[R] Extension provokes crash in unzReadCurrentFile

[Mark White]

> > On Mon, 8 Nov 2004, Mark White wrote:
> > > Any idea what might be causing a compressed file read?

Prof Brian Ripley writes:
> > It's not a compressed file read, but rather from the interface for unz()  
> > connections to zip files.  That is very unlikely to be used on a
> > non-Windows system, so if that really is being called this looks like
> > considerable internal corruption.
>
Peter Dalgaard writes:
> In any case, since you're obviously running a more than half-decent
> operating system, and you seem to know how to operate the debugger
> (gdb?), could you please tell us what the backtrace ("bt", if gdb)
> says at the point of crash.

Sure -- trace from a (fairly typical) core dump below.

However, I tentatively think I've found the problem now:
hearing that this func shouldn't be called at all gave me a
few other ideas.  Changing the length of a large test vector
completely changed the top few functions in the trace, and I
then found an R_MakeExternalPtr with the wrong protection
argument, causing the GC to sometimes clear away the vector
before it was next accessed.

Haven't seen a crash since then, some hopefully that was it.
Thanks for your help.

Mark <><

--------------------------------------------------

(gdb) where
#0  0x80697c8 in do_attributesgets (call=0x1737d000, op=0x81fc5f0, args=0x0, 
    env=0x48371736) at attrib.c:744
#1  0x48371758 in ?? ()
#2  0x48371dd1 in ?? ()
#3  0x809c471 in unzReadCurrentFile (file=0x8ce4e7c, buf=0x8225d9c, 
    len=141386072) at dounzip.c:1248
#4  0x80acf7d in bcEval (body=0x8ce4e7c, rho=0x86d6e7c) at eval.c:2811
#5  0x80af0b9 in bcEval (body=0x8ce4e0c, rho=0x86d6e7c) at eval.c:3061
#6  0x80ae553 in bcEval (body=0x8ce4df0, rho=0x81fc040) at eval.c:3055
#7  0x80acdd7 in bcEval (body=0x8ce4df0, rho=0x86d6e7c) at eval.c:2808
#8  0x80ae518 in bcEval (body=0x8ce4f78, rho=0x81fd9c8) at eval.c:3055
#9  0x80acdd7 in bcEval (body=0x8ce4f78, rho=0x86d6e7c) at eval.c:2808
#10 0x80ad39e in bcEval (body=0x86d6ae0, rho=0x8de5f24) at eval.c:2884
#11 0x80d5b66 in nmmin (n=141388512, Bvec=0x8de5f24, X=0x86d6904, 
    Fmin=0x8dab894, fminfn=0x86d6894, fail=0x81fc7b0, 
    abstol=6.9523080897444509e-270, intol=5.8871398777326369e-266, 
    ex=0x86d6894, alpha=4.4536092707482937e-268, bet=8.1937066744817333e-267, 
    gamm=1.5190943468362191e-309, trace=2, fncount=0xbfbfc03c, 
    maxit=-1077951856) at optim.c:795
#12 0x80d6434 in lbfgsb (n=136004430, m=149385256, x=0x8b0e8b0, l=0x86d6904, 
    u=0x8dab894, nbd=0x8dab894, Fmin=0x81fc7b0, fminfn=0xbfbfc348, 
    fmingr=0x8dab894, fail=0x81fd8b0, ex=0x8b0e8b0, 
    factr=-NaN(0xffffa1bfb9000), pgtol=6.9650001374865742e-174, 
    fncount=0x8128faf, grcount=0x2, maxit=0, msg=0x8e77028 "³", 
    trace=-1077950876, nREPORT=20) at optim.c:1025
#13 0x80afb55 in bcEval (body=0x8b0e8b0, rho=0x81fd8b0) at eval.c:3063
#14 0x8129c6e in Rf_initialize_R (ac=145811632, av=0x81fd8b0) at system.c:170
#15 0x80acdd7 in bcEval (body=0x8b0e8b0, rho=0x8dab894) at eval.c:2808
#16 0x80aecad in bcEval (body=0x8b0e904, rho=0x81fdac4) at eval.c:3060
#17 0x80acdd7 in bcEval (body=0x8b0e904, rho=0x8dab894) at eval.c:2808
#18 0x80ae518 in bcEval (body=0x8b0e93c, rho=0x81fd9c8) at eval.c:3055
#19 0x80acdd7 in bcEval (body=0x8b0e93c, rho=0x8dab894) at eval.c:2808
#20 0x80ae0e4 in bcEval (body=0x8b0ea00, rho=0x81fc190) at eval.c:3052
#21 0x80acdd7 in bcEval (body=0x8b0ea00, rho=0x8dab894) at eval.c:2808
#22 0x80ae518 in bcEval (body=0x8b0e564, rho=0x81fd9c8) at eval.c:3055
#23 0x80acdd7 in bcEval (body=0x8b0e564, rho=0x8dab894) at eval.c:2808
#24 0x80ad39e in bcEval (body=0x8dac75c, rho=0x8b0e59c) at eval.c:2884
#25 0x80acff6 in bcEval (body=0x8dac75c, rho=0x822cae0) at eval.c:2812
#26 0x80ae518 in bcEval (body=0x8dac778, rho=0x81fd9c8) at eval.c:3055
#27 0x80acdd7 in bcEval (body=0x8dac778, rho=0x822cae0) at eval.c:2808
#28 0x80ae271 in bcEval (body=0x8dab824, rho=0x81fc1e4) at eval.c:3053
#29 0x80acdd7 in bcEval (body=0x8dab824, rho=0x822cae0) at eval.c:2808
#30 0x80c9a7d in Rf_allocVector (type=136497888, length=0) at memory.c:1787
#31 0x80c9bc7 in Rf_allocVector (type=136497888, length=0) at memory.c:1820
#32 0x80ca402 in Rf_protect (s=0x3001f) at memory.c:2074
#33 0x80ca41c in Rf_unprotect (l=0) at memory.c:2082
#34 0x805c3ad in do_getRtoCConverterDescriptions (call=0x1, op=0xbfbfd220, 
    args=0xbfbfd228, env=0x246) at CConverters.c:244
#35 0x805c1a0 in R_addToCConverter (matcher=0x1, converter=0xbfbfd220, 
    reverse=0xbfbfd228, userData=0x481c0bc0, desc=0x481cd200 "z¸PÕ\001")
    at CConverters.c:80
(gdb)