Re: a problem with linux 2.6.11 and sa

[George Georgalis <georgalis@gmail.com>]

On Tue, 8 Mar 2005 12:19:53 -0500, George Georgalis <george@galis.org> wrote:
> On Tue, Mar 08, 2005 at 11:58:14AM -0500, George Georgalis wrote:
> >On Tue, Mar 08, 2005 at 01:37:03PM +0000, Nix wrote:
> >>On Thu, 3 Mar 2005, George Georgalis uttered the following:
> >>> 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?
> >>
> >>The entire implementation of pipes has been radically revised between
> >>2.6.10 and 2.6.11: see, e.g., <http://lwn.net/Articles/118750/> and
> >><http://lwn.net/Articles/119682/>.
> >>
> >>Bugs have been spotted in this area in 2.6.10: this may be
> >>another one.
> >
> >Thanks, my issue is clearly between 2.6.10 and 2.6.11; though I won't be
> >able to drill down anything more specific, for a while. The links
> >do look relevant but I cannot say for sure.

Here is a problem with 2.6.10:

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

or

tail -n93  mediafiles.txt | while read file; do mplayer $file ; done

for each file path in that text file I get:

Failed to open /dev/rtc: Permission denied (it should be readable by the user.)

In addition the audio pcm level is set to zero (presumably by mplayer).

This does work:
for file in `cat mediafiles.txt`; do mplayer $file ; done

but discovering and fixing code now broke will be unpleasent.
What exactly is going on? 

// George

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