63 lines · cpp
1//===-- memprof_shadow_setup.cpp -----------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of MemProfiler, a memory profiler.10//11// Set up the shadow memory.12//===----------------------------------------------------------------------===//13 14#include "sanitizer_common/sanitizer_platform.h"15 16#include "memprof_internal.h"17#include "memprof_mapping.h"18 19namespace __memprof {20 21static void ProtectGap(uptr addr, uptr size) {22 if (!flags()->protect_shadow_gap) {23 // The shadow gap is unprotected, so there is a chance that someone24 // is actually using this memory. Which means it needs a shadow...25 uptr GapShadowBeg = RoundDownTo(MEM_TO_SHADOW(addr), GetPageSizeCached());26 uptr GapShadowEnd =27 RoundUpTo(MEM_TO_SHADOW(addr + size), GetPageSizeCached()) - 1;28 if (Verbosity())29 Printf("protect_shadow_gap=0:"30 " not protecting shadow gap, allocating gap's shadow\n"31 "|| `[%p, %p]` || ShadowGap's shadow ||\n",32 (void *)GapShadowBeg, (void *)GapShadowEnd);33 ReserveShadowMemoryRange(GapShadowBeg, GapShadowEnd,34 "unprotected gap shadow");35 return;36 }37 __sanitizer::ProtectGap(addr, size, kZeroBaseShadowStart,38 kZeroBaseMaxShadowStart);39}40 41void InitializeShadowMemory() {42 uptr shadow_start = FindDynamicShadowStart();43 // Update the shadow memory address (potentially) used by instrumentation.44 __memprof_shadow_memory_dynamic_address = shadow_start;45 46 if (kLowShadowBeg)47 shadow_start -= GetMmapGranularity();48 49 if (Verbosity())50 PrintAddressSpaceLayout();51 52 // mmap the low shadow plus at least one page at the left.53 if (kLowShadowBeg)54 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");55 // mmap the high shadow.56 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");57 // protect the gap.58 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);59 CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);60}61 62} // namespace __memprof63