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--- libmalloc/libmalloc-166.200.60/src/nanov2_malloc.c
+++ libmalloc/libmalloc-374.100.5/src/nanov2_malloc.c
@@ -29,25 +29,31 @@
#pragma mark Forward Declarations
#if OS_VARIANT_NOTRESOLVED
-static void nanov2_statistics(nanozonev2_t *nanozone, malloc_statistics_t *stats);
+static kern_return_t
+nanov2_statistics_task_printer(task_t task, vm_address_t zone_address,
+ memory_reader_t reader, print_task_printer_t printer,
+ malloc_statistics_t *stats);
+static kern_return_t
+nanov2_statistics_task(task_t task, vm_address_t zone_address,
+ memory_reader_t reader, malloc_statistics_t *stats);
#endif // OS_VARIANT_NOTRESOLVED
#pragma mark -
#pragma mark Externals for resolved functions
-extern void *nanov2_allocate(nanozonev2_t *nanozone, size_t rounded_size,
+MALLOC_NOEXPORT extern void *nanov2_allocate(nanozonev2_t *nanozone, size_t rounded_size,
boolean_t clear);
-extern void nanov2_free_to_block(nanozonev2_t *nanozone, void *ptr,
+MALLOC_NOEXPORT extern void nanov2_free_to_block(nanozonev2_t *nanozone, void *ptr,
nanov2_size_class_t size_class);
-extern boolean_t nanov2_madvise_block(nanozonev2_t *nanozone,
+MALLOC_NOEXPORT extern boolean_t nanov2_madvise_block(nanozonev2_t *nanozone,
nanov2_block_meta_t *block_metap, nanov2_block_t *blockp,
nanov2_size_class_t size_class);
-extern size_t nanov2_pointer_size(nanozonev2_t *nanozone, void *ptr,
+MALLOC_NOEXPORT extern size_t nanov2_pointer_size(nanozonev2_t *nanozone, void *ptr,
boolean_t allow_inner);
-extern size_t nanov2_pressure_relief(nanozonev2_t *nanozone, size_t goal);
+MALLOC_NOEXPORT extern size_t nanov2_pressure_relief(nanozonev2_t *nanozone, size_t goal);
#if OS_VARIANT_RESOLVED
-extern boolean_t nanov2_allocate_new_region(nanozonev2_t *nanozone);
+MALLOC_NOEXPORT extern nanov2_arena_t *nanov2_allocate_new_region(nanozonev2_t *nanozone);
#endif // OS_VARIANT_RESOLVED
#pragma mark -
@@ -104,9 +110,9 @@
#if OS_VARIANT_NOTRESOLVED
// Madvise policy. Set from the MallocNanoMadvisePolicy environment variable.
-nanov2_madvise_policy_t nanov2_madvise_policy;
-
-nanov2_policy_config_t nanov2_policy_config = {
+MALLOC_NOEXPORT nanov2_madvise_policy_t nanov2_madvise_policy;
+
+MALLOC_NOEXPORT nanov2_policy_config_t nanov2_policy_config = {
.block_scan_policy = NANO_SCAN_CAPACITY_BASED,
.block_scan_min_capacity = DEFAULT_SCAN_MIN_CAPACITY,
.block_scan_max_capacity = DEFAULT_SCAN_MAX_CAPACITY,
@@ -117,8 +123,8 @@
#else // OS_VARIANT_NOTRESOLVED
-extern nanov2_policy_config_t nanov2_policy_config;
-extern nanov2_madvise_policy_t nanov2_madvise_policy;
+MALLOC_NOEXPORT extern nanov2_policy_config_t nanov2_policy_config;
+MALLOC_NOEXPORT extern nanov2_madvise_policy_t nanov2_madvise_policy;
#endif // OS_VARIANT_NOTRESOLVED
@@ -133,7 +139,7 @@
// up to 64. One unit corresponds to BLOCKS_PER_UNIT blocks in the corresponding
// size class, so 64 units maps to a total of 64 * 64 = 4096 blocks and each
// block is 16K, making a total of 64MB, which is the size of an arena.
-int block_units_by_size_class[] = {
+static int block_units_by_size_class[] = {
2, // 16-byte allocations (less 1 for the metadata block)
10, // 32-byte allocations
11, // 48-byte allocations
@@ -163,18 +169,18 @@
// Offsets to the first and last blocks for each size class within an arena, in
// the logical address space. These tables are constructed from the values in
// the block_units_by_size_class table.
-int first_block_offset_by_size_class[NANO_SIZE_CLASSES];
-int last_block_offset_by_size_class[NANO_SIZE_CLASSES];
+MALLOC_NOEXPORT int first_block_offset_by_size_class[NANO_SIZE_CLASSES];
+MALLOC_NOEXPORT int last_block_offset_by_size_class[NANO_SIZE_CLASSES];
// Table mapping the part of a logical address that depends on size class to
// the size class. Also built from the block_units_by_size_class table.
-int ptr_offset_to_size_class[TOTAL_BLOCK_UNITS];
+MALLOC_NOEXPORT int ptr_offset_to_size_class[TOTAL_BLOCK_UNITS];
// Number of slots in a block, indexed by size class. Note that there is a small
// amount of wastage in some size classes because the block size is not always
// exactly divisible by the allocation size. The number of wasted bytes is shown
// in parentheses in the comments below.
-const int slots_by_size_class[] = {
+MALLOC_NOEXPORT const int slots_by_size_class[] = {
NANOV2_BLOCK_SIZE/(1 * NANO_REGIME_QUANTA_SIZE), // 16 bytes: 1024 (0)
NANOV2_BLOCK_SIZE/(2 * NANO_REGIME_QUANTA_SIZE), // 32 bytes: 512 (0)
NANOV2_BLOCK_SIZE/(3 * NANO_REGIME_QUANTA_SIZE), // 48 bytes: 341 (16)
@@ -233,13 +239,14 @@
// Given a block metadata pointer, returns whether the block is active (that is,
// it is being used for allocations, it has allocations that have not been freed,
-// or is waiting to be madvised).
+// or is waiting to be madvised and is not a guard block).
static MALLOC_ALWAYS_INLINE MALLOC_INLINE boolean_t
nanov2_is_block_active(nanov2_block_meta_t block_meta)
{
return block_meta.next_slot != SLOT_NULL
&& block_meta.next_slot != SLOT_MADVISING
- && block_meta.next_slot != SLOT_MADVISED;
+ && block_meta.next_slot != SLOT_MADVISED
+ && block_meta.next_slot != SLOT_GUARD;
}
#if OS_VARIANT_RESOLVED
@@ -306,7 +313,6 @@
return (void *)(((uintptr_t)ptr) & NANOV2_ARENA_ADDRESS_MASK);
}
-#if OS_VARIANT_RESOLVED
// Given a pointer that is assumed to be in the Nano zone, returns the address
// of its containing region. Works for both real and logical pointers.
static MALLOC_ALWAYS_INLINE MALLOC_INLINE nanov2_region_t *
@@ -314,7 +320,6 @@
{
return (nanov2_region_t *)(((uintptr_t)ptr) & NANOV2_REGION_ADDRESS_MASK);
}
-#endif // OS_VARIANT_RESOLVED
// Given a pointer that is assumed to be in the Nano zone, returns the real
// address of its metadata block. Works for both real and logical pointers.
