check all os_commit calls and return NULL on failure

Author: daanx

include/mimalloc/internal.h

@@ -126,13 +126,13 @@ bool        _mi_os_has_overcommit(void);
 bool        _mi_os_has_virtual_reserve(void);
 
 bool        _mi_os_reset(void* addr, size_t size);
-bool        _mi_os_commit(void* p, size_t size, bool* is_zero);
-bool        _mi_os_commit_ex(void* addr, size_t size, bool* is_zero, size_t stat_size);
 bool        _mi_os_decommit(void* addr, size_t size);
-bool        _mi_os_protect(void* addr, size_t size);
 bool        _mi_os_unprotect(void* addr, size_t size);
 bool        _mi_os_purge(void* p, size_t size);
 bool        _mi_os_purge_ex(void* p, size_t size, bool allow_reset, size_t stat_size);
+mi_decl_nodiscard bool _mi_os_commit(void* p, size_t size, bool* is_zero);
+mi_decl_nodiscard bool _mi_os_commit_ex(void* addr, size_t size, bool* is_zero, size_t stat_size);
+mi_decl_nodiscard bool _mi_os_protect(void* addr, size_t size);
 
 void*       _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid);
 void*       _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_memid_t* memid);

src/os.c

@@ -300,7 +300,10 @@ static void* mi_os_prim_alloc_aligned(size_t size, size_t alignment, bool commit
 
       // explicitly commit only the aligned part
       if (commit) {
-        _mi_os_commit(p, size, NULL);
+        if (!_mi_os_commit(p, size, NULL)) {
+          mi_os_prim_free(p, over_size, 0);
+          return NULL;
+        }
       }
     }
     else  { // mmap can free inside an allocation

src/page.c

@@ -37,7 +37,7 @@ static inline mi_block_t* mi_page_block_at(const mi_page_t* page, void* page_sta
 }
 
 static void mi_page_init(mi_heap_t* heap, mi_page_t* page, size_t size, mi_tld_t* tld);
-static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page, mi_tld_t* tld);
+static bool mi_page_extend_free(mi_heap_t* heap, mi_page_t* page, mi_tld_t* tld);
 
 #if (MI_DEBUG>=3)
 static size_t mi_page_list_count(mi_page_t* page, mi_block_t* head) {
@@ -630,14 +630,14 @@ static mi_decl_noinline void mi_page_free_list_extend( mi_page_t* const page, co
 // Note: we also experimented with "bump" allocation on the first
 // allocations but this did not speed up any benchmark (due to an
 // extra test in malloc? or cache effects?)
-static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page, mi_tld_t* tld) {
+static bool mi_page_extend_free(mi_heap_t* heap, mi_page_t* page, mi_tld_t* tld) {
   mi_assert_expensive(mi_page_is_valid_init(page));
   #if (MI_SECURE<=2)
   mi_assert(page->free == NULL);
   mi_assert(page->local_free == NULL);
-  if (page->free != NULL) return;
+  if (page->free != NULL) return true;
   #endif
-  if (page->capacity >= page->reserved) return;
+  if (page->capacity >= page->reserved) return true;
 
   size_t page_size;
   //uint8_t* page_start =
@@ -673,6 +673,7 @@ static void mi_page_extend_free(mi_heap_t* heap, mi_page_t* page, mi_tld_t* tld)
   page->capacity += (uint16_t)extend;
   mi_stat_increase(tld->stats.page_committed, extend * bsize);
   mi_assert_expensive(mi_page_is_valid_init(page));
+  return true;
 }
 
 // Initialize a fresh page
@@ -724,8 +725,10 @@ static void mi_page_init(mi_heap_t* heap, mi_page_t* page, size_t block_size, mi
   mi_assert_expensive(mi_page_is_valid_init(page));
 
   // initialize an initial free list
-  mi_page_extend_free(heap,page,tld);
-  mi_assert(mi_page_immediate_available(page));
+  if (mi_page_extend_free(heap,page,tld)) {
+    mi_assert(mi_page_immediate_available(page));
+  }
+  return;
 }
 
 
@@ -817,9 +820,14 @@ static mi_page_t* mi_page_queue_find_free_ex(mi_heap_t* heap, mi_page_queue_t* p
   if (page_candidate != NULL) {
     page = page_candidate;
   }
-  if (page != NULL && !mi_page_immediate_available(page)) {
-    mi_assert_internal(mi_page_is_expandable(page));
-    mi_page_extend_free(heap, page, heap->tld);
+  if (page != NULL) {
+    if (!mi_page_immediate_available(page)) {
+      mi_assert_internal(mi_page_is_expandable(page));
+      if (!mi_page_extend_free(heap, page, heap->tld)) {
+        page = NULL; // failed to extend
+      }
+    }
+    mi_assert_internal(page == NULL || mi_page_immediate_available(page));
   }
 
   if (page == NULL) {

src/segment.c

@@ -182,7 +182,9 @@ static bool mi_page_not_in_queue(const mi_page_t* page, mi_segments_tld_t* tld)
 
 static void mi_segment_protect_range(void* p, size_t size, bool protect) {
   if (protect) {
-    _mi_os_protect(p, size);
+    if (!_mi_os_protect(p, size)) {
+      _mi_error_message(EFAULT,"unable to protect segment memory at %p\n", p);
+    }
   }
   else {
     _mi_os_unprotect(p, size);