GNU bug report logs - #39954
[3.0.0] ‘frame-local-ref’ returns (SCM)0x0

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: bug-guile <at> gnu.org
Subject: [3.0.0] ‘frame-local-ref’ returns (SCM)0x0
Date: Fri, 06 Mar 2020 17:05:04 +0100

The example below leads to a Guile 3.0.0 segfault while trying to
display a backtrace from the evaluator:

--8<---------------cut here---------------start------------->8---
$ cat ~/src/guile-debugging/scm_is_values-abort.scm
(use-modules (ice-9 time))

(time (ash 1 #;(expt 2 82) 4835703278458516698824704))
$ guile ~/src/guile-debugging/scm_is_values-abort.scm
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /home/ludo/src/guile-debugging/scm_is_values-abort.scm
;;; WARNING: compilation of /home/ludo/src/guile-debugging/scm_is_values-abort.scm failed:
;;; In procedure bytevector-u32-native-set!: Argument 3 out of range: 1125899906842624
Backtrace:
           3 (primitive-load "/home/ludo/src/guile-debugging/scm_is_values-abort.scm")
In ice-9/time.scm:
    38:18  2 (time-proc #<procedure 7faa1889c2c0 at ice-9/eval.scm:330:13 ()>)
In unknown file:
Adres-eraro(nekropsio elŝutita)
$ gdb $(which guile) core

[...]

