support full secure build

This commit is contained in:
daanx 2024-12-22 17:25:58 -08:00
parent 516e644359
commit 773fe7ae5b
7 changed files with 82 additions and 37 deletions

View file

@ -190,7 +190,7 @@
<SDLCheck>true</SDLCheck> <SDLCheck>true</SDLCheck>
<ConformanceMode>Default</ConformanceMode> <ConformanceMode>Default</ConformanceMode>
<AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories> <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
<PreprocessorDefinitions>MI_DEBUG=3;MI_SECURE=4;%(PreprocessorDefinitions);</PreprocessorDefinitions> <PreprocessorDefinitions>MI_DEBUG=3;MI_GUARDED=1;%(PreprocessorDefinitions);</PreprocessorDefinitions>
<CompileAs>CompileAsCpp</CompileAs> <CompileAs>CompileAsCpp</CompileAs>
<SupportJustMyCode>false</SupportJustMyCode> <SupportJustMyCode>false</SupportJustMyCode>
<LanguageStandard>stdcpp20</LanguageStandard> <LanguageStandard>stdcpp20</LanguageStandard>

View file

@ -46,11 +46,13 @@ terms of the MIT license. A copy of the license can be found in the file
// Define MI_STAT as 1 to maintain statistics; set it to 2 to have detailed statistics (but costs some performance). // Define MI_STAT as 1 to maintain statistics; set it to 2 to have detailed statistics (but costs some performance).
// #define MI_STAT 1 // #define MI_STAT 1
// Define MI_SECURE to enable security mitigations // Define MI_SECURE to enable security mitigations. The lowest two have minimal performance impact:
// #define MI_SECURE 1 // guard page around metadata // #define MI_SECURE 1 // guard page around metadata
// #define MI_SECURE 2 // guard page around each mimalloc page // #define MI_SECURE 2 // guard page around each mimalloc page (can fragment VMA's with large heaps..)
// #define MI_SECURE 3 // encode free lists (detect corrupted free list (buffer overflow), and invalid pointer free) //
// #define MI_SECURE 4 // checks for double free. (may be more expensive) // The next two levels can have more performance cost:
// #define MI_SECURE 3 // randomize allocations, encode free lists (detect corrupted free list (buffer overflow), and invalid pointer free)
// #define MI_SECURE 4 // checks for double free. (may be more expensive)
#if !defined(MI_SECURE) #if !defined(MI_SECURE)
#define MI_SECURE 0 #define MI_SECURE 0

