diff options
Diffstat (limited to 'contrib/compiler-rt/lib/ubsan/ubsan_diag.cc')
-rw-r--r-- | contrib/compiler-rt/lib/ubsan/ubsan_diag.cc | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/ubsan/ubsan_diag.cc b/contrib/compiler-rt/lib/ubsan/ubsan_diag.cc new file mode 100644 index 0000000..76ce2bd --- /dev/null +++ b/contrib/compiler-rt/lib/ubsan/ubsan_diag.cc @@ -0,0 +1,366 @@ +//===-- ubsan_diag.cc -----------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// 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_diag.h" +#include "ubsan_init.h" +#include "ubsan_flags.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_symbolizer.h" +#include <stdio.h> + +using namespace __ubsan; + +static void MaybePrintStackTrace(uptr pc, uptr bp) { + // We assume that flags are already parsed: InitIfNecessary + // 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 void MaybeReportErrorSummary(Location Loc) { + if (!common_flags()->print_summary) + return; + // Don't try to unwind the stack trace in UBSan summaries: just use the + // provided location. + if (Loc.isSourceLocation()) { + SourceLocation SLoc = Loc.getSourceLocation(); + if (!SLoc.isInvalid()) { + ReportErrorSummary("undefined-behavior", SLoc.getFilename(), + SLoc.getLine(), ""); + return; + } + } + ReportErrorSummary("undefined-behavior"); +} + +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(); } +}; +} + +Location __ubsan::getCallerLocation(uptr CallerLoc) { + if (!CallerLoc) + return Location(); + + uptr Loc = StackTrace::GetPreviousInstructionPc(CallerLoc); + return getFunctionLocation(Loc, 0); +} + +Location __ubsan::getFunctionLocation(uptr Loc, const char **FName) { + if (!Loc) + return Location(); + InitIfNecessary(); + + SymbolizedStack *Frames = Symbolizer::GetOrInit()->SymbolizePC(Loc); + const AddressInfo &Info = Frames->info; + + if (!Info.module) { + Frames->ClearAll(); + return Location(Loc); + } + + if (FName && Info.function) + *FName = internal_strdup(Info.function); + + if (!Info.file) { + ModuleLocation MLoc(internal_strdup(Info.module), Info.module_offset); + Frames->ClearAll(); + return MLoc; + } + + SourceLocation SLoc(internal_strdup(Info.file), Info.line, Info.column); + Frames->ClearAll(); + return SLoc; +} + +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 PrintHex(UIntMax Val) { +#if HAVE_INT128_T + Printf("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(Location Loc) { + InternalScopedString LocBuffer(1024); + switch (Loc.getKind()) { + case Location::LK_Source: { + SourceLocation SLoc = Loc.getSourceLocation(); + if (SLoc.isInvalid()) + LocBuffer.append("<unknown>"); + else + RenderSourceLocation(&LocBuffer, SLoc.getFilename(), SLoc.getLine(), + SLoc.getColumn(), common_flags()->strip_path_prefix); + break; + } + case Location::LK_Module: { + ModuleLocation MLoc = Loc.getModuleLocation(); + RenderModuleLocation(&LocBuffer, MLoc.getModuleName(), MLoc.getOffset(), + common_flags()->strip_path_prefix); + break; + } + case Location::LK_Memory: + LocBuffer.append("%p", Loc.getMemoryLocation()); + break; + case Location::LK_Null: + LocBuffer.append("<unknown>"); + break; + } + Printf("%s:", LocBuffer.data()); +} + +static void renderText(const char *Message, const Diag::Arg *Args) { + for (const char *Msg = Message; *Msg; ++Msg) { + if (*Msg != '%') { + char Buffer[64]; + unsigned I; + for (I = 0; Msg[I] && Msg[I] != '%' && I != 63; ++I) + Buffer[I] = Msg[I]; + Buffer[I] = '\0'; + Printf(Buffer); + Msg += I - 1; + } else { + const Diag::Arg &A = Args[*++Msg - '0']; + switch (A.Kind) { + case Diag::AK_String: + Printf("%s", A.String); + break; + case Diag::AK_Mangled: { + Printf("'%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) + Printf("%lld", (long long)A.SInt); + else + PrintHex(A.SInt); + break; + case Diag::AK_UInt: + if (A.UInt <= UINT64_MAX) + Printf("%llu", (unsigned long long)A.UInt); + else + PrintHex(A.UInt); + break; + case Diag::AK_Float: { + // FIXME: Support floating-point formatting in sanitizer_common's + // printf, and stop using snprintf here. + char Buffer[32]; + snprintf(Buffer, sizeof(Buffer), "%Lg", (long double)A.Float); + Printf("%s", Buffer); + break; + } + case Diag::AK_Pointer: + Printf("%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 renderMemorySnippet(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. + for (uptr P = Min; P != Max; ++P) { + unsigned char C = *reinterpret_cast<const unsigned char*>(P); + Printf("%s%02x", (P % 8 == 0) ? " " : " ", C); + } + Printf("\n"); + + // Emit highlights. + Printf(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 = '~'; + char Buffer[] = { Pad, Pad, P == Loc ? '^' : Byte, Byte, 0 }; + Printf((P % 8 == 0) ? Buffer : &Buffer[1]); + } + Printf("%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--) + Printf(" "); + renderText(InRange->getText(), Args); + Printf("\n"); + // FIXME: We only support naming one range for now! + break; + } + + Spaces += 2; + } + + // 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; + Printf(Decor.Bold()); + + renderLocation(Loc); + + switch (Level) { + case DL_Error: + Printf("%s runtime error: %s%s", + Decor.Warning(), Decor.EndWarning(), Decor.Bold()); + break; + + case DL_Note: + Printf("%s note: %s", Decor.Note(), Decor.EndNote()); + break; + } + + renderText(Message, Args); + + Printf("%s\n", Decor.Default()); + + if (Loc.isMemoryLocation()) + renderMemorySnippet(Decor, Loc.getMemoryLocation(), Ranges, + NumRanges, Args); +} + +ScopedReport::ScopedReport(ReportOptions Opts, Location SummaryLoc) + : Opts(Opts), SummaryLoc(SummaryLoc) { + InitIfNecessary(); + CommonSanitizerReportMutex.Lock(); +} + +ScopedReport::~ScopedReport() { + MaybePrintStackTrace(Opts.pc, Opts.bp); + MaybeReportErrorSummary(SummaryLoc); + CommonSanitizerReportMutex.Unlock(); + if (Opts.DieAfterReport || flags()->halt_on_error) + Die(); +} + +bool __ubsan::MatchSuppression(const char *Str, SuppressionType Type) { + Suppression *s; + // If .preinit_array is not used, it is possible that the UBSan runtime is not + // initialized. + if (!SANITIZER_CAN_USE_PREINIT_ARRAY) + InitIfNecessary(); + return SuppressionContext::Get()->Match(Str, Type, &s); +} |