IRC.

16 files changed, 1016 insertions, 13 deletions

diff --git a/open_issues/anatomy_of_a_hurd_system.mdwn b/open_issues/anatomy_of_a_hurd_system.mdwn
index 13599e19..99ef170b 100644
--- a/open_issues/anatomy_of_a_hurd_system.mdwn
+++ b/open_issues/anatomy_of_a_hurd_system.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -122,3 +122,147 @@ IRC, OFTC, #debian-hurd, 2011-11-02:
       system (via libdiskfs).
     <tschwinge> sekon_: This may help a bit:
       http://www.gnu.org/software/hurd/hurd/hurd_hacking_guide.html
+
+---
+
+IRC, freenode, #hurd, 2012-01-08:
+
+    <abique> can you tell me how is done in hurd:  "ls | grep x" ?
+    <abique> in bash
+    <youpi> ls's standard output is a port to the pflocal server, and grep x's
+      standard input is a port to the pflocal server
+    <youpi> the connexion between both ports inside the pflocal server being
+      done by bash when it calls pipe()
+    <abique> youpi, so STDOUT_FILENO, STDIN_FILENO, STDERR_FILENO still exists
+      ?
+    <youpi> sure, hurd is compatible with posix
+    <abique> so bash 1) creates T1 (ls) and T2 (grep), then create a pipe at
+      the pflocal server, then connects both ends to T1 and T2, then start(T1),
+      start(T2) ?
+    <youpi> not exactly
+    <youpi> it's like on usual unix, bash creates the pipe before creating the
+      tasks
+    <youpi> then forks to create both of them, handling them each side of the
+      pipe
+    <abique> ok I see
+    <youpi> s/handling/handing/
+    <abique> but when you do pipe() on linux, it creates a kernel object, this
+      time it's 2 port on the pflocal ?
+    <youpi> yes
+    <abique> how are spawned tasks ?
+    <abique> with fork() ?
+    <youpi> yes
+    <youpi> which is just task_create() and duplicating the ports into the new
+      task
+    <abique> ok
+    <abique> so it's easy to rewrite fork() with a good control of duplicated
+      fd
+    <abique> about threading, mutexes, conditions, etc.. are kernel objects or
+      just userland objects ?
+    <youpi> just ports
+    <youpi> (only threads are kernel objects)
+    <abique> so, about efficiency, are pipes and mutexes efficient ?
+    <youpi> depends what you call "efficient"
+    <youpi> it's less efficient than on linux, for sure
+    <youpi> but enough for a workable system
+    <abique> maybe hurd is the right place for a userland thread library like
+      pth or any fiber library
+    <abique> ?
+    <youpi> hurd already uses a userland thread library
+    <youpi> libcthreads
+    <abique> is it M:N ?
+    <youpi> libthreads, actually
+    <youpi> yes
+    <abique> nice
+    <abique> is the task scheduler in the kernel ?
+    <youpi> the kernel thread scheduler, yes, of course
+    <youpi> there has to be one
+    <abique> are the posix open()/readdir()/etc... the direct vfs or wraps an
+      hurd layer libvfs ?
+    <youpi> they wrap RPCs to the filesystem servers
+    <antrik> the Bushnell paper is probably the closest we have to a high-level
+      documentation of these concepts...
+    <antrik> the Hurd does not have a central VFS component at all. name
+      lookups are performed directly on the individual FS servers
+    <antrik> that's probably the most fundamental design feature of the Hurd
+    <antrik> (all filesystem operations actually, not only lookups)
+
+IRC, freenode, #hurd, 2012-01-09:
+
+    <braunr> youpi: are you sure cthreads are M:N ? i'm almost sure they're 1:1
+    <braunr> and no modern OS is a right place for any thread userspace
+      library, as they wouldn't have support to run threads on different
+      processors (unless processors can be handled by userspace servers, but
+      still, it requires intimate cooperation between the threading library and
+      the kernel/userspace server in any case
+    <youpi> braunr: in libthreads, they are M:N
+    <youpi> you can run threads on different processors by using several kernel
+      threads, there's no problem in there, a lot of projects do this
+    <braunr> a pure userspace library can't use kernel threads
+    <braunr> at least pth was explacitely used on systems like bsd at a time
+      when they didn't have kernel threads exactly for that reason
+    <braunr> explicitely*
+    <braunr> and i'm actually quite surprised to learn that we have an M:N
+      threading model :/
+    <youpi> why do you say "can't" ?
