[Python-Dev] valgrind report

Sun Jun 6 16:52:45 EDT 2004

I checked in several changes to support valgrind better.  Mostly it
was documentation changes (additions).  The changes should be minimal
enough to be considered for backporting to 2.3.5.  Although I did not
mark all the checkins as such.  At the end of this mail are the
remaining issues that valgrind reports.

There were very few problems reported.  Valgrind was run on gentoo,
dual amd athlon box with 1GB.

I checked in a fix to Modules/binascii.c.  Someone familiar with
the module should review this change.  It fixed an uninitialized
memory read.  It would be nice to improve the comment.

I fixed a memory leak in Modules/posixmodule.c when callin utime().
The code is a bit complex, so it would be good to review this
change carefully as well.

Neal
--

These are from most important to fix to least important.

I submitted a patch to fix a bunch of possible memory leaks.
the patch fixes at least one memory leak not reported here.
The fixes are in the same location as these leaks.

        http://sourceforge.net/tracker/index.php?func=detail&aid=967763&group_id=5470&atid=305470

BSD DB memory leaks:
--------------------

 4 bytes in 1 blocks are definitely lost in loss record 7 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x3C928265: make_key_dbt (_bsddb.c:400)
    by 0x3C92DE4F: DBC_set_range (_bsddb.c:2911)

 8 bytes in 2 blocks are definitely lost in loss record 29 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x3C928265: make_key_dbt (_bsddb.c:400)
    by 0x3C929088: DB_get (_bsddb.c:1349)

I'm not sure which test caused these leaks.  I will try narrow
these two down.  I suspect one may be test_import.py.

Import/compile related memory leaks:
------------------------------------

128 bytes in 1 blocks are definitely lost in loss record 221 of 799
   at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
   by 0x807CDB7: new_arena (obmalloc.c:500)
   by 0x807CAF2: PyObject_Malloc (obmalloc.c:699)
   by 0x807D5A7: PyString_FromStringAndSize (stringobject.c:73)
   by 0x80D6D43: r_object (marshal.c:500)
   by 0x80D63D5: r_object (marshal.c:621)
   by 0x80D5E01: r_object (marshal.c:546)
   by 0x80D6380: r_object (marshal.c:616)
   by 0x80D7683: PyMarshal_ReadLastObjectFromFile (marshal.c:665)
   by 0x80D0CAA: load_source_module (import.c:690)
   by 0x80CEA8D: load_module (import.c:1616)
   by 0x80CF977: import_submodule (import.c:2210)
   by 0x80CF4A2: load_next (import.c:2030)
   by 0x80D14D8: import_module_ex (import.c:1865)
   by 0x80D054B: PyImport_ImportModuleEx (import.c:1906)

256 bytes in 1 blocks are definitely lost in loss record 252 of 799
   at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
   by 0x807CDB7: new_arena (obmalloc.c:500)
   by 0x807CAF2: PyObject_Malloc (obmalloc.c:699)
   by 0x80F8914: PyNode_AddChild (node.c:95)
   by 0x80F8BE1: PyParser_AddToken (parser.c:112)
   by 0x8055AF2: parsetok (parsetok.c:166)
   by 0x80DBFAD: Py_CompileStringFlags (pythonrun.c:1375)
   by 0x80A2AAC: builtin_compile (bltinmodule.c:391)
   by 0x81019F9: PyCFunction_Call (methodobject.c:108)
   by 0x80AA71D: call_function (ceval.c:3377)
   by 0x80AE5FF: eval_frame (ceval.c:1990)
   by 0x80A93AD: PyEval_EvalCodeEx (ceval.c:2543)
   by 0x80AA898: fast_function (ceval.c:3468)
   by 0x80AA3F3: call_function (ceval.c:3397)
   by 0x80AE5FF: eval_frame (ceval.c:1990)

The thread leaks may occur at most once in a program.  I'm not sure.

Thread memory leaks:
--------------------

 16 bytes in 1 blocks are definitely lost in loss record 63 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x80DF227: PyThread_allocate_lock (thread_pthread.h:262)
    by 0x80ABC43: PyEval_InitThreads (ceval.c:162)
    by 0x80E287F: thread_PyThread_start_new_thread (threadmodule.c:243)

 64 bytes in 4 blocks are definitely lost in loss record 132 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x80E2843: thread_PyThread_start_new_thread (threadmodule.c:233)

Initialization memory leaks:
----------------------------

 64 bytes in 1 blocks are definitely lost in loss record 139 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x807CE32: new_arena (obmalloc.c:452)
    by 0x807CAF2: PyObject_Malloc (obmalloc.c:699)
    by 0x80E1566: _PyObject_GC_Malloc (gcmodule.c:1183)
    by 0x80E166C: _PyObject_GC_NewVar (gcmodule.c:1214)
    by 0x8084A71: PyTuple_New (tupleobject.c:68)
    by 0x8087B2F: PyType_Ready (typeobject.c:3161)
    by 0x8087B39: PyType_Ready (typeobject.c:3147)
    by 0x807BE01: _Py_ReadyTypes (object.c:1802)
    by 0x80D9B93: Py_Initialize (pythonrun.c:167)
    by 0x805510A: Py_Main (main.c:376)
    by 0x8054DAA: main (python.c:23)

I don't know if we can fix any of these.  They may all be within
non-Python libraries.

DL memory leaks:
----------------

 17 bytes in 1 blocks are definitely lost in loss record 90 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x3C0060D9: _dl_map_object (in /lib/ld-2.3.2.so)
    by 0x3C25E0AA: (within /lib/libc-2.3.2.so)
    by 0x3C00B247: _dl_catch_error (in /lib/ld-2.3.2.so)
    by 0x3C25E6C8: _dl_open (in /lib/libc-2.3.2.so)
    by 0x3C06DCF7: (within /lib/libdl-2.3.2.so)
    by 0x3C00B247: _dl_catch_error (in /lib/ld-2.3.2.so)
    by 0x3C06D485: (within /lib/libdl-2.3.2.so)
    by 0x3C06DD4B: dlopen (in /lib/libdl-2.3.2.so)
    by 0x3F9DD3E2: dl_open (dlmodule.c:184)

Readline memory leaks:
----------------------

 40 bytes in 2 blocks are definitely lost in loss record 116 of 663
    at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
    by 0x3CB85EF1: xmalloc (in /lib/libreadline.so.4.3)

Reading password/group memory leaks:
------------------------------------

36 bytes in 1 blocks are definitely lost in loss record 162 of 799
   at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
   by 0x3C23EBC2: (within /lib/libc-2.3.2.so)
   by 0x3C23E4F2: __nss_database_lookup (in /lib/libc-2.3.2.so)
   by 0x3FA3533D: ???
   by 0x3FA355B0: ???
   by 0x3C23F5FD: (within /lib/libc-2.3.2.so)
   by 0x3C200131: setgrent (in /lib/libc-2.3.2.so)
   by 0x3CA32E17: grp_getgrall (grpmodule.c:123)

36 bytes in 1 blocks are definitely lost in loss record 163 of 799
   at 0x3C01DA1D: malloc (vg_replace_malloc.c:109)
   by 0x3C23EBC2: (within /lib/libc-2.3.2.so)
   by 0x3C23E4F2: __nss_database_lookup (in /lib/libc-2.3.2.so)
   by 0x3FA362FD: ???
   by 0x3FA3780C: ???
   by 0x3C201597: getpwnam_r (in /lib/libc-2.3.2.so)
   by 0x3C20103D: getpwnam (in /lib/libc-2.3.2.so)
   by 0x3CB48D80: pwd_getpwnam (pwdmodule.c:130)