commit 7cb54ca93cffc949b16611d5b6c66844524143d8

Author: Josh Stone <jistone@redhat.com>

Date:   Thu Oct 17 16:05:25 2013 -0700

    Fix DYNINST_index_lock state and ppc64 writeFunctionPtr

    There are two fixes in this patch to resolve hangs that we've seen on

    ppc64 tests, most notably in test_thread_5.

    The first is that DYNINST_index_lock may be left in a locked state from

    DYNINSTthreadIndexSLOW when DYNINST_thread_hash_size is 0.  This simply

    needs an unlock in that error path.

    The second resolves *why* DYNINST_thread_hash_size is 0, even after it

    was correctly initialized to 40.  This turned out to be corruption when

    the mutator writeFunctionPtr sets DYNINST_pthread_self.  Those symbols

    in libdyninstAPI_RT.so happen to be arranged like so:

        0000000000031180 B DYNINST_pthread_self

        0000000000031188 B DYNINST_sysEntry

        0000000000031190 B DYNINST_thread_hash_size

    So writeFunctionPtr was sending three longs: the function descriptor

    correctly in DYNINST_pthread_self; the toc in DYNINST_sysEntry, a dead

    variable; and the guilty 0x0 in DYNINST_thread_hash_size.  The only

    thing a function pointer actually needs is the function descriptor.

    For comparison, on EL5 and EL6 our build has the symbols like so:

        000000000002c400 B DYNINST_pthread_self

        000000000002c408 B DYNINSTlinkSave

        000000000002c410 B DYNINSTtocSave

        000000000002c418 B DYNINST_sysEntry

        000000000002c420 B DYNINST_thread_hash_tids

        000000000002c428 B DYNINST_thread_hash_size

    So that still clobbered data, but DYNINSTlinkSave and DYNINSTtocSave are

    both unused variables -- no harm done.

    Signed-off-by: Josh Stone <jistone@redhat.com>

diff --git a/dyninstAPI/src/inst-power.C b/dyninstAPI/src/inst-power.C

index c2accaf..74436ec 100644

--- a/dyninstAPI/src/inst-power.C

+++ b/dyninstAPI/src/inst-power.C

@@ -2589,20 +2589,11 @@ bool writeFunctionPtr(AddressSpace *p, Address addr, func_instance *f)

 #else

     // 64-bit ELF PowerPC Linux uses r2 (same as AIX) for TOC base register

     if (p->getAddressWidth() == sizeof(uint64_t)) {

-        Address buffer[3];

         Address val_to_write = f->addr();

         // Use function descriptor address, if available.

         if (f->getPtrAddress()) val_to_write = f->getPtrAddress();

-        assert(p->proc());

-        Address toc = p->proc()->getTOCoffsetInfo(f);

-        buffer[0] = val_to_write;

-        buffer[1] = toc;

-        buffer[2] = 0x0;

-

-        if (!p->writeDataSpace((void *) addr, sizeof(buffer), buffer))

-            fprintf(stderr, "%s[%d]:  writeDataSpace failed\n",

-                            FILE__, __LINE__);

-        return true;

+        return p->writeDataSpace((void *) addr,

+                                 sizeof(val_to_write), &val_to_write);

     }

     else {

         // Originally copied from inst-x86.C

diff --git a/dyninstAPI_RT/src/RTthread.c b/dyninstAPI_RT/src/RTthread.c

index 9897563..2a80f58 100644

--- a/dyninstAPI_RT/src/RTthread.c

+++ b/dyninstAPI_RT/src/RTthread.c

@@ -119,6 +119,7 @@ unsigned DYNINSTthreadIndexSLOW(dyntid_t tid) {

      **/

     if (!DYNINST_thread_hash_size) {

         //Uninitialized tramp guard.

+        tc_lock_unlock(&DYNINST_index_lock);

         return DYNINST_max_num_threads;

     }