@@ -388,15 +393,40 @@
return (nanov2_arena_t *)region;
}
+#if OS_VARIANT_RESOLVED
+// Given an atomically-observed current_region_next_arena pointer, returns
+// whether or not it's a usable arena or a limit arena (indicating exhaustion of
+// the current region).
+static MALLOC_ALWAYS_INLINE MALLOC_INLINE bool
+nanov2_current_region_next_arena_is_limit(
+ nanov2_arena_t *current_region_next_arena)
+{
+ // The first arena of a region is never stored in current_region_next_arena,
+ // so a value at the beginning of a region must be a limit arena.
+ return current_region_next_arena == (nanov2_arena_t *)(
+ nanov2_region_address_for_ptr(current_region_next_arena));
+}
+#endif // OS_VARIANT_RESOLVED
+
+// Given an atomically-observed current_region_next_arena pointer, returns the
+// base of the current region at the time of the observation.
+static MALLOC_ALWAYS_INLINE MALLOC_INLINE nanov2_region_t *
+nanov2_current_region_base(nanov2_arena_t *current_region_next_arena)
+{
+ return nanov2_region_address_for_ptr(
+ (void *)(((uintptr_t)current_region_next_arena) - 1));
+}
+
// Given a region pointer, returns a pointer to the arena after the last
// active arena in the region.
static MALLOC_ALWAYS_INLINE MALLOC_INLINE nanov2_arena_t *
-nanov2_limit_arena_for_region(nanozonev2_t *nanozone, nanov2_region_t *region)
+nanov2_limit_arena_for_region(nanozonev2_t __unused *nanozone,
+ nanov2_region_t *region, nanov2_arena_t *current_region_next_arena)
{
// The first arena is colocated with the region itself.
nanov2_arena_t *limit_arena;
- if (region == nanozone->current_region_base) {
- limit_arena = nanozone->current_region_next_arena;
+ if (region == nanov2_current_region_base(current_region_next_arena)) {
+ limit_arena = current_region_next_arena;
} else {
limit_arena = nanov2_first_arena_for_region(region + 1);
}
@@ -415,16 +445,51 @@
nanov2_metablock_meta_index(nanozone)];
}
+#if OS_VARIANT_RESOLVED
// Given a pointer to a region, returns a pointer to the region that follows it,
-// or NULL if there isn't one.
+// or NULL if there isn't one. We may observe linkage to a new region that
+// hasn't yet actually been installed into current_region_next_arena; ignore the
+// linkage in this case.
static MALLOC_ALWAYS_INLINE MALLOC_INLINE nanov2_region_t *
-nanov2_next_region_for_region(nanozonev2_t *nanozone, nanov2_region_t *region)
+nanov2_next_region_for_region(nanozonev2_t *nanozone, nanov2_region_t *region,
+ nanov2_arena_t *current_region_next_arena)
{
nanov2_region_linkage_t *linkage =
nanov2_region_linkage_for_region(nanozone, region);
- int offset = linkage->next_region_offset;
- return offset ? region + offset : NULL;
-}
+ int offset = os_atomic_load(&linkage->next_region_offset, relaxed);
+ if (!offset) {
+ return NULL;
+ }
+
+ nanov2_region_t *next_region = region + offset;
+ return (nanov2_arena_t *)next_region < current_region_next_arena ?
+ next_region : NULL;
+}
+#endif // OS_VARIANT_RESOLVED
+
+#if OS_VARIANT_NOTRESOLVED
+// Given a pointer to a region, returns a pointer to the region that follows it,
+// or NULL if there isn't one. This variant is used when mapping the nanozone
+// for another process.
+static MALLOC_ALWAYS_INLINE MALLOC_INLINE nanov2_region_t *
+nanov2_next_region_for_region_offset(nanozonev2_t *nanozone,
+ nanov2_region_t *region, off_t region_offset,
+ nanov2_arena_t *current_region_next_arena)
+{
+ nanov2_region_linkage_t *linkage =
+ nanov2_region_linkage_for_region(nanozone, region);
+ nanov2_region_linkage_t *mapped_linkage = (nanov2_region_linkage_t *)(
+ ((uintptr_t)linkage + region_offset));
+ int offset = os_atomic_load(&mapped_linkage->next_region_offset, relaxed);
+ if (!offset) {
+ return NULL;
+ }
+
+ nanov2_region_t *next_region = region + offset;
+ return (nanov2_arena_t *)next_region < current_region_next_arena ?
+ next_region : NULL;
+}
+#endif // OS_VARIANT_NOTRESOLVED
// Given the index of a slot in a block of a given size and the base address of
// the block, returns a pointer to the start of the slot. This works for both
@@ -567,18 +632,83 @@
static MALLOC_ALWAYS_INLINE MALLOC_INLINE int
nanov2_get_allocation_block_index(void)
{
+#if CONFIG_NANO_USES_HYPER_SHIFT
if (os_likely(nano_common_max_magazines_is_ncpu)) {
// Default case is max magazines == physical number of CPUs, which
- // must be > _os_cpu_number() >> hyper_shift, so the modulo
+ // must be > _malloc_cpu_number() >> hyper_shift, so the modulo
// operation is not required.
- return _os_cpu_number() >> hyper_shift;
- }
+ return _malloc_cpu_number() >> hyper_shift;
+ }
+#else // CONFIG_NANO_USES_HYPER_SHIFT
+ if (os_likely(nano_common_max_magazines_is_ncpu)) {
+ // Default case is max magazines == logical number of CPUs, which
+ // must be > _malloc_cpu_number() so the modulo operation is not required.
+ return _malloc_cpu_number();
+ }
+#endif // CONFIG_NANO_USES_HYPER_SHIFT
+
+ unsigned int shift = 0;
+#if CONFIG_NANO_USES_HYPER_SHIFT
+ shift = hyper_shift;
+#endif // CONFIG_NANO_USES_HYPER_SHIFT
+
if (os_likely(_os_cpu_number_override == -1)) {
- return (_os_cpu_number() >> hyper_shift) % nano_common_max_magazines;
- }
- return (_os_cpu_number_override >> hyper_shift) % nano_common_max_magazines;
+ return (_malloc_cpu_number() >> shift) % nano_common_max_magazines;
+ }
+ return (_os_cpu_number_override >> shift) % nano_common_max_magazines;
}
#endif // OS_VARIANT_RESOLVED
+
+#pragma mark -
+#pragma mark Guard Blocks
+
+// Converts a given block (specified by absolute block number) in an arena into
+// a guard block. The block will be marked as in-use so that it is not available
+// for allocations and its permissions are set to PROT_READ. Note that
+// PROT_READ is used instead of PROT_NONE because the latter breaks the
+// enumerator, which tries to map the whole region and fails if there are
+// PROT_NONE pages in the range. We can't fix that in the allocator because the
+// code that does the mapping is part of the sampling tools and is simply
+// invoked as a callback from the enumerator.
