Fontconfig lockup (was Re: System software teleconference minutes - 2007-04-03)

[Bert Freudenberg]

Sure. I'm not saying fc is not faulty, but that this fault exposes  
another bug deeper in the system.

- Bert -

On Apr 4, 2007, at 14:08 , Jim Gettys wrote:

> Please try fontconfig 2.4.2; we are using 2.4.1, which has a known
> corruption problem in its database.  Reading between the lines of
> Keith's commit message in the fix in 2.4.2, almost anything could
> happen.  I'd suspect this bug long before delving into libc.
>                               - Jim
>
>
> On Wed, 2007-04-04 at 09:04 +0200, Bert Freudenberg wrote:
>> On Apr 4, 2007, at 4:26 , Mitch Bradley wrote:
>>> * Blocker bugs for trial-1
>>>
>>> * Sugar crashes/hangs
>>>
>>>   It seems to happen every 15 to 20 reboots.  It can be triggered by
>>> stopping
>>>   Sugar, restarting, then mouse-over.  It seems to be a double- 
>>> free in
>>> fontconfig.
>>>   May need Behdad or Keith to look at it.  First try later release -
>>> 242.  There
>>>   is a segfault bug that is reported to have been fixed in mmap  
>>> shared
>>> fontconfig data.
>>
>> Maybe we should have a libc person looking at that - the trigger for
>> the freeze seems to be expat freeing something (called from
>> fontconfig), but the actual lockup is due to libc trying to get a
>> backtrace, which involves dlopen() causing another free() which
>> locks. See backtrace at
>>
>> http://dev.laptop.org/attachment/ticket/1245/bt.log