Retro68/gcc/libsanitizer/ubsan/ubsan_diag.cc
2017-10-07 02:16:47 +02:00

427 lines
14 KiB
C++

//===-- ubsan_diag.cc -----------------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Diagnostic reporting for the UBSan runtime.
//
//===----------------------------------------------------------------------===//
#include "ubsan_platform.h"
#if CAN_SANITIZE_UB
#include "ubsan_diag.h"
#include "ubsan_init.h"
#include "ubsan_flags.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "sanitizer_common/sanitizer_report_decorator.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "sanitizer_common/sanitizer_stacktrace_printer.h"
#include "sanitizer_common/sanitizer_suppressions.h"
#include "sanitizer_common/sanitizer_symbolizer.h"
#include <stdio.h>
using namespace __ubsan;
static void MaybePrintStackTrace(uptr pc, uptr bp) {
// We assume that flags are already parsed, as UBSan runtime
// will definitely be called when we print the first diagnostics message.
if (!flags()->print_stacktrace)
return;
// We can only use slow unwind, as we don't have any information about stack
// top/bottom.
// FIXME: It's better to respect "fast_unwind_on_fatal" runtime flag and
// fetch stack top/bottom information if we have it (e.g. if we're running
// under ASan).
if (StackTrace::WillUseFastUnwind(false))
return;
BufferedStackTrace stack;
stack.Unwind(kStackTraceMax, pc, bp, 0, 0, 0, false);
stack.Print();
}
static const char *ConvertTypeToString(ErrorType Type) {
switch (Type) {
#define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) \
case ErrorType::Name: \
return SummaryKind;
#include "ubsan_checks.inc"
#undef UBSAN_CHECK
}
UNREACHABLE("unknown ErrorType!");
}
static const char *ConvertTypeToFlagName(ErrorType Type) {
switch (Type) {
#define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) \
case ErrorType::Name: \
return FSanitizeFlagName;
#include "ubsan_checks.inc"
#undef UBSAN_CHECK
}
UNREACHABLE("unknown ErrorType!");
}
static void MaybeReportErrorSummary(Location Loc, ErrorType Type) {
if (!common_flags()->print_summary)
return;
if (!flags()->report_error_type)
Type = ErrorType::GenericUB;
const char *ErrorKind = ConvertTypeToString(Type);
if (Loc.isSourceLocation()) {
SourceLocation SLoc = Loc.getSourceLocation();
if (!SLoc.isInvalid()) {
AddressInfo AI;
AI.file = internal_strdup(SLoc.getFilename());
AI.line = SLoc.getLine();
AI.column = SLoc.getColumn();
AI.function = internal_strdup(""); // Avoid printing ?? as function name.
ReportErrorSummary(ErrorKind, AI);
AI.Clear();
return;
}
} else if (Loc.isSymbolizedStack()) {
const AddressInfo &AI = Loc.getSymbolizedStack()->info;
ReportErrorSummary(ErrorKind, AI);
return;
}
ReportErrorSummary(ErrorKind);
}
namespace {
class Decorator : public SanitizerCommonDecorator {
public:
Decorator() : SanitizerCommonDecorator() {}
const char *Highlight() const { return Green(); }
const char *EndHighlight() const { return Default(); }
const char *Note() const { return Black(); }
const char *EndNote() const { return Default(); }
};
}
SymbolizedStack *__ubsan::getSymbolizedLocation(uptr PC) {
InitAsStandaloneIfNecessary();
return Symbolizer::GetOrInit()->SymbolizePC(PC);
}
Diag &Diag::operator<<(const TypeDescriptor &V) {
return AddArg(V.getTypeName());
}
Diag &Diag::operator<<(const Value &V) {
if (V.getType().isSignedIntegerTy())
AddArg(V.getSIntValue());
else if (V.getType().isUnsignedIntegerTy())
AddArg(V.getUIntValue());
else if (V.getType().isFloatTy())
AddArg(V.getFloatValue());
else
AddArg("<unknown>");
return *this;
}
/// Hexadecimal printing for numbers too large for Printf to handle directly.
