GNU bug report logs - #12095
Protecting pointer on bytevector with guardian does not protect memory

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Package: guile;

Reported by: Patrick Bernaud <patrickb <at> chez.com>

Date: Mon, 30 Jul 2012 16:48:01 UTC

Severity: normal

Done: ludo <at> gnu.org (Ludovic Courtès)

Bug is archived. No further changes may be made.

Full log

Message #11 received at 12095 <at> debbugs.gnu.org (full text, mbox):

From: Daniel Hartwig <mandyke <at> gmail.com>
To: Ian Price <ianprice90 <at> googlemail.com>
Cc: Patrick Bernaud <patrickb <at> chez.com>, 12095 <at> debbugs.gnu.org
Subject: Re: bug#12095: Protecting pointer on bytevector with guardian does
	not protect memory
Date: Tue, 7 Aug 2012 11:32:10 +0800

[Message part 1 (text/plain, inline)]
On 7 August 2012 00:37, Ian Price <ianprice90 <at> googlemail.com> wrote:
> Patrick Bernaud <patrickb <at> chez.com> writes:
>
>> With auto compilation turned on, it looks like the problem can not be
>> reproduced.

That is to say, when using --fresh-auto-compile.

>
> I cannot reproduce this on 32 bit fedora 16 with guile (GNU Guile)
> 2.0.6-dirty (commit 1321a36ed61deb9431b41768dc92cb7230c9afa1). However,
> there was one caveat, as I didn't have html prag, I substituted for
> various other libraries (ice-9 regex)/(ice-9 threads)/(sxml simple)/ and
> my own (pfds queues).
>
> Is this bug somehow particular to htmlprag, or can you confirm it with others?

On x86 Debian sid I reproduced the bug by loading (web server) with
the original test.scm from the mailing list.

The bug report copy differs from the original by replacing
parse-c-struct with pointer->bytevector.

I attach test1.scm, with a loop to load many modules one at a time.
Curiously, when using pointer->bytevector the contents change (for me)
only when freshly compiling:

$ guile --fresh-auto-compile test1.scm
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /home/daniel/Downloads/test1.scm
;;; compiled /home/daniel/.cache/guile/ccache/2.0-LE-4-2.0/home/daniel/Downloads/test1.scm.go
#<pointer 0xa1cdb7c>
#vu8(1 1 1 1 1 1 1 1 1 1)
Contents differ after (web http)
#vu8(110 116 104 101 115 105 122 101 0 1)
#<pointer 0xa1cdb7c>
$ guile test1.scm
#<pointer 0x82c754c>
#vu8(1 1 1 1 1 1 1 1 1 1)
#<pointer 0x82c754c>

With the original (using parse-c-struct) it was the other way around.

[test1.scm (application/octet-stream, attachment)]
This bug report was last modified 12 years and 291 days ago.

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