+static MALLOC_ALWAYS_INLINE MALLOC_INLINE void
+nanov2_create_guard_block(nanozonev2_t *nanozone, nanov2_arena_t *arena,
+ nanov2_block_index_t block_index) {
+ // Mark the block as in-use in the meta data
+ static nanov2_block_meta_t in_use_block = {
+ .in_use = 1,
+ .next_slot = SLOT_GUARD
+ };
+ nanov2_meta_index_t block_meta_index =
+ nanov2_block_index_to_meta_index(block_index);
+ nanov2_arena_metablock_t *block_metap = nanov2_metablock_address_for_ptr(
+ nanozone, arena);
+ block_metap->arena_block_meta[block_meta_index] = in_use_block;
+ void *block_ptr = &arena->blocks[block_index];
+
+ // Apply PROT_NONE to the block itself.
+ kern_return_t err = mprotect(block_ptr, NANOV2_BLOCK_SIZE, PROT_READ);
+ if (err != KERN_SUCCESS) {
+ malloc_report(ASL_LEVEL_ERR, "Failed to create guard block at %p (%d)\n",
+ block_ptr, err);
+ }
+}
+
+// Creates the guard blocks for an arena, if required. The guard blocks are
+// the first and last physical blocks in the arena that are not the metadata
+// block.
+static MALLOC_ALWAYS_INLINE MALLOC_INLINE void
+nanov2_init_guard_blocks(nanozonev2_t *nanozone, nanov2_arena_t *arena)
+{
+ if (nanozone->debug_flags & MALLOC_ALL_GUARD_PAGE_FLAGS) {
+ // Use the first and last blocks in the arena as guard regions,
+ // avoiding the metadata block.
+ nanov2_meta_index_t meta_index = nanov2_metablock_meta_index(nanozone);
+ nanov2_create_guard_block(nanozone, arena, meta_index == 0 ? 1 : 0);
+ nanov2_create_guard_block(nanozone, arena,
+ meta_index == NANOV2_BLOCKS_PER_ARENA - 1 ?
+ NANOV2_BLOCKS_PER_ARENA - 2 : NANOV2_BLOCKS_PER_ARENA - 1);
+ }
+}
#pragma mark -
#pragma mark Allocator Initialization
@@ -688,7 +818,7 @@
boolean_t max_found = FALSE;
boolean_t lim_found = FALSE;
const char *value = ptr;
-
+
if (ptr) {
if (!strcmp(ptr, first_fit_key)) {
block_scan_policy = NANO_SCAN_FIRST_FIT;
@@ -743,7 +873,7 @@
}
}
}
-
+
if (!failed) {
nanov2_policy_config.block_scan_policy = block_scan_policy;
nanov2_policy_config.block_scan_min_capacity = scan_min_capacity;
@@ -907,14 +1037,14 @@
// determine whether the pointer is for a Nano V2 allocation and, if not,
// delegates to the helper zone. Returns 0 if the pointer is not to memory
// allocated by Nano V2 or attributable to the helper zone.
-size_t
+MALLOC_NOEXPORT size_t
nanov2_size(nanozonev2_t *nanozone, const void *ptr)
{
size_t size = nanov2_pointer_size(nanozone, (void *)ptr, FALSE);
return size ? size : nanozone->helper_zone->size(nanozone->helper_zone, ptr);
}
-void *
+MALLOC_NOEXPORT void *
nanov2_malloc(nanozonev2_t *nanozone, size_t size)
{
size_t rounded_size = _nano_common_good_size(size);
@@ -933,7 +1063,7 @@
return nanozone->helper_zone->malloc(nanozone->helper_zone, size);
}
-void
+MALLOC_NOEXPORT void
nanov2_free_definite_size(nanozonev2_t *nanozone, void *ptr, size_t size)
{
// Check whether it's a Nano pointer and get the size. We should only get
@@ -951,7 +1081,7 @@
size);
}
-void
+MALLOC_NOEXPORT void
nanov2_free(nanozonev2_t *nanozone, void *ptr)
{
if (ptr && nanov2_has_valid_signature(ptr)) {
@@ -969,7 +1099,7 @@
return nanozone->helper_zone->free(nanozone->helper_zone, ptr);
}
-void *
+MALLOC_NOEXPORT void *
nanov2_calloc(nanozonev2_t *nanozone, size_t num_items, size_t size)
{
size_t total_bytes;
@@ -1000,7 +1130,7 @@
#endif // OS_VARIANT_NOTRESOLVED
#if OS_VARIANT_RESOLVED
-void *
+MALLOC_NOEXPORT void *
nanov2_realloc(nanozonev2_t *nanozone, void *ptr, size_t new_size)
{
// If we are given a NULL pointer, just allocate memory of the requested
@@ -1050,7 +1180,7 @@
return ptr;
}
}
-
+
// If we reach this point, we allocated new memory. Copy the existing
// content to the new location and release the old allocation.
MALLOC_ASSERT(new_ptr);
@@ -1072,13 +1202,14 @@
#endif // OS_VARIANT_NOTRESOLVED
#if OS_VARIANT_RESOLVED
-boolean_t
+MALLOC_NOEXPORT boolean_t
nanov2_claimed_address(nanozonev2_t *nanozone, void *ptr)
{
- return nanov2_pointer_size(nanozone, ptr, TRUE) != 0;
-}
-
-unsigned
+ return nanov2_pointer_size(nanozone, ptr, TRUE)
+ || malloc_zone_claimed_address(nanozone->helper_zone, ptr);
+}
+
+MALLOC_NOEXPORT unsigned
nanov2_batch_malloc(nanozonev2_t *nanozone, size_t size, void **results,
unsigned count)
{
@@ -1105,7 +1236,7 @@
nanozone->helper_zone, size, results, count - allocated);
}
-void
+MALLOC_NOEXPORT void
nanov2_batch_free(nanozonev2_t *nanozone, void **to_be_freed, unsigned count)
{
if (count) {
@@ -1151,9 +1282,12 @@
// until we reach our goal.
nanov2_region_t *region = nanozone->first_region_base;
nanov2_meta_index_t metablock_meta_index = nanov2_metablock_meta_index(nanozone);
+ nanov2_arena_t *current_region_next_arena = os_atomic_load(
+ &nanozone->current_region_next_arena, acquire);
while (region) {
nanov2_arena_t *arena = nanov2_first_arena_for_region(region);
- nanov2_arena_t *arena_after_region = nanov2_limit_arena_for_region(nanozone, region);
+ nanov2_arena_t *arena_after_region = nanov2_limit_arena_for_region(
+ nanozone, region, current_region_next_arena);
while (arena < arena_after_region) {
// Scan all of the blocks in the arena, skipping the metadata block.
nanov2_arena_metablock_t *meta_blockp =
@@ -1185,9 +1319,10 @@
}
arena++;
}
- region = nanov2_next_region_for_region(nanozone, region);
- }
-
+ region = nanov2_next_region_for_region(nanozone, region,
+ current_region_next_arena);
+ }
+
done:
MAGMALLOC_PRESSURERELIEFEND((void *)nanozone, name, (int)goal, (int)total);
MALLOC_TRACE(TRACE_nano_memory_pressure | DBG_FUNC_END,
@@ -1242,7 +1377,7 @@
if (kr) {
return kr;
}
- boolean_t self_zone = (nanozonev2_t *)zone_address == nanozone;
+ boolean_t self_zone = mach_task_is_self(task) && (nanozonev2_t *)zone_address == nanozone;
memcpy(&zone_copy, nanozone, sizeof(zone_copy));
nanozone = &zone_copy;
nanov2_meta_index_t metablock_meta_index = nanov2_metablock_meta_index(nanozone);
@@ -1250,6 +1385,8 @@
// Process the zone one region at a time. Report each in-use block as a
// pointer range and each in-use slot as a pointer.
