MALLOC_INLINE void
+medium_inplace_checksum_ptr(rack_t *rack, inplace_linkage_s *linkage, void *ptr)
+{
+ uintptr_t checksum = free_list_gen_checksum((uintptr_t)ptr ^ rack->cookie ^ (uintptr_t)rack);
+ linkage->checksum = checksum;
+ linkage->ptr = ptr;
+}
+
+static MALLOC_INLINE free_list_t
+medium_inplace_unchecksum_ptr(rack_t *rack, inplace_linkage_s *linkage)
+{
+ if (linkage->checksum != (uint8_t)free_list_gen_checksum((uintptr_t)linkage->ptr ^ rack->cookie ^ (uintptr_t)rack)) {
+ free_list_checksum_botch(rack, linkage, linkage->ptr);
+ __builtin_trap();
+ }
+
+ return (free_list_t){ .p = linkage->ptr };
+}
+
+static MALLOC_INLINE free_list_t
+medium_inplace_unchecksum_ptr_task(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, rack_t *rack, inplace_linkage_s *linkage)
+{
+ inplace_linkage_s *mapped_linkage;
+ rack_t *mapped_rack;
+ if (reader(task, (vm_address_t)linkage, sizeof(*linkage),
+ (void **)&mapped_linkage)) {
+ printer("Unable to map medium linkage pointer %p\n", linkage);
+ return (free_list_t){ .p = NULL };
+ }
+
+ if (reader(task, (vm_address_t)rack,
+ sizeof(struct rack_s), (void **)&mapped_rack)) {
+ printer("Failed to map medium rack\n");
+ return (free_list_t){ .p = NULL };
+ }
+
+ if (mapped_linkage->checksum != (uint8_t)free_list_gen_checksum(
+ (uintptr_t)mapped_linkage->ptr ^ mapped_rack->cookie ^ (uintptr_t)rack)) {
+ free_list_checksum_botch(rack, linkage, mapped_linkage->ptr);
+ __builtin_trap();
+ }
+
+ return (free_list_t){ .p = mapped_linkage->ptr };
+}
+
+static MALLOC_INLINE free_list_t
+medium_inplace_free_entry_get_previous(rack_t *rack, medium_inplace_free_entry_t ptr)
+{
+ return medium_inplace_unchecksum_ptr(rack, &ptr->previous);
+}
+
+static MALLOC_INLINE void
+medium_inplace_free_entry_set_previous(rack_t *rack, medium_inplace_free_entry_t entry, free_list_t previous)
+{
+ medium_inplace_checksum_ptr(rack, &entry->previous, previous.p);
+}
+
+static MALLOC_INLINE free_list_t
+medium_inplace_free_entry_get_next(rack_t *rack, medium_inplace_free_entry_t ptr)
+{
+ return medium_inplace_unchecksum_ptr(rack, &ptr->next);
+}
+
+static MALLOC_INLINE free_list_t
+medium_inplace_free_entry_get_next_task(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, rack_t *rack,
+ medium_inplace_free_entry_t ptr)
+{
+ return medium_inplace_unchecksum_ptr_task(task, reader, printer, rack,
+ &ptr->next);
+}
+
+static MALLOC_INLINE void
+medium_inplace_free_entry_set_next(rack_t *rack, medium_inplace_free_entry_t entry, free_list_t next)
+{
+ medium_inplace_checksum_ptr(rack, &entry->next, next.p);
+}
+
+#pragma mark OOB free list
+
+// Returns true if the address and size of the free list entry would result
+// in the free entry being the only data on a given page.
+static MALLOC_INLINE boolean_t
+medium_needs_oob_free_entry(void *ptr, msize_t msize)
+{
+ return ((trunc_page_quanta((uintptr_t)ptr) == (uintptr_t)ptr) &&
+ (MEDIUM_BYTES_FOR_MSIZE(msize) >= vm_kernel_page_size));
+}
+
+// Returns true if the address given lies within the region's OOB free
+// list entries, rather than a free_list_t in the region's heap space.
+static MALLOC_INLINE boolean_t
+medium_is_oob_free_entry(free_list_t ptr)
+{
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(ptr.p);
+ return (((uintptr_t)ptr.p >= (uintptr_t)®ion->medium_oob_free_entries[0]) &&
+ ((uintptr_t)ptr.p < (uintptr_t)®ion->medium_oob_free_entries[MEDIUM_OOB_COUNT]));
+}
+
+static MALLOC_INLINE void
+medium_oob_free_entry_set_previous(oob_free_entry_t oobe, free_list_t previous)
+{
+ // MALLOC_ASSERT(medium_is_oob_free_entry(previous) || !((uintptr_t)previous.p & 0x1fffffff));
+ oobe->prev = (uintptr_t)previous.p;
+}
+
+static MALLOC_INLINE free_list_t
+medium_oob_free_entry_get_previous(oob_free_entry_t oobe)
+{
+ return (free_list_t){ .p = (void *)oobe->prev };
+}
+
+static MALLOC_INLINE void
+medium_oob_free_entry_set_next(oob_free_entry_t oobe, free_list_t next)
+{
+ // MALLOC_ASSERT(medium_is_oob_free_entry(next) || !((uintptr_t)next.p & 0x1fffffff));
+ oobe->next = (uintptr_t)next.p;
+}
+
+static MALLOC_INLINE free_list_t
+medium_oob_free_entry_get_next(oob_free_entry_t oobe)
+{
+ return (free_list_t){ .p = (void *)oobe->next };
+}
+
+static MALLOC_INLINE free_list_t
+medium_oob_free_entry_get_next_task(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, oob_free_entry_t oobe)
+{
+ oob_free_entry_t mapped_oobe;
+ if (reader(task, (vm_address_t)oobe, sizeof(*oobe),
+ (void **)&mapped_oobe)) {
+ printer("Failed to map medium oobe pointer\n");
+ return (free_list_t){ .p = NULL };
+ }
+ return (free_list_t){ .p = (void *)mapped_oobe->next };
+}
+
+static MALLOC_INLINE void *
+medium_oob_free_entry_get_ptr(oob_free_entry_t oobe)
+{
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(oobe);
+ uint16_t block = oobe->ptr & ~MEDIUM_IS_OOB;
+ return (void *)((uintptr_t)region + (block << SHIFT_MEDIUM_QUANTUM));
+}
+
+static MALLOC_INLINE void *
+medium_oob_free_entry_get_ptr_task(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, oob_free_entry_t oobe)
+{
+ // We need to map the oob_free_entry_t to read the pointer value.
+ oob_free_entry_t mapped_oobe;
+ if (reader(task, (vm_address_t)oobe, sizeof(*oobe),
+ (void **)&mapped_oobe)) {
+ printer("Failed to map medium oobe pointer\n");
+ return NULL;
+ }
+
+ if (!(mapped_oobe->ptr & MEDIUM_IS_OOB)) {
+ return NULL;
+ }
+
+ // The rest of this code works with target process addresses and returns an
+ // address in the target process.
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(oobe);
+ uint16_t block = mapped_oobe->ptr & ~MEDIUM_IS_OOB;
+ return (void *)((uintptr_t)region + (block << SHIFT_MEDIUM_QUANTUM));
+}
+
+static MALLOC_INLINE void
+medium_oob_free_entry_set_ptr(oob_free_entry_t oobe, void *ptr)
+{
+ oobe->ptr = MEDIUM_IS_OOB | (MEDIUM_REGION_OFFSET_FOR_PTR(ptr) >> SHIFT_MEDIUM_QUANTUM);
+}
+
+static MALLOC_INLINE void
+medium_oob_free_entry_set_free(oob_free_entry_t oobe)
+{
+ oobe->prev = ~0;
+ oobe->next = ~0;
+ oobe->ptr = 0;
+}
+
+// Finds the first unused OOB free list entry in the pointer's region.
+// Returns NULL if all of the OOB entries are used.
+static MALLOC_INLINE oob_free_entry_t
+medium_oob_free_find_empty(void *ptr, msize_t msize)
+{
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(ptr);
+
+ // There are 61 of these entries at the end of a medium region.
+ // If this changes, then a linear search through the list may
+ // become an unsuitable choice.
+ for (int i=0; i < MEDIUM_OOB_COUNT; i++) {
+ if (region->medium_oob_free_entries[i].ptr == 0) {
+ return ®ion->medium_oob_free_entries[i];
+ }
+ }
+
+#if DEBUG_MALLOC
+ malloc_report(ASL_LEVEL_INFO, "used all slots of OOB entries\n");
+#endif
+ return NULL;
+}
+
+static MALLOC_INLINE oob_free_entry_t
+medium_oob_free_find_ptr(void *ptr, msize_t msize)
+{
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(ptr);
+
+ // There are 61 of these entries at the end of a medium region.
+ // If this changes, then a linear search through the list may
+ // become an unsuitable choice.
+ for (int i=0; i < MEDIUM_OOB_COUNT; i++) {
+ oob_free_entry_t oob = ®ion->medium_oob_free_entries[i];
+ if (medium_oob_free_entry_get_ptr(oob) == ptr &&
+ oob->ptr & MEDIUM_IS_OOB) {
+ return ®ion->medium_oob_free_entries[i];
+ }
+ }
+
+ return NULL;
+}
+
+#pragma mark generic free list
+
+static MALLOC_INLINE void
+medium_free_list_set_previous(rack_t *rack, free_list_t entry, free_list_t previous)
+{
+ if (medium_is_oob_free_entry(entry)) {
+ medium_oob_free_entry_set_previous(entry.oob, previous);
+ } else {
+ medium_inplace_free_entry_set_previous(rack, entry.medium_inplace, previous);
+ }
+}
+
+static MALLOC_INLINE free_list_t
+medium_free_list_get_previous(rack_t *rack, free_list_t ptr)
+{
+ MALLOC_ASSERT(ptr.p);
+ if (medium_is_oob_free_entry(ptr)) {
+ return medium_oob_free_entry_get_previous(ptr.oob);
+ } else {
+ return medium_inplace_free_entry_get_previous(rack, ptr.medium_inplace);
+ }
+}
+
+static MALLOC_INLINE void
+medium_free_list_set_next(rack_t *rack, free_list_t entry, free_list_t next)
+{
+ if (medium_is_oob_free_entry(entry)) {
+ medium_oob_free_entry_set_next(entry.oob, next);
+ } else {
+ medium_inplace_free_entry_set_next(rack, entry.medium_inplace, next);
+ }
+}
+
+static MALLOC_INLINE free_list_t
+medium_free_list_get_next(rack_t *rack, free_list_t ptr)
+{
+ MALLOC_ASSERT(ptr.p);
+ if (medium_is_oob_free_entry(ptr)) {
+ return medium_oob_free_entry_get_next(ptr.oob);
+ } else {
+ return medium_inplace_free_entry_get_next(rack, ptr.medium_inplace);
+ }
+}
+
+static MALLOC_INLINE free_list_t
+medium_free_list_get_next_task(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, rack_t *rack, free_list_t ptr)
+{
+ MALLOC_ASSERT(ptr.p);
+ if (medium_is_oob_free_entry(ptr)) {
+ return medium_oob_free_entry_get_next_task(task, reader, printer, ptr.oob);
+ } else {
+ return medium_inplace_free_entry_get_next_task(task, reader, printer,
+ rack, ptr.medium_inplace);
+ }
+}
+
+static MALLOC_INLINE void *
+medium_free_list_get_ptr(rack_t *rack, free_list_t ptr)
+{
+ if (!ptr.p) {
+ return NULL;
+ } else if (medium_is_oob_free_entry(ptr)) {
+ return medium_oob_free_entry_get_ptr(ptr.oob);
+ } else {
+ return (void *)ptr.p;
+ }
+}
+
+static MALLOC_INLINE void *
+medium_free_list_get_ptr_task(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, free_list_t ptr)
+{
+ if (!ptr.p) {
+ return NULL;
+ } else if (medium_is_oob_free_entry(ptr)) {
+ return medium_oob_free_entry_get_ptr_task(task, reader, printer, ptr.oob);
+ } else {
+ return (void *)ptr.p;
+ }
+}
+
+// Returns a free_list_t that is either inline or not based on the
+// pointer and msize.
+static MALLOC_INLINE free_list_t
+medium_free_list_from_ptr(rack_t *rack, void *ptr, msize_t msize)
+{
+ MALLOC_ASSERT(msize);
+
+ // The default is to put the free_list_t in the memory that
+ // the pointer leads to.
+ free_list_t entry;
+ entry.p = ptr;
+
+ // If the pointer is page aligned, and the msize is greater
+ // than a whole page, then we try and put the entry in
+ // the out-of-band area instead.
+ if (medium_needs_oob_free_entry(ptr, msize)) {
+ oob_free_entry_t oobe = medium_oob_free_find_empty(ptr, msize);
+ if (oobe) {
+ medium_oob_free_entry_set_ptr(oobe, ptr);
+ entry.oob = oobe;
+ }
+ }
+
+ return entry;
+}
+
+static MALLOC_INLINE void
+medium_free_mark_free(rack_t *rack, free_list_t entry, msize_t msize)
+{
+ // Marks both the start and end block of a free-list entry as free.
+ void *ptr = medium_free_list_get_ptr(rack, entry);
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(ptr);
+ uintptr_t start_index = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ uintptr_t end_index = MEDIUM_META_INDEX_FOR_PTR(ptr + MEDIUM_BYTES_FOR_MSIZE(msize) - 1);
+ MALLOC_ASSERT(start_index <= end_index);
+
+ medium_meta_header_set_is_free(meta_headers, start_index, msize);
+ medium_meta_header_set_is_free(meta_headers, end_index, msize);
+}
+
+static MALLOC_INLINE void
+medium_free_mark_middle(rack_t *rack, free_list_t entry, msize_t msize)
+{
+ // Marks both the start and end block of a free-list entry as "middle" (unfree).
+ void *ptr = medium_free_list_get_ptr(rack, entry);
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(ptr);
+ uintptr_t start_index = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ uintptr_t end_index = MEDIUM_META_INDEX_FOR_PTR(ptr + MEDIUM_BYTES_FOR_MSIZE(msize) - 1);
+ MALLOC_ASSERT(start_index <= end_index);
+ MALLOC_ASSERT((meta_headers[start_index] & ~MEDIUM_IS_FREE) == msize);
+
+ medium_meta_header_set_middle(meta_headers, start_index);
+ medium_meta_header_set_middle(meta_headers, end_index);
+}
+
+static MALLOC_INLINE void
+medium_free_mark_unfree(rack_t *rack, free_list_t entry, msize_t msize)
+{
+ // Marks both the start and end block of a free-list entry as not free.
+ void *ptr = medium_free_list_get_ptr(rack, entry);
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(ptr);
+ uintptr_t start_index = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ uintptr_t end_index = MEDIUM_META_INDEX_FOR_PTR(ptr +
+ MEDIUM_BYTES_FOR_MSIZE(msize) - 1);
+ MALLOC_ASSERT(start_index <= end_index);
+
+ medium_meta_header_set_not_free(meta_headers, start_index);
+ medium_meta_header_set_not_free(meta_headers, end_index);
+}
+
+static MALLOC_INLINE unsigned int
+medium_free_list_count(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, rack_t *rack, free_list_t ptr)
+{
+ unsigned int count = 0;
+ while (ptr.p) {
+ count++;
+ ptr = medium_free_list_get_next_task(task, reader, printer, rack, ptr);
+ }
+ return count;
+}
+
+/*
+ * Adds an item to the proper free list, and also marks the meta-header of the
+ * block properly.
+ * Assumes szone has been locked
+ */
+static free_list_t
+medium_free_list_add_ptr(rack_t *rack, magazine_t *medium_mag_ptr, void *ptr, msize_t msize)
+{
+ grain_t slot = MEDIUM_FREE_SLOT_FOR_MSIZE(rack, msize);
+ free_list_t free_head = medium_mag_ptr->mag_free_list[slot];
+
+ // This will either return the free_list_t for the current pointer, or attempt
+ // to reserve an OOB entry for us.