Core was generated by `guile /home/ludo/src/guile-debugging/scm_is_values-abort.scm'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007faa1d3e4d74 in scm_is_values (x=0x0) at values.h:30
30	values.h: Dosiero aŭ dosierujo ne ekzistas.
[Current thread is 1 (Thread 0x7faa1ccf9b80 (LWP 9971))]
ERROR: In procedure type-pointer:
ERROR: In procedure gdbscm_type_pointer: Wrong type argument in position 1 (expecting gdb:type): #f
Error while executing Scheme code.(gdb) bt
#0  0x00007faa1d3e4d74 in scm_is_values (
    x=<error reading variable: ERROR: Cannot access memory at address 0x0>0x0) at values.h:30
#1  vm_regular_engine (thread=0x7faa1c9d5d80) at vm-engine.c:974
#2  0x00007faa1d3e61a5 in scm_call_n (proc=<optimized out>, argv=argv <at> entry=0x7ffcac33bf40, nargs=nargs <at> entry=4)
    at vm.c:1589
#3  0x00007faa1d3620d4 in scm_call_4 (proc=<optimized out>, arg1=arg1 <at> entry="#<vector>" = {...}, 
    arg2=arg2 <at> entry=#<port #<port-type file 7faa1ac60b40> 7faa1acac3c0>, arg3=arg3 <at> entry=#:count, 
    arg4=arg4 <at> entry=20) at eval.c:517
#4  0x00007faa1d3555f9 in display_backtrace_body (a=<optimized out>) at backtrace.c:239
#5  0x00007faa1d36387a in scm_c_with_exception_handler (type=type <at> entry=#t, 
    handler=handler <at> entry=0x7faa1d3db630 <catch_post_unwind_handler>, 
    handler_data=handler_data <at> entry=0x7ffcac33c0f0, thunk=thunk <at> entry=0x7faa1d3db770 <catch_body>, 
    thunk_data=thunk_data <at> entry=0x7ffcac33c0f0) at exceptions.c:170
#6  0x00007faa1d3db96d in scm_c_catch (tag=tag <at> entry=#t, body=body <at> entry=0x7faa1d3554d0 <display_backtrace_body>, 
    body_data=body_data <at> entry=0x7ffcac33c160, handler=handler <at> entry=0x7faa1d3558b0 <error_during_backtrace>, 
    handler_data=handler_data <at> entry=0x7faa1acac3c0, pre_unwind_handler=pre_unwind_handler <at> entry=0x0, 
    pre_unwind_handler_data=0x0) at throw.c:168
#7  0x00007faa1d3db98e in scm_internal_catch (tag=tag <at> entry=#t, 
    body=body <at> entry=0x7faa1d3554d0 <display_backtrace_body>, body_data=body_data <at> entry=0x7ffcac33c160, 
    handler=handler <at> entry=0x7faa1d3558b0 <error_during_backtrace>, handler_data=handler_data <at> entry=0x7faa1acac3c0)
    at throw.c:177
#8  0x00007faa1d3554c5 in scm_display_backtrace_with_highlights (stack=stack <at> entry="#<struct stack>" = {...}, 
    port=port <at> entry=#<port #<port-type file 7faa1ac60b40> 7faa1acac3c0>, first=first <at> entry=#f, 
    depth=depth <at> entry=#f, highlights=highlights <at> entry=()) at backtrace.c:277
#9  0x00007faa1d35e01f in print_exception_and_backtrace (
    args=(#f "Value out of range ~S to ~S: ~S" (0 #<bignum 7faa188852a0> #<bignum 7faa188852e0>) (#<bignum 7faa188852e0>)), tag=out-of-range, port=#<port #<port-type file 7faa1ac60b40> 7faa1acac3c0>) at continuations.c:409
#10 pre_unwind_handler (error_port=0x7faa1acac3c0, tag=out-of-range, 
    args=(#f "Value out of range ~S to ~S: ~S" (0 #<bignum 7faa188852a0> #<bignum 7faa188852e0>) (#<bignum 7faa188852e0>))) at continuations.c:453
#11 0x00007faa1d3db6eb in catch_pre_unwind_handler (data=0x7ffcac33cb90, 
    exn="#<struct &compound-exception>" = {...}) at throw.c:135
#12 0x00007faa1d3e4d6c in vm_regular_engine (thread=0x7faa1c9d5d80) at vm-engine.c:972
#13 0x00007faa1d3e61a5 in scm_call_n (proc=proc <at> entry=#<unmatched-tag 10045>, argv=<optimized out>, nargs=5)
    at vm.c:1589
#14 0x00007faa1d3623d4 in scm_apply_0 (proc=#<unmatched-tag 10045>, args=()) at eval.c:603
#15 0x00007faa1d36307d in scm_apply_1 (proc=<optimized out>, arg1=arg1 <at> entry=out-of-range, 
    args=args <at> entry=(#f "Value out of range ~S to ~S: ~S" (0 #<bignum 7faa188852a0> #<bignum 7faa188852e0>) (#<bignum 7faa188852e0>))) at eval.c:609
#16 0x00007faa1d3dbb29 in scm_throw (key=key <at> entry=out-of-range, 
    args=(#f "Value out of range ~S to ~S: ~S" (0 #<bignum 7faa188852a0> #<bignum 7faa188852e0>) (#<bignum 7faa188852e0>))) at throw.c:262
#17 0x00007faa1d3dbc79 in scm_ithrow (key=key <at> entry=out-of-range, args=<optimized out>, 
    no_return=no_return <at> entry=1) at throw.c:457
#18 0x00007faa1d360585 in scm_error_scm (key=key <at> entry=out-of-range, subr=<optimized out>, 
    message=message <at> entry="Value out of range ~S to ~S: ~S", 
    args=args <at> entry=(0 #<bignum 7faa188852a0> #<bignum 7faa188852e0>), data=data <at> entry=(#<bignum 7faa188852e0>))
    at error.c:90
#19 0x00007faa1d36061f in scm_error (key=out-of-range, subr=subr <at> entry=0x0, 