+    <braunr> but i wanted to reply to abique and he's not around
+    <youpi> of course you need kernel threads
+    <youpi> but all you need is to bind them
+    <braunr> well, what i call a userspace threading library is a library that
+      completely implement threads without the support of the kernel
+    <braunr> or only limited support, like signals
+    <youpi> errr, you can't implement anything with absolutely no support of
+      the kernel
+    <braunr> pth used only SIGALRM iirc
+    <youpi> asking for more kernel threads to use more processors doesn't seem
+      much
+    <braunr> it's not
+    <braunr> but i'm refering to what abique said
+    <braunr> 01:32 < abique> maybe hurd is the right place for a userland
+      thread library like pth or any fiber library
+    <youpi> well, it's indeed more, because the glibc lets external libraries
+      provide their mutex
+    <youpi> while on linux, glibc doesn't
+    <braunr> i believe he meant removing thread support from the kernel :p
+    <youpi> ah
+    <braunr> and replying "nice" to an M:N threading model is also suspicious,
+      since experience seems to show 1:1 models are better
+    <youpi> "better" ????
+    <braunr> yes
+    <youpi> well
+    <youpi> I don't have any time to argue  about that
+    <youpi> because that'd be extremely long
+    <braunr> simpler, so far less bugs, and also less headache concerning posix
+      conformance
+    <youpi> but there's no absolute "better" here
+    <youpi> but less performant
+    <youpi> less flexible
+    <braunr> that's why i mention experience :)
+    <youpi> I mean experience too
+    <braunr> why less performant ?
+    <youpi> because you pay kernel transition
+    <youpi> because you don't know anything about the application threads
+    <youpi> etc.
+    <braunr> really ?
+    <youpi> yes
+    <braunr> i fail to see where the overhead is
+    <youpi> I'm not saying m:n is generally better than 1:1 either
+    <youpi> thread switch, thread creation, etc.
+    <braunr> creation is slower, i agree, but i'm not sure it's used frequently
+      enough to really matter
+    <youpi> it is sometimes used frequently enough
+    <youpi> and in those cases it would be a headache to avoid it
+    <braunr> ok
+    <braunr> i thought thread pools were used in those cases
+    <youpi> synchronized with kernel mutexes ?
+    <youpi> that's still slow
+    <braunr> it reduces to the thread switch overhead
+    <braunr> which, i agree is slightly slower
+    <braunr> ok, i's a bit less performant :)
+    <braunr> well don't futexes exist just for that too ?
+    <youpi> yes and no
+    <youpi> in that case they don't help
+    <youpi> because they do sleep
+    <youpi> they help only when the threads are living
+    <braunr> ok
+    <youpi> now as I said I don't have to talk much more, I have to leave :)
diff --git a/open_issues/bpf.mdwn b/open_issues/bpf.mdwn
index 73f73093..98b50430 100644
--- a/open_issues/bpf.mdwn
+++ b/open_issues/bpf.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2009 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2009, 2012 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -70,3 +70,373 @@ This is a collection of resources concerning *Berkeley Packet Filter*s.
       * [[!GNU_Savannah_patch 6622]] -- pfinet uses the BPF filter
 
       * [[!GNU_Savannah_patch 6851]] -- fix a bug in BPF
+
+
+# IRC
+
+## IRC, freenode, #hurd, 2012-01-13
+
+    <braunr> hm, i think the bpf code needs a complete redesign :p
+    <braunr> unless it's actually a true hurdish way to do things
+    <braunr> antrik: i need your help :)
+    <braunr> antrik: I need advice on the bpf "architecture"
+    <braunr> the current implementation uses a translator installed at /dev/bpf
+    <braunr> which means packets from the kernel are copied to that translator
+      and then to client applications
+    <braunr> does that seem ok to you ?
+    <braunr> couldn't the translator be used to set a direct link between the
+      kernel and the client app ?
+    <braunr> which approach seems the more Hurdish to you ? (<= this is what I
+      need your help on)
+    <pinotree> braunr: so there would be a roundtrip like kernel → bpf
+      translator → pfinet?
+    <antrik> braunr: TBH, I don't see why we need a BPF translator at all...
+    <braunr> antrik: it handles the ioctls
+    <braunr> pinotree: pfinet isn't involved (it was merely modified to use the
+      "new" filter format to specify it used the old packet filter, and not
+      bpf)
+    <antrik> braunr: do we really need to emulate the ioctl()s? can't we assume
+      that all packages using BPF will just use libpcap?
+    <antrik> (and even if we *do* want to emulate ioctl()s, why can't we handle
+      this is libc?)
