1 //===-- hwasan_malloc_bisect.h ----------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of HWAddressSanitizer. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "sanitizer_common/sanitizer_hash.h" 14 #include "hwasan.h" 15 16 namespace __hwasan { 17 18 static u32 malloc_hash(StackTrace *stack, uptr orig_size) { 19 uptr len = Min(stack->size, (unsigned)7); 20 MurMur2HashBuilder H(len); 21 H.add(orig_size); 22 // Start with frame #1 to skip __sanitizer_malloc frame, which is 23 // (a) almost always the same (well, could be operator new or new[]) 24 // (b) can change hashes when compiler-rt is rebuilt, invalidating previous 25 // bisection results. 26 // Because of ASLR, use only offset inside the page. 27 for (uptr i = 1; i < len; ++i) H.add(((u32)stack->trace[i]) & 0xFFF); 28 return H.get(); 29 } 30 31 static inline bool malloc_bisect(StackTrace *stack, uptr orig_size) { 32 uptr left = flags()->malloc_bisect_left; 33 uptr right = flags()->malloc_bisect_right; 34 if (LIKELY(left == 0 && right == 0)) 35 return true; 36 if (!stack) 37 return true; 38 // Allow malloc_bisect_right > (u32)(-1) to avoid spelling the latter in 39 // decimal. 40 uptr h = (uptr)malloc_hash(stack, orig_size); 41 if (h < left || h > right) 42 return false; 43 if (flags()->malloc_bisect_dump) { 44 Printf("[alloc] %u %zu\n", h, orig_size); 45 stack->Print(); 46 } 47 return true; 48 } 49 50 } // namespace __hwasan 51