    message=message <at> entry=0x7faa1d4010f0 "Value out of range ~S to ~S: ~S", 
    args=(0 #<bignum 7faa188852a0> #<bignum 7faa188852e0>), rest=rest <at> entry=(#<bignum 7faa188852e0>))
    at error.c:62
#20 0x00007faa1d393d87 in scm_i_range_error (bad_val=bad_val <at> entry=#<bignum 7faa188852e0>, min=0, 
    max=max <at> entry=#<bignum 7faa188852a0>) at numbers.c:9764
#21 0x00007faa1d39cd13 in scm_to_uint64 (val=#<bignum 7faa188852e0>) at conv-uinteger.i.c:38
#22 0x00007faa1d3e4882 in vm_regular_engine (thread=0x7faa1c9d5d80) at vm-engine.c:1533
#23 0x00007faa1d3e61a5 in scm_call_n (proc=<optimized out>, argv=argv <at> entry=0x7ffcac33c648, nargs=nargs <at> entry=1)
    at vm.c:1589
#24 0x00007faa1d3631e7 in scm_primitive_eval (exp=<optimized out>) at eval.c:671
#25 0x00007faa1d38c30b in scm_primitive_load (filename=<optimized out>) at load.c:131
#26 0x00007faa1d3e4d6c in vm_regular_engine (thread=0x7faa1c9d5d80) at vm-engine.c:972
#27 0x00007faa1d3e61a5 in scm_call_n (proc=<optimized out>, argv=argv <at> entry=0x7ffcac33c818, nargs=nargs <at> entry=1)
    at vm.c:1589
#28 0x00007faa1d3631e7 in scm_primitive_eval (exp=<optimized out>, 
    exp <at> entry=((@ (ice-9 control) %) (begin ((@@ (ice-9 command-line) load/lang) "/home/ludo/src/guile-debugging/scm_is_values-abort.scm") (quit)))) at eval.c:671
#29 0x00007faa1d363243 in scm_eval (
    exp=((@ (ice-9 control) %) (begin ((@@ (ice-9 command-line) load/lang) "/home/ludo/src/guile-debugging/scm_is_values-abort.scm") (quit))), module_or_state=module_or_state <at> entry="#<struct module>" = {...}) at eval.c:705
#30 0x00007faa1d3bc130 in scm_shell (argc=2, argv=0x7ffcac33ce78) at script.c:357
#31 0x00007faa1d37ab4d in invoke_main_func (body_data=0x7ffcac33cd20) at init.c:308
#32 0x00007faa1d35de3a in c_body (d=0x7ffcac33cc60) at continuations.c:430
#33 0x00007faa1d3e4d6c in vm_regular_engine (thread=0x7faa1c9d5d80) at vm-engine.c:972
#34 0x00007faa1d3e61a5 in scm_call_n (proc=<optimized out>, argv=argv <at> entry=0x7ffcac33ca20, nargs=nargs <at> entry=2)
    at vm.c:1589
#35 0x00007faa1d36207a in scm_call_2 (proc=<optimized out>, arg1=<optimized out>, arg2=<optimized out>)
    at eval.c:503
#36 0x00007faa1d36387a in scm_c_with_exception_handler (type=type <at> entry=#t, 
    handler=handler <at> entry=0x7faa1d3db630 <catch_post_unwind_handler>, 
    handler_data=handler_data <at> entry=0x7ffcac33cb90, thunk=thunk <at> entry=0x7faa1d3db770 <catch_body>, 
    thunk_data=thunk_data <at> entry=0x7ffcac33cb90) at exceptions.c:170
#37 0x00007faa1d3db96d in scm_c_catch (tag=tag <at> entry=#t, body=body <at> entry=0x7faa1d35de30 <c_body>, 
    body_data=body_data <at> entry=0x7ffcac33cc60, handler=handler <at> entry=0x7faa1d35e0d0 <c_handler>, 
    handler_data=handler_data <at> entry=0x7ffcac33cc60, 
    pre_unwind_handler=pre_unwind_handler <at> entry=0x7faa1d35df30 <pre_unwind_handler>, 
    pre_unwind_handler_data=0x7faa1acac3c0) at throw.c:168
#38 0x00007faa1d35e3e3 in scm_i_with_continuation_barrier (body=body <at> entry=0x7faa1d35de30 <c_body>, 
    body_data=body_data <at> entry=0x7ffcac33cc60, handler=handler <at> entry=0x7faa1d35e0d0 <c_handler>, 
    handler_data=handler_data <at> entry=0x7ffcac33cc60, 
    pre_unwind_handler=pre_unwind_handler <at> entry=0x7faa1d35df30 <pre_unwind_handler>, 
    pre_unwind_handler_data=0x7faa1acac3c0) at continuations.c:368
#39 0x00007faa1d35e475 in scm_c_with_continuation_barrier (func=<optimized out>, data=<optimized out>)
    at continuations.c:464
#40 0x00007faa1d3da40f in with_guile (base=0x7ffcac33ccc8, data=0x7ffcac33ccf0) at threads.c:645
#41 0x00007faa1d2bfa68 in GC_call_with_stack_base ()
   from /gnu/store/3xs3dnc28p9fi8in7hkfcdx20incrdvq-libgc-7.6.12/lib/libgc.so.1
#42 0x00007faa1d3da728 in scm_i_with_guile (dynamic_state=<optimized out>, data=data <at> entry=0x7ffcac33ccf0, 
    func=func <at> entry=0x7faa1d37ab30 <invoke_main_func>) at threads.c:688
#43 scm_with_guile (func=func <at> entry=0x7faa1d37ab30 <invoke_main_func>, data=data <at> entry=0x7ffcac33cd20)
    at threads.c:694
#44 0x00007faa1d37acc2 in scm_boot_guile (argc=argc <at> entry=2, argv=argv <at> entry=0x7ffcac33ce78, 
    main_func=main_func <at> entry=0x401240 <inner_main>, closure=closure <at> entry=0x0) at init.c:291
#45 0x0000000000401100 in main (argc=2, argv=0x7ffcac33ce78) at guile.c:95
--8<---------------cut here---------------end--------------->8---