+ free_list_t free_ptr = medium_free_list_from_ptr(rack, ptr, msize);
+
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_report(ASL_LEVEL_INFO, "in %s, ptr=%p, msize=%d\n", __FUNCTION__, ptr, msize);
+ }
+ if (((uintptr_t)ptr) & (MEDIUM_QUANTUM - 1)) {
+ malloc_zone_error(rack->debug_flags, true, "medium_free_list_add_ptr: Unaligned ptr %p\n", ptr);
+ }
+ if (!msize) {
+ malloc_zone_error(rack->debug_flags, true, "medium_free_list_add_ptr: msize=0, %p\n", ptr);
+ }
+#endif
+
+ medium_free_list_set_previous(rack, free_ptr, (free_list_t){ .p = NULL });
+ medium_free_list_set_next(rack, free_ptr, free_head);
+
+ // Set the start and end blocks of the meta header as "free". Marking the last block
+ // allows coalescing the regions when we free adjacent regions.
+ medium_free_mark_free(rack, free_ptr, msize);
+
+ if (medium_free_list_get_ptr(rack, free_head)) {
+#if DEBUG_MALLOC
+ if (medium_free_list_get_previous(szone, free_head)) {
+ malloc_zone_error(rack->debug_flags, true, "medium_free_list_add_ptr: Internal invariant broken (free_head->previous != NULL)\n"
+ "ptr=%p slot=%d free_head=%p previous=%p\n", ptr, slot, (void *)free_head, free_head->previous.p);
+ }
+ if (!MEDIUM_PTR_IS_FREE(medium_free_list_get_ptr(szone, free_head))) {
+ malloc_zone_error(rack->debug_flags, true, "medium_free_list_add_ptr: Internal invariant broken (free_head is not a free pointer)\n"
+ "ptr=%p slot=%d free_head=%p\n", ptr, slot, (void *)medium_free_list_get_ptr(szone, free_head));
+ }
+#endif
+ medium_free_list_set_previous(rack, free_head, free_ptr);
+ } else {
+ BITMAPN_SET(medium_mag_ptr->mag_bitmap, slot);
+ }
+
+ medium_mag_ptr->mag_free_list[slot] = free_ptr;
+ return free_ptr;
+}
+
+/*
+ * Removes the item pointed to by ptr in the proper free list.
+ * Assumes szone has been locked
+ */
+static void
+medium_free_list_remove_ptr_no_clear(rack_t *rack, magazine_t *medium_mag_ptr, free_list_t entry, msize_t msize)
+{
+ grain_t slot = MEDIUM_FREE_SLOT_FOR_MSIZE(rack, msize);
+ free_list_t next, previous;
+
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_report(ASL_LEVEL_INFO, "In %s, ptr=%p, msize=%d\n", __FUNCTION__, ptr, msize);
+ }
+#endif
+
+ previous = medium_free_list_get_previous(rack, entry);
+ next = medium_free_list_get_next(rack, entry);
+
+ if (!medium_free_list_get_ptr(rack, previous)) {
+ // The block to remove is the head of the free list
+#if DEBUG_MALLOC
+ if (medium_mag_ptr->mag_free_list[slot] != ptr) {
+ malloc_zone_error(rack->debug_flags, true,
+ "medium_free_list_remove_ptr_no_clear: Internal invariant broken (medium_mag_ptr->mag_free_list[slot])\n"
+ "ptr=%p slot=%d msize=%d medium_mag_ptr->mag_free_list[slot]=%p\n", ptr, slot, msize,
+ (void *)medium_mag_ptr->mag_free_list[slot]);
+ return;
+ }
+#endif
+ medium_mag_ptr->mag_free_list[slot] = next;
+ if (!medium_free_list_get_ptr(rack, next)) {
+ BITMAPN_CLR(medium_mag_ptr->mag_bitmap, slot);
+ }
+ } else {
+ // Check that the next pointer of "previous" points to "entry".
+ free_list_t prev_next = medium_free_list_get_next(rack, previous);
+ if (medium_free_list_get_ptr(rack, prev_next) != medium_free_list_get_ptr(rack, entry)) {
+ malloc_zone_error(rack->debug_flags, true,
+ "medium_free_list_remove_ptr_no_clear: Internal invariant broken (next ptr of prev) for %p, prev_next=%p\n",
+ medium_free_list_get_ptr(rack, entry), medium_free_list_get_ptr(rack, prev_next));
+ __builtin_unreachable(); // Always crashes in malloc_zone_error().
+ }
+ medium_free_list_set_next(rack, previous, next);
+ }
+
+ if (medium_free_list_get_ptr(rack, next)) {
+ // Check that the previous pointer of "next" points to "entry".
+ free_list_t next_prev = medium_free_list_get_previous(rack, next);
+ if (medium_free_list_get_ptr(rack, next_prev) != medium_free_list_get_ptr(rack, entry)) {
+ malloc_zone_error(rack->debug_flags, true,
+ "medium_free_list_remove_ptr_no_clear: Internal invariant broken (prev ptr of next) for %p, next_prev=%p\n",
+ medium_free_list_get_ptr(rack, entry), medium_free_list_get_ptr(rack, next_prev));
+ __builtin_unreachable(); // Always crashes in malloc_zone_error().
+ }
+ medium_free_list_set_previous(rack, next, previous);
+ }
+
+ if (medium_is_oob_free_entry(entry)) {
+ medium_oob_free_entry_set_free(entry.oob);
+ }
+}
+
+static void
+medium_free_list_remove_ptr(rack_t *rack, magazine_t *medium_mag_ptr, free_list_t entry, msize_t msize)
+{
+ // In the general case we want to ensure we marked these entries as "middle"
+ // while we are in this function. However, when we're moving free list entries
+ // from/to the recirc depot we rely on the metadata bits being intact to
+ // reconstruct the free list. In that case we have to be able to skip this
+ // metadata manipulation.
+ medium_free_mark_middle(rack, entry, msize);
+ medium_free_list_remove_ptr_no_clear(rack, medium_mag_ptr, entry, msize);
+}
+
+// Find a free list entry by its pointer address. This should only really be used
+// by medium_finalize_region, or similar, where the free_list_t entry of a known
+// pointer is desired. Otherwise it is cheaper to always pull off the free lists.
+static free_list_t
+medium_free_list_find_by_ptr(rack_t *rack, magazine_t *medium_mag_ptr, void *ptr, msize_t msize)
+{
+ if (*MEDIUM_METADATA_FOR_PTR(ptr) == (MEDIUM_IS_FREE | msize)) {
+ // If the block is marked free, and of size `msize`, then we first must check
+ // if the alignment+size is such that we could have use an OOB-entry.
+ if (medium_needs_oob_free_entry(ptr, msize)) {
+ // Scan the OOB entries looking for this address.
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(ptr);
+ for (int i=0; i<MEDIUM_OOB_COUNT; i++) {
+ if (!region->medium_oob_free_entries[i].ptr) {
+ continue;
+ }
+ if (medium_oob_free_entry_get_ptr(®ion->medium_oob_free_entries[i]) == ptr) {
+ return (free_list_t){ .oob = ®ion->medium_oob_free_entries[i] };
+ }
+ }
+ }
+
+ // Otherwise, the freed pointer will be in place.
+ return (free_list_t){ .p = ptr };
+ }
+
+ malloc_zone_error(rack->debug_flags, true,
+ "medium_free_list_find_by_ptr: ptr is not free (ptr metadata !MEDIUM_IS_FREE), "
+ "ptr=%p msize=%d metadata=0x%x\n", ptr, msize, *MEDIUM_METADATA_FOR_PTR(ptr));
+ __builtin_trap();
+}
+
+void
+medium_finalize_region(rack_t *rack, magazine_t *medium_mag_ptr)
+{
+ void *last_block, *previous_block;
+ msize_t last_msize, previous_msize, last_index;
+ free_list_t previous;
+
+ // It is possible that the block prior to the last block in the region has
+ // been free'd, but was not coalesced with the free bytes at the end of the
+ // block, since we treat the bytes at the end of the region as "in use" in
+ // the meta headers. Attempt to coalesce the last block with the previous
+ // block, so we don't violate the "no consecutive free blocks" invariant.
+ //
+ // FIXME: If we could calculate the previous medium free size in the same
+ // manner as tiny_previous_preceding_free, it would eliminate the
+ // index & previous msize checks, which are a guard against reading
+ // bogus data out of in-use or written-on-freed memory.
+ //
+ // FIXME: Need to investigate how much work would be required to increase
+ // 'mag_bytes_free_at_end' when freeing the preceding block, rather
+ // than performing this workaround.
+ //
+ if (medium_mag_ptr->mag_bytes_free_at_end) {
+ last_block = MEDIUM_REGION_HEAP_END(medium_mag_ptr->mag_last_region) - medium_mag_ptr->mag_bytes_free_at_end;
+ last_msize = MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end);
+
+ last_index = MEDIUM_META_INDEX_FOR_PTR(last_block);
+ previous_msize = MEDIUM_PREVIOUS_MSIZE(last_block);
+
+ if (last_index && (previous_msize <= last_index)) {
+ previous_block = (void *)((uintptr_t)last_block - MEDIUM_BYTES_FOR_MSIZE(previous_msize));
+
+ if (MEDIUM_PTR_IS_FREE(previous_block)) {
+ previous = medium_free_list_find_by_ptr(rack, medium_mag_ptr, previous_block, previous_msize);
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, previous, previous_msize);
+ last_block = previous_block;
+ last_msize += previous_msize;
+ }
+ }
+
+ // splice last_block into the free list
+ medium_free_list_add_ptr(rack, medium_mag_ptr, last_block, last_msize);
+ medium_mag_ptr->mag_bytes_free_at_end = 0;
+ }
+
+#if CONFIG_ASLR_INTERNAL
+ free_list_t next;
+
+ if (medium_mag_ptr->mag_bytes_free_at_start) {
+ last_block = MEDIUM_REGION_ADDRESS(medium_mag_ptr->mag_last_region);
+ last_msize = MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_start);
+
+ void *next_block = (void *)((uintptr_t)last_block + medium_mag_ptr->mag_bytes_free_at_start);
+ if (MEDIUM_PTR_IS_FREE(next_block)) {
+ msize_t next_msize = MEDIUM_PTR_SIZE(next_block);
+ next = medium_free_list_find_by_ptr(rack, medium_mag_ptr, next_block, next_msize);
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, next, next_msize);
+ last_msize += next_msize;
+ }
+
+ // splice last_block into the free list
+ medium_free_list_add_ptr(rack, medium_mag_ptr, last_block, last_msize);
+ medium_mag_ptr->mag_bytes_free_at_start = 0;
+ }
+#endif
+
+ // TODO: Will we ever need to coalesce the blocks at the beginning and end when we finalize?
+ medium_mag_ptr->mag_last_region = NULL;
+}
+
+int
+medium_free_detach_region(rack_t *rack, magazine_t *medium_mag_ptr, region_t r)
+{
+ uintptr_t start = (uintptr_t)MEDIUM_REGION_HEAP_BASE(r);
+ uintptr_t current = start;
+ uintptr_t limit = (uintptr_t)MEDIUM_REGION_HEAP_END(r);
+ int total_alloc = 0;
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(start);
+
+ while (current < limit) {
+ unsigned index = MEDIUM_META_INDEX_FOR_PTR(current);
+ msize_t msize_and_free = meta_headers[index];
+ boolean_t is_free = msize_and_free & MEDIUM_IS_FREE;
+ msize_t msize = msize_and_free & ~MEDIUM_IS_FREE;
+
+ if (!msize) {
+#if DEBUG_MALLOC
+ boolean_t is_free = msize_and_free & MEDIUM_IS_FREE;
+ malloc_report(ASL_LEVEL_ERR, "*** medium_free_detach_region error with %p: msize=%d is_free=%d\n", (void *)current, msize, is_free);
+#endif
+ break;
+ }
+
+ if (is_free) {
+ free_list_t entry = medium_free_list_find_by_ptr(rack, medium_mag_ptr, (void *)current, msize);
+ medium_free_list_remove_ptr_no_clear(rack, medium_mag_ptr, entry, msize);
+ } else {
+ total_alloc++;
+ }
+ current += MEDIUM_BYTES_FOR_MSIZE(msize);
+ }
+ return total_alloc;
+}
+
+size_t
+medium_free_reattach_region(rack_t *rack, magazine_t *medium_mag_ptr, region_t r)
+{
+ uintptr_t start = (uintptr_t)MEDIUM_REGION_HEAP_BASE(r);
+ uintptr_t current = start;
+ uintptr_t limit = (uintptr_t)MEDIUM_REGION_HEAP_END(r);
+ size_t total_alloc = 0;
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(start);
+
+ while (current < limit) {
+ unsigned index = MEDIUM_META_INDEX_FOR_PTR(current);
+ msize_t msize_and_free = meta_headers[index];
+ boolean_t is_free = msize_and_free & MEDIUM_IS_FREE;
+ msize_t msize = msize_and_free & ~MEDIUM_IS_FREE;
+
+ if (!msize) {
+#if DEBUG_MALLOC
+ malloc_report(ASL_LEVEL_ERR, "*** medium_free_reattach_region error with %p: msize=%d is_free=%d\n", (void *)current, msize, is_free);
+#endif
+ break;
+ }
+ if (is_free) {
+ medium_free_list_add_ptr(rack, medium_mag_ptr, (void *)current, msize);
+ } else {
+ total_alloc += MEDIUM_BYTES_FOR_MSIZE(msize);
+ }
+ current += MEDIUM_BYTES_FOR_MSIZE(msize);
+ }
+ return total_alloc;
+}
+
+typedef struct _medium_advisory_s {
+ struct _medium_advisory_s *next;
+ size_t size;
+} medium_advisory_s, *medium_advisory_t;
+
+void
+medium_free_scan_madvise_free(rack_t *rack, magazine_t *depot_ptr, region_t r)
+{
+ uintptr_t start = (uintptr_t)MEDIUM_REGION_HEAP_BASE(r);
+ uintptr_t current = start;
+ uintptr_t limit = (uintptr_t)MEDIUM_REGION_HEAP_END(r);
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(start);
+ msize_t *madv_headers = MEDIUM_MADVISE_HEADER_FOR_PTR(start);
+
+ medium_advisory_t advisories = NULL;
+
+ // Scan the metadata identifying blocks which span one or more pages. Mark
+ // the pages MADV_FREE taking care to preserve free list management data.
+ while (current < limit) {
+ unsigned index = MEDIUM_META_INDEX_FOR_PTR(current);
+
+ msize_t alloc_msize = meta_headers[index] & ~MEDIUM_IS_FREE;
+ bool alloc_is_free = meta_headers[index] & MEDIUM_IS_FREE;
+
+ if (alloc_is_free && alloc_msize == MEDIUM_MAX_MSIZE) {
+ // The first allocation is both free and covers the entire of the
+ // zone.