+    <braunr> antrik: that's what i'm wondering actually
+    <braunr> even if assuming all packages use libpcap, i'd like our bpf
+      interface to be close to what bsds have, and most importantly, what
+      libpcap expects from a bpf interface
+    <antrik> well, why? if we already have a library handling the abstraction,
+      I don't see much point in complicating the design and use by adding
+      another layer :-)
+    <braunr> so you would advise adapting libpcap to include a hurd specific
+      module ?
+    <antrik> there are two reasons for adding translators: more robustness or
+      more flexibility... so far I don't see how a BPF translator would add
+      either
+    <braunr> right
+    <antrik> yes
+    <braunr> so we'd end up with a bpf-like interface, the same instructions
+      and format, with different control calls
+    <antrik> right
+    <antrik> note that I had more or less the same desicion to make for KGI
+      (emulate Linux/BSD ioctl()s, or implement a backend in libggi for
+      handling Hurd-specific RPC; and after much consideration, I decided on
+      the latter)
+
+
+## IRC, freenode, #hurd, 2012-01-16
+
+    <braunr> antrik: is there an existing facility to easily give a send right
+      to the device master port to a task ?
+    <braunr> another function of the bpf translator is to handle the /dev/bpf
+      node, and most importantly its permissions
+    <braunr> so that users which have read/write access to the node have access
+      to the packet filter
+    <braunr> i guess the translator could limit itself to that functionality
+    <braunr> and then provide a device port on which libpcap operates directly
+      by means of device_{g,s}et_status/device_set_filter
+    <antrik> braunr: I don't see the point in seperating permissions for filter
+      from permissions from general network device access...
+    <antrik> as for device master port, all root tasks can obtain it from proc
+      IIRC
+    <braunr> antrik: yes, but how do we allow non-root users to access that
+      facility ?
+    <braunr> on a unix like system, it's a matter of changing the permissions
+      of /dev/bpf
+    <antrik> with devnode, non-root users can get access to specific device
+      nodes, including network devices
+    <braunr> i can't imagine the hurd being less flexible for that
+    <braunr> ah devnode
+    <braunr> good
+    <antrik> so we can for example make /dev/eth0 accessible by users of some
+      group
+    <braunr> what's devnode exactly ?
+    <antrik> it's a very simple translator that implements an FS node that
+      looks somewhat like a file, but the only operation it supports is
+      obtaining a pseudo device master port, giving access to a specific Mach
+      device
+    <braunr> is it already part of the hurd ?
+    <braunr> or hurdextras maybe ?
+    <antrik> it's only in zhengda's branch
+    <braunr> ah
+    <antrik> needed for both eth-multipexer and DDE
+    <braunr> and bpf soon i guess
+    <antrik> indeed :-)
+    <braunr> "obtaining a pseudo device master port", i believe you meant a
+      pseudo device port
+    <antrik> I must admit that I don't remember exactly whether devnode proxies
+      device_open(), so clients direct get a port to the device in question, or
+      whether it implements a pseudo device master port...
+    <antrik> but definitely not a pseudo device port :-)
+    <braunr> i'm almost positive it gives the target device port, otherwise i
+      don't see the point
+    <braunr> i don't understand the user of the "pseudo" word here either
+    <braunr> s/user/use/
+    <braunr> aiui, devnode should be started as root (or in any way which gives
+      it the device master port)
+    <antrik> the point is that the client doesn't need to know the Mach device
+      name, and also is not bound to actual kernel devices
+    <braunr> and when started, implement the required permissions before giving
+      clients a device port to the specific device it was installed for
+    <braunr> right
+    <braunr> but it mustn't be a proxy
+    <antrik> yes, devnode needs access to either the real master device port
+      (for kernel devices), or one provided by eth-multiplexer or the DDE
+      network driver
+    <braunr> well, a very simple proxy for deviceopen
+    <braunr> ok
+    <braunr> that seems exactly what i wanted to do
+    <braunr> we now need to see if we can integrate it separately
+    <braunr> create a separate branch that works for the current gnumach code,
+      and merge dde/other specific code later on
+    <antrik> you mean independent of eth-multiplexer or DDE? yes, it was
+      generally agreed that devnode is a good idea in any case. I have no idea
+      why there are no device nodes for network devices on other UNIX
+      systems...
+    <braunr> i've been wondering that for years too :)
+    <antrik> zhengda's branch has a pfinet modified to a) use devnode, and b)
+      use BPF
+    <braunr> why bpf ?
+    <braunr> for more specific filters maybe ?
+    <antrik> hm... don't remember whether there was any technical reason for
+      going with BPF; I guess it just seemed more reasonable to invest new work
+      in BPF rather than obsolete Mach-specific NPF...