View file

@ -25,6 +25,12 @@ terms of the MIT license. A copy of the license can be found in the file
#define MI_META_PAGE_SIZE MI_ARENA_SLICE_SIZE #define MI_META_PAGE_SIZE MI_ARENA_SLICE_SIZE
#define MI_META_PAGE_ALIGN MI_ARENA_SLICE_ALIGN #define MI_META_PAGE_ALIGN MI_ARENA_SLICE_ALIGN
#if MI_SECURE
#define MI_META_PAGE_GUARD_SIZE (4*MI_KiB)
#else
#define MI_META_PAGE_GUARD_SIZE (0)
#endif
#define MI_META_BLOCK_SIZE (128) // large enough such that META_MAX_SIZE > 4k (even on 32-bit) #define MI_META_BLOCK_SIZE (128) // large enough such that META_MAX_SIZE > 4k (even on 32-bit)
#define MI_META_BLOCK_ALIGN MI_META_BLOCK_SIZE #define MI_META_BLOCK_ALIGN MI_META_BLOCK_SIZE
#define MI_META_BLOCKS_PER_PAGE (MI_ARENA_SLICE_SIZE / MI_META_BLOCK_SIZE) // 1024 #define MI_META_BLOCKS_PER_PAGE (MI_ARENA_SLICE_SIZE / MI_META_BLOCK_SIZE) // 1024
@ -41,7 +47,7 @@ static mi_decl_cache_align _Atomic(mi_meta_page_t*) mi_meta_pages = MI_ATOMIC_V
#if MI_DEBUG > 1 #if MI_DEBUG > 1
static mi_meta_page_t* mi_meta_page_of_ptr(void* p, size_t* block_idx) { static mi_meta_page_t* mi_meta_page_of_ptr(void* p, size_t* block_idx) {
mi_meta_page_t* mpage = (mi_meta_page_t*)mi_align_down_ptr(p,MI_META_PAGE_ALIGN); mi_meta_page_t* mpage = (mi_meta_page_t*)((uint8_t*)mi_align_down_ptr(p,MI_META_PAGE_ALIGN) + MI_META_PAGE_GUARD_SIZE);
if (block_idx != NULL) { if (block_idx != NULL) {
*block_idx = ((uint8_t*)p - (uint8_t*)mpage) / MI_META_BLOCK_SIZE; *block_idx = ((uint8_t*)p - (uint8_t*)mpage) / MI_META_BLOCK_SIZE;
} }
@ -54,9 +60,9 @@ static mi_meta_page_t* mi_meta_page_next( mi_meta_page_t* mpage ) {
} }
static void* mi_meta_block_start( mi_meta_page_t* mpage, size_t block_idx ) { static void* mi_meta_block_start( mi_meta_page_t* mpage, size_t block_idx ) {
mi_assert_internal(_mi_is_aligned(mpage,MI_META_PAGE_ALIGN)); mi_assert_internal(_mi_is_aligned((uint8_t*)mpage - MI_META_PAGE_GUARD_SIZE, MI_META_PAGE_ALIGN));
mi_assert_internal(block_idx < MI_META_BLOCKS_PER_PAGE); mi_assert_internal(block_idx < MI_META_BLOCKS_PER_PAGE);
void* p = ((uint8_t*)mpage + (block_idx * MI_META_BLOCK_SIZE)); void* p = ((uint8_t*)mpage - MI_META_PAGE_GUARD_SIZE + (block_idx * MI_META_BLOCK_SIZE));
mi_assert_internal(mpage == mi_meta_page_of_ptr(p,NULL)); mi_assert_internal(mpage == mi_meta_page_of_ptr(p,NULL));
return p; return p;
} }
@ -66,22 +72,32 @@ static mi_meta_page_t* mi_meta_page_zalloc(void) {
// allocate a fresh arena slice // allocate a fresh arena slice
// note: careful with _mi_subproc as it may recurse into mi_tld and meta_page_zalloc again.. // note: careful with _mi_subproc as it may recurse into mi_tld and meta_page_zalloc again..
mi_memid_t memid; mi_memid_t memid;
mi_meta_page_t* mpage = (mi_meta_page_t*)_mi_arena_alloc_aligned(_mi_subproc(), MI_ARENA_SLICE_SIZE, MI_ARENA_SLICE_ALIGN, 0, uint8_t* base = (uint8_t*)_mi_arena_alloc_aligned(_mi_subproc(), MI_META_PAGE_SIZE, MI_META_PAGE_ALIGN, 0,
true /* commit*/, true /* allow large */, true /* commit*/, (MI_SECURE==0) /* allow large? */,
NULL /* req arena */, 0 /* thread_seq */, &memid); NULL /* req arena */, 0 /* thread_seq */, &memid);
if (mpage == NULL) return NULL; if (base == NULL) return NULL;
mi_assert_internal(_mi_is_aligned(mpage,MI_META_PAGE_ALIGN)); mi_assert_internal(_mi_is_aligned(base,MI_META_PAGE_ALIGN));
if (!memid.initially_zero) { if (!memid.initially_zero) {
_mi_memzero_aligned(mpage, MI_ARENA_SLICE_SIZE); _mi_memzero_aligned(base, MI_ARENA_SLICE_SIZE);
} }
// initialize the page // guard pages
#if MI_SECURE
if (!memid.is_pinned) {
_mi_os_decommit(base, MI_META_PAGE_GUARD_SIZE);
_mi_os_decommit(base + MI_META_PAGE_SIZE - MI_META_PAGE_GUARD_SIZE, MI_META_PAGE_GUARD_SIZE);
}
#endif
// initialize the page and free block bitmap
mi_meta_page_t* mpage = (mi_meta_page_t*)(base + MI_META_PAGE_GUARD_SIZE);
mpage->memid = memid; mpage->memid = memid;
mi_bitmap_init(&mpage->blocks_free, MI_META_BLOCKS_PER_PAGE, true /* already_zero */); mi_bitmap_init(&mpage->blocks_free, MI_META_BLOCKS_PER_PAGE, true /* already_zero */);
const size_t mpage_size = offsetof(mi_meta_page_t,blocks_free) + mi_bitmap_size(MI_META_BLOCKS_PER_PAGE, NULL); const size_t mpage_size = offsetof(mi_meta_page_t,blocks_free) + mi_bitmap_size(MI_META_BLOCKS_PER_PAGE, NULL);
const size_t info_blocks = _mi_divide_up(mpage_size,MI_META_BLOCK_SIZE); const size_t info_blocks = _mi_divide_up(mpage_size,MI_META_BLOCK_SIZE);
mi_assert_internal(info_blocks < MI_META_BLOCKS_PER_PAGE); const size_t guard_blocks = _mi_divide_up(MI_META_PAGE_GUARD_SIZE, MI_META_BLOCK_SIZE);
mi_bitmap_unsafe_setN(&mpage->blocks_free, info_blocks, MI_META_BLOCKS_PER_PAGE - info_blocks); mi_assert_internal(info_blocks + 2*guard_blocks < MI_META_BLOCKS_PER_PAGE);
mi_bitmap_unsafe_setN(&mpage->blocks_free, info_blocks + guard_blocks, MI_META_BLOCKS_PER_PAGE - info_blocks - 2*guard_blocks);
// push atomically in front of the meta page list // push atomically in front of the meta page list
// (note: there is no ABA issue since we never free meta-pages) // (note: there is no ABA issue since we never free meta-pages)