+#if DEBUG_MALLOC
+ // first block is all free
+ malloc_report(ASL_LEVEL_ERR, "*** medium_free_scan_madvise_free "
+ "first block is all free! %p: msize=%d is_free=%d\n",
+ (void *)current, alloc_msize, alloc_is_free);
+#endif
+ uintptr_t pgLo = round_page_kernel(start + sizeof(medium_inplace_free_entry_s) +
+ sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_kernel(start - sizeof(msize_t) +
+ (NUM_MEDIUM_BLOCKS << SHIFT_MEDIUM_QUANTUM));
+
+ if (pgLo < pgHi) {
+ medium_advisory_t mat = (medium_advisory_t)pgLo;
+ mat->next = advisories;
+ mat->size = pgHi - pgLo;
+ advisories = mat;
+ }
+ break;
+ }
+ if (!alloc_msize) {
+#if DEBUG_MALLOC
+ malloc_report(ASL_LEVEL_ERR, "*** medium_free_scan_madvise_free "
+ "error with %p: msize=%d is_free=%d\n", (void *)current,
+ msize, is_free);
+#endif
+ break;
+ }
+ if (alloc_is_free) {
+ msize_t advise_msize = madv_headers[index]
+ & ~MEDIUM_IS_ADVISED;
+ bool run_is_advised = madv_headers[index]
+ & MEDIUM_IS_ADVISED;
+
+ if (advise_msize != alloc_msize || !run_is_advised) {
+ uintptr_t pgLo = round_page_kernel(current +
+ sizeof(medium_inplace_free_entry_s) + sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_kernel(current - sizeof(msize_t) +
+ MEDIUM_BYTES_FOR_MSIZE(alloc_msize));
+
+ if (pgLo < pgHi) {
+ medium_advisory_t mat = (medium_advisory_t)pgLo;
+ mat->next = advisories;
+ mat->size = pgHi - pgLo;
+ advisories = mat;
+ }
+
+ memset(&madv_headers[index], 0, sizeof(uint16_t) * alloc_msize);
+ medium_madvise_header_mark_clean(madv_headers, index,
+ alloc_msize);
+ }
+ }
+ current += MEDIUM_BYTES_FOR_MSIZE(alloc_msize);
+ }
+
+ if (advisories) {
+ OSAtomicIncrement32Barrier(
+ &(REGION_TRAILER_FOR_MEDIUM_REGION(r)->pinned_to_depot));
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+ while (advisories) {
+ uintptr_t addr = (uintptr_t)advisories;
+ size_t size = advisories->size;
+ advisories = advisories->next;
+
+ mvm_madvise_free(rack, r, addr, addr + size, NULL,
+ rack->debug_flags & MALLOC_DO_SCRIBBLE);
+ }
+ SZONE_MAGAZINE_PTR_LOCK(depot_ptr);
+ OSAtomicDecrement32Barrier(
+ &(REGION_TRAILER_FOR_MEDIUM_REGION(r)->pinned_to_depot));
+ }
+}
+
+static region_t
+medium_find_msize_region(rack_t *rack, magazine_t *medium_mag_ptr, mag_index_t mag_index, msize_t msize)
+{
+ void *ptr;
+ grain_t slot = MEDIUM_FREE_SLOT_FOR_MSIZE(rack, msize);
+ free_list_t *free_list = medium_mag_ptr->mag_free_list;
+ free_list_t *the_slot = free_list + slot;
+ free_list_t *limit;
+ unsigned bitmap;
+
+ // Assumes we've locked the magazine
+ CHECK_MAGAZINE_PTR_LOCKED(szone, medium_mag_ptr, __PRETTY_FUNCTION__);
+
+ // Look for an exact match by checking the freelist for this msize.
+ ptr = medium_free_list_get_ptr(rack, *the_slot);
+ if (ptr) {
+ return MEDIUM_REGION_FOR_PTR(ptr);
+ }
+
+ // Mask off the bits representing slots holding free blocks smaller than
+ // the size we need.
+ //
+ // BITMAPN_CTZ implementation
+ unsigned idx = slot >> 5;
+ bitmap = 0;
+ unsigned mask = ~((1 << (slot & 31)) - 1);
+ for (; idx < MEDIUM_FREELIST_BITMAP_WORDS(rack); ++idx) {
+ bitmap = medium_mag_ptr->mag_bitmap[idx] & mask;
+ if (bitmap != 0) {
+ break;
+ }
+ mask = ~0U;
+ }
+ // Check for fallthrough: No bits set in bitmap
+ if ((bitmap == 0) && (idx == MEDIUM_FREELIST_BITMAP_WORDS(rack))) {
+ return NULL;
+ }
+
+ // Start looking at the first set bit, plus 32 bits for every word of
+ // zeroes or entries that were too medium.
+ slot = BITMAP32_CTZ((&bitmap)) + (idx * 32);
+
+ limit = free_list + MEDIUM_FREE_SLOT_COUNT(rack) - 1;
+ free_list += slot;
+
+ if (free_list < limit) {
+ ptr = medium_free_list_get_ptr(rack, *free_list);
+ if (ptr) {
+ return MEDIUM_REGION_FOR_PTR(ptr);
+ } else {
+ /* Shouldn't happen. Fall through to look at last slot. */
+#if DEBUG_MALLOC
+ malloc_report(ASL_LEVEL_ERR, "in medium_malloc_from_free_list(), mag_bitmap out of sync, slot=%d\n", slot);
+#endif
+ }
+ }
+
+ // We are now looking at the last slot, which contains blocks equal to, or
+ // due to coalescing of free blocks, larger than (num_medium_slots - 1) * (medium quantum size).
+ ptr = medium_free_list_get_ptr(rack, *limit);
+ if (ptr) {
+ return MEDIUM_REGION_FOR_PTR(ptr);
+ }
+
+ return NULL;
+}
+
+static boolean_t
+medium_get_region_from_depot(rack_t *rack, magazine_t *medium_mag_ptr, mag_index_t mag_index, msize_t msize)
+{
+ magazine_t *depot_ptr = &(rack->magazines[DEPOT_MAGAZINE_INDEX]);
+
+#if DEBUG_MALLOC
+ if (DEPOT_MAGAZINE_INDEX == mag_index) {
+ malloc_zone_error(rack->debug_flags, true, "medium_get_region_from_depot called for magazine index -1\n", NULL, NULL);
+ return 0;
+ }
+#endif
+
+ SZONE_MAGAZINE_PTR_LOCK(depot_ptr);
+
+ // Appropriate a Depot'd region that can satisfy requested msize.
+ region_trailer_t *node;
+ region_t sparse_region;
+ msize_t try_msize = msize;
+
+ while (1) {
+ sparse_region = medium_find_msize_region(rack, depot_ptr, DEPOT_MAGAZINE_INDEX, try_msize);
+ if (NULL == sparse_region) { // Depot empty?
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+ return 0;
+ }
+
+ node = REGION_TRAILER_FOR_MEDIUM_REGION(sparse_region);
+ if (0 == node->pinned_to_depot) {
+ // Found one!
+ break;
+ }
+
+ // Try the next msize up - maybe the head of its free list will be in
+ // a region we can use. Once we get the region we'll still allocate the
+ // original msize.
+ try_msize++;
+
+ if (try_msize > NUM_MEDIUM_SLOTS) {
+ // Tried all the msizes but couldn't get a usable region. Let's
+ // give up for now and we'll allocate a new region from the kernel.
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+ return 0;
+ }
+ }
+
+ // disconnect node from Depot
+ recirc_list_extract(rack, depot_ptr, node);
+
+ // Iterate the region pulling its free entries off the (locked) Depot's free list
+ int objects_in_use = medium_free_detach_region(rack, depot_ptr, sparse_region);
+
+ // Transfer ownership of the region
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(sparse_region) = mag_index;
+ MALLOC_ASSERT(node->pinned_to_depot == 0);
+
+ // Iterate the region putting its free entries on its new (locked) magazine's free list
+ size_t bytes_inplay = medium_free_reattach_region(rack, medium_mag_ptr, sparse_region);
+
+ depot_ptr->mag_num_bytes_in_objects -= bytes_inplay;
+ depot_ptr->num_bytes_in_magazine -= MEDIUM_REGION_PAYLOAD_BYTES;
+ depot_ptr->mag_num_objects -= objects_in_use;
+
+ medium_mag_ptr->mag_num_bytes_in_objects += bytes_inplay;
+ medium_mag_ptr->num_bytes_in_magazine += MEDIUM_REGION_PAYLOAD_BYTES;
+ medium_mag_ptr->mag_num_objects += objects_in_use;
+
+ // connect to magazine as first node
+ recirc_list_splice_first(rack, medium_mag_ptr, node);
+
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+
+ MAGMALLOC_DEPOTREGION(MEDIUM_SZONE_FROM_RACK(rack), (int)mag_index, (void *)sparse_region, MEDIUM_REGION_SIZE,
+ (int)BYTES_USED_FOR_MEDIUM_REGION(sparse_region)); // DTrace USDT Probe
+
+ return 1;
+}
+
+#if CONFIG_MADVISE_PRESSURE_RELIEF
+void
+medium_madvise_pressure_relief(rack_t *rack)
+{
+ mag_index_t mag_index;
+ magazine_t *medium_depot_ptr = &rack->magazines[DEPOT_MAGAZINE_INDEX];
+
+ for (mag_index = 0; mag_index < rack->num_magazines; mag_index++) {
+ size_t index;
+ for (index = 0; index < rack->region_generation->num_regions_allocated; ++index) {
+ rack_region_lock(rack);
+
+ region_t medium = rack->region_generation->hashed_regions[index];
+ if (!medium || medium == HASHRING_REGION_DEALLOCATED) {
+ rack_region_unlock(rack);
+ continue;
+ }
+
+ region_trailer_t *trailer =
+ REGION_TRAILER_FOR_MEDIUM_REGION(medium);
+ // Make sure that the owning magazine doesn't try and take this out
+ // from under our feet.
+ trailer->dispose_flags |= RACK_DISPOSE_DELAY;
+ rack_region_unlock(rack);
+
+ magazine_t *mag_ptr = mag_lock_zine_for_region_trailer(rack->magazines,
+ trailer, MAGAZINE_INDEX_FOR_MEDIUM_REGION(medium));
+
+ // If acquiring the region lock was enough to prevent the owning
+ // magazine from deallocating the region, free it now so we don't
+ // do wasted work.
+ if (rack_region_maybe_dispose(rack, medium, MEDIUM_REGION_SIZE, trailer)) {
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+ continue;
+ }
+
+ /* Ordering is important here, the magazine of a region may potentially change
+ * during mag_lock_zine_for_region_trailer, so src_mag_index must be taken
+ * after we've obtained the lock.
+ */
+ mag_index_t src_mag_index = MAGAZINE_INDEX_FOR_MEDIUM_REGION(medium);
+
+ /* We can (and must) ignore magazines that are already in the recirc depot. */
+ if (src_mag_index == DEPOT_MAGAZINE_INDEX) {
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+ continue;
+ }
+
+ if (REGION_TRAILER_FOR_MEDIUM_REGION(medium)->pinned_to_depot > 0) {
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+ continue;
+ }
+
+ if (medium == mag_ptr->mag_last_region && (mag_ptr->mag_bytes_free_at_end || mag_ptr->mag_bytes_free_at_start)) {
+ medium_finalize_region(rack, mag_ptr);
+ }
+
+ /* Because this region is currently in use, we can't safely madvise it while
+ * it's attached to the magazine. For this operation we have to remove it from
+ * the current mag, attach it to the depot and then madvise.
+ */
+
+ recirc_list_extract(rack, mag_ptr, REGION_TRAILER_FOR_MEDIUM_REGION(medium));
+ int objects_in_use = medium_free_detach_region(rack, mag_ptr, medium);
+
+ SZONE_MAGAZINE_PTR_LOCK(medium_depot_ptr);
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(medium) = DEPOT_MAGAZINE_INDEX;
+ MALLOC_ASSERT(REGION_TRAILER_FOR_MEDIUM_REGION(medium)->pinned_to_depot == 0);
+
+ size_t bytes_inplay = medium_free_reattach_region(rack, medium_depot_ptr, medium);
+
+ /* Fix up the metadata of the target magazine while the region is in the depot. */
+ mag_ptr->mag_num_bytes_in_objects -= bytes_inplay;
+ mag_ptr->num_bytes_in_magazine -= MEDIUM_REGION_PAYLOAD_BYTES;
+ mag_ptr->mag_num_objects -= objects_in_use;
+
+ /* Now we can drop the magazine lock of the source mag. */
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+
+ medium_depot_ptr->mag_num_bytes_in_objects += bytes_inplay;
+ medium_depot_ptr->num_bytes_in_magazine += MEDIUM_REGION_PAYLOAD_BYTES;
+ medium_depot_ptr->mag_num_objects -= objects_in_use;
+
+ recirc_list_splice_last(rack, medium_depot_ptr, REGION_TRAILER_FOR_MEDIUM_REGION(medium));
+
+ /* Actually do the scan, done holding the depot lock, the call will drop the lock
+ * around the actual madvise syscalls.
+ */
+ medium_free_scan_madvise_free(rack, medium_depot_ptr, medium);
+
+ /* Now the region is in the recirc depot, the next allocations to require more
+ * blocks will come along and take one of these regions back out of the depot.
+ * As OS X madvise's reuse on an per-region basis, we leave as many of these
+ * regions in the depot as possible after memory pressure.
+ */
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_depot_ptr);
+ }
+ }
+}
+#endif // CONFIG_MADVISE_PRESSURE_RELIEF
+
+static MALLOC_INLINE void
+medium_madvise_free_range_conditional_no_lock(rack_t *rack, magazine_t *mag_ptr,
+ size_t trigger_level, region_t region, free_list_t *fl, msize_t flmsz,
+ void *ptr, size_t sz)
+{
+ region_trailer_t *node = REGION_TRAILER_FOR_MEDIUM_REGION(region);
+ msize_t *madvh = MEDIUM_MADVISE_HEADER_FOR_PTR(ptr);
+ msize_t trigger_msize = trigger_level >> SHIFT_MEDIUM_QUANTUM;
+
+ size_t free_header_size = sizeof(medium_inplace_free_entry_s) + sizeof(msize_t);
+ size_t free_trailer_size = sizeof(msize_t);
+ // We have to avoid the free_list header at the start of the allocation
+ // unless the entry is out in the OOB area, in which case, we can madvise
+ // the whole region.
+ if (medium_is_oob_free_entry(*fl)) {
+ free_header_size = 0;
+ free_trailer_size = 0;
+ }
+
+ uintptr_t rangep = (uintptr_t)medium_free_list_get_ptr(rack, *fl);
+ msize_t range_idx = MEDIUM_META_INDEX_FOR_PTR(rangep);
+ msize_t range_msz = flmsz;
+
+ msize_t src_idx = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ msize_t src_msz = MEDIUM_MSIZE_FOR_BYTES(sz);
+ msize_t src_end_idx = src_idx + src_msz - 1;
+ medium_madvise_header_mark_middle(madvh, src_idx);
+ medium_madvise_header_mark_middle(madvh, src_idx + src_msz - 1);
+
+ msize_t left_end_idx = src_idx - 1;
+ msize_t left_msz = src_idx - range_idx;
+ msize_t right_start_idx = src_idx + src_msz;
+ msize_t right_end_idx = range_idx + range_msz - 1;
+ msize_t right_msz = right_end_idx - right_start_idx + 1;
+
+ msize_t dirty_msz = src_msz;
+
+ size_t vote_force = 0;
+ msize_t left_dirty_msz = 0;
+ if (range_idx < src_idx) {
+ // Peek back one block and see if the range directly in front of this
+ // one had any blocks that had not been madvised.
+ left_dirty_msz = medium_madvise_header_dirty_len(madvh, left_end_idx);
+ if (left_dirty_msz) {
+ dirty_msz += left_dirty_msz;
+ } else if (src_idx - range_idx > src_msz) {
+ // The left-hand region was actually clean, so only choose to
+ // madvise if the center region is enclosured by clean data.
+ vote_force++;
+ }
+ medium_madvise_header_mark_middle(madvh, range_idx);
+ medium_madvise_header_mark_middle(madvh, left_end_idx);
+ }
+
+ msize_t right_dirty_msz = 0;
+ if (right_end_idx > src_end_idx) {
+ // Same as above, if we had trailing data coalesced with this entry
+ // and that was not madvised, consider it, too.
