Hello,
just tried to reproduce the crash I came to following stack:
gdb -q --args dieharder -g 207 -a
Program received signal SIGSEGV, Segmentation fault.
gsl_rng_get (r=0x0) at ../gsl/gsl_rng.h:161
161 return (r->type->get) (r->state);
(gdb) bt
#0 gsl_rng_get (r=0x0) at ../gsl/gsl_rng.h:161
#1 0x00007ffff7b5dcc6 in XOR_get (vstate=0x633030) at rng_XOR.c:42
#2 0x00007ffff7b59ed0 in rgb_timing (test=test@entry=0x635ac0,
timing=timing@entry=0x7fffffffdb90) at rgb_timing.c:38
#3 0x0000000000405889 in time_rng () at time_rng.c:38
#4 0x000000000040252f in select_rng (gennum=<optimized out>,
genname=genname@entry=0x60a7c0 <generator_name> "", initial_seed=<optimized
out>) at choose_rng.c:252
#5 0x000000000040262a in choose_rng () at choose_rng.c:60
#6 0x0000000000402141 in main (argc=4, argv=0x7fffffffdcf8) at dieharder.c:71
gsl_rng_get/XOR_get:42 relies here to have state->grngs[1] initialized.
I tried to follow it and got to gsl_rng_set/XOR_set in
function rgb_timing that should put the seed to the generator.
Unfortunately gvcount is here just 1, leaving just grngs[0] set.
state->grngs[0] = gsl_rng_alloc(dh_rng_types[14]);
...
for(i=1;i<gvcount;i++){
...
state->grngs[i] = gsl_rng_alloc(dh_rng_types[gnumbs[i]]);
Further reading down leads to this comment saying we need at least one
additional -g parameter:
rng_XOR.c:
/*
* This is a special XOR generator that takes a list of GSL
* wrapped rngs and XOR's their uint output together to produce
* each new random number. Note that it SKIPS THE FIRST ONE which
* MUST be the XOR rng itself. So there have to be at least two -g X
* stanzas on the command line to use XOR, and if there aren't three
* or more it doesn't "do" anything but use the second one.
*/
So this command "dieharder -g 207 -a" is probably not expected
to work and "just" fails to produce an error message.
Kind regards,
Bernhard
BTW: Kind of the same problem could be observed when using such
a command line: "dieharder -g 207 -g 207 -a".
This crashes later after exhausting the whole stack.