nanov2_region_t *region = nanozone->first_region_base;
+ nanov2_arena_t *current_region_next_arena = os_atomic_load(
+ &nanozone->current_region_next_arena, acquire);
while (region) {
mach_vm_address_t vm_addr = (mach_vm_address_t)NULL;
kern_return_t kr = reader(task, (vm_address_t)region, NANOV2_REGION_SIZE, (void **)&vm_addr);
@@ -1261,7 +1398,8 @@
// and its mapped address in this process.
mach_vm_offset_t ptr_offset = (mach_vm_address_t)region - vm_addr;
nanov2_arena_t *arena = nanov2_first_arena_for_region(region);
- nanov2_arena_t *limit_arena = nanov2_limit_arena_for_region(nanozone, region);
+ nanov2_arena_t *limit_arena = nanov2_limit_arena_for_region(nanozone, region,
+ current_region_next_arena);
vm_range_t ptr_range;
while (arena < limit_arena) {
// Find the metadata block and process every entry, apart from the
@@ -1375,7 +1513,8 @@
nanov2_region_linkage_t *mapped_region_linkagep =
NANOV2_ZONE_PTR_TO_MAPPED_PTR(nanov2_region_linkage_t *,
region_linkagep, ptr_offset);
- int offset = mapped_region_linkagep->next_region_offset;
+ int offset = os_atomic_load(&mapped_region_linkagep->next_region_offset,
+ relaxed);
region = offset ? region + offset : NULL;
}
return 0;
@@ -1394,72 +1533,94 @@
static boolean_t
nanov2_check(nanozonev2_t *nanozone)
{
- // Does nothing, just like Nano V1.
+ // Does nothing
return 1;
}
static void
-nanov2_print(nanozonev2_t *nanozone, boolean_t verbose)
-{
+nanov2_print(task_t task, unsigned level, vm_address_t zone_address,
+ memory_reader_t reader, print_task_printer_t printer)
+{
+ // Ensure that we have configured enough of the allocator to be able to
+ // examine its data structures. In tools that do not directly use Nano, we
+ // won't have done this yet. nanov2_configure() runs the initialization
+ // only once.
+ nanov2_configure();
+
+ nanozonev2_t *mapped_nanozone;
+ if (reader(task, (vm_address_t)zone_address, sizeof(nanozonev2_t),
+ (void **)&mapped_nanozone)) {
+ printer("Failed to map nanozonev2_s at %p\n", zone_address);
+ return;
+ }
+
// Zone-wide statistics
malloc_statistics_t stats;
- nanov2_statistics_t *nano_stats = &nanozone->statistics;
- nanov2_statistics(nanozone, &stats);
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "Nanozonev2 %p: blocks in use: %llu, size in use: %llu allocated size: %llu, "
- "allocated regions: %d, region holes: %d\n",
- nanozone, (uint64_t)stats.blocks_in_use, (uint64_t)stats.size_in_use,
- (uint64_t)stats.size_allocated, nano_stats->allocated_regions,
- nano_stats->region_address_clashes);
+ nanov2_statistics_task_printer(task, zone_address, reader, printer, &stats);
+ nanov2_statistics_t *nano_stats = &mapped_nanozone->statistics;
+ printer("Nanozonev2 %p: blocks in use: %llu, size in use: %llu "
+ "allocated size: %llu, allocated regions: %d, region holes: %d\n",
+ zone_address, (uint64_t)stats.blocks_in_use,
+ (uint64_t)stats.size_in_use, (uint64_t)stats.size_allocated,
+ nano_stats->allocated_regions, nano_stats->region_address_clashes);
#if DEBUG_MALLOC
// Per-size class statistics
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "\nPer size-class statistics:\n");
+ printer("\nPer size-class statistics:\n");
for (int i = 0; i < NANO_SIZE_CLASSES; i++) {
nanov2_size_class_statistics *cs = &nano_stats->size_class_statistics[i];
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- " Class %d: ", i);
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "total alloc: %llu, total frees: %llu, madvised blocks: %llu, madvise races: %llu",
- cs->total_allocations, cs->total_frees, cs->madvised_blocks,
- cs->madvise_races);
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX, "\n");
+ printer(" Class %d: ", i);
+ printer("total alloc: %llu, total frees: %llu, madvised blocks: %llu, "
+ "madvise races: %llu",
+ cs->total_allocations, cs->total_frees, cs->madvised_blocks,
+ cs->madvise_races);
+ printer("\n");
}
#endif // DEBUG_MALLOC
// Per-context block pointers.
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "Current Allocation Blocks By Size Class/Context [CPU]\n");
+ printer("Current Allocation Blocks By Size Class/Context [CPU]\n");
for (int i = 0; i < NANO_SIZE_CLASSES; i++) {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- " Class %d: ", i);
+ printer(" Class %d: ", i);
for (int j = 0; j < MAX_CURRENT_BLOCKS; j++) {
- if (nanozone->current_block[i][j]) {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "%d: %p; ", j, nanozone->current_block[i][j]);
+ if (mapped_nanozone->current_block[i][j]) {
+ printer("%d: %p; ", j, mapped_nanozone->current_block[i][j]);
}
}
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX, "\n");
- }
-
- nanov2_meta_index_t metablock_meta_index = nanov2_metablock_meta_index(nanozone);
- nanov2_region_t *region = nanozone->first_region_base;
+ printer("\n");
+ }
+
+ nanov2_meta_index_t metablock_meta_index =
+ nanov2_metablock_meta_index(mapped_nanozone);
+ nanov2_region_t *region = mapped_nanozone->first_region_base;
+ // Use a single, consistent snapshot of current_region_next_arena throughout
+ // iteration, ignoring any arenas or regions allocated after it.
+ nanov2_arena_t *current_region_next_arena = os_atomic_load(
+ &mapped_nanozone->current_region_next_arena, acquire);
int region_index = 0;
while (region) {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "\nRegion %d: base address %p\n", region_index, region);
+ printer("\nRegion %d: base address %p\n", region_index, region);
+ nanov2_region_t *mapped_region;
+ if (reader(task, (vm_address_t)region, sizeof(nanov2_region_t),
+ (void **)&mapped_region)) {
+ printer("Failed to map nanov2 region at %p\n", region);
+ return;
+ }
+ off_t region_offset = (uintptr_t)mapped_region - (uintptr_t)region;
nanov2_arena_t *arena = nanov2_first_arena_for_region(region);
- nanov2_arena_t *limit_arena = nanov2_limit_arena_for_region(nanozone, region);
+ nanov2_arena_t *limit_arena = nanov2_limit_arena_for_region(
+ mapped_nanozone, region, current_region_next_arena);
int arena_index = 0;
while (arena < limit_arena) {
// Find the metadata block and process every entry, apart from the
// one for the metadata block itself.
