Hi!
I was trying out the journal and the journalctl utility sometimes
crashed on me. After some debugging, I tracked it down to the fact
that next_with_matches() holds the "c" object pointer through the
journal_file_next_entry_for_data() call -- which apparently may re-map
the journal file, invalidating the pointer.
The attached patch fixes this crash for me, but being unfamiliar with
the code, I don't know if I'm doing the right thing.
This patch is also available from my github repository:
git://github.com/intgr/systemd.git
https://github.com/intgr/systemd
Regards,
Marti
For the record, here's the original stack trace at the time of remapping:
ret=0x7fff1d5cdec0) at src/journal/journal-file.c:330
ret=0x7fff1d5cdf28) at src/journal/journal-file.c:414
ret=0x7fff1d5ce0a0, offset=0x7fff1d5ce098) at
src/journal/journal-file.c:1101
i=5705, ret=0x7fff1d5ce0a0, offset=0x7fff1d5ce098) at
src/journal/journal-file.c:1147
p=6413608, data_offset=66600, direction=DIRECTION_DOWN,
ret=0x7fff1d5ce0a0, offset=0x7fff1d5ce098) at
src/journal/journal-file.c:1626
direction=DIRECTION_DOWN, ret=0x7fff1d5ce120, offset=0x7fff1d5ce128)
at src/journal/sd-journal.c:533
direction=DIRECTION_DOWN, ret=0x7fff1d5ce170, offset=0x7fff1d5ce178)
at src/journal/sd-journal.c:595
src/journal/sd-journal.c:651
From 9266fc6a58065a7c5dab67430fd78925e519dce9 Mon Sep 17 00:00:00 2001
From: Marti Raudsepp <marti@juffo.org>
Date: Fri, 9 Mar 2012 16:23:00 +0200
Subject: [PATCH] journal: Don't hold pointers to journal while remapping
This would cause a segfault otherwise.
After long consideration we came to the conclusion that user
configuration in /etc should always override the (generally computer
generated) configuration in /run. User configuration should always be
what matters over anything else. Hence rearrange the search orders
accordingly.
In general this should change very little as overriding like this is
seldomn done so far, and the order between /etc and /usr stays the same.
If a client connects to us repeatedly always using the same source port
and we instantiate a service for the incoming connection this might
clash with an old instance. Hence, include the connection number, the
same way we do it for AF_UNIX to make connections unique.
https://bugs.freedesktop.org/show_bug.cgi?id=45297
This device is a combination USB hub, displaylink graphics, and e2i touchscreen
Bus 001 Device 005: ID 058f:6254 Alcor Micro Corp. USB Hub
Bus 001 Device 006: ID 17e9:401a Newnham Research
Bus 001 Device 007: ID 1ac7:0001
|__ Port 1: Dev 5, If 0, Class=hub, Driver=hub/4p, 480M
|__ Port 2: Dev 6, If 0, Class=vend., Driver=udlfb, 480M
|__ Port 2: Dev 6, If 1, Class=HID, Driver=usbhid, 480M
|__ Port 3: Dev 7, If 0, Class=vend., Driver=usbtouchscreen, 12M
we need to make sure that configuration data we expose via the bus ends
up in using getting an assert(). Even though configuration data is only
parsed from trusted sources we should be more careful with what we read.