View file

@ -577,10 +577,16 @@ static mi_page_t* mi_arena_page_try_find_abandoned(mi_subproc_t* subproc, size_t
return NULL; return NULL;
} }
#if MI_SECURE < 2
#define MI_ARENA_GUARD_PAGE_SIZE (0)
#else
#define MI_ARENA_GUARD_PAGE_SIZE (4*MI_KiB)
#endif
static mi_page_t* mi_arena_page_alloc_fresh(mi_subproc_t* subproc, size_t slice_count, size_t block_size, size_t block_alignment, static mi_page_t* mi_arena_page_alloc_fresh(mi_subproc_t* subproc, size_t slice_count, size_t block_size, size_t block_alignment,
mi_arena_t* req_arena, size_t tseq) mi_arena_t* req_arena, size_t tseq)
{ {
const bool allow_large = true; const bool allow_large = (MI_SECURE < 2); // 2 = guard page at end of each arena page
const bool commit = true; const bool commit = true;
const bool os_align = (block_alignment > MI_PAGE_MAX_OVERALLOC_ALIGN); const bool os_align = (block_alignment > MI_PAGE_MAX_OVERALLOC_ALIGN);
const size_t page_alignment = MI_ARENA_SLICE_ALIGN; const size_t page_alignment = MI_ARENA_SLICE_ALIGN;
@ -615,6 +621,14 @@ static mi_page_t* mi_arena_page_alloc_fresh(mi_subproc_t* subproc, size_t slice_
mi_assert_internal(_mi_is_aligned(page, MI_PAGE_ALIGN)); mi_assert_internal(_mi_is_aligned(page, MI_PAGE_ALIGN));
mi_assert_internal(!os_align || _mi_is_aligned((uint8_t*)page + page_alignment, block_alignment)); mi_assert_internal(!os_align || _mi_is_aligned((uint8_t*)page + page_alignment, block_alignment));
// guard page at the end
const size_t page_body_size = mi_size_of_slices(slice_count) - MI_ARENA_GUARD_PAGE_SIZE;
#if MI_SECURE >= 2
if (memid.initially_committed && !memid.is_pinned) {
_mi_os_decommit((uint8_t*)page + page_body_size, MI_ARENA_GUARD_PAGE_SIZE);
}
#endif
// claimed free slices: initialize the page partly // claimed free slices: initialize the page partly
if (!memid.initially_zero) { if (!memid.initially_zero) {
mi_track_mem_undefined(page, slice_count * MI_ARENA_SLICE_SIZE); mi_track_mem_undefined(page, slice_count * MI_ARENA_SLICE_SIZE);
@ -625,7 +639,7 @@ static mi_page_t* mi_arena_page_alloc_fresh(mi_subproc_t* subproc, size_t slice_
} }
#if MI_DEBUG > 1 #if MI_DEBUG > 1
if (memid.initially_zero) { if (memid.initially_zero) {
if (!mi_mem_is_zero(page, mi_size_of_slices(slice_count))) { if (!mi_mem_is_zero(page, page_body_size)) {
_mi_error_message(EFAULT, "internal error: page memory was not zero initialized.\n"); _mi_error_message(EFAULT, "internal error: page memory was not zero initialized.\n");
memid.initially_zero = false; memid.initially_zero = false;
_mi_memzero_aligned(page, sizeof(*page)); _mi_memzero_aligned(page, sizeof(*page));
@ -655,7 +669,7 @@ static mi_page_t* mi_arena_page_alloc_fresh(mi_subproc_t* subproc, size_t slice_
// otherwise start after the info // otherwise start after the info
block_start = mi_page_info_size(); block_start = mi_page_info_size();
} }
const size_t reserved = (os_align ? 1 : (mi_size_of_slices(slice_count) - block_start) / block_size); const size_t reserved = (os_align ? 1 : (page_body_size - block_start) / block_size);
mi_assert_internal(reserved > 0 && reserved <= UINT16_MAX); mi_assert_internal(reserved > 0 && reserved <= UINT16_MAX);