I traced it to ‘frame-call-representation’ calling ‘frame-local-ref’ via
‘application-arguments’, and getting (SCM)0x0 from there.

Ludo’.

PS: The ‘ash’ example is taken from <https://issues.guix.gnu.org/issue/39947>.

Message #8 received at 39954 <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: 39954 <at> debbugs.gnu.org
Subject: Re: bug#39954: [3.0.0] ‘frame-local-ref’ returns (SCM)0x0
Date: Sat, 21 Mar 2020 18:57:14 +0100

More generally, it seems that ‘frame-local-ref’ gets it wrong anytime it
sees a stack frame for a subr.

Ludo’.

Message #11 received at 39954 <at> debbugs.gnu.org (full text, mbox):

From: Maxime Devos <maximedevos <at> telenet.be>
To: 50153 <at> debbugs.gnu.org, 39954 <at> debbugs.gnu.org
Subject: Re: bug#50153: Acknowledgement (call-with-values outside tail
 position + backtrace + compilation causes segfault)
Date: Sat, 21 Aug 2021 20:30:25 +0200

[Message part 1 (text/plain, inline)]

This looks rather similar to 39954 <at> debbugs.gnu.org,
looking at the backtrace from GDB, maybe the cause is the same?

Thread 1 "guile" received signal SIGSEGV, Segmentation fault.
0x00007ffff7f40f3f in scm_is_values (x=<optimized out>) at values.h:30
30	  return SCM_HAS_TYP7 (x, scm_tc7_values);
(gdb) bt
#0  0x00007ffff7f40f3f in scm_is_values (x=<optimized out>) at values.h:30
#1  vm_debug_engine (thread=0x7ffff744cd80) at vm-engine.c:974
#2  0x00007ffff7f45c2d in scm_call_n (proc=0x7ffff49612a0, argv=argv <at> entry=0x7fffffffc080, 
    nargs=nargs <at> entry=4) at vm.c:1608
#3  0x00007ffff7ec1234 in scm_call_4 (proc=<optimized out>, arg1=arg1 <at> entry=0x7ffff35162d0, 
    arg2=arg2 <at> entry=0x7ffff5ad4600, arg3=arg3 <at> entry=0x7ffff495a0b0, arg4=arg4 <at> entry=0x52) at eval.c:517
#4  0x00007ffff7eb3815 in display_backtrace_body (a=<optimized out>) at backtrace.c:239
#5  0x00007ffff7ec29ea in scm_c_with_exception_handler (type=type <at> entry=0x404, 
    handler=handler <at> entry=0x7ffff7f3aed0 <catch_post_unwind_handler>, 
    handler_data=handler_data <at> entry=0x7fffffffc230, thunk=thunk <at> entry=0x7ffff7f3b010 <catch_body>, 
    thunk_data=thunk_data <at> entry=0x7fffffffc230) at exceptions.c:170
#6  0x00007ffff7f3b20d in scm_c_catch (tag=tag <at> entry=0x404, 
    body=body <at> entry=0x7ffff7eb36f0 <display_backtrace_body>, body_data=body_data <at> entry=0x7fffffffc2a0, 
    handler=handler <at> entry=0x7ffff7eb3b20 <error_during_backtrace>, 
    handler_data=handler_data <at> entry=0x7ffff5ad4600, pre_unwind_handler=pre_unwind_handler <at> entry=0x0, 
    pre_unwind_handler_data=0x0) at throw.c:168
#7  0x00007ffff7f3b22e in scm_internal_catch (tag=tag <at> entry=0x404, 
    body=body <at> entry=0x7ffff7eb36f0 <display_backtrace_body>, body_data=body_data <at> entry=0x7fffffffc2a0, 
    handler=handler <at> entry=0x7ffff7eb3b20 <error_during_backtrace>, 
    handler_data=handler_data <at> entry=0x7ffff5ad4600) at throw.c:177
#8  0x00007ffff7eb36e5 in scm_display_backtrace_with_highlights (stack=stack <at> entry=0x7ffff38604a0, 
    port=port <at> entry=0x7ffff5ad4600, first=first <at> entry=0x4, depth=depth <at> entry=0x4, 
    highlights=highlights <at> entry=0x304) at backtrace.c:277
#9  0x00007ffff7eb3970 in scm_backtrace_with_highlights (highlights=0x304) at backtrace.c:310
