hwasan_malloc_bisect.h
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//===-- hwasan_malloc_bisect.h ----------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of HWAddressSanitizer.
//
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_hash.h"
#include "hwasan.h"
namespace __hwasan {
static u32 malloc_hash(StackTrace *stack, uptr orig_size) {
uptr len = Min(stack->size, (unsigned)7);
MurMur2HashBuilder H(len);
H.add(orig_size);
// Start with frame #1 to skip __sanitizer_malloc frame, which is
// (a) almost always the same (well, could be operator new or new[])
// (b) can change hashes when compiler-rt is rebuilt, invalidating previous
// bisection results.
// Because of ASLR, use only offset inside the page.
for (uptr i = 1; i < len; ++i) H.add(((u32)stack->trace[i]) & 0xFFF);
return H.get();
}
static inline bool malloc_bisect(StackTrace *stack, uptr orig_size) {
uptr left = flags()->malloc_bisect_left;
uptr right = flags()->malloc_bisect_right;
if (LIKELY(left == 0 && right == 0))
return true;
if (!stack)
return true;
// Allow malloc_bisect_right > (u32)(-1) to avoid spelling the latter in
// decimal.
uptr h = (uptr)malloc_hash(stack, orig_size);
if (h < left || h > right)
return false;
if (flags()->malloc_bisect_dump) {
Printf("[alloc] %u %zu\n", h, orig_size);
stack->Print();
}
return true;
}
} // namespace __hwasan