2005-03-03 17:46:38

by George Georgalis

[permalink] [raw]
Subject: problem with linux 2.6.11 and sa

Please keep me in cc as I'm not presently subscribed to lkml)

I recall a problem a while back with a pipe from
/proc/kmsg that was sent by root to a program with a
user uid. The fix was to run the logging program as
root. Has that protected pipe method been extended
since 2.6.8.1?


I'm very defiantly seeing a problem with the 2.6.11
kernel and my spamassassin setup. However, it's not
clear exactly where the problem is, seems like sa
but it might be 2.6.11 with daemontools + qmail +
QMAIL_QUEUE.

A sure sign of it is no logs (with debug) for
remote sa connections which score "0/0" and correct
operation with local "cat spam.txt | spamc -R"; fix
is to use the older kernel.

SA has stopped stdout logging completely with 2.6.11
in addition to the all pass score. But the message
seems to go through my temp queue (for testing) and
sent on to my local MDA. I'm not sure if it's a sa
problem with the kernel or the new kernel doing
something new with pipes from tcp connections.
Maybe the new kernel is not making files available
(eg 0 bytes), until the writing pipe is closed?
That would make my SA test a zero byte file, which
would pass, close, become full, and the file piped
to local MDA is full? ...humm then I'd get a score
of "0/5"... this sounds like a SA problem with the
new kernel, ideas?


// George


--
George Georgalis, systems architect, administrator Linux BSD IXOYE
http://galis.org/george/ cell:646-331-2027 mailto:[email protected]


2005-03-21 22:27:42

by Andrew Morton

[permalink] [raw]
Subject: Re: problem with linux 2.6.11 and sa

"George Georgalis" <[email protected]> wrote:
>
> I'm very defiantly seeing a problem with the 2.6.11
> kernel and my spamassassin setup. However, it's not
> clear exactly where the problem is, seems like sa
> but it might be 2.6.11 with daemontools + qmail +
> QMAIL_QUEUE.
>
> A sure sign of it is no logs (with debug) for
> remote sa connections which score "0/0" and correct
> operation with local "cat spam.txt | spamc -R"; fix
> is to use the older kernel.
>
> SA has stopped stdout logging completely with 2.6.11
> in addition to the all pass score. But the message
> seems to go through my temp queue (for testing) and
> sent on to my local MDA. I'm not sure if it's a sa
> problem with the kernel or the new kernel doing
> something new with pipes from tcp connections.
> Maybe the new kernel is not making files available
> (eg 0 bytes), until the writing pipe is closed?
> That would make my SA test a zero byte file, which
> would pass, close, become full, and the file piped
> to local MDA is full? ...humm then I'd get a score
> of "0/5"... this sounds like a SA problem with the
> new kernel, ideas?

George, did you end up getting to the bottom of this? I'd be suspecting a
bug in the new pipe code, or an application bug which was triggered by the
new pipe code.

2005-03-21 22:53:26

by George Georgalis

[permalink] [raw]
Subject: Re: problem with linux 2.6.11 and sa

On Mon, Mar 21, 2005 at 02:25:55PM -0800, Andrew Morton wrote:
>"George Georgalis" <[email protected]> wrote:
>>
>> I'm very defiantly seeing a problem with the 2.6.11
>> kernel and my spamassassin setup. However, it's not
>> clear exactly where the problem is, seems like sa
>> but it might be 2.6.11 with daemontools + qmail +
>> QMAIL_QUEUE.
>>
>> A sure sign of it is no logs (with debug) for
>> remote sa connections which score "0/0" and correct
>> operation with local "cat spam.txt | spamc -R"; fix
>> is to use the older kernel.
>>
>> SA has stopped stdout logging completely with 2.6.11
>> in addition to the all pass score. But the message
>> seems to go through my temp queue (for testing) and
>> sent on to my local MDA. I'm not sure if it's a sa
>> problem with the kernel or the new kernel doing
>> something new with pipes from tcp connections.
>> Maybe the new kernel is not making files available
>> (eg 0 bytes), until the writing pipe is closed?
>> That would make my SA test a zero byte file, which
>> would pass, close, become full, and the file piped
>> to local MDA is full? ...humm then I'd get a score
>> of "0/5"... this sounds like a SA problem with the
>> new kernel, ideas?
>
>George, did you end up getting to the bottom of this? I'd be suspecting a
>bug in the new pipe code, or an application bug which was triggered by the
>new pipe code.

Hi! No resolution, I've been overloaded on a work related project. The
best I can say is no problem noticed with 2.6.8.1, 2.6.10 works for smtp
code below but fails mplayer commands; 2.6.11 failed smtp code, didn't
test mplayer on 2.6.11 and haven't tried any newer kernels.

while read file; do mplayer $file ; done <mediafiles.txt # fails

for file in `cat mediafiles.txt`; do mplayer $file ; done # works

mplayer foo.mpg # works
mplayer foo.mpg < mediafiles.txt # confuses binary for keboard input

This is the code that seems to fail per quote above, stdin is the smtp
DATA

tmp="${scq}/`safecat "${scq}/tmp" "${scq}" </dev/stdin`" \
|| { echo "Error $?"; exit 71; } # put the pipeline to disk, if possible
# ${scq}/tmp is a temp for this function ${scq} is temp for this
# program
score=`spamc -x -c <"$tmp"` # score it with spamd
sce=$?

I saw some notes on the new multi page pipes, me thinks its related but
that's all I know...

Regards,
// George


--
George Georgalis, systems architect, administrator Linux BSD IXOYE
http://galis.org/george/ cell:646-331-2027 mailto:[email protected]