IV24389: INLINE ASM MAY CAUSE SEGMENTATION FAULT

July 2012 PTF for XL C/C++ for AIX, V11.1
July 2012 PTF for XL C for AIX, V11.1
October 2012 PTF for XL C/C++ for AIX, V11.1
October 2012 PTF for XL C for AIX, V11.1
February 2013 PTF for XL C for AIX, V11.1
February 2013 PTF for XL C/C++ for AIX, V11.1

APAR status

• Closed as program error.

Error description

• When inline assembly (asm("")) is used in a compilation unit,
  the C++ compiler does not handle C++ exceptions correctly.
  
  The symptoms range  from exceptions not being thrown, to not
  being caught correctly, to segmentation faults.
  
  Consider the following testcase test.cc:
  
  ///////////// test.cc //////////////////
  
  #include <cstdio>
  #include <exception>
  using namespace std;
  
  void junk() {
    asm("nop");
  }
  
  int main(int argc, char** argv) try {
    throw std::exception();
  } catch (...) {
    puts("Caught Exception");
  }
  ///////////////////////////////////////
  
  Compile testcase:
  
  $xlC test.cc
  
  Execute the binary:
  
  $./a.out
  Segmentation fault
  

Local fix

• N/A
  

Problem summary

• parts of ehframe descriptor are missing or wrong in inline asm
  

Problem conclusion

• recommended for C++ users who also use inline asm
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  LI76731

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  XL C FOR AIX

• Fixed component ID

  5724X1200

Applicable component levels

• RB10 PSY U852940

     UP C