page->reserved = (uint16_t)reserved; page->reserved = (uint16_t)reserved;
page->page_start = (uint8_t*)page + block_start; page->page_start = (uint8_t*)page + block_start;
@ -708,7 +722,7 @@ static mi_page_t* mi_singleton_page_alloc(mi_heap_t* heap, size_t block_size, si
mi_tld_t* const tld = heap->tld; mi_tld_t* const tld = heap->tld;
const bool os_align = (block_alignment > MI_PAGE_MAX_OVERALLOC_ALIGN); const bool os_align = (block_alignment > MI_PAGE_MAX_OVERALLOC_ALIGN);
const size_t info_size = (os_align ? MI_PAGE_ALIGN : mi_page_info_size()); const size_t info_size = (os_align ? MI_PAGE_ALIGN : mi_page_info_size());
const size_t slice_count = mi_slice_count_of_size(info_size + block_size); const size_t slice_count = mi_slice_count_of_size(info_size + block_size + MI_ARENA_GUARD_PAGE_SIZE);
mi_page_t* page = mi_arena_page_alloc_fresh(tld->subproc, slice_count, block_size, block_alignment, req_arena, tld->thread_seq); mi_page_t* page = mi_arena_page_alloc_fresh(tld->subproc, slice_count, block_size, block_alignment, req_arena, tld->thread_seq);
if (page == NULL) return NULL; if (page == NULL) return NULL;
@ -717,6 +731,7 @@ static mi_page_t* mi_singleton_page_alloc(mi_heap_t* heap, size_t block_size, si
mi_assert(page->reserved == 1); mi_assert(page->reserved == 1);
mi_assert_internal(_mi_ptr_page(page)==page); mi_assert_internal(_mi_ptr_page(page)==page);
mi_assert_internal(_mi_ptr_page(mi_page_start(page))==page); mi_assert_internal(_mi_ptr_page(mi_page_start(page))==page);
_mi_page_init(heap, page);
return page; return page;
} }
@ -774,6 +789,13 @@ void _mi_arena_page_free(mi_page_t* page) {
} }
#endif #endif
// recommit guard page at the end?
#if MI_SECURE >= 2
if (!page->memid.is_pinned) {
_mi_os_commit((uint8_t*)page + mi_memid_size(page->memid) - MI_ARENA_GUARD_PAGE_SIZE, MI_ARENA_GUARD_PAGE_SIZE, NULL);
}
#endif
// unregister page // unregister page
_mi_page_map_unregister(page); _mi_page_map_unregister(page);
if (page->memid.memkind == MI_MEM_ARENA) { if (page->memid.memkind == MI_MEM_ARENA) {
@ -1114,12 +1136,17 @@ static bool mi_manage_os_memory_ex2(mi_subproc_t* subproc, void* start, size_t s
mi_arena_t* arena = (mi_arena_t*)start; mi_arena_t* arena = (mi_arena_t*)start;
// commit & zero if needed // commit & zero if needed
bool is_zero = memid.initially_zero; const size_t os_page_size = _mi_os_page_size();
if (!memid.initially_committed) { if (!memid.initially_committed) {
_mi_os_commit(arena, mi_size_of_slices(info_slices), NULL); // security: always leave a guard OS page decommitted at the end (already part of info_slices)
_mi_os_commit(arena, mi_size_of_slices(info_slices) - os_page_size, NULL);
} }
if (!is_zero) { else if (!memid.is_pinned) {
_mi_memzero(arena, mi_size_of_slices(info_slices)); // security: decommit a guard OS page at the end of the arena info
_mi_os_decommit((uint8_t*)arena + mi_size_of_slices(info_slices) - os_page_size, os_page_size);
}
if (!memid.initially_zero) {
_mi_memzero(arena, mi_size_of_slices(info_slices) - os_page_size);
} }
// init // init

