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[asan] Refactor shadow memory initialization out of AsanInitInternal [NFC] 

Differential Revision: https://reviews.llvm.org/D27137

llvm-svn: 288072
This commit is contained in:
Kuba Mracek 2016-11-28 21:40:41 +00:00
parent 3ab3fef2f1
commit 87b3634615
1 changed files with 74 additions and 70 deletions
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144
compiler-rt/lib/asan/asan_rtl.cc
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@ -423,6 +423,79 @@ static void PrintAddressSpaceLayout() {
kHighShadowBeg > kMidMemEnd);
}
static void InitializeShadowMemory() {
// Set the shadow memory address to uninitialized.
__asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
uptr shadow_start = kLowShadowBeg;
// Detect if a dynamic shadow address must used and find a available location
// when necessary. When dynamic address is used, the macro |kLowShadowBeg|
// expands to |__asan_shadow_memory_dynamic_address| which is
// |kDefaultShadowSentinel|.
if (shadow_start == kDefaultShadowSentinel) {
__asan_shadow_memory_dynamic_address = 0;
CHECK_EQ(0, kLowShadowBeg);
uptr granularity = GetMmapGranularity();
uptr alignment = 8 * granularity;
uptr left_padding = granularity;
uptr space_size = kHighShadowEnd + left_padding;
shadow_start = FindAvailableMemoryRange(space_size, alignment, granularity);
CHECK_NE((uptr)0, shadow_start);
CHECK(IsAligned(shadow_start, alignment));
}
// Update the shadow memory address (potentially) used by instrumentation.
__asan_shadow_memory_dynamic_address = shadow_start;
if (kLowShadowBeg)
shadow_start -= GetMmapGranularity();
bool full_shadow_is_available =
MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
#if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) && \
!ASAN_FIXED_MAPPING
if (!full_shadow_is_available) {
kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
}
#endif
if (Verbosity()) PrintAddressSpaceLayout();
if (full_shadow_is_available) {
// 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);
} else if (kMidMemBeg &&
MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
CHECK(kLowShadowBeg != kLowShadowEnd);
// mmap the low shadow plus at least one page at the left.
ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
// mmap the mid shadow.
ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
// mmap the high shadow.
ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
// protect the gaps.
ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
} else {
Report("Shadow memory range interleaves with an existing memory mapping. "
"ASan cannot proceed correctly. ABORTING.\n");
Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
shadow_start, kHighShadowEnd);
DumpProcessMap();
Die();
}
}
static void AsanInitInternal() {
if (LIKELY(asan_inited)) return;
SanitizerToolName = "AddressSanitizer";
@ -474,78 +547,9 @@ static void AsanInitInternal() {
ReplaceSystemMalloc();
// Set the shadow memory address to uninitialized.
__asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
uptr shadow_start = kLowShadowBeg;
// Detect if a dynamic shadow address must used and find a available location
// when necessary. When dynamic address is used, the macro |kLowShadowBeg|
// expands to |__asan_shadow_memory_dynamic_address| which is
// |kDefaultShadowSentinel|.
if (shadow_start == kDefaultShadowSentinel) {
__asan_shadow_memory_dynamic_address = 0;
CHECK_EQ(0, kLowShadowBeg);
uptr granularity = GetMmapGranularity();
uptr alignment = 8 * granularity;
uptr left_padding = granularity;
uptr space_size = kHighShadowEnd + left_padding;
shadow_start = FindAvailableMemoryRange(space_size, alignment, granularity);
CHECK_NE((uptr)0, shadow_start);
CHECK(IsAligned(shadow_start, alignment));
}
// Update the shadow memory address (potentially) used by instrumentation.
__asan_shadow_memory_dynamic_address = shadow_start;
if (kLowShadowBeg)
shadow_start -= GetMmapGranularity();
bool full_shadow_is_available =
MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
#if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) && \
!ASAN_FIXED_MAPPING
if (!full_shadow_is_available) {
kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
}
#endif
if (Verbosity()) PrintAddressSpaceLayout();
DisableCoreDumperIfNecessary();
if (full_shadow_is_available) {
// 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);
} else if (kMidMemBeg &&
MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
CHECK(kLowShadowBeg != kLowShadowEnd);
// mmap the low shadow plus at least one page at the left.
ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
// mmap the mid shadow.
ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
// mmap the high shadow.
ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
// protect the gaps.
ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
} else {
Report("Shadow memory range interleaves with an existing memory mapping. "
"ASan cannot proceed correctly. ABORTING.\n");
Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
shadow_start, kHighShadowEnd);
DumpProcessMap();
Die();
}
InitializeShadowMemory();
AsanTSDInit(PlatformTSDDtor);
InstallDeadlySignalHandlers(AsanOnDeadlySignal);