+ right_dirty_msz = medium_madvise_header_dirty_len(madvh, right_start_idx);
+ if (right_dirty_msz) {
+ dirty_msz += right_dirty_msz;
+ } else if (right_end_idx - right_start_idx > src_msz) {
+ vote_force++;
+ }
+ medium_madvise_header_mark_middle(madvh, right_start_idx);
+ medium_madvise_header_mark_middle(madvh, right_end_idx);
+ }
+
+ // We absolutely can't madvise lower than the free-list entry pointer plus
+ // the header size. When the entry is OOB, there's no header or footer to
+ // store in memory.
+ uintptr_t safe_start_ptr = round_page_kernel(rangep + free_header_size);
+ uintptr_t safe_end_ptr = trunc_page_kernel(rangep +
+ MEDIUM_BYTES_FOR_MSIZE(range_msz) - free_trailer_size);
+
+ // If the target region is madvisable, then madvise whatever we can but
+ // bound it by the safe_start/end pointers to make sure we don't clobber
+ // the free-list.
+ bool should_madvise = (vote_force == 2) || (dirty_msz >= trigger_msize);
+ if (magazine_medium_madvise_window_scale_factor > 1) {
+ // trigger_msize is an unsigned short, but it's possible that trigger level was larger than UINT16_MAX
+ // even after we shifted it. In this case the window rolls around to 0. This is even more likely
+ // if we're scaling the window up. We should fix the truncation bug above, but doing so
+ // will cause a memory regression. For now, we avoid using trigger_msize iff we're scaling
+ // the window up since truncating to 0 would be self-defeating in this case.
+ // See rdar://82128639 for details
+ should_madvise = (vote_force == 2) || (MEDIUM_BYTES_FOR_MSIZE(dirty_msz) >= trigger_level);
+ }
+ if (should_madvise) {
+ uintptr_t lo = MAX((uintptr_t)MEDIUM_PTR_FOR_META_INDEX(region, range_idx),
+ safe_start_ptr);
+ uintptr_t hi = MIN((uintptr_t)MEDIUM_PTR_FOR_META_INDEX(region, range_idx) +
+ MEDIUM_BYTES_FOR_MSIZE(range_msz), safe_end_ptr);
+
+ // The page that contains the freelist entry needs to be marked as not
+ // having been madvised. Note that the quantum is larger than the kernel page size
+ // so if safe_start_ptr and rangep are on different pages, we just mark
+ // the whole block as clean.
+ if (range_idx < MEDIUM_META_INDEX_FOR_PTR(safe_start_ptr)) {
+ medium_madvise_header_mark_dirty(madvh, range_idx,
+ MEDIUM_META_INDEX_FOR_PTR(safe_start_ptr) - range_idx);
+ }
+ if (range_idx + range_msz > MEDIUM_META_INDEX_FOR_PTR(safe_end_ptr)) {
+ medium_madvise_header_mark_dirty(madvh,
+ MEDIUM_META_INDEX_FOR_PTR(safe_end_ptr), range_idx +
+ range_msz - MEDIUM_META_INDEX_FOR_PTR(safe_end_ptr));
+ }
+
+ medium_madvise_header_mark_clean(madvh,
+ MEDIUM_META_INDEX_FOR_PTR(lo),
+ MEDIUM_META_INDEX_FOR_PTR(hi) - MEDIUM_META_INDEX_FOR_PTR(lo));
+
+ // Mark the whole region as off-limits for the allocator while we drop
+ // the lock and go to the kernel.
+ medium_free_mark_unfree(rack, *fl, flmsz);
+ medium_free_list_remove_ptr_no_clear(rack, mag_ptr, *fl, flmsz);
+ OSAtomicIncrement32Barrier(&node->pinned_to_depot);
+ SZONE_MAGAZINE_PTR_UNLOCK(mag_ptr);
+
+ mvm_madvise_free(rack, region, lo, hi,
+ &rack->last_madvise, rack->debug_flags & MALLOC_DO_SCRIBBLE);
+
+ SZONE_MAGAZINE_PTR_LOCK(mag_ptr);
+ OSAtomicDecrement32Barrier(&node->pinned_to_depot);
+ *fl = medium_free_list_add_ptr(rack, mag_ptr, (void *)rangep, flmsz);
+ } else {
+ // We chose not to madvise, we need to re-mark the region as dirty
+ // for when we come back to it later.
+ if (left_dirty_msz < left_msz) {
+ /* The preceding block was clean. */
+ medium_madvise_header_mark_clean(madvh, range_idx,
+ left_msz - left_dirty_msz);
+ }
+ if (right_dirty_msz < right_msz) {
+ /* The trailing block was clean. */
+ medium_madvise_header_mark_clean(madvh, right_start_idx +
+ right_dirty_msz, right_msz - right_dirty_msz);
+ }
+ medium_madvise_header_mark_dirty(madvh, src_idx - left_dirty_msz,
+ src_msz + right_dirty_msz + left_dirty_msz);
+ }
+}
+
+#if CONFIG_AGGRESSIVE_MADVISE || CONFIG_RECIRC_DEPOT
+static MALLOC_INLINE void
+medium_madvise_free_range_no_lock(rack_t *rack,
+ magazine_t *medium_mag_ptr,
+ size_t trigger_level,
+ region_t region,
+ free_list_t freee,
+ msize_t fmsize,
+ void *headptr,
+ size_t headsize)
+{
+ void *ptr = medium_free_list_get_ptr(rack, freee);
+ region_trailer_t *node = REGION_TRAILER_FOR_MEDIUM_REGION(region);
+
+ // Lock on medium_magazines[mag_index] is already held here.
+ // Calculate the first page in the coalesced block that would be safe to mark MADV_FREE
+ size_t free_header_size = sizeof(medium_inplace_free_entry_s) + sizeof(msize_t);
+
+ // If the free_list_t entry is out-of-line then we don't need to reserve any space
+ // at the start of the region.
+ if (medium_is_oob_free_entry(freee)) {
+ free_header_size = 0;
+ }
+
+ uintptr_t safe_ptr = (uintptr_t)ptr + free_header_size;
+ uintptr_t round_safe = round_page_kernel(safe_ptr);
+
+ // Calculate the last page in the coalesced block that would be safe to mark MADV_FREE
+ uintptr_t safe_extent = (uintptr_t)ptr + MEDIUM_BYTES_FOR_MSIZE(fmsize);
+ uintptr_t trunc_extent = trunc_page_kernel(safe_extent);
+
+ // If the region spans more than the madvise trigger level, then mark the
+ // pages as advise-freed.
+ if (round_safe + trigger_level < trunc_extent) {
+ // Extend the freed block by the free region header and tail sizes to include pages
+ // we may have coalesced that no longer host free region tails and headers.
+ // This may extend over in-use ranges, but the MIN/MAX clamping below will fix that up.
+ uintptr_t lo = trunc_page_kernel((uintptr_t)headptr);
+ uintptr_t hi = round_page_kernel((uintptr_t)headptr + headsize + free_header_size);
+
+ uintptr_t free_lo = MAX(round_safe, lo);
+ uintptr_t free_hi = MIN(trunc_extent, hi);
+
+ if (free_lo < free_hi) {
+ // Before unlocking, ensure that the metadata for the freed region
+ // makes it look not free but includes the length. This ensures that
+ // any code that inspects the metadata while we are unlocked sees
+ // a valid state and will not try to use or coalesce freed memory
+ // into it.
+ medium_free_mark_unfree(rack, freee, fmsize);
+ medium_free_list_remove_ptr_no_clear(rack, medium_mag_ptr, freee, fmsize);
+ OSAtomicIncrement32Barrier(&(node->pinned_to_depot));
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ mvm_madvise_free(rack, region, free_lo, free_hi, &rack->last_madvise, rack->debug_flags & MALLOC_DO_SCRIBBLE);
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+ OSAtomicDecrement32Barrier(&(node->pinned_to_depot));
+ medium_free_list_add_ptr(rack, medium_mag_ptr, ptr, fmsize);
+ }
+ }
+}
+#endif // CONFIG_AGGRESSIVE_MADVISE || CONFIG_RECIRC_DEPOT
+
+#if CONFIG_RECIRC_DEPOT
+static region_t
+medium_free_try_depot_unmap_no_lock(rack_t *rack, magazine_t *depot_ptr, region_trailer_t *node)
+{
+ if (0 < node->bytes_used || 0 < node->pinned_to_depot || depot_ptr->recirculation_entries < recirc_retained_regions) {
+ return NULL;
+ }
+
+ // disconnect first node from Depot
+ recirc_list_extract(rack, depot_ptr, node);
+
+ // Iterate the region pulling its free entries off the (locked) Depot's free list
+ region_t sparse_region = MEDIUM_REGION_FOR_PTR(node);
+ int objects_in_use = medium_free_detach_region(rack, depot_ptr, sparse_region);
+
+ if (0 == objects_in_use) {
+ if (!rack_region_remove(rack, sparse_region, node)) {
+ return NULL;
+ }
+ depot_ptr->num_bytes_in_magazine -= MEDIUM_REGION_PAYLOAD_BYTES;
+
+ // Caller will transfer ownership of the region back to the OS with no locks held
+ MAGMALLOC_DEALLOCREGION(MEDIUM_SZONE_FROM_RACK(rack), (void *)sparse_region, (int)MEDIUM_REGION_SIZE); // DTrace USDT Probe
+ return sparse_region;
+
+ } else {
+ malloc_zone_error(rack->debug_flags, true, "medium_free_try_depot_unmap_no_lock objects_in_use not zero: %d\n", objects_in_use);
+ return NULL;
+ }
+}
+
+static boolean_t
+medium_free_do_recirc_to_depot(rack_t *rack, magazine_t *medium_mag_ptr, mag_index_t mag_index)
+{
+ // The entire magazine crossed the "emptiness threshold". Transfer a region
+ // from this magazine to the Depot. Choose a region that itself has crossed the emptiness threshold (i.e
+ // is at least fraction "f" empty.) Such a region will be marked "suitable" on the recirculation list.
+ region_trailer_t *node = medium_mag_ptr->firstNode;
+
+ while (node && (!node->recirc_suitable || node->pinned_to_depot)) {
+ node = node->next;
+ }
+
+ if (NULL == node) {
+#if DEBUG_MALLOC
+ malloc_report(ASL_LEVEL_ERR, "*** medium_free_do_recirc_to_depot end of list\n");
+#endif
+ return TRUE; // Caller must SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ }
+
+ region_t sparse_region = MEDIUM_REGION_FOR_PTR(node);
+
+ // Deal with unclaimed memory -- mag_bytes_free_at_end or mag_bytes_free_at start
+ if (sparse_region == medium_mag_ptr->mag_last_region &&
+ (medium_mag_ptr->mag_bytes_free_at_end || medium_mag_ptr->mag_bytes_free_at_start)) {
+ medium_finalize_region(rack, medium_mag_ptr);
+ }
+
+ // disconnect "suitable" node from magazine
+ recirc_list_extract(rack, medium_mag_ptr, node);
+
+ // Iterate the region pulling its free entries off its (locked) magazine's free list
+ int objects_in_use = medium_free_detach_region(rack, medium_mag_ptr, sparse_region);
+ magazine_t *depot_ptr = &(rack->magazines[DEPOT_MAGAZINE_INDEX]);
+
+ // hand over the region to the (locked) Depot
+ SZONE_MAGAZINE_PTR_LOCK(depot_ptr);
+ // this will cause medium_free_list_add_ptr called by medium_free_reattach_region to use
+ // the depot as its target magazine, rather than magazine formerly associated with sparse_region
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(sparse_region) = DEPOT_MAGAZINE_INDEX;
+ node->pinned_to_depot = 0;
+
+ // Iterate the region putting its free entries on Depot's free list
+ size_t bytes_inplay = medium_free_reattach_region(rack, depot_ptr, sparse_region);
+
+ medium_mag_ptr->mag_num_bytes_in_objects -= bytes_inplay;
+ medium_mag_ptr->num_bytes_in_magazine -= MEDIUM_REGION_PAYLOAD_BYTES;
+ medium_mag_ptr->mag_num_objects -= objects_in_use;
+
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr); // Unlock the originating magazine
+
+ depot_ptr->mag_num_bytes_in_objects += bytes_inplay;
+ depot_ptr->num_bytes_in_magazine += MEDIUM_REGION_PAYLOAD_BYTES;
+ depot_ptr->mag_num_objects += objects_in_use;
+
+ // connect to Depot as last node
+ recirc_list_splice_last(rack, depot_ptr, node);
+
+ MAGMALLOC_RECIRCREGION(MEDIUM_SZONE_FROM_RACK(rack), (int)mag_index, (void *)sparse_region, MEDIUM_REGION_SIZE,
+ (int)BYTES_USED_FOR_MEDIUM_REGION(sparse_region)); // DTrace USDT Probe
+
+#if CONFIG_AGGRESSIVE_MADVISE
+ if (!aggressive_madvise_enabled)
+#endif
+ {
+ // Mark free'd dirty pages with MADV_FREE to reduce memory pressure
+ medium_free_scan_madvise_free(rack, depot_ptr, sparse_region);
+ }
+
+ // If the region is entirely empty vm_deallocate() it outside the depot lock
+ region_t r_dealloc = medium_free_try_depot_unmap_no_lock(rack, depot_ptr, node);
+ SZONE_MAGAZINE_PTR_UNLOCK(depot_ptr);
+ if (r_dealloc) {
+ mvm_deallocate_pages(r_dealloc, MEDIUM_REGION_SIZE,
+ MALLOC_FIX_GUARD_PAGE_FLAGS(rack->debug_flags));
+ }
+ return FALSE; // Caller need not unlock the originating magazine
+}
+
+static MALLOC_INLINE boolean_t
+medium_free_try_recirc_to_depot(rack_t *rack,
+ magazine_t *medium_mag_ptr,
+ mag_index_t mag_index,
+ region_t region,
+ free_list_t freee,
+ msize_t msize,
+ void *headptr,
+ size_t headsize)
+{
+ region_trailer_t *node = REGION_TRAILER_FOR_MEDIUM_REGION(region);
+ size_t bytes_used = node->bytes_used;
+
+ if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ // Emptiness discriminant
+ if (bytes_used < DENSITY_THRESHOLD(MEDIUM_REGION_PAYLOAD_BYTES)) {
+ /* Region has crossed threshold from density to sparsity. Mark it "suitable" on the
+ * recirculation candidates list. */
+ node->recirc_suitable = TRUE;
+ } else {
+ /* After this free, we've found the region is still dense, so it must have been even more so before
+ * the free. That implies the region is already correctly marked. Do nothing. */
+ }
+
+ // Has the entire magazine crossed the "emptiness threshold"? If so, transfer a region
+ // from this magazine to the Depot. Choose a region that itself has crossed the emptiness threshold (i.e
+ // is at least fraction "f" empty.) Such a region will be marked "suitable" on the recirculation list.
+
+ size_t a = medium_mag_ptr->num_bytes_in_magazine; // Total bytes allocated to this magazine
+ size_t u = medium_mag_ptr->mag_num_bytes_in_objects; // In use (malloc'd) from this magaqzine
+
+ if (a - u > ((3 * MEDIUM_REGION_PAYLOAD_BYTES) / 2) && u < DENSITY_THRESHOLD(a)) {
+ return medium_free_do_recirc_to_depot(rack, medium_mag_ptr, mag_index);
+ }
+
+ } else {
+#if CONFIG_AGGRESSIVE_MADVISE
+ if (!aggressive_madvise_enabled)
+#endif
+ {
+ // We are free'ing into the depot, so madvise as we do so unless we were madvising every incoming
+ // allocation anyway.