View file

@ -536,8 +536,8 @@ static uint8_t* mi_os_claim_huge_pages(size_t pages, size_t* total_size) {
start = huge_start; start = huge_start;
if (start == 0) { if (start == 0) {
// Initialize the start address after the 32TiB area // Initialize the start address after the 32TiB area
start = ((uintptr_t)32 << 40); // 32TiB virtual start address start = ((uintptr_t)8 << 40); // 8TiB virtual start address
#if (MI_SECURE>0 || MI_DEBUG==0) // security: randomize start of huge pages unless in debug mode #if (MI_SECURE>0 || MI_DEBUG==0) // security: randomize start of huge pages unless in debug mode
uintptr_t r = _mi_heap_random_next(mi_prim_get_default_heap()); uintptr_t r = _mi_heap_random_next(mi_prim_get_default_heap());
start = start + ((uintptr_t)MI_HUGE_OS_PAGE_SIZE * ((r>>17) & 0x0FFF)); // (randomly 12bits)*1GiB == between 0 to 4TiB start = start + ((uintptr_t)MI_HUGE_OS_PAGE_SIZE * ((r>>17) & 0x0FFF)); // (randomly 12bits)*1GiB == between 0 to 4TiB
#endif #endif

View file

@ -82,7 +82,7 @@ static bool mi_page_is_valid_init(mi_page_t* page) {
mi_assert_internal(mi_page_block_size(page) > 0); mi_assert_internal(mi_page_block_size(page) > 0);
mi_assert_internal(page->used <= page->capacity); mi_assert_internal(page->used <= page->capacity);
mi_assert_internal(page->capacity <= page->reserved); mi_assert_internal(page->capacity <= page->reserved);
// const size_t bsize = mi_page_block_size(page); // const size_t bsize = mi_page_block_size(page);
// uint8_t* start = mi_page_start(page); // uint8_t* start = mi_page_start(page);
//mi_assert_internal(start + page->capacity*page->block_size == page->top); //mi_assert_internal(start + page->capacity*page->block_size == page->top);
@ -475,7 +475,7 @@ static mi_decl_noinline void mi_heap_generic_collect(mi_heap_t* heap) {
static void mi_page_free_list_extend_secure(mi_heap_t* const heap, mi_page_t* const page, const size_t bsize, const size_t extend, mi_stats_t* const stats) { static void mi_page_free_list_extend_secure(mi_heap_t* const heap, mi_page_t* const page, const size_t bsize, const size_t extend, mi_stats_t* const stats) {
MI_UNUSED(stats); MI_UNUSED(stats);
#if (MI_SECURE<=2) #if (MI_SECURE<3)
mi_assert_internal(page->free == NULL); mi_assert_internal(page->free == NULL);
mi_assert_internal(page->local_free == NULL); mi_assert_internal(page->local_free == NULL);
#endif #endif
@ -533,7 +533,7 @@ static void mi_page_free_list_extend_secure(mi_heap_t* const heap, mi_page_t* co
static mi_decl_noinline void mi_page_free_list_extend( mi_page_t* const page, const size_t bsize, const size_t extend, mi_stats_t* const stats) static mi_decl_noinline void mi_page_free_list_extend( mi_page_t* const page, const size_t bsize, const size_t extend, mi_stats_t* const stats)
{ {
MI_UNUSED(stats); MI_UNUSED(stats);
#if (MI_SECURE <= 2) #if (MI_SECURE<3)
mi_assert_internal(page->free == NULL); mi_assert_internal(page->free == NULL);
mi_assert_internal(page->local_free == NULL); mi_assert_internal(page->local_free == NULL);
#endif #endif
@ -561,7 +561,7 @@ static mi_decl_noinline void mi_page_free_list_extend( mi_page_t* const page, co
----------------------------------------------------------- */ ----------------------------------------------------------- */
#define MI_MAX_EXTEND_SIZE (4*1024) // heuristic, one OS page seems to work well. #define MI_MAX_EXTEND_SIZE (4*1024) // heuristic, one OS page seems to work well.
#if (MI_SECURE>0) #if (MI_SECURE>=3)
#define MI_MIN_EXTEND (8*MI_SECURE) // extend at least by this many #define MI_MIN_EXTEND (8*MI_SECURE) // extend at least by this many
