[Bug testsuite/13430] New: user space stmt_rel.exp testcase counts the wrong thing

[Bug testsuite/13430] New: user space stmt_rel.exp testcase counts the wrong thing

[mjw at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13430

             Bug #: 13430
           Summary: user space stmt_rel.exp testcase counts the wrong
                    thing
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: testsuite
        AssignedTo: systemtap@sourceware.org
        ReportedBy: mjw@redhat.com
    Classification: Unclassified


stmt_rel.exp has two test cases, a kernel one and a user space one.

The user space one tests setting a relative statement probe on the (inlined)
Move function of a towers of hanoi program. It then checks that that probe
point is being hit 8192 times.

But this is for a tower of 14 disks. So the number of Moves should be 2^14-1 =
16383. This is also the sanity check used in the stmt_rel.c program itself:
  if (movesdone != 16383)
    printf (" Error in Towers.\n");

The reason for this discrepancy (and why it fails on anything but x86_64) is
that only one of the inlined instances of Move is being probed.

Looking at the program with gdb disassemble /m we see:

91    static inline void
92    Move (int s1, int s2)
93    {
94      Push (Pop (s1), s2);
95      movesdone = movesdone + 1;
   0x000000000040059e <+78>:    addl   $0x1,0x200e1b(%rip)        # 0x6013c0
<movesdone>
   0x0000000000400650 <+256>:    addl   $0x1,0x200d69(%rip)        # 0x6013c0
<movesdone>
   0x00000000004006f2 <+418>:    addl   $0x1,0x200cc7(%rip)        # 0x6013c0
<movesdone>

96    }

But stap -vvv reveals that only one location is being probed (the last one):
probe Move@/home/mark/src/systemtap/testsuite/systemtap.base/stmt_rel.c:1
process=/usr/local/build/systemtap-obj/testsuite/stmt_rel.x reloc=.absolute
pc=0x4006f2

Using an unoptimized stmt_rel.x program does hit Move 16383 times (since there
is only one address to probe).

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[Bug testsuite/13430] user space stmt_rel.exp testcase counts the wrong thing

[scox at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13430

Stan Cox <scox at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |scox at redhat dot com
         AssignedTo|systemtap at sourceware dot |scox at redhat dot com
                   |org                         |

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