+ medium_madvise_free_range_no_lock(rack, medium_mag_ptr,
+ vm_kernel_page_size, region, freee, msize, headptr, headsize);
+ }
+
+ if (0 < bytes_used || 0 < node->pinned_to_depot) {
+ /* Depot'd region is still live. Leave it in place on the Depot's recirculation list
+ * so as to avoid thrashing between the Depot's free list and a magazines's free list
+ * with detach_region/reattach_region */
+ } else {
+ /* Depot'd region is just now empty. Consider return to OS. */
+ region_t r_dealloc = medium_free_try_depot_unmap_no_lock(rack, medium_mag_ptr, node);
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ if (r_dealloc) {
+ mvm_deallocate_pages(r_dealloc, MEDIUM_REGION_SIZE, MALLOC_FIX_GUARD_PAGE_FLAGS(rack->debug_flags));
+ }
+ return FALSE; // Caller need not unlock
+ }
+ }
+ return TRUE; // Caller must do SZONE_MAGAZINE_PTR_UNLOCK(tiny_mag_ptr)
+}
+#endif // CONFIG_RECIRC_DEPOT
+
+static MALLOC_INLINE boolean_t
+medium_free_no_lock(rack_t *rack, magazine_t *medium_mag_ptr, mag_index_t mag_index, region_t region, void *ptr, msize_t msize)
+{
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(ptr);
+ unsigned index = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ size_t original_size = MEDIUM_BYTES_FOR_MSIZE(msize);
+ void *next_block = ptr + original_size;
+ msize_t next_index = index + msize;
+
+ MALLOC_TRACE(TRACE_medium_free, (uintptr_t)rack, (uintptr_t)medium_mag_ptr, (uintptr_t)ptr, MEDIUM_BYTES_FOR_MSIZE(msize));
+
+ void *original_ptr = ptr;
+
+#if DEBUG_MALLOC
+ if (!msize) {
+ malloc_zone_error(rack->debug_flags, true, "trying to free medium block "
+ "that is too small in medium_free_no_lock(), ptr=%p, msize=%d\n",
+ ptr, msize);
+ }
+ if (medium_madvise_header_dirty_len(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr), index) == 0) {
+ malloc_zone_error(rack->debug_flags, true, "incoming freed block is not "
+ "marked as dirty in madvise metadata, ptr=%p, msize=%d\n",
+ ptr, msize);
+ }
+#endif
+
+ // Check that the region cookie is intact.
+ region_check_cookie(region, ®ION_COOKIE_FOR_MEDIUM_REGION(region));
+
+ // We try to coalesce this block with the preceeding one
+ if (index > 0 && (meta_headers[index - 1] & MEDIUM_IS_FREE)) {
+ msize_t previous_msize = meta_headers[index - 1] & ~MEDIUM_IS_FREE;
+ grain_t previous_index = index - previous_msize;
+
+ // Check if the metadata for the start of the block is also free.
+ if (meta_headers[previous_index] == (previous_msize | MEDIUM_IS_FREE)) {
+ void *previous_ptr = (void *)((uintptr_t)ptr - MEDIUM_BYTES_FOR_MSIZE(previous_msize));
+ free_list_t previous = medium_free_list_find_by_ptr(rack, medium_mag_ptr, previous_ptr, previous_msize);
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, previous, previous_msize);
+ ptr = previous_ptr;
+ medium_meta_header_set_middle(meta_headers, index); // This block is now a middle block.
+ msize += previous_msize;
+ index -= previous_msize;
+ } else {
+ _os_set_crash_log_message("medium free list metadata inconsistency (headers[previous] != previous size)");
+ __builtin_trap();
+ }
+ }
+
+ // Try to coalesce with this block with the next block
+ if ((next_block < MEDIUM_REGION_HEAP_END(region)) && (meta_headers[next_index] & MEDIUM_IS_FREE)) {
+ msize_t next_msize = meta_headers[next_index] & ~MEDIUM_IS_FREE;
+ free_list_t next = medium_free_list_find_by_ptr(rack, medium_mag_ptr, next_block, next_msize);
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, next, next_msize);
+ msize += next_msize;
+ }
+
+ if (rack->debug_flags & MALLOC_DO_SCRIBBLE) {
+ if (!msize) {
+ malloc_zone_error(rack->debug_flags, true, "incorrect size information for %p - block header was damaged\n", ptr);
+ } else {
+ memset(ptr, SCRABBLE_BYTE, MEDIUM_BYTES_FOR_MSIZE(msize));
+ }
+ }
+
+ free_list_t freee = medium_free_list_add_ptr(rack, medium_mag_ptr, ptr, msize);
+
+ // use original_size and not msize to avoid double counting the coalesced blocks
+ medium_mag_ptr->mag_num_bytes_in_objects -= original_size;
+ medium_mag_ptr->mag_num_objects--;
+
+ // Update this region's bytes in use count
+ region_trailer_t *trailer = REGION_TRAILER_FOR_MEDIUM_REGION(region);
+ size_t bytes_used = trailer->bytes_used - original_size;
+ trailer->bytes_used = (unsigned int)bytes_used;
+
+#if CONFIG_AGGRESSIVE_MADVISE
+ if (aggressive_madvise_enabled) {
+ medium_madvise_free_range_no_lock(rack, medium_mag_ptr,
+ vm_kernel_page_size, region, freee, msize, original_ptr, original_size);
+ }
+ else
+#endif
+ {
+ // Always attempt to madvise free regions that exceed the conditional
+ // madvise limit size.
+ medium_madvise_free_range_conditional_no_lock(rack, medium_mag_ptr,
+ medium_sliding_madvise_granularity(medium_mag_ptr), region, &freee,
+ msize, original_ptr, original_size);
+ }
+
+ // Caller must do SZONE_MAGAZINE_PTR_UNLOCK(tiny_mag_ptr) if this function
+ // returns TRUE.
+ boolean_t needs_unlock = TRUE;
+
+#if CONFIG_RECIRC_DEPOT
+ needs_unlock = medium_free_try_recirc_to_depot(rack, medium_mag_ptr, mag_index, region, freee, msize, original_ptr, original_size);
+#endif
+ return needs_unlock;
+}
+
+// Allocates from the last region or a freshly allocated region
+static void *
+medium_malloc_from_region_no_lock(rack_t *rack,
+ magazine_t *medium_mag_ptr,
+ mag_index_t mag_index,
+ msize_t msize,
+ void *aligned_address)
+{
+ void *ptr;
+
+ // Before anything we transform the mag_bytes_free_at_end or mag_bytes_free_at_start - if any - to a regular free block
+ /* FIXME: last_block needs to be coalesced with previous entry if free, <rdar://5462322> */
+ if (medium_mag_ptr->mag_bytes_free_at_end || medium_mag_ptr->mag_bytes_free_at_start) {
+ medium_finalize_region(rack, medium_mag_ptr);
+ }
+
+ medium_region_t region = (medium_region_t)aligned_address;
+
+ // Tag the region at "aligned_address" as belonging to us,
+ // and so put it under the protection of the magazine lock we are holding.
+ // Do this before advertising "aligned_address" on the hash ring(!)
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(region) = mag_index;
+
+ // Insert the new region into the hash ring
+ rack_region_insert(rack, region);
+
+ medium_mag_ptr->mag_last_region = region;
+ BYTES_USED_FOR_MEDIUM_REGION(region) = MEDIUM_BYTES_FOR_MSIZE(msize);
+
+#if CONFIG_ASLR_INTERNAL
+ int offset_msize = malloc_entropy[1] & MEDIUM_ENTROPY_MASK;
+#if DEBUG_MALLOC
+ if (getenv("MallocASLRForce")) {
+ offset_msize = strtol(getenv("MallocASLRForce"), NULL, 0) & MEDIUM_ENTROPY_MASK;
+ }
+ if (getenv("MallocASLRPrint")) {
+ malloc_report(ASL_LEVEL_INFO, "Region: %p offset: %d\n", region, offset_msize);
+ }
+#endif
+#else
+ int offset_msize = 0;
+#endif
+ ptr = (void *)(MEDIUM_REGION_HEAP_BASE(region) +
+ MEDIUM_BYTES_FOR_MSIZE(offset_msize));
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr),
+ offset_msize, msize);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr),
+ offset_msize, msize);
+ medium_mag_ptr->mag_num_objects++;
+ medium_mag_ptr->mag_num_bytes_in_objects += MEDIUM_BYTES_FOR_MSIZE(msize);
+ medium_mag_ptr->num_bytes_in_magazine += MEDIUM_REGION_PAYLOAD_BYTES;
+
+ // add a big free block at the end, mark as already advised clean
+ // because we haven't touched it.
+ msize_t trailing_offset = offset_msize + msize;
+ msize_t trailing_msize = NUM_MEDIUM_BLOCKS - msize - offset_msize;
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr),
+ trailing_offset, trailing_msize);
+ medium_madvise_header_mark_clean(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr),
+ trailing_offset, trailing_msize);
+ medium_mag_ptr->mag_bytes_free_at_end =
+ MEDIUM_BYTES_FOR_MSIZE(NUM_MEDIUM_BLOCKS - msize - offset_msize);
+
+#if CONFIG_ASLR_INTERNAL
+ // add a big free block at the start
+ medium_mag_ptr->mag_bytes_free_at_start = MEDIUM_BYTES_FOR_MSIZE(offset_msize);
+ if (offset_msize) {
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr), 0,
+ offset_msize);
+ medium_madvise_header_mark_clean(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr), 0,
+ offset_msize);
+ }
+#else
+ medium_mag_ptr->mag_bytes_free_at_start = 0;
+#endif
+
+ // connect to magazine as last node
+ recirc_list_splice_last(rack, medium_mag_ptr,
+ REGION_TRAILER_FOR_MEDIUM_REGION(region));
+
+ return ptr;
+}
+
+void *
+medium_memalign(szone_t *szone, size_t alignment, size_t size, size_t span)
+{
+ msize_t mspan = MEDIUM_MSIZE_FOR_BYTES(span + MEDIUM_QUANTUM - 1);
+ void *p = medium_malloc_should_clear(&szone->medium_rack, mspan, 0);
+
+ if (NULL == p) {
+ return NULL;
+ }
+
+ size_t offset = ((uintptr_t)p) & (alignment - 1); // p % alignment
+ size_t pad = (0 == offset) ? 0 : alignment - offset; // p + pad achieves desired alignment
+
+ msize_t msize = MEDIUM_MSIZE_FOR_BYTES(size + MEDIUM_QUANTUM - 1);
+ msize_t mpad = MEDIUM_MSIZE_FOR_BYTES(pad + MEDIUM_QUANTUM - 1);
+ msize_t mwaste = mspan - msize - mpad; // excess blocks
+
+ if (mpad > 0) {
+ void *q = (void *)(((uintptr_t)p) + pad);
+
+ // Mark q as block header and in-use, thus creating two blocks.
+ magazine_t *medium_mag_ptr = mag_lock_zine_for_region_trailer(
+ szone->medium_rack.magazines,
+ REGION_TRAILER_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(p)),
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(p)));
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(p), MEDIUM_META_INDEX_FOR_PTR(p), mpad);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(p), MEDIUM_META_INDEX_FOR_PTR(p), mpad);
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(q), MEDIUM_META_INDEX_FOR_PTR(q), msize + mwaste);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(q), MEDIUM_META_INDEX_FOR_PTR(q), msize + mwaste);
+ medium_mag_ptr->mag_num_objects++;
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+
+ // Give up mpad blocks beginning at p to the medium free list
+ free_medium(&szone->medium_rack, p, MEDIUM_REGION_FOR_PTR(p), MEDIUM_BYTES_FOR_MSIZE(mpad));
+
+ p = q; // advance p to the desired alignment
+ }
+ if (mwaste > 0) {
+ void *q = (void *)(((uintptr_t)p) + MEDIUM_BYTES_FOR_MSIZE(msize));
+ // Mark q as block header and in-use, thus creating two blocks.
+ magazine_t *medium_mag_ptr = mag_lock_zine_for_region_trailer(szone->medium_rack.magazines,
+ REGION_TRAILER_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(p)),
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(p)));
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(p), MEDIUM_META_INDEX_FOR_PTR(p), msize);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(p), MEDIUM_META_INDEX_FOR_PTR(p), msize);
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(q), MEDIUM_META_INDEX_FOR_PTR(q), mwaste);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(q), MEDIUM_META_INDEX_FOR_PTR(q), mwaste);
+ medium_mag_ptr->mag_num_objects++;
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+
+ // Give up mwaste blocks beginning at q to the medium free list
+ free_medium(&szone->medium_rack, q, MEDIUM_REGION_FOR_PTR(q), MEDIUM_BYTES_FOR_MSIZE(mwaste));
+ }
+
+ return p; // p has the desired size and alignment, and can later be free()'d
+}
+
+boolean_t
+medium_claimed_address(rack_t *rack, void *ptr)
+{
+ region_t r = medium_region_for_ptr_no_lock(rack, ptr);
+ return r && ptr >= MEDIUM_REGION_HEAP_BASE(r)
+ && ptr < MEDIUM_REGION_HEAP_END(r);
+}
+
+void *
+medium_try_shrink_in_place(rack_t *rack, void *ptr, size_t old_size, size_t new_good_size)
+{
+ msize_t new_msize = MEDIUM_MSIZE_FOR_BYTES(new_good_size);
+ msize_t mshrinkage = MEDIUM_MSIZE_FOR_BYTES(old_size) - new_msize;
+
+ if (mshrinkage) {
+ void *q = (void *)((uintptr_t)ptr + MEDIUM_BYTES_FOR_MSIZE(new_msize));
+ magazine_t *medium_mag_ptr = mag_lock_zine_for_region_trailer(rack->magazines,
+ REGION_TRAILER_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr)),
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr)));
+
+ // Mark q as block header and in-use, thus creating two blocks.
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr), MEDIUM_META_INDEX_FOR_PTR(ptr), new_msize);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr), MEDIUM_META_INDEX_FOR_PTR(ptr), new_msize);
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(q), MEDIUM_META_INDEX_FOR_PTR(q), mshrinkage);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(q), MEDIUM_META_INDEX_FOR_PTR(q), mshrinkage);
+ medium_mag_ptr->mag_num_objects++;
+
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ free_medium(rack, q, MEDIUM_REGION_FOR_PTR(q), 0);
+ }
+
+ return ptr;
+}
+
+boolean_t
+medium_try_realloc_in_place(rack_t *rack, void *ptr, size_t old_size, size_t new_size)
+{
+ // returns 1 on success
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(ptr);
+ msize_t *madv_headers = MEDIUM_MADVISE_HEADER_FOR_PTR(ptr);
+ unsigned index;
+ msize_t old_msize, new_msize;
+ unsigned next_index;
+ void *next_block;
+ msize_t next_msize_and_free;
+ boolean_t is_free;
+ msize_t next_msize, leftover_msize;
+ void *leftover;
+
+ index = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ old_msize = MEDIUM_MSIZE_FOR_BYTES(old_size);
+ new_msize = MEDIUM_MSIZE_FOR_BYTES(new_size + MEDIUM_QUANTUM - 1);
+ next_index = index + old_msize;
+
+ if (next_index >= NUM_MEDIUM_BLOCKS) {
+ return 0;
+ }
+ next_block = (char *)ptr + old_size;
+
+#if DEBUG_MALLOC
+ if ((uintptr_t)next_block & (MEDIUM_QUANTUM - 1)) {
+ malloc_zone_error(rack->debug_flags, true, "internal invariant broken in realloc(next_block) for %p\n", next_block);
+ }
+ if (meta_headers[index] != old_msize) {
+ malloc_report(ASL_LEVEL_ERR, "*** medium_try_realloc_in_place incorrect old %d %d\n", meta_headers[index], old_msize);
+ }
+#endif
+
+ magazine_t *medium_mag_ptr = mag_lock_zine_for_region_trailer(rack->magazines,
+ REGION_TRAILER_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr)),
+ MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr)));
+ if (DEPOT_MAGAZINE_INDEX == MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr))) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0;
+ }
+
+ msize_t coalesced_msize = new_msize - old_msize;
+#if CONFIG_MEDIUM_CACHE
+ void *last_free_ptr = medium_mag_ptr->mag_last_free;
+ msize_t last_free_msize = medium_mag_ptr->mag_last_free_msize;
+ if (last_free_ptr == next_block && old_msize + last_free_msize >= new_msize) {
+ /*
+ * There is a block in mag_last_free and it's immediately after
+ * this block and it's large enough. We can use some or all of it.
