Weird *** longjmp causes uninitialized stack frame *** error?

[KvS]

Hi all,

I'm very sorry, but I have yet another error I don't understand. I was
playing around with evaluating the gamma function. The following piece
of code is fine (on Sage v 4.6):

i=sqrt(-1)
for k in range(100):
print k; r1=random(); r2=random()
#try:
# xx=100*r1-i; yy=100*r2
# res=gamma(xx)*gamma(yy)/gamma(xx+yy)
#except:
# pass

If I now uncomment the last four lines (besides that I don't
understand the error itself, there should be no error at all because
of the try-except-block no?):

i=sqrt(-1)
for k in range(100):
print k; r1=random(); r2=random()
try:
xx=100*r1-i; yy=100*r2
res=gamma(xx)*gamma(yy)/gamma(xx+yy)
except:
pass

I get in every run somewhere in the loop an error, like this:

0
1
2
3
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8
*** longjmp causes uninitialized stack frame ***:
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
b\
in/python terminated
======= Backtrace: =========
/lib/libc.so.6(__fortify_fail+0x50)[0x2b2970]
/lib/libc.so.6(+0xe58da)[0x2b28da]
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/libpari-gmp-2.4.so.3(pari_err+0x2ae)[0x255af0e]
======= Memory map: ========
00110000-00116000 r-xp 00000000 08:05 30103
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_struct.so
00116000-00117000 r--p 00005000 08:05 30103
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_struct.so
00117000-00119000 rw-p 00006000 08:05 30103
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_struct.so
00119000-0011d000 r-xp 00000000 08:05 30067
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/strop.so
0011d000-0011e000 r--p 00003000 08:05 30067
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/strop.so
0011e000-00120000 rw-p 00004000 08:05 30067
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/strop.so
00120000-00125000 r-xp 00000000 08:05 30055
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_collections.so
00125000-00126000 r--p 00004000 08:05 30055
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_collections.so
00126000-00127000 rw-p 00005000 08:05 30055
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_collections.so
00127000-0012e000 r-xp 00000000 08:05 30076
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/itertools.so
0012e000-0012f000 r--p 00006000 08:05 30076
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/itertools.so
0012f000-00132000 rw-p 00007000 08:05 30076
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/itertools.so
00132000-00133000 r-xp 00000000 08:05 30165
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_weakref.so
00133000-00134000 r--p 00000000 08:05 30165
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_weakref.so
00134000-00135000 rw-p 00001000 08:05 30165
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_weakref.so
00135000-00141000 r-xp 00000000 08:05 192736
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/build/sage/misc/randstate.so
00141000-00142000 r--p 0000b000 08:05 192736
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/build/sage/misc/randstate.so
00142000-0014c000 rw-p 0000c000 08:05 192736
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/build/sage/misc/randstate.so
0014c000-0015c000 r-xp 00000000 08:05 199735
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/c_lib/libcsage.so
0015c000-0015d000 r--p 0000f000 08:05 199735
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/c_lib/libcsage.so
0015d000-0015e000 rw-p 00010000 08:05 199735
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/c_lib/libcsage.so
0015e000-00178000 r-xp 00000000 08:05 32695 /lib/libgcc_s.so.1
00178000-00179000 r--p 00019000 08:05 32695 /lib/libgcc_s.so.1
00179000-0017a000 rw-p 0001a000 08:05 32695 /lib/libgcc_s.so.1
0017a000-0018c000 r-xp 00000000 08:05 192836
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/build/sage/misc/misc_c.so
0018c000-0018d000 r--p 00011000 08:05 192836
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/build/sage/misc/misc_c.so
0018d000-00194000 rw-p 00012000 08:05 192836
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/devel/
s\
age-main/build/sage/misc/misc_c.so
00194000-001ab000 r-xp 00000000 08:05 30072
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/bz2.so
001ab000-001ac000 r--p 00016000 08:05 30072
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/bz2.so
001ac000-001af000 rw-p 00017000 08:05 30072
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/bz2.so
001af000-001cb000 r-xp 00000000 08:05 46306 /lib/ld-2.12.1.so
001cb000-001cc000 r--p 0001b000 08:05 46306 /lib/ld-2.12.1.so
001cc000-001cd000 rw-p 0001c000 08:05 46306 /lib/ld-2.12.1.so
001cd000-00324000 r-xp 00000000 08:05 46342 /lib/libc-2.12.1.so
00324000-00326000 r--p 00157000 08:05 46342 /lib/libc-2.12.1.so
00326000-00327000 rw-p 00159000 08:05 46342 /lib/libc-2.12.1.so
00327000-0032a000 rw-p 00000000 00:00 0
0032a000-0032c000 r-xp 00000000 08:05 30054
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_random.so
0032c000-0032d000 r--p 00001000 08:05 30054
/usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-Linux/local/
l\
ib/python2.6/lib-dynload/_random.so9

I know nothing about low level programming, yet it does look like an
error somewhere in the compiled part of Python's random(), no?

