[llvm] r206146 - tools: simplify symbol handling in objdump

[Saleem Abdulrasool]

On Mon, Apr 14, 2014 at 4:28 AM, Evgeniy Stepanov <eugeni.stepanov at gmail.com
> wrote:

> Hi,
>
> something in this change caused a heap buffer overflow:
>
> http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/3022/steps/check-llvm%20asan/logs/stdio


Somehow I managed to miss two lines in my commit :-(.  Thanks for the heads
up about this failure!  Ill fix this shortly (after I re-run tests).


>
> On Mon, Apr 14, 2014 at 6:37 AM, Saleem Abdulrasool
> <compnerd at compnerd.org> wrote:
> > Author: compnerd
> > Date: Sun Apr 13 21:37:28 2014
> > New Revision: 206146
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=206146&view=rev
> > Log:
> > tools: simplify symbol handling in objdump
> >
> > Rather than switching behaviour on whether a previous symbol has an
> auxiliary
> > symbol record for the next count of elements, simply iterate over the
> auxiliary
> > symbols right after processing the current symbol entry.  This makes the
> > behaviour much simpler to follow and similar to llvm-readobj and
> yaml2obj.
> >
> > Modified:
> >     llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
> >
> > Modified: llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp
> > URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp?rev=206146&r1=206145&r2=206146&view=diff
> >
> ==============================================================================
> > --- llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp (original)
> > +++ llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp Sun Apr 13 21:37:28
> 2014
> > @@ -664,14 +664,31 @@ static void PrintSectionContents(const O
> >
> >  static void PrintCOFFSymbolTable(const COFFObjectFile *coff) {
> >    const coff_file_header *header;
> > -  if (error(coff->getHeader(header))) return;
> > -  int aux_count = 0;
> > -  const coff_symbol *symbol = 0;
> > -  for (int i = 0, e = header->NumberOfSymbols; i != e; ++i) {
> > -    if (aux_count--) {
> > -      if (symbol->isSectionDefinition()) {
> > +  if (error(coff->getHeader(header)))
> > +    return;
> > +
> > +  for (unsigned SI = 0, SE = header->NumberOfSymbols; SI != SE; ++SI) {
> > +    const coff_symbol *Symbol;
> > +    StringRef Name;
> > +    if (error(coff->getSymbol(SI, Symbol)))
> > +      return;
> > +
> > +    if (error(coff->getSymbolName(Symbol, Name)))
> > +      return;
> > +
> > +    outs() << "[" << format("%2d", SI) << "]"
> > +           << "(sec " << format("%2d", int(Symbol->SectionNumber)) <<
> ")"
> > +           << "(fl 0x00)" // Flag bits, which COFF doesn't have.
> > +           << "(ty " << format("%3x", unsigned(Symbol->Type)) << ")"
> > +           << "(scl " << format("%3x", unsigned(Symbol->StorageClass))
> << ") "
> > +           << "(nx " << unsigned(Symbol->NumberOfAuxSymbols) << ") "
> > +           << "0x" << format("%08x", unsigned(Symbol->Value)) << " "
> > +           << Name << "\n";
> > +
> > +    for (unsigned AI = 0, AE = Symbol->NumberOfAuxSymbols; AI < AE;
> ++AI, ++SI) {
> > +      if (Symbol->isSectionDefinition()) {
> >          const coff_aux_section_definition *asd;
> > -        if (error(coff->getAuxSymbol<coff_aux_section_definition>(i,
> asd)))
> > +        if (error(coff->getAuxSymbol<coff_aux_section_definition>(SI +
> 1, asd)))
> >            return;
> >
> >          outs() << "AUX "
> > @@ -683,31 +700,17 @@ static void PrintCOFFSymbolTable(const C
> >                 << format("assoc %d comdat %d\n"
> >                           , unsigned(asd->Number)
> >                           , unsigned(asd->Selection));
> > -      } else if (symbol->isFileRecord()) {
> > +      } else if (Symbol->isFileRecord()) {
> >          const coff_aux_file *AF;
> > -        if (error(coff->getAuxSymbol<coff_aux_file>(i, AF)))
> > +        if (error(coff->getAuxSymbol<coff_aux_file>(SI + 1, AF)))
> >            return;
> >
> > -        StringRef Name(AF->FileName, (aux_count + 1) *
> COFF::SymbolSize);
> > +        StringRef Name(AF->FileName,
> > +                       Symbol->NumberOfAuxSymbols * COFF::SymbolSize);
> >          outs() << "AUX " << Name.rtrim(StringRef("\0", 1))  << '\n';
> > -        i = i + aux_count;
> > -        aux_count = 0;
> >        } else {
> >          outs() << "AUX Unknown\n";
> >        }
> > -    } else {
> > -      StringRef name;
> > -      if (error(coff->getSymbol(i, symbol))) return;
> > -      if (error(coff->getSymbolName(symbol, name))) return;
> > -      outs() << "[" << format("%2d", i) << "]"
> > -             << "(sec " << format("%2d", int(symbol->SectionNumber)) <<
> ")"
> > -             << "(fl 0x00)" // Flag bits, which COFF doesn't have.
> > -             << "(ty " << format("%3x", unsigned(symbol->Type)) << ")"
> > -             << "(scl " << format("%3x",
> unsigned(symbol->StorageClass)) << ") "
> > -             << "(nx " << unsigned(symbol->NumberOfAuxSymbols) << ") "
> > -             << "0x" << format("%08x", unsigned(symbol->Value)) << " "
> > -             << name << "\n";
> > -      aux_count = symbol->NumberOfAuxSymbols;
> >      }
> >    }
> >  }
> >
> >
> > _______________________________________________
> > llvm-commits mailing list
> > llvm-commits at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>



-- 
Saleem Abdulrasool
compnerd (at) compnerd (dot) org
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