+ */
+ leftover_msize = last_free_msize - coalesced_msize;
+ if (leftover_msize) {
+ medium_mag_ptr->mag_last_free_msize -= coalesced_msize;
+ medium_mag_ptr->mag_last_free += new_size - old_size;
+ // The block in mag_last_free is still marked as header and in-use, so copy that
+ // state to the block that remains. The state for the block that we're going to
+ // use is adjusted by the medium_meta_header_set_middle() call below.
+ medium_meta_header_set_in_use(meta_headers, index + new_msize, leftover_msize);
+
+ /* Propagate the madvise information from the block we're using to the leftover block. */
+ if (madv_headers[next_index] & MEDIUM_IS_ADVISED) {
+ medium_madvise_header_mark_clean(madv_headers, index + new_msize, leftover_msize);
+ } else {
+ medium_madvise_header_mark_dirty(madv_headers, index + new_msize, leftover_msize);
+ }
+ } else {
+ // Using the whole block.
+ medium_mag_ptr->mag_last_free = NULL;
+ medium_mag_ptr->mag_last_free_msize = 0;
+ medium_mag_ptr->mag_last_free_rgn = NULL;
+ }
+ medium_meta_header_set_in_use(meta_headers, index, new_msize);
+ medium_madvise_header_mark_dirty(madv_headers, index, new_msize);
+ medium_meta_header_set_middle(meta_headers, next_index);
+ medium_madvise_header_mark_middle(madv_headers, next_index);
+ } else {
+#endif // CONFIG_MEDIUM_CACHE
+ /*
+ * Try to expand into unused space immediately after this block.
+ */
+ msize_t unused_msize = MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end);
+ void *unused_start = MEDIUM_REGION_HEAP_END(MEDIUM_REGION_FOR_PTR(ptr)) - medium_mag_ptr->mag_bytes_free_at_end;
+ if (medium_mag_ptr->mag_last_region == MEDIUM_REGION_FOR_PTR(ptr)
+ && coalesced_msize < unused_msize && unused_start == ptr + old_size) {
+ // Extend the in-use for this block to the new size
+ medium_meta_header_set_in_use(meta_headers, index, new_msize);
+ medium_madvise_header_mark_dirty(madv_headers, index, new_msize);
+
+ // Clear the in-use size for the start of the area we extended into
+ medium_meta_header_set_middle(meta_headers, next_index);
+ medium_madvise_header_mark_middle(madv_headers, next_index);
+
+ // Reduce mag_bytes_free_at_end and update its in-use size.
+ medium_mag_ptr->mag_bytes_free_at_end -= MEDIUM_BYTES_FOR_MSIZE(coalesced_msize);
+ medium_meta_header_set_in_use(meta_headers, index + new_msize,
+ MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end));
+ medium_madvise_header_mark_clean(madv_headers, index + new_msize,
+ MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end));
+ } else {
+ /*
+ * Look for a free block immediately afterwards. If it's large enough, we can consume (part of)
+ * it.
+ */
+ next_msize_and_free = meta_headers[next_index];
+ is_free = next_msize_and_free & MEDIUM_IS_FREE;
+ if (!is_free) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0; // next_block is in use;
+ }
+
+ next_msize = next_msize_and_free & ~MEDIUM_IS_FREE;
+ if (old_msize + next_msize < new_msize) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0; // even with next block, not enough
+ }
+
+ // The following block is big enough; pull it from its freelist and chop off enough to satisfy
+ // our needs.
+ free_list_t freee = medium_free_list_find_by_ptr(rack, medium_mag_ptr, next_block, next_msize);
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, freee, next_msize);
+ medium_meta_header_set_middle(meta_headers, next_index);
+ medium_madvise_header_mark_middle(madv_headers, next_index);
+ leftover_msize = old_msize + next_msize - new_msize;
+ if (leftover_msize) {
+ /* there's some left, so put the remainder back */
+ leftover = (unsigned char *)ptr + MEDIUM_BYTES_FOR_MSIZE(new_msize);
+ medium_free_list_add_ptr(rack, medium_mag_ptr, leftover, leftover_msize);
+ msize_t leftover_index = MEDIUM_META_INDEX_FOR_PTR(leftover);
+ if (madv_headers[leftover_index] & MEDIUM_IS_ADVISED) {
+ medium_madvise_header_mark_clean(madv_headers, leftover_index, leftover_msize);
+ } else {
+ medium_madvise_header_mark_dirty(madv_headers, leftover_index, leftover_msize);
+ }
+ }
+ medium_meta_header_set_in_use(meta_headers, index, new_msize);
+ medium_madvise_header_mark_dirty(madv_headers, index, new_msize);
+ }
+#if CONFIG_MEDIUM_CACHE
+ }
+#endif // CONFIG_MEDIUM_CACHE
+#if DEBUG_MALLOC
+ if (MEDIUM_BYTES_FOR_MSIZE(new_msize) > szone->large_threshold) {
+ malloc_report(ASL_LEVEL_ERR, "*** realloc in place for %p exceeded msize=%d\n", new_msize);
+ }
+
+ if (LOG(szone, ptr)) {
+ malloc_report(ASL_LEVEL_INFO, "in medium_try_realloc_in_place(), ptr=%p, msize=%d\n", ptr, *MEDIUM_METADATA_FOR_PTR(ptr));
+ }
+#endif
+ medium_mag_ptr->mag_num_bytes_in_objects += MEDIUM_BYTES_FOR_MSIZE(new_msize - old_msize);
+
+ // Update this region's bytes in use count
+ region_trailer_t *node = REGION_TRAILER_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr));
+ size_t bytes_used = node->bytes_used + MEDIUM_BYTES_FOR_MSIZE(new_msize - old_msize);
+ node->bytes_used = (unsigned int)bytes_used;
+
+ // Emptiness discriminant
+ if (bytes_used < DENSITY_THRESHOLD(MEDIUM_REGION_PAYLOAD_BYTES)) {
+ /* After this reallocation the region is still sparse, so it must have been even more so before
+ * the reallocation. That implies the region is already correctly marked. Do nothing. */
+ } else {
+ /* Region has crossed threshold from sparsity to density. Mark it not "suitable" on the
+ * recirculation candidates list. */
+ node->recirc_suitable = FALSE;
+ }
+
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ return 1;
+}
+
+static char *medium_check_fail_msg = "check: incorrect medium region ";
+
+#define MEDIUM_CHECK_FAIL(fmt, ...) \
+ malloc_zone_check_fail(medium_check_fail_msg, \
+ "%ld, counter=%d\n" fmt, region_index, counter, __VA_ARGS__);
+
+boolean_t
+medium_check_region(rack_t *rack, region_t region, size_t region_index,
+ unsigned counter)
+{
+ void *ptr = MEDIUM_REGION_HEAP_BASE(region);
+ msize_t *meta_headers = MEDIUM_META_HEADER_FOR_PTR(ptr);
+ void *region_end = MEDIUM_REGION_HEAP_END(region);
+ msize_t prev_free = 0;
+ unsigned index;
+ msize_t msize_and_free;
+ msize_t msize;
+ free_list_t free_head, previous, next;
+ msize_t *follower;
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr));
+ magazine_t *medium_mag_ptr = &(rack->magazines[mag_index]);
+
+ // Assumes locked
+ CHECK_MAGAZINE_PTR_LOCKED(szone, medium_mag_ptr, __PRETTY_FUNCTION__);
+
+ if (region == medium_mag_ptr->mag_last_region) {
+ ptr += medium_mag_ptr->mag_bytes_free_at_start;
+ region_end -= medium_mag_ptr->mag_bytes_free_at_end;
+ }
+
+ while (ptr < region_end) {
+ index = MEDIUM_META_INDEX_FOR_PTR(ptr);
+ msize_and_free = meta_headers[index];
+ if (!(msize_and_free & MEDIUM_IS_FREE)) {
+ // block is in use
+ msize = msize_and_free;
+ if (!msize) {
+ MEDIUM_CHECK_FAIL("*** invariant broken: null msize ptr=%p num_medium_regions=%d end=%p\n", ptr,
+ (int)rack->num_regions, region_end);
+ return 0;
+ }
+#if !CONFIG_RELAXED_INVARIANT_CHECKS
+ if (MEDIUM_BYTES_FOR_MSIZE(msize) > szone->large_threshold) {
+ MEDIUM_CHECK_FAIL("*** invariant broken for %p this medium msize=%d - size is too large\n", ptr, msize_and_free);
+ return 0;
+ }
+#endif // CONFIG_RELAXED_INVARIANT_CHECKS
+ ptr += MEDIUM_BYTES_FOR_MSIZE(msize);
+ prev_free = 0;
+ } else {
+ // free pointer
+ msize = msize_and_free & ~MEDIUM_IS_FREE;
+ free_head = (free_list_t){ .p = ptr };
+ follower = (msize_t *)FOLLOWING_MEDIUM_PTR(ptr, msize);
+ if (!msize) {
+ MEDIUM_CHECK_FAIL("*** invariant broken for free block %p this msize=%d\n", ptr, msize);
+ return 0;
+ }
+#if !CONFIG_RELAXED_INVARIANT_CHECKS
+ if (prev_free) {
+ MEDIUM_CHECK_FAIL("*** invariant broken for %p (2 free in a row)\n", ptr);
+ return 0;
+ }
+#endif
+
+ // <rdar://problem/24680189> check for possible OOB entry if needed
+ if (medium_needs_oob_free_entry(ptr, msize)) {
+ oob_free_entry_t oob = medium_oob_free_find_ptr(ptr, msize);
+ if (oob) {
+ free_head.oob = oob;
+ }
+ }
+
+ previous = medium_free_list_get_previous(rack, free_head);
+ next = medium_free_list_get_next(rack, free_head);
+ if (previous.p && !MEDIUM_PTR_IS_FREE(medium_free_list_get_ptr(rack, previous))) {
+ MEDIUM_CHECK_FAIL("*** invariant broken for %p (previous %p is not a free pointer)\n", ptr, medium_free_list_get_ptr(rack, previous));
+ return 0;
+ }
+ if (next.p && !MEDIUM_PTR_IS_FREE(medium_free_list_get_ptr(rack, next))) {
+ MEDIUM_CHECK_FAIL("*** invariant broken for %p (next %p is not a free pointer)\n", ptr, medium_free_list_get_ptr(rack, next));
+ return 0;
+ }
+ if (MEDIUM_PREVIOUS_MSIZE(follower) != msize) {
+ MEDIUM_CHECK_FAIL("*** invariant broken for medium free %p followed by %p in region %p [%p-%p] "
+ "(end marker incorrect) should be %d; in fact %d\n",
+ ptr, follower, region, MEDIUM_REGION_HEAP_BASE(region),
+ region_end, msize, MEDIUM_PREVIOUS_MSIZE(follower));
+ return 0;
+ }
+ ptr = (unsigned char *)follower;
+ prev_free = MEDIUM_IS_FREE;
+ }
+ }
+ return 1;
+}
+
+kern_return_t
+medium_in_use_enumerator(task_t task,
+ void *context,
+ unsigned type_mask,
+ szone_t *szone,
+ memory_reader_t reader,
+ vm_range_recorder_t recorder)
+{
+ size_t num_regions;
+ size_t index;
+ region_t *regions;
+ vm_range_t buffer[MAX_RECORDER_BUFFER];
+ unsigned count = 0;
+ kern_return_t err;
+ region_t region;
+ vm_range_t range;
+ vm_range_t admin_range;
+ vm_range_t ptr_range;
+ unsigned char *mapped_region;
+ msize_t *block_header;
+ unsigned block_index;
+ unsigned block_limit;
+ msize_t msize_and_free;
+ msize_t msize;
+ magazine_t *medium_mag_base = NULL;
+
+ region_hash_generation_t *srg_ptr;
+ err = reader(task, (vm_address_t)szone->medium_rack.region_generation, sizeof(region_hash_generation_t), (void **)&srg_ptr);
+ if (err) {
+ return err;
+ }
+
+ num_regions = srg_ptr->num_regions_allocated;
+ err = reader(task, (vm_address_t)srg_ptr->hashed_regions, sizeof(region_t) * num_regions, (void **)®ions);
+ if (err) {
+ return err;
+ }
+
+ if (type_mask & MALLOC_PTR_IN_USE_RANGE_TYPE) {
+ // Map in all active magazines. Do this outside the iteration over regions.
+ err = reader(task, (vm_address_t)(szone->medium_rack.magazines), szone->medium_rack.num_magazines * sizeof(magazine_t),
+ (void **)&medium_mag_base);
+ if (err) {
+ return err;
+ }
+ }
+
+ for (index = 0; index < num_regions; ++index) {
+ region = regions[index];
+ if (HASHRING_OPEN_ENTRY != region && HASHRING_REGION_DEALLOCATED != region) {
+ range.address = (vm_address_t)MEDIUM_REGION_HEAP_BASE(region);
+ range.size = MEDIUM_HEAP_SIZE;
+ if (type_mask & MALLOC_ADMIN_REGION_RANGE_TYPE) {
+ admin_range.address = MEDIUM_REGION_METADATA(region);
+ admin_range.size = MEDIUM_METADATA_SIZE;
+ recorder(task, context, MALLOC_ADMIN_REGION_RANGE_TYPE, &admin_range, 1);
+ }
+ if (type_mask & (MALLOC_PTR_REGION_RANGE_TYPE | MALLOC_ADMIN_REGION_RANGE_TYPE)) {
+ ptr_range.address = range.address;
+ ptr_range.size = MEDIUM_HEAP_SIZE;
+ recorder(task, context, MALLOC_PTR_REGION_RANGE_TYPE, &ptr_range, 1);
+ }
+ if (type_mask & MALLOC_PTR_IN_USE_RANGE_TYPE) {
+ err = reader(task, (vm_address_t)region,
+ (vm_size_t)MEDIUM_REGION_SIZE, (void **)&mapped_region);
+ if (err) {
+ return err;
+ }
+
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_MEDIUM_REGION(mapped_region);
+ magazine_t *medium_mag_ptr = medium_mag_base + mag_index;
+
+ int cached_free_blocks = 0;
+#if CONFIG_MEDIUM_CACHE
+ // Each magazine could have a pointer to a cached free block from
+ // this region. Count the regions that have such a pointer.
+ for (mag_index = 0; mag_index < szone->medium_rack.num_magazines; mag_index++) {
+ if (region == (medium_mag_base + mag_index)->mag_last_free_rgn) {
+ cached_free_blocks++;
+ }
+ }
+#endif // CONFIG_MEDIUM_CACHE
+
+ block_header = MEDIUM_META_HEADER_FOR_REGION(mapped_region);
+ block_index = 0;
+ block_limit = NUM_MEDIUM_BLOCKS;
+ if (region == medium_mag_ptr->mag_last_region) {
+ block_index += MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_start);
+ block_limit -= MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end);
+ }
+ for (;block_index < block_limit; block_index += msize) {
+ msize_and_free = block_header[block_index];
+ msize = msize_and_free & ~MEDIUM_IS_FREE;
+ if (!msize) {
+ return KERN_FAILURE; // Somethings amiss. Avoid looping at this block_index.
+ }
+ if (!(msize_and_free & MEDIUM_IS_FREE)) {
+ void *ptr = MEDIUM_REGION_HEAP_BASE(region) + MEDIUM_BYTES_FOR_MSIZE(block_index);
+#if CONFIG_MEDIUM_CACHE
+ // If there are still magazines that have cached free
+ // blocks in this region, check whether this is one of
+ // them and don't return the block pointer if it is.
