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//===-- memprof_shadow_setup.cpp -----------------------------------------===//
//
// 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 MemProfiler, a memory profiler.
//
// Set up the shadow memory.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_platform.h"
#include "memprof_internal.h"
#include "memprof_mapping.h"
namespace __memprof {
static void ProtectGap(uptr addr, uptr size) {
if (!flags()->protect_shadow_gap) {
// The shadow gap is unprotected, so there is a chance that someone
// is actually using this memory. Which means it needs a shadow...
uptr GapShadowBeg = RoundDownTo(MEM_TO_SHADOW(addr), GetPageSizeCached());
uptr GapShadowEnd =
RoundUpTo(MEM_TO_SHADOW(addr + size), GetPageSizeCached()) - 1;
if (Verbosity())
Printf("protect_shadow_gap=0:"
" not protecting shadow gap, allocating gap's shadow\n"
"|| `[%p, %p]` || ShadowGap's shadow ||\n",
GapShadowBeg, GapShadowEnd);
ReserveShadowMemoryRange(GapShadowBeg, GapShadowEnd,
"unprotected gap shadow");
return;
}
__sanitizer::ProtectGap(addr, size, kZeroBaseShadowStart,
kZeroBaseMaxShadowStart);
}
void InitializeShadowMemory() {
uptr shadow_start = FindDynamicShadowStart();
// Update the shadow memory address (potentially) used by instrumentation.
__memprof_shadow_memory_dynamic_address = shadow_start;
if (kLowShadowBeg)
shadow_start -= GetMmapGranularity();
if (Verbosity())
PrintAddressSpaceLayout();
// mmap the low shadow plus at least one page at the left.
if (kLowShadowBeg)
ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
// mmap the high shadow.
ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
// protect the gap.
ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
}
} // namespace __memprof
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