nanov2_arena_metablock_t *arena_meta_blockp =
- nanov2_metablock_address_for_ptr(nanozone, arena);
-
+ nanov2_metablock_address_for_ptr(mapped_nanozone, arena);
+ nanov2_arena_metablock_t *mapped_arena_meta_blockp =
+ (nanov2_arena_metablock_t *)((uintptr_t)arena_meta_blockp + region_offset);
nanov2_block_meta_t *block_metap = &arena_meta_blockp->arena_block_meta[0];
+ nanov2_block_meta_t *mapped_block_metap = &mapped_arena_meta_blockp->arena_block_meta[0];
int active_blocks = 0;
int madvisable_blocks = 0;
@@ -1471,7 +1632,7 @@
// Skip the metadata block.
continue;
}
- nanov2_block_meta_t meta = block_metap[i];
+ nanov2_block_meta_t meta = mapped_block_metap[i];
switch (meta.next_slot) {
case SLOT_NULL:
unused_blocks++;
@@ -1490,8 +1651,7 @@
break;
}
}
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "Arena #%d: base address %p. Blocks - active: %d, "
+ printer("Arena #%d: base address %p. Blocks - active: %d, "
"madvisable: %d, madvising: %d, madvised: %d, unused: %d\n",
arena_index, arena, active_blocks, madvisable_blocks,
madvising_blocks, madvised_blocks, unused_blocks);
@@ -1506,9 +1666,9 @@
// Skip the metadata block.
continue;
}
- nanov2_block_meta_t meta = block_metap[i];
+ nanov2_block_meta_t meta = mapped_block_metap[i];
nanov2_size_class_t size_class =
- nanov2_size_class_for_meta_index(nanozone, i);
+ nanov2_size_class_for_meta_index(mapped_nanozone, i);
switch (meta.next_slot) {
case SLOT_FULL:
case SLOT_BUMP:
@@ -1523,85 +1683,97 @@
break;
}
}
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "Size classes with allocated blocks: ");
+ printer("Size classes with allocated blocks: ");
for (int i = 0; i < NANO_SIZE_CLASSES; i++) {
if (non_empty_size_classes[i]) {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "%d ", i);
+ printer("%d ", i);
}
}
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX, "\n");
-
- for (nanov2_meta_index_t i = 0; i < NANOV2_BLOCKS_PER_ARENA; i++) {
- if (i == metablock_meta_index) {
- // Skip the metadata block.
- continue;
- }
- nanov2_block_meta_t meta = block_metap[i];
- if (!nanov2_is_block_active(meta) && !verbose) {
- continue;
- }
- nanov2_size_class_t size_class =
- nanov2_size_class_for_meta_index(nanozone, i);
- char *slot_text;
- switch (meta.next_slot) {
- case SLOT_NULL:
- slot_text = "NOT USED";
- break;
- case SLOT_FULL:
- slot_text = "FULL";
- break;
- case SLOT_CAN_MADVISE:
- slot_text = "CAN MADVISE";
- break;
- case SLOT_MADVISING:
- slot_text = "MADVISING";
- break;
- case SLOT_MADVISED:
- slot_text = "MADVISED";
- break;
- default:
- slot_text = NULL;
- break;
- }
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- " Block %d: base %p; metadata: %p, size %d (class %d) in-use: %d ",
- i, nanov2_block_address_from_meta_index(nanozone, arena, i),
- &block_metap[i], nanov2_size_from_size_class(size_class),
- size_class, meta.in_use);
- if (slot_text) {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "%s\n", slot_text);
- } else {
- int allocated = slots_by_size_class[size_class] - meta.free_count - 1;
- if (meta.next_slot == SLOT_BUMP) {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "BUMP (free list empty)");
+ printer("\n");
+
+ if (level >= MALLOC_VERBOSE_PRINT_LEVEL) {
+ for (nanov2_meta_index_t i = 0; i < NANOV2_BLOCKS_PER_ARENA; i++) {
+ if (i == metablock_meta_index) {
+ // Skip the metadata block.
+ continue;
+ }
+ nanov2_block_meta_t meta = mapped_block_metap[i];
+ if (!nanov2_is_block_active(meta)) {
+ continue;
+ }
+ nanov2_size_class_t size_class =
+ nanov2_size_class_for_meta_index(mapped_nanozone, i);
+ char *slot_text;
+ switch (meta.next_slot) {
+ case SLOT_NULL:
+ slot_text = "NOT USED";
+ break;
+ case SLOT_FULL:
+ slot_text = "FULL";
+ break;
+ case SLOT_CAN_MADVISE:
+ slot_text = "CAN MADVISE";
+ break;
+ case SLOT_MADVISING:
+ slot_text = "MADVISING";
+ break;
+ case SLOT_MADVISED:
+ slot_text = "MADVISED";
+ break;
+ default:
+ slot_text = NULL;
+ break;
+ }
+ printer(" Block %d: base %p; metadata: %p, size %d "
+ "(class %d) in-use: %d ",
+ i, nanov2_block_address_from_meta_index(mapped_nanozone, arena, i),
+ &block_metap[i], nanov2_size_from_size_class(size_class),
+ size_class, meta.in_use);
+ if (slot_text) {
+ printer("%s\n", slot_text);
} else {
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- "next_slot (1-based) = %d", meta.next_slot);
+ int allocated = slots_by_size_class[size_class] - meta.free_count - 1;
+ if (meta.next_slot == SLOT_BUMP) {
+ printer("BUMP (free list empty)");
+ } else {
+ printer("next_slot (1-based) = %d", meta.next_slot);
}
- malloc_report(MALLOC_REPORT_NOLOG | MALLOC_REPORT_NOPREFIX,
- ", allocated slots: %d, free slots = %d, occupancy: %d%%\n",
- allocated, meta.free_count + 1,
- (100 * allocated)/slots_by_size_class[size_class]);
+ printer(", allocated slots: %d, free slots = %d, "
+ "occupancy: %d%%\n",
+ allocated, meta.free_count + 1,
+ (100 * allocated)/slots_by_size_class[size_class]);
+ }
}
}
arena++;
arena_index++;
}
- region = nanov2_next_region_for_region(nanozone, region);
+ region = nanov2_next_region_for_region_offset(mapped_nanozone, region,
+ region_offset, current_region_next_arena);
region_index++;
}
+}
+
+static void
+nanov2_print_self(nanozonev2_t *nanozone, boolean_t verbose)
+{
+ nanov2_print(mach_task_self(), verbose ? MALLOC_VERBOSE_PRINT_LEVEL : 0,
+ (vm_address_t)nanozone, _malloc_default_reader, malloc_report_simple);
+}
+
+static void
+nanov2_print_task(task_t task, unsigned level, vm_address_t zone_address,
+ memory_reader_t reader, print_task_printer_t printer)
+{
+ nanov2_print(task, level, zone_address, reader, printer);
}
static void
nanov2_log(malloc_zone_t *zone, void *log_address)
{
- // Does nothing, just like Nano V1.
+ // Does nothing
}
static void
@@ -1630,35 +1802,74 @@
}
static void
-nanov2_statistics(nanozonev2_t *nanozone, malloc_statistics_t *stats)
-{
+nanov2_null_printer(const char __unused *fmt, ...)
