[ python-Bugs-1165761 ] KeyboardInterrupt causes segmentation fault with threads

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Bugs item #1165761, was opened at 2005-03-17 21:18
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Category: Threads
Group: Python 2.4
Status: Open
Resolution: None
Priority: 5
Submitted By: Jeff Stearns (jeffstearns)
Assigned to: Nobody/Anonymous (nobody)
Summary: KeyboardInterrupt causes segmentation fault with threads

Initial Comment:
The attached sample program crashes Python 2.4.1c1 with a 
segmentation fault if it is interupted.

I wrote a simple program which simulates multiple HTTP clients.

The program is mult-threaded.

It runs on Debian with a 2.6 kernel.

If the program is interrupted (via ^C), Python 2.4.1c1 takes a 
segmentation fault.

Investigation with gdb shows that the error occurs within 
PyEval_EvalFrame at line 1661 below.
It's executing an END_FINALLY bytecode.
The offending statement is
   v = POP();
The value of v is 0.
This is then passed to PyInt_Check(), which attempts to dereference 
a NULL pointer.


1659                    case END_FINALLY:
1660                            v = POP();
1661                            if (PyInt_Check(v)) {
1662                                    why = (enum why_code) 
PyInt_AS_LONG(v);
1663                                    assert(why != WHY_YIELD);
1664                                    if (why == WHY_RETURN ||
1665                                        why == WHY_CONTINUE)
1666                                            retval = POP();
1667                            }



#0  PyEval_EvalFrame (f=0x821cd04) at Python/ceval.c:1661
#1  0x080ae6bd in fast_function (func=0x4030df8d, 
pp_stack=0xbfffe85c, n=1, na=1076944740, nk=1079484852) at 
Python/ceval.c:3629
#2  0x080ae254 in call_function (pp_stack=0xbfffe85c, 
oparg=1076944740) at Python/ceval.c:3568
#3  0x080ac7a6 in PyEval_EvalFrame (f=0x8227d04) at Python/
ceval.c:2163
#4  0x080ad21e in PyEval_EvalCodeEx (co=0x4037e660, 
globals=0x4030df64, locals=0x4030df8d, args=0x40295c78, 
argcount=1, kws=0x0, kwcount=0, defs=0x0, defcount=0, 
closure=0x0)
    at Python/ceval.c:2730
#5  0x08105647 in function_call (func=0x4038a304, 
arg=0x40295c6c, kw=0x0) at Objects/funcobject.c:548
#6  0x0805c409 in PyObject_Call (func=0x8148088, 
arg=0x4030df64, kw=0x4030df64) at Objects/abstract.c:1751
#7  0x08062e38 in instancemethod_call (func=0x4038a304, 
arg=0x40295c6c, kw=0x4030df64) at Objects/classobject.c:2431
#8  0x0805c409 in PyObject_Call (func=0x8148088, 
arg=0x4030df64, kw=0x4030df64) at Objects/abstract.c:1751
#9  0x080ae0e7 in PyEval_CallObjectWithKeywords 
(func=0x4030df64, arg=0x4028702c, kw=0x405785a4) at Python/
ceval.c:3419
#10 0x0809101c in slot_tp_del (self=0x4057a1b4) at Objects/
typeobject.c:4818
#11 0x08086f93 in subtype_dealloc (self=0x4057a1b4) at Objects/
typeobject.c:669
#12 0x08062a4c in instancemethod_dealloc (im=0x4057857c) at 
Objects/classobject.c:2225
#13 0x080790a4 in dict_dealloc (mp=0x4056aacc) at Objects/
dictobject.c:734
#14 0x0805e544 in instance_dealloc (inst=0x40569dcc) at Objects/
classobject.c:687
#15 0x081042cb in frame_dealloc (f=0x8218f14) at Objects/
frameobject.c:418
#16 0x080dc1e9 in PyThreadState_Clear (tstate=0x81f9820) at 
Python/pystate.c:217
#17 0x080dbdf8 in PyInterpreterState_Clear (interp=0x8148048) at 
Python/pystate.c:93
#18 0x080dcef2 in Py_Finalize () at Python/pythonrun.c:408
#19 0x08055391 in Py_Main (argc=1, argv=0xbfffee14) at Modules/
main.c:504
#20 0x08054eeb in main (argc=1076944740, argv=0x4030df64) at 
Modules/python.c:23


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