+ boolean_t block_cached = false;
+ if (cached_free_blocks) {
+ for (mag_index = 0; mag_index < szone->medium_rack.num_magazines; mag_index++) {
+ if (ptr == (medium_mag_base + mag_index)->mag_last_free) {
+ block_cached = true;
+ cached_free_blocks--;
+ break;
+ }
+ }
+ }
+ if (block_cached) {
+ continue;
+ }
+#endif // CONFIG_MEDIUM_CACHE
+ // Block in use
+ buffer[count].address = (vm_address_t)ptr;
+ buffer[count].size = MEDIUM_BYTES_FOR_MSIZE(msize);
+ count++;
+ if (count >= MAX_RECORDER_BUFFER) {
+ recorder(task, context, MALLOC_PTR_IN_USE_RANGE_TYPE, buffer, count);
+ count = 0;
+ }
+ }
+ }
+ if (count) {
+ recorder(task, context, MALLOC_PTR_IN_USE_RANGE_TYPE, buffer, count);
+ count = 0;
+ }
+ }
+ }
+ }
+ return 0;
+}
+
+static void *
+medium_malloc_from_free_list(rack_t *rack, magazine_t *medium_mag_ptr, mag_index_t mag_index, msize_t msize)
+{
+ msize_t this_msize;
+ bool was_madvised;
+ grain_t slot = MEDIUM_FREE_SLOT_FOR_MSIZE(rack, msize);
+ free_list_t *free_list = medium_mag_ptr->mag_free_list;
+ free_list_t *the_slot = free_list + slot;
+ free_list_t *limit;
+ unsigned bitmap;
+ msize_t leftover_msize;
+ void *leftover_ptr;
+ void *ptr;
+
+ // Assumes we've locked the region
+ CHECK_MAGAZINE_PTR_LOCKED(szone, medium_mag_ptr, __PRETTY_FUNCTION__);
+
+ // Look for an exact match by checking the freelist for this msize.
+ if (medium_free_list_get_ptr(rack, *the_slot)) {
+ ptr = medium_free_list_get_ptr(rack, *the_slot);
+ this_msize = msize;
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, *the_slot, msize);
+ goto return_medium_alloc;
+ }
+
+ // Mask off the bits representing slots holding free blocks smaller than
+ // the size we need. If there are no larger free blocks, try allocating
+ // from the free space at the end of the medium region.
+ //
+ // BITMAPN_CTZ implementation
+ unsigned idx = slot >> 5;
+ bitmap = 0;
+ unsigned mask = ~((1 << (slot & 31)) - 1);
+ for (; idx < MEDIUM_FREELIST_BITMAP_WORDS(rack); ++idx) {
+ bitmap = medium_mag_ptr->mag_bitmap[idx] & mask;
+ if (bitmap != 0) {
+ break;
+ }
+ mask = ~0U;
+ }
+ // Check for fallthrough: No bits set in bitmap
+ if ((bitmap == 0) && (idx == MEDIUM_FREELIST_BITMAP_WORDS(rack))) {
+ goto try_medium_from_end;
+ }
+
+ // Start looking at the first set bit, plus 32 bits for every word of
+ // zeroes or entries that were too medium.
+ slot = BITMAP32_CTZ((&bitmap)) + (idx * 32);
+
+ // FIXME: Explain use of - 1 here, last slot has special meaning
+ limit = free_list + MEDIUM_FREE_SLOT_COUNT(rack) - 1;
+ free_list += slot;
+
+ // Attempt to pull off the free_list slot that we now think is full.
+ if ((ptr = medium_free_list_get_ptr(rack, *free_list))) {
+ this_msize = MEDIUM_PTR_SIZE(ptr);
+ was_madvised = (medium_madvise_header_dirty_len(
+ MEDIUM_MADVISE_HEADER_FOR_PTR(ptr), MEDIUM_META_INDEX_FOR_PTR(ptr)) == 0);
+ medium_free_list_remove_ptr(rack, medium_mag_ptr, *free_list, this_msize);
+ goto add_leftover_and_proceed;
+ }
+
+#if DEBUG_MALLOC
+ malloc_report(ASL_LEVEL_ERR, "in medium_malloc_from_free_list(), mag_bitmap out of sync, slot=%d\n", slot);
+#endif
+
+try_medium_from_end:
+ // Let's see if we can use medium_mag_ptr->mag_bytes_free_at_end
+ if (medium_mag_ptr->mag_bytes_free_at_end >= MEDIUM_BYTES_FOR_MSIZE(msize)) {
+ ptr = MEDIUM_REGION_HEAP_END(medium_mag_ptr->mag_last_region) -
+ medium_mag_ptr->mag_bytes_free_at_end;
+ medium_mag_ptr->mag_bytes_free_at_end -= MEDIUM_BYTES_FOR_MSIZE(msize);
+ if (medium_mag_ptr->mag_bytes_free_at_end) {
+ // let's mark this block as in use to serve as boundary
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr),
+ MEDIUM_META_INDEX_FOR_PTR((unsigned char *)ptr + MEDIUM_BYTES_FOR_MSIZE(msize)),
+ MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end));
+ medium_madvise_header_mark_clean(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr),
+ MEDIUM_META_INDEX_FOR_PTR((unsigned char *)ptr + MEDIUM_BYTES_FOR_MSIZE(msize)),
+ MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_end));
+ }
+ this_msize = msize;
+ goto return_medium_alloc;
+ }
+#if CONFIG_ASLR_INTERNAL
+ // Try from start if nothing left at end
+ if (medium_mag_ptr->mag_bytes_free_at_start >= MEDIUM_BYTES_FOR_MSIZE(msize)) {
+ ptr = MEDIUM_REGION_ADDRESS(medium_mag_ptr->mag_last_region) +
+ medium_mag_ptr->mag_bytes_free_at_start -
+ MEDIUM_BYTES_FOR_MSIZE(msize);
+ medium_mag_ptr->mag_bytes_free_at_start -= MEDIUM_BYTES_FOR_MSIZE(msize);
+ if (medium_mag_ptr->mag_bytes_free_at_start) {
+ // let's mark this block as in use to serve as boundary
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr), 0,
+ MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_start));
+ medium_madvise_header_mark_clean(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr), 0,
+ MEDIUM_MSIZE_FOR_BYTES(medium_mag_ptr->mag_bytes_free_at_start));
+ }
+ this_msize = msize;
+ goto return_medium_alloc;
+ }
+#endif
+ return NULL;
+
+add_leftover_and_proceed:
+ if (this_msize > msize) {
+ leftover_msize = this_msize - msize;
+ leftover_ptr = (unsigned char *)ptr + MEDIUM_BYTES_FOR_MSIZE(msize);
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_report(ASL_LEVEL_INFO, "in medium_malloc_from_free_list(), adding leftover ptr=%p, this_msize=%d\n", ptr, this_msize);
+ }
+#endif
+ medium_free_list_add_ptr(rack, medium_mag_ptr, leftover_ptr, leftover_msize);
+ if (was_madvised) {
+ medium_madvise_header_mark_clean(
+ MEDIUM_MADVISE_HEADER_FOR_PTR(leftover_ptr),
+ MEDIUM_META_INDEX_FOR_PTR(leftover_ptr), leftover_msize);
+ } else {
+ medium_madvise_header_mark_dirty(
+ MEDIUM_MADVISE_HEADER_FOR_PTR(leftover_ptr),
+ MEDIUM_META_INDEX_FOR_PTR(leftover_ptr), leftover_msize);
+ }
+ this_msize = msize;
+ }
+
+return_medium_alloc:
+ medium_mag_ptr->mag_num_objects++;
+ medium_mag_ptr->mag_num_bytes_in_objects += MEDIUM_BYTES_FOR_MSIZE(this_msize);
+
+ // Check that the region cookie is intact and update the region's bytes in use count
+ medium_region_t region = MEDIUM_REGION_FOR_PTR(ptr);
+ region_check_cookie(region, ®ION_COOKIE_FOR_MEDIUM_REGION(region));
+
+ region_trailer_t *trailer = REGION_TRAILER_FOR_MEDIUM_REGION(region);
+ size_t bytes_used = trailer->bytes_used + MEDIUM_BYTES_FOR_MSIZE(this_msize);
+ trailer->bytes_used = (unsigned int)bytes_used;
+
+ // Emptiness discriminant
+ if (bytes_used < DENSITY_THRESHOLD(MEDIUM_REGION_PAYLOAD_BYTES)) {
+ /* After this allocation the region is still sparse, so it must have been even more so before
+ * the allocation. That implies the region is already correctly marked. Do nothing. */
+ } else {
+ /* Region has crossed threshold from sparsity to density. Mark in not "suitable" on the
+ * recirculation candidates list. */
+ trailer->recirc_suitable = FALSE;
+ }
+#if DEBUG_MALLOC
+ if (LOG(szone, ptr)) {
+ malloc_report(ASL_LEVEL_INFO, "in medium_malloc_from_free_list(), ptr=%p, this_msize=%d, msize=%d\n", ptr, this_msize, msize);
+ }
+#endif
+ medium_meta_header_set_in_use(MEDIUM_META_HEADER_FOR_PTR(ptr),
+ MEDIUM_META_INDEX_FOR_PTR(ptr), this_msize);
+ medium_madvise_header_mark_dirty(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr),
+ MEDIUM_META_INDEX_FOR_PTR(ptr), this_msize);
+ return ptr;
+}
+
+void *
+medium_malloc_should_clear(rack_t *rack, msize_t msize, boolean_t cleared_requested)
+{
+ void *ptr;
+ mag_index_t mag_index = rack_get_thread_index(rack) % rack->num_magazines;
+ magazine_t *medium_mag_ptr = &(rack->magazines[mag_index]);
+
+ MALLOC_TRACE(TRACE_medium_malloc, (uintptr_t)rack, MEDIUM_BYTES_FOR_MSIZE(msize), (uintptr_t)medium_mag_ptr, cleared_requested);
+
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+
+#if CONFIG_MEDIUM_CACHE
+ ptr = medium_mag_ptr->mag_last_free;
+
+ if (medium_mag_ptr->mag_last_free_msize == msize) {
+ // we have a winner
+ medium_mag_ptr->mag_last_free = NULL;
+ medium_mag_ptr->mag_last_free_msize = 0;
+ medium_mag_ptr->mag_last_free_rgn = NULL;
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ if (cleared_requested) {
+ memset(ptr, 0, MEDIUM_BYTES_FOR_MSIZE(msize));
+ }
+ return ptr;
+ }
+#endif /* CONFIG_MEDIUM_CACHE */
+
+ while (1) {
+ ptr = medium_malloc_from_free_list(rack, medium_mag_ptr, mag_index, msize);
+ if (ptr) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ if (cleared_requested) {
+ memset(ptr, 0, MEDIUM_BYTES_FOR_MSIZE(msize));
+ }
+ return ptr;
+ }
+
+ if (medium_get_region_from_depot(rack, medium_mag_ptr, mag_index, msize)) {
+ ptr = medium_malloc_from_free_list(rack, medium_mag_ptr, mag_index, msize);
+ if (ptr) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ if (cleared_requested) {
+ memset(ptr, 0, MEDIUM_BYTES_FOR_MSIZE(msize));
+ }
+ return ptr;
+ }
+ }
+
+ // The magazine is exhausted. A new region (heap) must be allocated to satisfy this call to malloc().
+ // The allocation, an mmap() system call, will be performed outside the magazine spin locks by the first
+ // thread that suffers the exhaustion. That thread sets "alloc_underway" and enters a critical section.
+ // Threads arriving here later are excluded from the critical section, yield the CPU, and then retry the
+ // allocation. After some time the magazine is resupplied, the original thread leaves with its allocation,
+ // and retry-ing threads succeed in the code just above.
+ if (!medium_mag_ptr->alloc_underway) {
+ void *fresh_region;
+
+ // time to create a new region (do this outside the magazine lock)
+ medium_mag_ptr->alloc_underway = TRUE;
+ OSMemoryBarrier();
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ fresh_region = mvm_allocate_pages(MEDIUM_REGION_SIZE,
+ MEDIUM_BLOCKS_ALIGN,
+ MALLOC_FIX_GUARD_PAGE_FLAGS(rack->debug_flags),
+ VM_MEMORY_MALLOC_MEDIUM);
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+
+ // DTrace USDT Probe
+ MAGMALLOC_ALLOCREGION(MEDIUM_SZONE_FROM_RACK(rack), (int)mag_index,
+ fresh_region, MEDIUM_REGION_SIZE);
+
+ if (!fresh_region) { // out of memory!
+ medium_mag_ptr->alloc_underway = FALSE;
+ OSMemoryBarrier();
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return NULL;
+ }
+
+ region_set_cookie(®ION_COOKIE_FOR_MEDIUM_REGION(fresh_region));
+ ptr = medium_malloc_from_region_no_lock(rack, medium_mag_ptr,
+ mag_index, msize, fresh_region);
+
+ // we don't clear because this freshly allocated space is pristine
+ medium_mag_ptr->alloc_underway = FALSE;
+ OSMemoryBarrier();
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ return ptr;
+ } else {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ yield();
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+ }
+ }
+ /* NOTREACHED */
+}
+
+size_t
+medium_size(rack_t *rack, const void *ptr)
+{
+ if (medium_region_for_ptr_no_lock(rack, ptr)) {
+ if (MEDIUM_META_INDEX_FOR_PTR(ptr) >= NUM_MEDIUM_BLOCKS) {
+ return 0;
+ }
+ msize_t msize_and_free = *MEDIUM_METADATA_FOR_PTR(ptr);
+ if (msize_and_free & MEDIUM_IS_FREE) {
+ return 0;
+ }
+#if CONFIG_MEDIUM_CACHE
+ {
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr));
+ if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ magazine_t *medium_mag_ptr = &(rack->magazines[mag_index]);
+
+ if (ptr == medium_mag_ptr->mag_last_free) {
+ return 0;
+ }
+ } else {
+ for (mag_index = 0; mag_index < rack->num_magazines; mag_index++) {
+ magazine_t *medium_mag_ptr = &(rack->magazines[mag_index]);
+
+ if (ptr == medium_mag_ptr->mag_last_free) {
+ return 0;
+ }
+ }
+ }
+ }
+#endif
+ return MEDIUM_BYTES_FOR_MSIZE(msize_and_free);
+ }
+
+ return 0;
+}
+
+static MALLOC_NOINLINE void
+free_medium_botch(rack_t *rack, void *ptr)
+{
+ malloc_zone_error(rack->debug_flags, true, "double free for ptr %p\n", ptr);
+}
+
+void
+free_medium(rack_t *rack, void *ptr, region_t medium_region, size_t known_size)
+{
+ msize_t msize;
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_MEDIUM_REGION(MEDIUM_REGION_FOR_PTR(ptr));
+ magazine_t *medium_mag_ptr = &(rack->magazines[mag_index]);
+
+ // ptr is known to be in medium_region
+ if (known_size) {
+ msize = MEDIUM_MSIZE_FOR_BYTES(known_size + MEDIUM_QUANTUM - 1);
+ } else {
+ msize = MEDIUM_PTR_SIZE(ptr);
+ if (MEDIUM_PTR_IS_FREE(ptr)) {
+ free_medium_botch(rack, ptr);
+ return;
+ }
+ }
+
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+
+#if CONFIG_MEDIUM_CACHE
+ // Depot does not participate in CONFIG_MEDIUM_CACHE since it can't be directly malloc()'d
+ if (DEPOT_MAGAZINE_INDEX != mag_index) {
+ void *ptr2 = medium_mag_ptr->mag_last_free; // Might be NULL
+ msize_t msize2 = medium_mag_ptr->mag_last_free_msize;
+ region_t rgn2 = medium_mag_ptr->mag_last_free_rgn;
+
+ /* check that we don't already have this pointer in the cache */
+ if (ptr == ptr2) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ free_medium_botch(rack, ptr);
+ return;
+ }
+
+ if ((rack->debug_flags & MALLOC_DO_SCRIBBLE) && msize) {
+ memset(ptr, SCRABBLE_BYTE, MEDIUM_BYTES_FOR_MSIZE(msize));
+ }
+
+ uint64_t madv_window = medium_sliding_madvise_granularity(medium_mag_ptr);
+ if (MEDIUM_BYTES_FOR_MSIZE(msize) > madv_window) {
+ uintptr_t lo = round_page_kernel((uintptr_t)ptr);
+ uintptr_t hi = trunc_page_kernel((uintptr_t)ptr + MEDIUM_BYTES_FOR_MSIZE(msize));
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ mvm_madvise_free(rack, medium_region, lo, hi, NULL, false);
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+
+ medium_madvise_header_mark_clean(MEDIUM_MADVISE_HEADER_FOR_PTR(ptr),
+ MEDIUM_META_INDEX_FOR_PTR(ptr), msize);
+
+ ptr2 = medium_mag_ptr->mag_last_free; // Might be NULL
+ msize2 = medium_mag_ptr->mag_last_free_msize;
+ rgn2 = medium_mag_ptr->mag_last_free_rgn;
+ }
+
+
+ medium_mag_ptr->mag_last_free = ptr;
+ medium_mag_ptr->mag_last_free_msize = msize;
+ medium_mag_ptr->mag_last_free_rgn = medium_region;
+
+ if (!ptr2) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ CHECK(szone, __PRETTY_FUNCTION__);
+ return;
+ }
+
+ msize = msize2;
+ ptr = ptr2;
+ medium_region = rgn2;
+ }
+#endif /* CONFIG_MEDIUM_CACHE */
+
+ // Now in the time it took to acquire the lock, the region may have migrated
+ // from one magazine to another. I.e. trailer->mag_index is volatile.