+{
+}
+
+static kern_return_t
+nanov2_statistics(task_t task, vm_address_t zone_address,
+ memory_reader_t reader, print_task_printer_t printer,
+ malloc_statistics_t *stats)
+{
+ printer = printer ? printer : nanov2_null_printer;
+ reader = !reader && task == mach_task_self() ? _malloc_default_reader : reader;
+
+ kern_return_t err;
+
+ // Ensure that we have configured enough of the allocator to be able to
+ // examine its data structures. In tools that do not directly use Nano, we
+ // won't have done this yet. nanov2_configure() runs the initialization
+ // only once.
+ nanov2_configure();
+
memset(stats, '\0', sizeof(*stats));
+ nanozonev2_t *mapped_nanozone;
+ err = reader(task, (vm_address_t)zone_address, sizeof(nanozonev2_t),
+ (void **)&mapped_nanozone);
+ if (err) {
+ printer("Failed to map nanozonev2_s at %p\n", zone_address);
+ return err;
+ }
+
nanov2_region_t *region;
- nanov2_arena_t * arena;
- nanov2_meta_index_t metadata_block_index = nanov2_metablock_meta_index(nanozone);
+ nanov2_arena_t *arena;
+ nanov2_meta_index_t metadata_block_index =
+ nanov2_metablock_meta_index(mapped_nanozone);
// Iterate over each arena in each region. Within each region, add
// statistics for each slot in each block, excluding the meta data block.
- for (region = nanozone->first_region_base; region;
- region = nanov2_next_region_for_region(nanozone, region)) {
+ nanov2_arena_t *current_region_next_arena = os_atomic_load(
+ &mapped_nanozone->current_region_next_arena, acquire);
+ for (region = mapped_nanozone->first_region_base; region;) {
+ nanov2_region_t *mapped_region;
+ err = reader(task, (vm_address_t)region, sizeof(nanov2_region_t), (void **)&mapped_region);
+ if (err) {
+ printer("Failed to map nanov2 region at %p\n", region);
+ return err;
+ }
+ off_t region_offset = (uintptr_t)mapped_region - (uintptr_t)region;
for (arena = nanov2_first_arena_for_region(region);
- arena < nanov2_limit_arena_for_region(nanozone, region);
+ arena < nanov2_limit_arena_for_region(mapped_nanozone, region,
+ current_region_next_arena);
arena++) {
nanov2_arena_metablock_t *meta_block =
- nanov2_metablock_address_for_ptr(nanozone, arena);
+ nanov2_metablock_address_for_ptr(mapped_nanozone, arena);
+ nanov2_arena_metablock_t *mapped_meta_block =
+ (nanov2_arena_metablock_t *)((uintptr_t)meta_block + region_offset);
for (nanov2_meta_index_t i = 0; i < NANOV2_BLOCKS_PER_ARENA; i++) {
if (i == metadata_block_index) {
// Skip the metadata block.
continue;
}
- nanov2_block_meta_t *block_metap = &meta_block->arena_block_meta[i];
+ nanov2_block_meta_t *mapped_block_metap = &mapped_meta_block->arena_block_meta[i];
nanov2_size_class_t size_class =
- nanov2_size_class_for_meta_index(nanozone, i);
+ nanov2_size_class_for_meta_index(mapped_nanozone, i);
int slot_size = nanov2_size_from_size_class(size_class);
- nanov2_block_meta_t meta = os_atomic_load(block_metap, relaxed);
+ nanov2_block_meta_t meta =
+ os_atomic_load(mapped_block_metap, relaxed);
int slots_in_use = 0;
switch (meta.next_slot) {
case SLOT_NULL:
@@ -1668,6 +1879,8 @@
case SLOT_MADVISING:
// FALLTHRU
case SLOT_MADVISED:
+ // FALLTHRU
+ case SLOT_GUARD:
// These blocks have no active content.
break;
case SLOT_FULL:
@@ -1689,18 +1902,43 @@
}
}
}
- }
-}
+ region = nanov2_next_region_for_region_offset(mapped_nanozone,
+ region, region_offset, current_region_next_arena);
+ }
+ return KERN_SUCCESS;
+}
+
+static void
+nanov2_statistics_self(nanozonev2_t *nanozone, malloc_statistics_t *stats)
+{
+ nanov2_statistics(mach_task_self(), (vm_address_t)nanozone,
+ _malloc_default_reader, malloc_report_simple, stats);
+}
+
+static kern_return_t
+nanov2_statistics_task_printer(task_t task, vm_address_t zone_address,
+ memory_reader_t reader, print_task_printer_t printer,
+ malloc_statistics_t *stats)
+{
+ return nanov2_statistics(task, zone_address, reader, printer, stats);
+}
+
+static kern_return_t
+nanov2_statistics_task(task_t task, vm_address_t zone_address, memory_reader_t reader, malloc_statistics_t *stats)
+{
+ return nanov2_statistics(task, zone_address, reader, NULL, stats);
+}
+
static const struct malloc_introspection_t nanov2_introspect = {
.enumerator = (void *)nanov2_ptr_in_use_enumerator,
.good_size = (void *)nanov2_good_size,
.check = (void *)nanov2_check,
- .print = (void *)nanov2_print,
+ .print = (void *)nanov2_print_self,
.log = (void *)nanov2_log,
.force_lock = (void *)nanov2_force_lock,
.force_unlock = (void *)nanov2_force_unlock,
- .statistics = (void *)nanov2_statistics,
+ .statistics = (void *)nanov2_statistics_self,
.zone_locked = (void *)nanov2_locked,
.enable_discharge_checking = NULL,
.disable_discharge_checking = NULL,
@@ -1710,6 +1948,8 @@
.enumerate_unavailable_without_blocks = NULL,
#endif // __BLOCKS__
.reinit_lock = (void *)nanov2_reinit_lock,
+ .print_task = (void *)nanov2_print_task,
+ .task_statistics = (void*)nanov2_statistics_task,
};
#endif // OS_VARIANT_NOTRESOLVED
@@ -1736,25 +1976,40 @@
return 0;
}
+ // Atomically load the value of current_region_next_arena. No thread is
+ // allowed to allocate from an arena until it observes a greater value of
+ // current_region_next_arena, which must have happened before now if we're
+ // being called in the context of a deallocation, so we can safely use it as
+ // the upper bound for an overall address range check.
+ nanov2_arena_t *current_region_next_arena = os_atomic_load(
+ &nanozone->current_region_next_arena, relaxed);
+
// Bounds check against the active address space.
if (ptr < (void *)nanozone->first_region_base ||
- ptr > (void *)nanozone->current_region_next_arena) {
+ ptr > (void *)current_region_next_arena) {
return 0;
}
#if NANOV2_MULTIPLE_REGIONS
// Need to check that the region part is valid because there could be holes.
// Do this only if we know there is a hole.
- // NOTE: in M2 convergence, use a hashed structure to make this more
- // efficient.
- if (nanozone->statistics.region_address_clashes) {
+ //
+ // If we're looking at a legitimately-allocated nano pointer, a load-acquire
+ // of current_region_next_arena must have already happened when its
+ // containing arena was first allocated from, so any region_address_clashes
+ // increment that preceded the store-release of current_region_next_arena
+ // should be visible.
+ //
+ // TODO: use a hashed structure to make this more efficient.