#10 0x00007ffff7f40f3b in vm_debug_engine (thread=0x7ffff744cd80) at vm-engine.c:972
#11 0x00007ffff7f45c2d in scm_call_n (proc=0x7ffff5a2e030, argv=argv <at> entry=0x7fffffffc498, 
    nargs=nargs <at> entry=1) at vm.c:1608
#12 0x00007ffff7ec2337 in scm_primitive_eval (exp=<optimized out>, exp <at> entry=0x7ffff5ba1a40)
    at eval.c:671
#13 0x00007ffff7ec2393 in scm_eval (exp=0x7ffff5ba1a40, 
    module_or_state=module_or_state <at> entry=0x7ffff5b93c80) at eval.c:705
#14 0x00007ffff7f1b780 in scm_shell (argc=4, argv=0x7fffffffcb08) at script.c:357
#15 0x00007ffff7edb1bd in invoke_main_func (body_data=0x7fffffffc9a0) at init.c:313
#16 0x00007ffff7ebc06a in c_body (d=0x7fffffffc8e0) at continuations.c:430
#17 0x00007ffff7f447d8 in vm_regular_engine (thread=0x7ffff744cd80) at vm-engine.c:972
#18 0x00007ffff7f45c2d in scm_call_n (proc=0x7ffff5b088a0, argv=argv <at> entry=0x7fffffffc6a0, 
    nargs=nargs <at> entry=2) at vm.c:1608
#19 0x00007ffff7ec11da in scm_call_2 (proc=<optimized out>, arg1=<optimized out>, arg2=<optimized out>)
    at eval.c:503
#20 0x00007ffff7ec29ea in scm_c_with_exception_handler (type=type <at> entry=0x404, 
    handler=handler <at> entry=0x7ffff7f3aed0 <catch_post_unwind_handler>, 
    handler_data=handler_data <at> entry=0x7fffffffc810, thunk=thunk <at> entry=0x7ffff7f3b010 <catch_body>, 
    thunk_data=thunk_data <at> entry=0x7fffffffc810) at exceptions.c:170
#21 0x00007ffff7f3b20d in scm_c_catch (tag=tag <at> entry=0x404, body=body <at> entry=0x7ffff7ebc060 <c_body>, 
    body_data=body_data <at> entry=0x7fffffffc8e0, handler=handler <at> entry=0x7ffff7ebc300 <c_handler>, 
    handler_data=handler_data <at> entry=0x7fffffffc8e0, 
    pre_unwind_handler=pre_unwind_handler <at> entry=0x7ffff7ebc160 <pre_unwind_handler>, 
    pre_unwind_handler_data=0x7ffff5ad45c0) at throw.c:168
#22 0x00007ffff7ebc603 in scm_i_with_continuation_barrier (body=body <at> entry=0x7ffff7ebc060 <c_body>, 
    body_data=body_data <at> entry=0x7fffffffc8e0, handler=handler <at> entry=0x7ffff7ebc300 <c_handler>, 
    handler_data=handler_data <at> entry=0x7fffffffc8e0, 
    pre_unwind_handler=pre_unwind_handler <at> entry=0x7ffff7ebc160 <pre_unwind_handler>, 
--Type <RET> for more, q to quit, c to continue without paging--c
    pre_unwind_handler_data=0x7ffff5ad45c0) at continuations.c:368
#23 0x00007ffff7ebc695 in scm_c_with_continuation_barrier (func=<optimized out>, data=<optimized out>) at continuations.c:464
#24 0x00007ffff7f39c9f in with_guile (base=0x7fffffffc948, data=0x7fffffffc970) at threads.c:645
#25 0x00007ffff7e16b48 in GC_call_with_stack_base () from /gnu/store/f6kngpp27585xh4564y9rvshqn8hph8v-libgc-8.0.4/lib/libgc.so.1
#26 0x00007ffff7f39fc8 in scm_i_with_guile (dynamic_state=<optimized out>, data=data <at> entry=0x7fffffffc970, func=func <at> entry=0x7ffff7edb1a0 <invoke_main_func>) at threads.c:688
#27 scm_with_guile (func=func <at> entry=0x7ffff7edb1a0 <invoke_main_func>, data=data <at> entry=0x7fffffffc9a0) at threads.c:694
#28 0x00007ffff7edb332 in scm_boot_guile (argc=argc <at> entry=4, argv=argv <at> entry=0x7fffffffcb08, main_func=main_func <at> entry=0x401230 <inner_main>, closure=closure <at> entry=0x0) at init.c:296
#29 0x00000000004010f6 in main (argc=4, argv=0x7fffffffcb08) at guile.c:94