Many thanks in advance for any pointers, Kees

[Volker Braun]

I'm getting the somewhat expected result:

sage: i=sqrt(-1) 

sage: for k in range(100): 

....:         print k; r1=random(); r2=random() 

....:     try: 

....:             xx=100*r1-i; yy=100*r2 

....:         res=gamma(xx)*gamma(yy)/gamma(xx+yy) 

....:     except: 

....:             pass 

....: 

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  ***   overflow in t_REAL->double conversion.

17

18

19

20

... and so on...

Try running your code in sage -gdb and then bt (backtrace) the stack.

Since you apparently are running a binary distribution, I'd bet that there is a slight mismatch between the overflow signal handler on your distribution and on the distribution that it was compiled for. So when the overflow occurs it longjmp's into the abyss....

[KvS]

Hi Volker,

I followed your suggestions and this is the output:

#0 0x0012e416 in __kernel_vsyscall ()
#1 0x0030e941 in raise () from /lib/libc.so.6
#2 0x00311e42 in abort () from /lib/libc.so.6
#3 0x00346305 in ?? () from /lib/libc.so.6
#4 0x003c9970 in __fortify_fail () from /lib/libc.so.6
#5 0x003c98da in ?? () from /lib/libc.so.6
#6 0x003c9849 in __longjmp_chk () from /lib/libc.so.6
#7 0x00b49f0e in pari_err (numerr=15) at ../src/language/init.c:980
#8 0x008eef06 in rtodbl (x=0xb7d3d708)
from /usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-
Linux/local/lib/libpari-gmp-2.4.so.3
#9 0x00eab396 in
__pyx_f_4sage_5rings_14complex_double_20ComplexDoubleElement__new_from_gen_c
(__pyx_v_self=0x843932c, __pyx_v_g=0xb7d3d738,
__pyx_v_sp=3084113776) at sage/rings/complex_double.c:6488
#10 0x00ebf6a6 in
__pyx_pf_4sage_5rings_14complex_double_20ComplexDoubleElement_gamma
(__pyx_v_self=0x843932c, unused=0x0) at sage/rings/complex_double.c:
12513
#11 0x0019cc81 in PyCFunction_Call (func=0x824732c, arg=0xb7fa502c,
kw=0x0)
at Objects/methodobject.c:90
#12 0x0015973c in PyObject_Call (func=0x824732c, arg=0xb7fa502c,
kw=0x0)
at Objects/abstract.c:2492
#13 0x0392f1c3 in py_tgamma (__pyx_v_x=0x843932c)
at sage/symbolic/pynac.cpp:9137
#14 0x03ad7169 in GiNaC::Number_T::tgamma (this=0xa6da6f4) at
numeric.cpp:1280
#0 0x0012e416 in __kernel_vsyscall ()
#1 0x0030e941 in raise () from /lib/libc.so.6
#2 0x00311e42 in abort () from /lib/libc.so.6
#3 0x00346305 in ?? () from /lib/libc.so.6
#4 0x003c9970 in __fortify_fail () from /lib/libc.so.6
#5 0x003c98da in ?? () from /lib/libc.so.6
#6 0x003c9849 in __longjmp_chk () from /lib/libc.so.6
#7 0x00b49f0e in pari_err (numerr=15) at ../src/language/init.c:980
#8 0x008eef06 in rtodbl (x=0xb7d3d708)
from /usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-
Linux/local/lib/libpari-gmp-2.4.so.3
#9 0x00eab396 in
__pyx_f_4sage_5rings_14complex_double_20ComplexDoubleElement__new_from_gen_c
(__pyx_v_self=0x843932c, __pyx_v_g=0xb7d3d738,
__pyx_v_sp=3084113776) at sage/rings/complex_double.c:6488
#10 0x00ebf6a6 in
__pyx_pf_4sage_5rings_14complex_double_20ComplexDoubleElement_gamma
(__pyx_v_self=0x843932c, unused=0x0) at sage/rings/complex_double.c:
12513
#11 0x0019cc81 in PyCFunction_Call (func=0x824732c, arg=0xb7fa502c,
kw=0x0)
at Objects/methodobject.c:90
#12 0x0015973c in PyObject_Call (func=0x824732c, arg=0xb7fa502c,
kw=0x0)
at Objects/abstract.c:2492
#13 0x0392f1c3 in py_tgamma (__pyx_v_x=0x843932c)
at sage/symbolic/pynac.cpp:9137
#14 0x03ad7169 in GiNaC::Number_T::tgamma (this=0xa6da6f4) at
numeric.cpp:1280
#0 0x0012e416 in __kernel_vsyscall ()
#1 0x0030e941 in raise () from /lib/libc.so.6
#2 0x00311e42 in abort () from /lib/libc.so.6