+ if (os_atomic_load(&nanozone->statistics.region_address_clashes, relaxed)) {
nanov2_region_t *ptr_region = nanov2_region_address_for_ptr(ptr);
nanov2_region_t *region = nanozone->first_region_base;
while (region) {
if (ptr_region == region) {
break;
}
- region = nanov2_next_region_for_region(nanozone, region);
+ region = nanov2_next_region_for_region(nanozone, region,
+ current_region_next_arena);
}
if (!region) {
// Reached the end of the region list without matching - not a
@@ -1883,45 +2138,62 @@
// Allocates a new region adjacent to the current one. If the allocation fails,
// keep sliding up by the size of a region until we either succeed or run out of
-// address space. The caller must own the Nanozone regions lock.
-boolean_t
+// address space. The caller must own the Nanozone regions lock. Returns the
+// first arena of the newly-allocated region if successful, or NULL otherwise.
+MALLOC_NOEXPORT nanov2_arena_t *
nanov2_allocate_new_region(nanozonev2_t *nanozone)
{
#if NANOV2_MULTIPLE_REGIONS
- boolean_t result = FALSE;
+ bool allocated = false;
_malloc_lock_assert_owner(&nanozone->regions_lock);
- nanov2_region_t *current_region = nanozone->current_region_base;
- nanov2_region_t *next_region = (nanov2_region_t *)nanozone->current_region_limit;
+ nanov2_region_t *current_region = nanov2_current_region_base(
+ os_atomic_load(&nanozone->current_region_next_arena, relaxed));
+ nanov2_region_t *next_region = current_region + 1;
while ((void *)next_region <= nanov2_max_region_base.addr) {
if (nanov2_allocate_region(next_region)) {
- nanozone->current_region_base = next_region;
- nanozone->current_region_next_arena = (nanov2_arena_t *)next_region;
- nanozone->current_region_limit = next_region + 1;
nanozone->statistics.allocated_regions++;
- result = TRUE;
+ allocated = true;
break;
}
next_region++;
- nanozone->statistics.region_address_clashes++;
- }
-
- if (result) {
- // Link this region to the previous one.
- nanov2_region_linkage_t *current_region_linkage =
- nanov2_region_linkage_for_region(nanozone, current_region);
- nanov2_region_linkage_t *next_region_linkage =
- nanov2_region_linkage_for_region(nanozone, next_region);
- uint16_t offset = next_region - current_region;
- current_region_linkage->next_region_offset = offset;
- next_region_linkage->next_region_offset = 0;
- }
-
- return result;
+
+ // Loaded atomically in nanov2_pointer_size() to determine whether or
+ // not it's necessary to walk the region list, so we need to increment
+ // atomically here. Published by the store-release of
+ // current_region_next_arena.
+ os_atomic_inc(&nanozone->statistics.region_address_clashes, relaxed);
+ }
+
+ if (!allocated) {
+ return NULL;
+ }
+
+ // Link this region to the previous one.
+ nanov2_region_linkage_t *current_region_linkage =
+ nanov2_region_linkage_for_region(nanozone, current_region);
+
+ // The linkage of the next region is in pristine memory, so already zero -
+ // don't touch it.
+
+ // Store-release the linkage update so any dependent loads through it
+ // observe the (implicit zero-)initialization of the next region.
+ uint16_t offset = next_region - current_region;
+ os_atomic_store(¤t_region_linkage->next_region_offset, offset,
+ release);
+
+ // Store-release the update to current_region_next_arena to publish the
+ // linkage update. Pairs with load-acquires of current_region_next_arena
+ // followed by walks of the region list.
+ nanov2_arena_t *first_arena = nanov2_first_arena_for_region(next_region);
+ os_atomic_store(&nanozone->current_region_next_arena, first_arena + 1,
+ release);
+
+ return first_arena;
#else // NANOV2_MULTIPLE_REGIONS
// On iOS, only one region is supported, so we fail since the first
// region is allocated separately.
- return FALSE;
+ return NULL;
#endif // CONFIG_NANOV2_MULTIPLE_REGIONS
}
#endif // OS_VARIANT_NOTRESOLVED
@@ -1936,6 +2208,7 @@
// unused region of the block if not. If the block is no longer in use or is
// full, NULL is returned and the caller is expected to find another block to
// allocate from.
+MALLOC_NOEXPORT
void *
nanov2_allocate_from_block(nanozonev2_t *nanozone,
nanov2_block_meta_t *block_metap, nanov2_size_class_t size_class)
@@ -2017,8 +2290,7 @@
ptr = nanov2_slot_in_block_ptr(blockp, size_class, slot);
}
- nanov2_free_slot_t *slotp =
- (nanov2_free_slot_t *)os_atomic_force_dependency_on(ptr,
+ nanov2_free_slot_t *slotp = os_atomic_inject_dependency(ptr,
(unsigned long)old_meta_view.bits);
if (from_free_list) {
// We grabbed the item from the free list. Check the free list canary
@@ -2027,15 +2299,12 @@
// write to it.
uintptr_t guard = os_atomic_load(&slotp->double_free_guard, relaxed);
if ((guard ^ nanozone->slot_freelist_cookie) != (uintptr_t)ptr) {
- malloc_zone_error(MALLOC_ABORT_ON_CORRUPTION, false,
+ malloc_zone_error(MALLOC_ABORT_ON_CORRUPTION, true,
"Heap corruption detected, free list is damaged at %p\n"
"*** Incorrect guard value: %lu\n", ptr, guard);
__builtin_unreachable();
}
}
-
- // Reset the canary value so that the slot no longer looks free.
- os_atomic_store(&slotp->double_free_guard, 0, relaxed);
#if DEBUG_MALLOC
nanozone->statistics.size_class_statistics[size_class].total_allocations++;
@@ -2255,7 +2524,7 @@
//
// In order to avoid races, this function must be called with the
// current_block_lock for the calling context [CPU] and size class locked.
-MALLOC_NOINLINE void *
+MALLOC_NOEXPORT MALLOC_NOINLINE void *
nanov2_find_block_and_allocate(nanozonev2_t *nanozone,
nanov2_size_class_t size_class, nanov2_block_meta_t **block_metapp)
{
@@ -2275,8 +2544,13 @@
start_region = nanov2_region_address_for_ptr(arena);
nanov2_arena_t *start_arena = arena;
nanov2_region_t *region = start_region;
- nanov2_arena_t *limit_arena = nanov2_limit_arena_for_region(nanozone, start_region);
- nanov2_arena_t *initial_region_next_arena = nanozone->current_region_next_arena;
+ // The load-acquire pairs with store-release in nanov2_allocate_new_region()
+ // to make the most recent region linkage update visible when we load it in
+ // nanov2_next_region_for_region() below.