+ // In which case the magazine lock we obtained (namely magazines[mag_index].mag_lock)
+ // is stale. If so, keep on tryin' ...
+ region_trailer_t *trailer = REGION_TRAILER_FOR_MEDIUM_REGION(medium_region);
+ mag_index_t refreshed_index;
+
+ while (mag_index != (refreshed_index = trailer->mag_index)) { // Note assignment
+
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+
+ mag_index = refreshed_index;
+ medium_mag_ptr = &(rack->magazines[mag_index]);
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+ }
+
+ if (medium_free_no_lock(rack, medium_mag_ptr, mag_index, medium_region, ptr, msize)) {
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ }
+
+ CHECK(szone, __PRETTY_FUNCTION__);
+}
+
+void
+print_medium_free_list(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, rack_t *rack)
+{
+ free_list_t ptr;
+ _SIMPLE_STRING b = _simple_salloc();
+ mag_index_t mag_index;
+
+ if (b) {
+ rack_t *mapped_rack;
+ magazine_t *mapped_magazines;
+ if (reader(task, (vm_address_t)rack, sizeof(struct rack_s),
+ (void **)&mapped_rack)) {
+ printer("Failed to map medium rack\n");
+ return;
+ }
+ if (reader(task, (vm_address_t)mapped_rack->magazines,
+ mapped_rack->num_magazines * sizeof(magazine_t),
+ (void **)&mapped_magazines)) {
+ printer("Failed to map medium rack magazines\n");
+ return;
+ }
+
+ _simple_sappend(b, "medium free sizes:\n");
+ grain_t free_slots = MEDIUM_FREE_SLOT_COUNT(mapped_rack);
+ for (mag_index = -1; mag_index < mapped_rack->num_magazines;
+ mag_index++) {
+ grain_t slot = 0;
+ if (mag_index == -1) {
+ _simple_sprintf(b, "\tRecirc depot: ");
+ } else {
+ _simple_sprintf(b, "\tMagazine %d: ", mag_index);
+ }
+ while (slot < free_slots) {
+ ptr = mapped_magazines[mag_index].mag_free_list[slot];
+ if (medium_free_list_get_ptr_task(task, reader, printer, ptr)) {
+ _simple_sprintf(b, "%s%y[%lld]; ", (slot == free_slots - 1) ?
+ ">=" : "", (slot + 1) * MEDIUM_QUANTUM,
+ medium_free_list_count(task, reader, printer,
+ rack, ptr));
+ }
+ slot++;
+ }
+ _simple_sappend(b, "\n");
+ }
+ printer("%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+}
+
+void
+print_medium_region(task_t task, memory_reader_t reader,
+ print_task_printer_t printer, szone_t *szone, int level,
+ region_t region, size_t bytes_at_start, size_t bytes_at_end)
+{
+ unsigned counts[1024];
+ unsigned in_use = 0;
+ uintptr_t start = (uintptr_t)MEDIUM_REGION_HEAP_BASE(region);
+ uintptr_t current = start + bytes_at_start;
+ uintptr_t limit = (uintptr_t)MEDIUM_REGION_HEAP_END(region) - bytes_at_end;
+ uintptr_t mapped_start;
+ msize_t msize_and_free;
+ msize_t msize;
+ unsigned ci;
+ _SIMPLE_STRING b;
+ uintptr_t pgTot = 0;
+ uintptr_t advTot = 0;
+
+ if (reader(task, (vm_address_t)start, MEDIUM_REGION_SIZE,
+ (void **)&mapped_start)) {
+ printer("Failed to map small region at %p\n", start);
+ return;
+ }
+ off_t start_offset = mapped_start - start;
+ region_t mapped_region = (region_t)mapped_start;
+
+ if (region == HASHRING_REGION_DEALLOCATED) {
+ if ((b = _simple_salloc()) != NULL) {
+ _simple_sprintf(b, "Medium region [unknown address] was returned to the OS\n");
+ printer("%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+ return;
+ }
+
+ memset(counts, 0, sizeof(counts));
+ while (current < limit) {
+ msize_and_free = *(uintptr_t *)((char *)MEDIUM_METADATA_FOR_PTR(current)
+ + start_offset);
+ msize = msize_and_free & ~MEDIUM_IS_FREE;
+ if (!msize) {
+ printer("*** error with %p: msize=%d, free: %x\n", (void *)current,
+ (unsigned)msize, msize_and_free & MEDIUM_IS_FREE);
+ break;
+ }
+ if (!(msize_and_free & MEDIUM_IS_FREE)) {
+ // block in use
+ if (msize < 1024) {
+ counts[msize]++;
+ }
+ in_use++;
+ } else {
+ uintptr_t pgLo = round_page_quanta(current +
+ sizeof(medium_inplace_free_entry_s) + sizeof(msize_t));
+ uintptr_t pgHi = trunc_page_quanta(current +
+ MEDIUM_BYTES_FOR_MSIZE(msize) - sizeof(msize_t));
+
+ if (pgLo < pgHi) {
+ pgTot += (pgHi - pgLo);
+ }
+
+ uintptr_t curAdv = current;
+ uintptr_t limAdv = current + MEDIUM_BYTES_FOR_MSIZE(msize);
+ while (curAdv < limAdv) {
+ msize_t adv = *(MEDIUM_MADVISE_HEADER_FOR_PTR(curAdv) +
+ MEDIUM_META_INDEX_FOR_PTR(curAdv));
+ uintptr_t bytes = MEDIUM_BYTES_FOR_MSIZE(adv & ~MEDIUM_IS_ADVISED);
+ if (adv & MEDIUM_IS_ADVISED) {
+ advTot += bytes;
+ }
+ curAdv += bytes;
+ }
+ }
+ current += MEDIUM_BYTES_FOR_MSIZE(msize);
+ }
+ if ((b = _simple_salloc()) != NULL) {
+ mag_index_t mag_index = MAGAZINE_INDEX_FOR_MEDIUM_REGION(mapped_region);
+ _simple_sprintf(b, "Medium region %p [%p-%p, %y] \t", region,
+ (void *)start, MEDIUM_REGION_HEAP_END(region),
+ (int)MEDIUM_REGION_SIZE);
+ if (mag_index == DEPOT_MAGAZINE_INDEX) {
+ _simple_sprintf(b, "Recirc depot \t");
+ } else {
+ _simple_sprintf(b, "Magazine=%d \t", mag_index);
+ }
+ _simple_sprintf(b, "Allocations in use=%d \t Bytes in use=%ly (%d%%) \t",
+ in_use, BYTES_USED_FOR_MEDIUM_REGION(region),
+ (int)(100.0F * BYTES_USED_FOR_MEDIUM_REGION(mapped_region))/MEDIUM_REGION_SIZE);
+ if (bytes_at_end || bytes_at_start) {
+ _simple_sprintf(b, "Untouched=%ly ", bytes_at_end + bytes_at_start);
+ }
+ _simple_sprintf(b, "Advised=%ly ", advTot);
+#if CONFIG_RECIRC_DEPOT
+ _simple_sprintf(b, medium_region_below_recirc_threshold(mapped_region) ?
+ "\tEmpty enough to be moved to recirc depot" :
+ "\tNot empty enough to be moved to recirc depot");
+#endif // CONFIG_RECIRC_DEPOT
+ _simple_sprintf(b, "Dirty=%ly ", MEDIUM_REGION_PAYLOAD_BYTES -
+ bytes_at_start - bytes_at_end -
+ BYTES_USED_FOR_MEDIUM_REGION(mapped_region) - advTot);
+ if (level >= MALLOC_VERBOSE_PRINT_LEVEL && in_use) {
+ _simple_sappend(b, "\n\tSizes in use: ");
+ for (ci = 0; ci < 1024; ci++) {
+ if (counts[ci]) {
+ _simple_sprintf(b, "%y[%d] ", MEDIUM_BYTES_FOR_MSIZE(ci),
+ counts[ci]);
+ }
+ }
+ }
+ printer("%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+}
+
+void
+print_medium_region_vis(szone_t *szone, region_t region)
+{
+ _SIMPLE_STRING b;
+
+ if (region == HASHRING_REGION_DEALLOCATED) {
+ if ((b = _simple_salloc()) != NULL) {
+ _simple_sprintf(b, "Medium region [unknown address] was returned "
+ "to the kernel\n");
+ malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
+ "%s\n", _simple_string(b));
+ _simple_sfree(b);
+ }
+ return;
+ }
+
+ msize_t *metah = MEDIUM_META_HEADER_FOR_PTR(region);
+ msize_t *madvh = MEDIUM_MADVISE_HEADER_FOR_PTR(region);
+
+ mag_index_t mag_idx = MAGAZINE_INDEX_FOR_MEDIUM_REGION(region);
+ magazine_t *mag = &szone->medium_rack.magazines[mag_idx];
+
+ msize_t cur_msz = 0;
+ bool is_free = false;
+ msize_t cur_adv_msz = 0;
+ bool is_advised = false;
+
+ if ((b = _simple_salloc()) == NULL) {
+ abort();
+ }
+
+ malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
+ "Medium region %p [%p-%p, %y, %y]\n", (void *)region,
+ MEDIUM_REGION_HEAP_BASE(region),
+ MEDIUM_REGION_HEAP_END(region), (int)MEDIUM_REGION_SIZE,
+ ((medium_region_t)region)->trailer.bytes_used);
+
+ for (size_t x = 0; x < NUM_MEDIUM_BLOCKS; x++) {
+ bool is_last_rgn = mag->mag_last_region == region;
+ bool is_in_free_trailer = is_last_rgn && ((x << SHIFT_MEDIUM_QUANTUM) >
+ (MEDIUM_REGION_SIZE - mag->mag_bytes_free_at_end));
+ bool is_blk_start = false;
+ bool is_blk_end = cur_msz == 1;
+ bool is_adv_boundary = false;
+
+ if (cur_msz == 0) {
+ cur_msz = metah[x] & ~MEDIUM_IS_FREE;
+ is_free = metah[x] & MEDIUM_IS_FREE;
+ is_blk_start = true;
+ }
+ if (cur_adv_msz == 0 && madvh[x]) {
+ cur_adv_msz = madvh[x] & ~MEDIUM_IS_FREE;
+ is_advised = madvh[x] & MEDIUM_IS_FREE;
+ is_adv_boundary = true;
+ }
+ if (cur_adv_msz > 0) {
+ cur_adv_msz--;
+ }
+
+ const char *sigil = "?";
+ if (is_in_free_trailer) {
+ sigil = "_";
+ } else if (cur_msz > 0) {
+ if (is_free) {
+ if (is_advised) { sigil = "~"; }
+ else if (is_blk_start && cur_msz == 1) { sigil = "."; }
+ else if (is_blk_start) { sigil = "<"; }
+ else if (is_blk_end) { sigil = ">"; }
+ else if (is_adv_boundary) { sigil = "!"; }
+ else { sigil = "."; }
+ } else {
+ if (is_blk_start && cur_msz == 1) { sigil = "#"; }
+ else if (is_blk_start) { sigil = "["; }
+ else if (is_blk_end) { sigil = "]"; }
+ else { sigil = "#"; }
+ }
+ cur_msz--;
+ }
+
+ if (x > 0 && (x % 128) == 0) {
+ malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX, "%s\n",
+ _simple_string(b));
+ _simple_sfree(b);
+ if ((b = _simple_salloc()) == NULL) {
+ abort();
+ }
+ if (is_in_free_trailer) {
+ break;
+ }
+ }
+
+ _simple_sappend(b, sigil);
+ }
+ _simple_sfree(b);
+}
+
+static char *medium_freelist_fail_msg = "check: medium free list incorrect";
+
+#define MEDIUM_FREELIST_FAIL(fmt, ...) \
+ malloc_zone_check_fail(medium_freelist_fail_msg, \
+ " (slot=%u), counter=%d\n" fmt, slot, counter, __VA_ARGS__);
+
+boolean_t
+medium_free_list_check(rack_t *rack, grain_t slot, unsigned counter)
+{
+ mag_index_t mag_index;
+
+ for (mag_index = -1; mag_index < rack->num_magazines; mag_index++) {
+ magazine_t *medium_mag_ptr = &(rack->magazines[mag_index]);
+ SZONE_MAGAZINE_PTR_LOCK(medium_mag_ptr);
+
+ unsigned count = 0;
+ free_list_t current = rack->magazines[mag_index].mag_free_list[slot];
+ free_list_t previous = (free_list_t){ .p = NULL };
+ msize_t msize_and_free;
+ void *ptr = NULL;
+
+ while ((ptr = medium_free_list_get_ptr(rack, current))) {
+ msize_and_free = *MEDIUM_METADATA_FOR_PTR(ptr);
+ if (!(msize_and_free & MEDIUM_IS_FREE)) {
+ MEDIUM_FREELIST_FAIL("*** in-use ptr in free list slot=%u count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0;
+ }
+ if (((uintptr_t)ptr) & (MEDIUM_QUANTUM - 1)) {
+ MEDIUM_FREELIST_FAIL("*** unaligned ptr in free list slot=%u count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0;
+ }
+ if (!medium_region_for_ptr_no_lock(rack, ptr)) {
+ MEDIUM_FREELIST_FAIL("*** ptr not in szone slot=%d count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0;
+ }
+ if (medium_free_list_get_previous(rack, current).p != previous.p) {
+ MEDIUM_FREELIST_FAIL("*** previous incorrectly set slot=%u count=%d ptr=%p\n", slot, count, ptr);
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ return 0;
+ }
+ previous = current;
+ current = medium_free_list_get_next(rack, current);
+ count++;
+ }
+
+ SZONE_MAGAZINE_PTR_UNLOCK(medium_mag_ptr);
+ }
+ return 1;
+}
+
+#endif // CONFIG_MEDIUM_ALLOCATOR