static void RenderHex(InternalScopedString *Buffer, UIntMax Val) {
#if HAVE_INT128_T
Buffer->append("0x%08x%08x%08x%08x", (unsigned int)(Val >> 96),
(unsigned int)(Val >> 64), (unsigned int)(Val >> 32),
(unsigned int)(Val));
#else
UNREACHABLE("long long smaller than 64 bits?");
#endif
}
static void RenderLocation(InternalScopedString *Buffer, Location Loc) {
switch (Loc.getKind()) {
case Location::LK_Source: {
SourceLocation SLoc = Loc.getSourceLocation();
if (SLoc.isInvalid())
Buffer->append("<unknown>");
else
RenderSourceLocation(Buffer, SLoc.getFilename(), SLoc.getLine(),
SLoc.getColumn(), common_flags()->symbolize_vs_style,
common_flags()->strip_path_prefix);
return;
}
case Location::LK_Memory:
Buffer->append("%p", Loc.getMemoryLocation());
return;
case Location::LK_Symbolized: {
const AddressInfo &Info = Loc.getSymbolizedStack()->info;
if (Info.file)
RenderSourceLocation(Buffer, Info.file, Info.line, Info.column,
common_flags()->symbolize_vs_style,
common_flags()->strip_path_prefix);
else if (Info.module)
RenderModuleLocation(Buffer, Info.module, Info.module_offset,
common_flags()->strip_path_prefix);
else
Buffer->append("%p", Info.address);
return;
}
case Location::LK_Null:
Buffer->append("<unknown>");
return;
}
}
static void RenderText(InternalScopedString *Buffer, const char *Message,
const Diag::Arg *Args) {
for (const char *Msg = Message; *Msg; ++Msg) {
if (*Msg != '%') {
Buffer->append("%c", *Msg);
continue;
}
const Diag::Arg &A = Args[*++Msg - '0'];
switch (A.Kind) {
case Diag::AK_String:
Buffer->append("%s", A.String);
break;
case Diag::AK_TypeName: {
if (SANITIZER_WINDOWS)
// The Windows implementation demangles names early.
Buffer->append("'%s'", A.String);
else
Buffer->append("'%s'", Symbolizer::GetOrInit()->Demangle(A.String));
break;
}
case Diag::AK_SInt:
// 'long long' is guaranteed to be at least 64 bits wide.
if (A.SInt >= INT64_MIN && A.SInt <= INT64_MAX)
Buffer->append("%lld", (long long)A.SInt);
else
RenderHex(Buffer, A.SInt);
break;
case Diag::AK_UInt:
if (A.UInt <= UINT64_MAX)
Buffer->append("%llu", (unsigned long long)A.UInt);
else
RenderHex(Buffer, A.UInt);
break;
case Diag::AK_Float: {
// FIXME: Support floating-point formatting in sanitizer_common's
// printf, and stop using snprintf here.
char FloatBuffer[32];
#if SANITIZER_WINDOWS
sprintf_s(FloatBuffer, sizeof(FloatBuffer), "%Lg", (long double)A.Float);
#else
snprintf(FloatBuffer, sizeof(FloatBuffer), "%Lg", (long double)A.Float);
#endif
Buffer->append("%s", FloatBuffer);
break;
}
case Diag::AK_Pointer:
Buffer->append("%p", A.Pointer);
break;
}
}
}
/// Find the earliest-starting range in Ranges which ends after Loc.
static Range *upperBound(MemoryLocation Loc, Range *Ranges,
unsigned NumRanges) {
Range *Best = 0;
for (unsigned I = 0; I != NumRanges; ++I)
if (Ranges[I].getEnd().getMemoryLocation() > Loc &&
(!Best ||
Best->getStart().getMemoryLocation() >
Ranges[I].getStart().getMemoryLocation()))
Best = &Ranges[I];
return Best;
}
static inline uptr subtractNoOverflow(uptr LHS, uptr RHS) {
return (LHS < RHS) ? 0 : LHS - RHS;
}
static inline uptr addNoOverflow(uptr LHS, uptr RHS) {
const uptr Limit = (uptr)-1;
return (LHS > Limit - RHS) ? Limit : LHS + RHS;
}
/// Render a snippet of the address space near a location.
static void PrintMemorySnippet(const Decorator &Decor, MemoryLocation Loc,
Range *Ranges, unsigned NumRanges,
const Diag::Arg *Args) {
// Show at least the 8 bytes surrounding Loc.
const unsigned MinBytesNearLoc = 4;
MemoryLocation Min = subtractNoOverflow(Loc, MinBytesNearLoc);
MemoryLocation Max = addNoOverflow(Loc, MinBytesNearLoc);
MemoryLocation OrigMin = Min;
for (unsigned I = 0; I < NumRanges; ++I) {
Min = __sanitizer::Min(Ranges[I].getStart().getMemoryLocation(), Min);
Max = __sanitizer::Max(Ranges[I].getEnd().getMemoryLocation(), Max);
}
// If we have too many interesting bytes, prefer to show bytes after Loc.
const unsigned BytesToShow = 32;
if (Max - Min > BytesToShow)
Min = __sanitizer::Min(Max - BytesToShow, OrigMin);
Max = addNoOverflow(Min, BytesToShow);
if (!IsAccessibleMemoryRange(Min, Max - Min)) {
Printf("<memory cannot be printed>\n");
return;
}
// Emit data.
InternalScopedString Buffer(1024);
for (uptr P = Min; P != Max; ++P) {
unsigned char C = *reinterpret_cast<const unsigned char*>(P);
Buffer.append("%s%02x", (P % 8 == 0) ? " " : " ", C);
}
Buffer.append("\n");
// Emit highlights.