+ nanov2_arena_t *initial_region_next_arena = os_atomic_load(
+ &nanozone->current_region_next_arena, acquire);
+ nanov2_arena_t *limit_arena = nanov2_limit_arena_for_region(nanozone,
+ start_region, initial_region_next_arena);
do {
nanov2_block_meta_t *block_metap = nanov2_find_block_in_arena(nanozone,
arena, size_class, start_block);
@@ -2312,13 +2586,15 @@
start_block = NULL;
arena++;
if (arena >= limit_arena) {
- region = nanov2_next_region_for_region(nanozone, region);
+ region = nanov2_next_region_for_region(nanozone, region,
+ initial_region_next_arena);
if (!region) {
// Reached the last region -- loop back to the first.
region = nanozone->first_region_base;
}
arena = nanov2_first_arena_for_region(region);
- limit_arena = nanov2_limit_arena_for_region(nanozone, region);
+ limit_arena = nanov2_limit_arena_for_region(nanozone, region,
+ initial_region_next_arena);
}
} while (arena != start_arena);
@@ -2329,24 +2605,42 @@
}
// Allocate a new arena and maybe a new region. To do either of those
- // things, we need to take the regions_lock. After doing so, check that
- // the state is unchanged. If it has, just assume that we might have some
- // new space to allocate into and try again.
+ // things, we need to take the regions_lock. After doing so, check that the
+ // state is unchanged. If it has, just assume that we might have some new
+ // space to allocate into and try again.
+
boolean_t failed = FALSE;
- arena = initial_region_next_arena;
+
_malloc_lock_lock(&nanozone->regions_lock);
- if (nanozone->current_region_next_arena == arena) {
- if ((void *)arena >= nanozone->current_region_limit) {
+ nanov2_arena_t *current_region_next_arena = os_atomic_load(
+ &nanozone->current_region_next_arena, relaxed);
+ if (current_region_next_arena == initial_region_next_arena) {
+ if (nanov2_current_region_next_arena_is_limit(
+ current_region_next_arena)) {
// Reached the end of the region. Allocate a new one, if we can.
- if (nanov2_allocate_new_region(nanozone)) {
- arena = nanozone->current_region_next_arena++;
- } else {
+ arena = nanov2_allocate_new_region(nanozone);
+ if (!arena) {
failed = TRUE;
}
} else {
- // Assign the new arena, in the same region.
- nanozone->current_region_next_arena = arena + 1;
- }
+ // Assign the new arena, in the current region.
+ arena = current_region_next_arena;
+
+ // Bump current_region_next_arena by 1. No need for an atomic add
+ // because we're under the regions_lock.
+ os_atomic_store(&nanozone->current_region_next_arena,
+ current_region_next_arena + 1, relaxed);
+ }
+
+ // Set up the guard blocks for the new arena, if requested
+ if (!failed) {
+ nanov2_init_guard_blocks(nanozone, arena);
+ }
+ } else {
+ // The arena just before current_region_next_arena is always the most
+ // recently allocated arena. Let's retry from that arena, which was
+ // allocated in the time since we started our last try.
+ arena = current_region_next_arena - 1;
}
_malloc_lock_unlock(&nanozone->regions_lock);
@@ -2541,10 +2835,10 @@
nanov2_create_zone(malloc_zone_t *helper_zone, unsigned debug_flags)
{
// Note: It is important that nanov2_create_zone resets _malloc_engaged_nano
- // if it is unable to enable the nanozone (and chooses not to abort). As
+ // if it is unable to enable the nanozone (and chooses not to abort). As
// several functions rely on _malloc_engaged_nano to determine if they
// should manipulate the nanozone, and these should not run if we failed
- // to create the zone.
+ // to create the zone.
MALLOC_ASSERT(_malloc_engaged_nano == NANO_V2);
// Get memory for the zone and disable Nano if we fail.
@@ -2556,7 +2850,7 @@
}
// Set up the basic_zone portion of the nanozonev2 structure
- nanozone->basic_zone.version = 10;
+ nanozone->basic_zone.version = 12;
nanozone->basic_zone.size = OS_RESOLVED_VARIANT_ADDR(nanov2_size);
nanozone->basic_zone.malloc = OS_RESOLVED_VARIANT_ADDR(nanov2_malloc);
nanozone->basic_zone.calloc = OS_RESOLVED_VARIANT_ADDR(nanov2_calloc);
@@ -2580,12 +2874,6 @@
// Prevent overwriting the function pointers in basic_zone.
mprotect(nanozone, sizeof(nanozone->basic_zone), PROT_READ);
- // Nano V2 zone does not support MALLOC_ADD_GUARD_PAGES
- if (debug_flags & MALLOC_ADD_GUARD_PAGES) {
- malloc_report(ASL_LEVEL_INFO, "nano does not support guard pages\n");
- debug_flags &= ~MALLOC_ADD_GUARD_PAGES;
- }
-
// Set up the remainder of the nanozonev2 structure
nanozone->debug_flags = debug_flags;
nanozone->helper_zone = helper_zone;
@@ -2610,7 +2898,7 @@
// align it to the block field of a Nano address.
nanozone->aslr_cookie = malloc_entropy[1] >> (64 - NANOV2_BLOCK_BITS);
nanozone->aslr_cookie_aligned = nanozone->aslr_cookie << NANOV2_OFFSET_BITS;
-
+
_malloc_lock_init(&nanozone->blocks_lock);
_malloc_lock_init(&nanozone->regions_lock);
_malloc_lock_init(&nanozone->madvise_lock);
@@ -2628,14 +2916,16 @@
}
nanov2_region_linkage_t *region_linkage =
nanov2_region_linkage_for_region(nanozone, region);
- region_linkage->next_region_offset = 0;
+ os_atomic_store(®ion_linkage->next_region_offset, 0, relaxed);
// Install the first region and pre-allocate the first arena.
nanozone->first_region_base = region;
- nanozone->current_region_base = region;
- nanozone->current_region_next_arena = ((nanov2_arena_t *)region) + 1;
- nanozone->current_region_limit = region + 1;
+ os_atomic_store(&nanozone->current_region_next_arena,
+ ((nanov2_arena_t *)region) + 1, release);
nanozone->statistics.allocated_regions = 1;
+
+ // Set up the guard blocks for the initial arena, if requested
+ nanov2_init_guard_blocks(nanozone, (nanov2_arena_t *)region);
return (malloc_zone_t *)nanozone;
}
@@ -2652,7 +2942,7 @@
// leak, but this is better than possibly crashing.
#if OS_VARIANT_RESOLVED
-void *
+MALLOC_NOEXPORT void *
nanov2_forked_malloc(nanozonev2_t *nanozone, size_t size)
{
// Just hand to the helper zone.
@@ -2674,7 +2964,7 @@
#if OS_VARIANT_RESOLVED
-void
+MALLOC_NOEXPORT void
nanov2_forked_free(nanozonev2_t *nanozone, void *ptr)
{
if (!ptr) {
@@ -2696,13 +2986,13 @@
/* NOTREACHED */
}
-void
+MALLOC_NOEXPORT void
nanov2_forked_free_definite_size(nanozonev2_t *nanozone, void *ptr, size_t size)
{
nanov2_forked_free(nanozone, ptr);
}
-void *
+MALLOC_NOEXPORT void *
nanov2_forked_realloc(nanozonev2_t *nanozone, void *ptr, size_t new_size)
{
// could occur through malloc_zone_realloc() path
@@ -2760,7 +3050,7 @@
#if OS_VARIANT_RESOLVED
-void
+MALLOC_NOEXPORT void
nanov2_forked_batch_free(nanozonev2_t *nanozone, void **to_be_freed,
unsigned count)
{