/*

This file is a simple way (on Linux) to do a certain kind

of test.  "Code Testing Through Fault Injection" in ":login;"

magazine (December, 2014. Usenix.org) by Peter Gutmann offered

a simple example by an unnamed friend: instrument malloc() so

on call N it returns NULL. Try with N from 0 to some higher

number (I used 0 to 100).  Run your chosen executable and

see how it fares.  This test exposed a couple bugs in libdwarf.

Here are some of the example core dumps (running dwarfgen):

2000: Could not allocate Dwarf_Error structure, abort() in libdwarf.

1000: FAIL:bad alloc caughtstd::bad_alloc

500:  FAIL:bad alloc caughtstd::bad_alloc

250:  FAIL:bad alloc caughtstd::bad_alloc

125:  Could not allocate Dwarf_Error structure, abort() in libdwarf.

      Aborted (core dumped)

100:  FAIL:bad alloc caughtstd::bad_alloc

46-60: FAIL:bad alloc caughtstd::bad_alloc  

45- Could not allocate Dwarf_Error structure, abort() in libdwarf.

    Aborted (core dumped)

42-44: FAIL:bad alloc caughtstd::bad_alloc  

30- 41: Could not allocate Dwarf_Error structure, abort() in libdwarf.

    Aborted (core dumped)

28-29  :FAIL:bad alloc caught std::bad_alloc

    Aborted (core dumped)

8,9,10,11-27: Could not allocate Dwarf_Error structure, abort() in libdwarf.

    Aborted (core dumped)

7: 6: FAIL:bad alloc caught std::bad_alloc

0,1,2,3,4,5: terminate called after throwing an instance of 'std::bad_alloc'

  what():  std::bad_alloc

  Aborted (core dumped)

-------HOW TO USE:

Configure generates the following for Makefile.

$(CXX) $(CXXFLAGS) -o $@ $(DGOBJECTS) $(LDFLAGS)

In the generated Makefile, replace the above line with

these two lines.

$(CC) $(CFLAGS) -c fakemalloc.o

$(CXX) $(CXXFLAGS) -o $@ $(DGOBJECTS) $(LDFLAGS) fakemalloc.o

Run tests using the script TESTmallocfail

-------

*/

static unsigned count;

extern void * __libc_malloc();

void *malloc(unsigned len)

{

  /*  Perhaps the test should be count >= FAILCOUNT  ??? */

  if (count == FAILCOUNT) {

    return 0;

  }

  count++;

  return __libc_malloc(len);

}