[signature.asc (application/pgp-signature, inline)]

Message #14 received at 39954 <at> debbugs.gnu.org (full text, mbox):

From: Maxime Devos <maximedevos <at> telenet.be>
To: 50153 <at> debbugs.gnu.org, 39954 <at> debbugs.gnu.org
Subject: Re: bug#50153: Acknowledgement (call-with-values outside tail
 position + backtrace + compilation causes segfault)
Date: Sat, 21 Aug 2021 22:17:56 +0200

[Message part 1 (text/plain, inline)]

I did some debugging on the C side, using 'rr':

LD_LIBRARY_PATH=.libs ../meta/uninstalled-env rr record ./.libs/guile --fresh-auto-compile -l ../crash.scm

it leads to a segfault, as expected.  According to #39954, which looks
similar, 'frame-local-ref' returns (SCM)0x0.  So I tried some reverse debugging:

rr replay guile-3
break scm_frame_local_ref
reverse-continue
reverse-continue

I noticed "repr" was STACK_ITEM_SCM, and item->as_scm was set to 0x07
(which is invalid).  On another run, it was set to 0x09 (also invalid?).
I modified scm_frame_local_ref a bit so it ignores these 0x07 and 0x09
and treats them like SCM_EOF_VAL instead.  That allows printing the backtrace,
though I don't see those #<eof> appearing in the output.

Would someone know what's going on here?

Greetings,
Maxime

[printf.patch (text/x-patch, inline)]

diff --git a/libguile/frames.c b/libguile/frames.c
index 0bb40579c..87afaec3d 100644
--- a/libguile/frames.c
+++ b/libguile/frames.c
@@ -41,6 +41,7 @@
 
 #include "frames.h"
 
+#include <stdio.h>
 
 SCM
 scm_c_make_frame (enum scm_vm_frame_kind kind, const struct scm_frame *frame)
@@ -272,6 +273,11 @@ scm_frame_local_ref (SCM frame, SCM index, SCM representation)
       switch (repr)
         {
           case STACK_ITEM_SCM:
+            fprintf(stderr, "i: %u  SCM: %p\n", (unsigned) i, (void*)item->as_u64);
+            if (item->as_u64 == 0x07)
+              return SCM_EOF_VAL;
+            if (item->as_u64 == 0x09)
+              return SCM_EOF_VAL;
             return item->as_scm;
           case STACK_ITEM_F64:
             return scm_from_double (item->as_f64);

[signature.asc (application/pgp-signature, inline)]

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Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.