#3 0x00346305 in ?? () from /lib/libc.so.6
#4 0x003c9970 in __fortify_fail () from /lib/libc.so.6
#5 0x003c98da in ?? () from /lib/libc.so.6
#6 0x003c9849 in __longjmp_chk () from /lib/libc.so.6
#7 0x00b49f0e in pari_err (numerr=15) at ../src/language/init.c:980
#8 0x008eef06 in rtodbl (x=0xb7d3d708)
from /usr/local/Sage/sage-4.6-linux-32bit-ubuntu_10.04_lts-i686-
Linux/local/lib/libpari-gmp-2.4.so.3
#9 0x00eab396 in
__pyx_f_4sage_5rings_14complex_double_20ComplexDoubleElement__new_from_gen_c
(__pyx_v_self=0x843932c, __pyx_v_g=0xb7d3d738,
__pyx_v_sp=3084113776) at sage/rings/complex_double.c:6488
#10 0x00ebf6a6 in
__pyx_pf_4sage_5rings_14complex_double_20ComplexDoubleElement_gamma
(__pyx_v_self=0x843932c, unused=0x0) at sage/rings/complex_double.c:
12513
#11 0x0019cc81 in PyCFunction_Call (func=0x824732c, arg=0xb7fa502c,
kw=0x0)
at Objects/methodobject.c:90
#12 0x0015973c in PyObject_Call (func=0x824732c, arg=0xb7fa502c,
kw=0x0)
at Objects/abstract.c:2492
#13 0x0392f1c3 in py_tgamma (__pyx_v_x=0x843932c)
at sage/symbolic/pynac.cpp:9137
#14 0x03ad7169 in GiNaC::Number_T::tgamma (this=0xa6da6f4) at
numeric.cpp:1280
#15 0x03ad93a2 in GiNaC::tgamma (x=...) at numeric.cpp:2380
#16 0x03a71212 in GiNaC::tgamma_eval (x=...) at inifcns_gamma.cpp:186
#17 0x03a184e6 in GiNaC::function::eval (this=0xbfffdadc, level=1)
at function.cpp:796
#18 0x03a016ba in GiNaC::ex::construct_from_basic (other=...) at
ex.cpp:312
#19 0x03d238ad in ex (__pyx_v_self=0xaa0ed8c, __pyx_args=0xb7fa502c,
__pyx_kwds=0x0)
at /home/wstein/build/sage-4.6/local//include/pynac/ex.h:266
#20 __pyx_pf_4sage_8symbolic_10expression_10Expression_gamma (
__pyx_v_self=0xaa0ed8c, __pyx_args=0xb7fa502c, __pyx_kwds=0x0)
at sage/symbolic/expression.cpp:22628
#21 0x0019cc48 in PyCFunction_Call (func=0xa97cdcc, arg=0xb7fa502c,
kw=0x0)
at Objects/methodobject.c:85
#22 0x0015973c in PyObject_Call (func=0xa97cdcc, arg=0xb7fa502c,
kw=0x0)
at Objects/abstract.c:2492
#23 0x03db43c8 in
__pyx_pf_4sage_8symbolic_8function_13GinacFunction___call__ (
__pyx_v_self=0x9c053ac, __pyx_args=0x855cf0c,
__pyx_kwds=0xaa113e4)
at sage/symbolic/function.cpp:6553
#24 0x001b4c6d in wrap_call (self=0x9c053ac, args=0x855cf0c,
wrapped=0x3db3d00, kwds=0xaa113e4) at Objects/typeobject.c:4591
#25 0x001755b0 in wrapper_call (wp=0xa9e308c, args=0x855cf0c,
kwds=0x6)
at Objects/descrobject.c:982
#26 0x0015973c in PyObject_Call (func=0xa9e308c, arg=0x855cf0c,
kw=0xaa113e4)

I am running Ubuntu 10.10 btw. Can we/you/I deduce something from the
above?

Many thanks, Kees

[Volker Braun]

My guess would be

#8  0x008eef06 in rtodbl (x=0xb7d3d708) 

This is where the over flow occurs, raises signal

#7  0x00b49f0e in pari_err (numerr=15) at ../src/language/init.c:980 

it is handled by the pari error handler, which attempts to longjmp back into rtodbl or some cleanup routine (did anyone forget to setjmp the target?) 

#6  0x003c9849 in __longjmp_chk () from /lib/libc.so.6 

the libc is nice enough to do some sanity checking before you longjmp into nirvana 

#4  0x003c9970 in __fortify_fail () from /lib/libc.so.6 

#5  0x003c98da in ?? () from /lib/libc.so.6 

Something is broken!

Bottom line: compile your own Sage.

[KvS]

Thanks a lot for your efforts Volker! I have no experience with
compiling code, but I will give it a go.

Should we report this somewhere, or is this just an inherent problem
with running precompiled binaries?

Cheers, Kees

[Volker Braun]

Unless you are running precisely 32bit ubuntu 10.04 lts there is nothing that Sage can do about it.