#else #else
#define MI_MIN_EXTEND (1) #define MI_MIN_EXTEND (1)
@ -574,7 +574,7 @@ static mi_decl_noinline void mi_page_free_list_extend( mi_page_t* const page, co
// extra test in malloc? or cache effects?) // extra test in malloc? or cache effects?)
static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page) { static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page) {
mi_assert_expensive(mi_page_is_valid_init(page)); mi_assert_expensive(mi_page_is_valid_init(page));
#if (MI_SECURE<=2) #if (MI_SECURE<3)
mi_assert(page->free == NULL); mi_assert(page->free == NULL);
mi_assert(page->local_free == NULL); mi_assert(page->local_free == NULL);
if (page->free != NULL) return; if (page->free != NULL) return;
@ -605,7 +605,7 @@ static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page) {
mi_assert_internal(extend < (1UL<<16)); mi_assert_internal(extend < (1UL<<16));
// and append the extend the free list // and append the extend the free list
if (extend < MI_MIN_SLICES || MI_SECURE==0) { //!mi_option_is_enabled(mi_option_secure)) { if (extend < MI_MIN_SLICES || MI_SECURE<3) { //!mi_option_is_enabled(mi_option_secure)) {
mi_page_free_list_extend(page, bsize, extend, &heap->tld->stats ); mi_page_free_list_extend(page, bsize, extend, &heap->tld->stats );
} }
else { else {
@ -621,7 +621,7 @@ static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page) {
void _mi_page_init(mi_heap_t* heap, mi_page_t* page) { void _mi_page_init(mi_heap_t* heap, mi_page_t* page) {
mi_assert(page != NULL); mi_assert(page != NULL);
mi_page_set_heap(page, heap); mi_page_set_heap(page, heap);
size_t page_size; size_t page_size;
uint8_t* page_start = mi_page_area(page, &page_size); MI_UNUSED(page_start); uint8_t* page_start = mi_page_area(page, &page_size); MI_UNUSED(page_start);
mi_track_mem_noaccess(page_start,page_size); mi_track_mem_noaccess(page_start,page_size);
@ -653,7 +653,7 @@ void _mi_page_init(mi_heap_t* heap, mi_page_t* page) {
#endif #endif
mi_assert_internal(page->block_size_shift == 0 || (mi_page_block_size(page) == ((size_t)1 << page->block_size_shift))); mi_assert_internal(page->block_size_shift == 0 || (mi_page_block_size(page) == ((size_t)1 << page->block_size_shift)));
mi_assert_expensive(mi_page_is_valid_init(page)); mi_assert_expensive(mi_page_is_valid_init(page));
// initialize an initial free list // initialize an initial free list
mi_page_extend_free(heap,page); mi_page_extend_free(heap,page);
mi_assert(mi_page_immediate_available(page)); mi_assert(mi_page_immediate_available(page));
@ -740,7 +740,7 @@ static mi_decl_noinline mi_page_t* mi_page_queue_find_free_ex(mi_heap_t* heap, m
} // for each page } // for each page
mi_debug_heap_stat_counter_increase(heap, searches, count); mi_debug_heap_stat_counter_increase(heap, searches, count);
// set the page to the best candidate // set the page to the best candidate
if (page_candidate != NULL) { if (page_candidate != NULL) {
page = page_candidate; page = page_candidate;

View file

@ -412,7 +412,7 @@ int _mi_prim_decommit(void* start, size_t size, bool* needs_recommit) {
int err = 0; int err = 0;
// decommit: use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE) // decommit: use MADV_DONTNEED as it decreases rss immediately (unlike MADV_FREE)
err = unix_madvise(start, size, MADV_DONTNEED); err = unix_madvise(start, size, MADV_DONTNEED);
#if !MI_DEBUG && !MI_SECURE #if !MI_DEBUG && MI_SECURE<=2
*needs_recommit = false; *needs_recommit = false;
#else #else
*needs_recommit = true; *needs_recommit = true;