mem: детект аномально больших аллокаций (LARGE ALLOC log + calloc overflow guard)

lib/mem.c

@@ -18,6 +18,9 @@
 #define PREV_OFFSET LOCATION_MAX
 #define NEXT_OFFSET (LOCATION_MAX + POINTER_SIZE)
 
+// Порог детекта аномально больших аллокаций (гигантские mmap-резервации, напр. VSZ ~4G)
+#define LARGE_ALLOC_LOG_THRESHOLD (8u * 1024u * 1024u)  // 8 МБ
+
 #if defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__)
 #include <execinfo.h>
 #include <pthread.h>
@@ -121,6 +124,10 @@ void u_check(void* ptr, const char* text, const char* location) {
 }
 
 void* u_malloc_impl(uint32_t size, const char* location) {
+    if (size >= LARGE_ALLOC_LOG_THRESHOLD) {
+        DEBUG_WARN(DEBUG_CATEGORY_SYS, "LARGE ALLOC: %u bytes (%.1f MB) at %s",
+                   size, (double)size / (1024.0 * 1024.0), location);
+    }
     uint32_t total = size + 12 + 2 * BOUNDARY_CHECK_SIZE + METADATA_SIZE;
     uint8_t* base = (uint8_t*)malloc(total);
     if (!base && size > 0) return NULL;
@@ -151,6 +158,10 @@ void* u_malloc_impl(uint32_t size, const char* location) {
 }
 
 void* u_calloc_impl(uint32_t nmemb, uint32_t size, const char* location) {
+    if (nmemb != 0 && size > UINT32_MAX / nmemb) {
+        DEBUG_ERROR(DEBUG_CATEGORY_SYS, "CALLOC OVERFLOW: %u * %u (wraps uint32) at %s", nmemb, size, location);
+        return NULL;
+    }
     uint32_t total_size = nmemb * size;
     void* ptr = u_malloc_impl(total_size, location);
     if (ptr) memset(ptr, 0, total_size);