Description of problem:  The dyninst library make a call to dwarf_src with error argument being NULL and libdwarf tries to use it anyway.


Version-Release number of selected component (if applicable):

libdwarf-20160115-2.fc24.x86_64
dyninst-9.1.0-4.fc25.x86_64
systemtap-3.0-0.20160208git40ae3a7.fc24.x86_64


How reproducible:

Always

Steps to Reproduce:
1. yum install "systemtap*" "dyninst*"
2. debuginfo-install dyninst
3. create test.c with:
#include <stdio.h>

int main(int argc, char **argv)
{
  printf("hello\n");
  return 0;
}
4. gcc -g -o hello test.c
5. stap -p4 -m crasher --dyninst -e 'probe process("hello").function("main:3") {log("hit")}' -c ./hello
6. gdb /usr/bin/stapdyn
7. run crasher.so -c ./hello


Actual results:


Starting program: /usr/bin/stapdyn crasher.so -c ./hello
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7ffff376c700 (LWP 6316)]
[New Thread 0x7ffff2d61700 (LWP 6317)]
[New Thread 0x7ffff2357700 (LWP 6318)]
Detaching after fork from child process 6319.

Thread 1 "stapdyn" received signal SIGSEGV, Segmentation fault.
dwarf_formstring (attr=0x55555634cb10, return_str=return_str@entry=0x7fffffffd450, error=error@entry=0x0)
    at dwarf_form.c:1183
1183	        if (dwarf_errno(*error) == DW_DLE_NO_TIED_FILE_AVAILABLE) {


Expected results:

The code should print out "hello" and "hit" and then exit without error
(gdb) run
The program being debugged has been started already.
Start it from the beginning? (y or n) y
hello
Starting program: /usr/bin/stapdyn crasher.so -c ./hello
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7ffff376c700 (LWP 6332)]
[New Thread 0x7ffff2d61700 (LWP 6333)]
[New Thread 0x7ffff2357700 (LWP 6334)]
Detaching after fork from child process 6335.
[New Thread 0x7fffebfff700 (LWP 6336)]
hello
hit
[Thread 0x7fffebfff700 (LWP 6336) exited]
[Thread 0x7ffff376c700 (LWP 6332) exited]
...



Additional info:

Removing the dyninst-debuginfo rpm allows things to run successfully.

According to /usr/share/doc/libdwarf-devel/libdwarf2.1.pdf there should be  check of error before it is used:

The following lists the processing steps taken upon detection of an error:
1.
Check the error argument; if not a NULL pointer, allocate and initialize a Dwarf_Error
descriptor with information describing the error, place this descriptor in the area pointed to by
error, and return a value indicating an error condition.


Traceback of how it got to the problem code:

(gdb) where
#0  dwarf_formstring (attr=0x555556372a70, return_str=return_str@entry=0x7fffffffd450, error=error@entry=0x0)
    at dwarf_form.c:1183
#1  0x00007ffff3dc41e2 in _dwarf_internal_get_die_comp_dir (die=die@entry=0x5555563729f0, 
    compdir_out=compdir_out@entry=0x7fffffffd4e8, compname_out=compname_out@entry=0x7fffffffd4e0, error=error@entry=0x0)
    at dwarf_util.c:118
#2  0x00007ffff3dbb174 in dwarf_srcfiles (die=die@entry=0x5555563729f0, srcfiles=srcfiles@entry=0x7fffffffd568, 
    srcfilecount=srcfilecount@entry=0x7fffffffd560, error=error@entry=0x0) at ./dwarf_line.c:369
#3  0x00007ffff732b037 in Dyninst::SymtabAPI::DwarfWalker::buildSrcFiles (this=this@entry=0x7fffffffd800, 
    entry=0x5555563729f0) at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/symtabAPI/src/dwarfWalker.C:253
#4  0x00007ffff732e3b4 in Dyninst::SymtabAPI::DwarfWalker::parseModule (this=this@entry=0x7fffffffd800, 
    is_info=is_info@entry=1, fixUnknownMod=@0x7fffffffd788: 0x5555558e1ef0)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/symtabAPI/src/dwarfWalker.C:237
#5  0x00007ffff732e7be in Dyninst::SymtabAPI::DwarfWalker::parse (this=this@entry=0x7fffffffd800)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/symtabAPI/src/dwarfWalker.C:135
#6  0x00007ffff72e2471 in Dyninst::SymtabAPI::Object::parseTypeInfo (this=<optimized out>, obj=obj@entry=0x5555558ac520)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/symtabAPI/src/Object-elf.C:5189
#7  0x00007ffff72a1596 in Dyninst::SymtabAPI::Symtab::parseTypes (this=0x5555558ac520)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/symtabAPI/src/Symtab.C:2435
#8  0x00007ffff75f379c in BPatch_module::parseTypesIfNecessary (this=0x55555647fb90)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/dyninstAPI/src/BPatch_module.C:260
#9  0x00007ffff75d4719 in BPatch_function::constructVarsAndParams (this=this@entry=0x555556478af0)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/dyninstAPI/src/BPatch_function.C:792
#10 0x00007ffff75d4aa9 in BPatch_function::getReturnType (this=this@entry=0x555556478af0)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/dyninstAPI/src/BPatch_function.C:354
#11 0x00007ffff75e0d77 in BPatch_funcCallExpr::BPatch_funcCallExpr (this=0x7fffffffdc50, func=..., args=...)
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/dyninstAPI/src/BPatch_snippet.C:819
#12 0x00007ffff75e9fab in BPatch_process::loadLibrary (this=0x5555557c9530, libname=0x5555557c9ab0 "/home/wcohen/crasher.so")
    at /usr/src/debug/dyninst-9.1.0/DyninstAPI-9.1.0/dyninstAPI/src/BPatch_process.C:1041
#13 0x0000555555563cde in mutatee::load_stap_dso(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ()
#14 0x0000555555562445 in mutator::create_process(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ()
#15 0x000055555555b732 in main ()