Buffer.append(Decor.Highlight());
Range *InRange = upperBound(Min, Ranges, NumRanges);
for (uptr P = Min; P != Max; ++P) {
char Pad = ' ', Byte = ' ';
if (InRange && InRange->getEnd().getMemoryLocation() == P)
InRange = upperBound(P, Ranges, NumRanges);
if (!InRange && P > Loc)
break;
if (InRange && InRange->getStart().getMemoryLocation() < P)
Pad = '~';
if (InRange && InRange->getStart().getMemoryLocation() <= P)
Byte = '~';
if (P % 8 == 0)
Buffer.append("%c", Pad);
Buffer.append("%c", Pad);
Buffer.append("%c", P == Loc ? '^' : Byte);
Buffer.append("%c", Byte);
}
Buffer.append("%s\n", Decor.EndHighlight());
// Go over the line again, and print names for the ranges.
InRange = 0;
unsigned Spaces = 0;
for (uptr P = Min; P != Max; ++P) {
if (!InRange || InRange->getEnd().getMemoryLocation() == P)
InRange = upperBound(P, Ranges, NumRanges);
if (!InRange)
break;
Spaces += (P % 8) == 0 ? 2 : 1;
if (InRange && InRange->getStart().getMemoryLocation() == P) {
while (Spaces--)
Buffer.append(" ");
RenderText(&Buffer, InRange->getText(), Args);
Buffer.append("\n");
// FIXME: We only support naming one range for now!
break;
}
Spaces += 2;
}
Printf("%s", Buffer.data());
// FIXME: Print names for anything we can identify within the line:
//
// * If we can identify the memory itself as belonging to a particular
// global, stack variable, or dynamic allocation, then do so.
//
// * If we have a pointer-size, pointer-aligned range highlighted,
// determine whether the value of that range is a pointer to an
// entity which we can name, and if so, print that name.
//
// This needs an external symbolizer, or (preferably) ASan instrumentation.
}
Diag::~Diag() {
// All diagnostics should be printed under report mutex.
CommonSanitizerReportMutex.CheckLocked();
Decorator Decor;
InternalScopedString Buffer(1024);
Buffer.append(Decor.Bold());
RenderLocation(&Buffer, Loc);
Buffer.append(":");
switch (Level) {
case DL_Error:
Buffer.append("%s runtime error: %s%s", Decor.Warning(), Decor.EndWarning(),
Decor.Bold());
break;
case DL_Note:
Buffer.append("%s note: %s", Decor.Note(), Decor.EndNote());
break;
}
RenderText(&Buffer, Message, Args);
Buffer.append("%s\n", Decor.Default());
Printf("%s", Buffer.data());
if (Loc.isMemoryLocation())
PrintMemorySnippet(Decor, Loc.getMemoryLocation(), Ranges, NumRanges, Args);
}
ScopedReport::ScopedReport(ReportOptions Opts, Location SummaryLoc,
ErrorType Type)
: Opts(Opts), SummaryLoc(SummaryLoc), Type(Type) {
InitAsStandaloneIfNecessary();
CommonSanitizerReportMutex.Lock();
}
ScopedReport::~ScopedReport() {
MaybePrintStackTrace(Opts.pc, Opts.bp);
MaybeReportErrorSummary(SummaryLoc, Type);
CommonSanitizerReportMutex.Unlock();
if (flags()->halt_on_error)
Die();
}
ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
static SuppressionContext *suppression_ctx = nullptr;
static const char kVptrCheck[] = "vptr_check";
static const char *kSuppressionTypes[] = {
#define UBSAN_CHECK(Name, SummaryKind, FSanitizeFlagName) FSanitizeFlagName,
#include "ubsan_checks.inc"
#undef UBSAN_CHECK
kVptrCheck,
};
void __ubsan::InitializeSuppressions() {
CHECK_EQ(nullptr, suppression_ctx);
suppression_ctx = new (suppression_placeholder) // NOLINT
SuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes));
suppression_ctx->ParseFromFile(flags()->suppressions);
}
bool __ubsan::IsVptrCheckSuppressed(const char *TypeName) {
InitAsStandaloneIfNecessary();
CHECK(suppression_ctx);
Suppression *s;
return suppression_ctx->Match(TypeName, kVptrCheck, &s);
}
bool __ubsan::IsPCSuppressed(ErrorType ET, uptr PC, const char *Filename) {
InitAsStandaloneIfNecessary();
CHECK(suppression_ctx);
const char *SuppType = ConvertTypeToFlagName(ET);
// Fast path: don't symbolize PC if there is no suppressions for given UB
// type.
if (!suppression_ctx->HasSuppressionType(SuppType))
return false;
Suppression *s = nullptr;
// Suppress by file name known to runtime.
if (Filename != nullptr && suppression_ctx->Match(Filename, SuppType, &s))
return true;
// Suppress by module name.
if (const char *Module = Symbolizer::GetOrInit()->GetModuleNameForPc(PC)) {
if (suppression_ctx->Match(Module, SuppType, &s))
return true;
}
// Suppress by function or source file name from debug info.
SymbolizedStackHolder Stack(Symbolizer::GetOrInit()->SymbolizePC(PC));
const AddressInfo &AI = Stack.get()->info;
return suppression_ctx->Match(AI.function, SuppType, &s) ||
suppression_ctx->Match(AI.file, SuppType, &s);
}
#endif // CAN_SANITIZE_UB