rename option pagemap_commit; always commit the page map on macos (for now)

ide/vs2022/mimalloc.vcxproj

@@ -190,7 +190,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>Default</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_DEBUG=3;MI_GUARDED=0;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_DEBUG=3;MI_SECURE=4;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <CompileAs>CompileAsCpp</CompileAs>
       <SupportJustMyCode>false</SupportJustMyCode>
       <LanguageStandard>stdcpp20</LanguageStandard>

include/mimalloc.h

@@ -398,8 +398,8 @@ typedef enum mi_option_e {
   mi_option_reclaim_on_free,            // allow to reclaim an abandoned segment on a free (=1)
   mi_option_full_page_retain,           // retain N full pages per size class (=2)
   mi_option_max_page_candidates,        // max candidate pages to consider for allocation (=4)
-  mi_option_max_vabits,                 // max virtual address bits to consider in user space (=48)
+  mi_option_max_vabits,                 // max user space virtual address bits to consider (=48)
-  mi_option_debug_commit_full_pagemap,  // commit the full pagemap to catch invalid pointer uses (=0)
+  mi_option_pagemap_commit,             // commit the full pagemap (to always catch invalid pointer uses) (=0)
   _mi_option_last,
   // legacy option names
   mi_option_large_os_pages = mi_option_allow_large_os_pages,

include/mimalloc/bits.h

@@ -120,7 +120,7 @@ typedef int32_t  mi_ssize_t;
 
 // use a flat page-map (or a 2-level one)
 #ifndef MI_PAGE_MAP_FLAT
-#if MI_MAX_VABITS <= 40
+#if MI_MAX_VABITS <= 40 && !defined(__APPLE__) 
 #define MI_PAGE_MAP_FLAT  1
 #else
 #define MI_PAGE_MAP_FLAT  0

include/mimalloc/internal.h

@@ -445,6 +445,7 @@ static inline mi_page_t* _mi_heap_get_free_small_page(mi_heap_t* heap, size_t si
 #if MI_PAGE_MAP_FLAT
 
 // flat page-map committed on demand
+// single indirection and low commit, but large initial virtual reserve (4 GiB with 48 bit virtual addresses)
 extern uint8_t* _mi_page_map;
 
 static inline size_t _mi_page_map_index(const void* p) {
@@ -471,6 +472,8 @@ static inline mi_page_t* _mi_unchecked_ptr_page(const void* p) {
 #else
 
 // 2-level page map:
+// double indirection but low commit and low virtual reserve.
+// 
 // The page-map is usually 4 MiB and points to sub maps of 64 KiB. 
 // The page-map is committed on-demand (in 64 KiB) parts (and sub-maps are committed on-demand as well)
 // One sub page-map = 64 KiB => covers 2^13 * 2^16 = 2^32 = 512 MiB address space

src/alloc.c

@@ -674,7 +674,7 @@ mi_decl_restrict void* _mi_heap_malloc_guarded(mi_heap_t* heap, size_t size, boo
     #if MI_STAT>1
     mi_heap_stat_increase(heap, malloc, mi_usable_size(p));
     #endif
-    _mi_stat_counter_increase(&heap->tld->stats.guarded_alloc_count, 1);
+    mi_heap_stat_counter_increase(heap, guarded_alloc_count, 1);
   }
   #if MI_DEBUG>3
   if (p != NULL && zero) {

src/options.c

@@ -102,6 +102,14 @@ typedef struct mi_option_desc_s {
 #endif
 #endif
 
+#ifndef MI_DEFAULT_PAGEMAP_COMMIT
+#if defined(__APPLE__)
+#define MI_DEFAULT_PAGEMAP_COMMIT 1
+#else
+#define MI_DEFAULT_PAGEMAP_COMMIT 0
+#endif
+#endif
+
 
 static mi_option_desc_t options[_mi_option_last] =
 {
@@ -165,7 +173,8 @@ static mi_option_desc_t options[_mi_option_last] =
   { 2,   UNINIT, MI_OPTION(full_page_retain) },
   { 4,   UNINIT, MI_OPTION(max_page_candidates) },
   { 0,   UNINIT, MI_OPTION(max_vabits) },
-  { 0,   UNINIT, MI_OPTION(debug_commit_full_pagemap) },
+  { MI_DEFAULT_PAGEMAP_COMMIT, 
+         UNINIT, MI_OPTION(pagemap_commit) },           // commit the full pagemap upfront?
 };
 
 static void mi_option_init(mi_option_desc_t* desc);

src/page-map.c

@@ -42,7 +42,7 @@ bool _mi_page_map_init(void) {
   // Allocate the page map and commit bits
   mi_page_map_max_address = (void*)(MI_PU(1) << vbits);
   const size_t page_map_size = (MI_ZU(1) << (vbits - MI_ARENA_SLICE_SHIFT));
-  const bool commit = (page_map_size <= 1*MI_MiB || mi_option_is_enabled(mi_option_debug_commit_full_pagemap)); // _mi_os_has_overcommit(); // commit on-access on Linux systems?
+  const bool commit = (page_map_size <= 1*MI_MiB || mi_option_is_enabled(mi_option_pagemap_commit)); // _mi_os_has_overcommit(); // commit on-access on Linux systems?
   const size_t commit_bits = _mi_divide_up(page_map_size, MI_PAGE_MAP_ENTRIES_PER_COMMIT_BIT);
   const size_t bitmap_size = (commit ? 0 : mi_bitmap_size(commit_bits, NULL));
   const size_t reserve_size = bitmap_size + page_map_size;
@@ -187,7 +187,7 @@ bool _mi_page_map_init(void) {
   const size_t os_page_size = _mi_os_page_size();
   const size_t page_map_size = _mi_align_up( page_map_count * sizeof(mi_page_t**), os_page_size);
   const size_t reserve_size = page_map_size + os_page_size;
-  const bool commit = page_map_size <= 64*MI_KiB || mi_option_is_enabled(mi_option_debug_commit_full_pagemap); // _mi_os_has_overcommit(); // commit on-access on Linux systems?
+  const bool commit = page_map_size <= 64*MI_KiB || mi_option_is_enabled(mi_option_pagemap_commit); // _mi_os_has_overcommit(); // commit on-access on Linux systems?
   _mi_page_map = (mi_page_t***)_mi_os_alloc_aligned(reserve_size, 1, commit, true /* allow large */, &mi_page_map_memid);
   if (_mi_page_map==NULL) {
     _mi_error_message(ENOMEM, "unable to reserve virtual memory for the page map (%zu KiB)\n", page_map_size / MI_KiB);

test/main-override-static.c

@@ -35,7 +35,7 @@ int main() {
   // corrupt_free();
   // block_overflow1();
   // block_overflow2();
-  // test_canary_leak();
+  test_canary_leak();
   // test_aslr();
   // invalid_free();
   // test_reserved();