+    <braunr> cspf could be removed altogether, i agree
+    <antrik> another plus side of his modified pfinet is that it actually sets
+      an appropriate filter for TCP/IP and the IP in use, rather than just
+      setting a dummy filter catching app packets (including those irrelevant
+      to the specific pfinet instance)
+    <antrik> err... catching all packets
+    <braunr> that's what i meant by "for more specific filters maybe ?"
+    <braunr> he was probably more comfortable with the bpf interface to write
+      his filter rules
+    <antrik> well, it would probably be doable with NPF too :-) so by itself
+      it's not a reason for switching to BPF...
+    <antrik> it's rather the other way around: as it was necessary to implement
+      filters in eth-multiplexer, and implementing BPF seemed more reasoable,
+      pfinet had to be changed to use BPF...
+    <braunr> antrik: where is zhengda's branch btw ?
+    <antrik> (I guess using proper filters with eth-multiplexer is not strictly
+      necessary; but it would be a major performance hit not to)
+    <antrik> it's in incubator.git
+    <antrik> but it's very messy
+    <braunr> ok
+    <antrik> at some point I asked him to provide cleaned up branches, and I'm
+      pretty sure he said he did, but I totally fail to remember where he
+      published them :-(
+    <braunr> hm, i don't like how devnode is "architectured" :/
+    <braunr> but it makes things a little more easy to get working i guess
+    <LarstiQ> antrik: any idea what to grep the logs on for that?
+    <braunr> ok never mind, devnode is fine
+    <braunr> exactly what i need
+    <braunr> i wonder however if it shouldn't be improved to better handle
+      permissions
+    <braunr> ok, never mind either, permission handling is fine
+    <braunr> so what are we waiting for ? :)
+    <antrik> I remember that there were some issues with permission handling,
+      but I don't remember whether all were fixed :-(
+    <antrik> LarstiQ: hm... good question...
+    <braunr> ah ?
+    <braunr> hm actually, there could be issues for packet filters, yes
+    <braunr> i guess we want to allow e.g. read-only opens for capture only
+    <antrik> braunr: that would have to be handled by the actual BPF
+      implementation I'd say
+    <braunr> it should already be the case
+    <antrik> what's the problem then?
+    <braunr> but when the actual device_open() is performed, the appropriate
+      permissions must be provided
+    <braunr> and checking those is the responsibility of the proxy, devnode in
+      this case
+    <antrik> and it doesn't do that?
+    <braunr> apparently not
+    <braunr> the only check is against the device name
+    <braunr> i'll begin playing with that first
+    <antrik> I vaguely remember that there has been discussion about the
+      relation of underlying device open mode and devnode open mode... but I
+      don't remember the outcome. in fact it was probably one of the
+      discussions I never got around to follow up on... :-(
+    <antrik> before you begin playing, take a look at the relevant messages in
+      the ML archive :-)
+    <antrik> must have been around two years ago
+    <braunr> ok
+    <antrik> some thread with me and scolobb (Sergiu Ivanov +- spelling) and
+      probably zhengda
+    <antrik> there might also be some outstanding patch(es) from scolobb, not
+      sure
+
+
+## IRC, freenode, #hurd, 2012-01-17
+
+    <braunr> antrik: i think i found the thread you mentioned about devnode
+    <braunr> neither sergiu nor zhengda considered the use of a read-only
+      device for packet filtering
+    <braunr> leading to assumptions such as "only receiving packets
+    <braunr> is not terribly useful, in view of the fact that you have to at
+      least
+    <braunr> request them, which implies *sending* packets :-)
+    <braunr> "
+    <braunr> IMO, devnode should definitely check its node permissions to build
+      the device open flags
+    <braunr> good news is that it doesn't depend on anything specific to other
+      incubator projects
+    <braunr> making it almost readily mergeable in the hurd
+    <braunr> i'm not sure devnode is an appropriate name though
+    <braunr> maybe something like device, or devproxy
+    <braunr> proxy-devopen maybe
+    <antrik> braunr: well, I don't remember the details of the disucssion; but
+      as I mentioned in some mail, I did actually want to write a followup,
+      just didn't get around to it... so I was definitely not in agreement with
+      some of the statements made by others. I just don't remember on which
+      point :-)
+    <antrik> which thread was it?
+    <antrik> anyways, this should in no way be specific to network
+      devices... the idea is simply that if the client has only read
+      permissions on the device node, it should only get to open the underlying
+      device for read. it's up to the kernel to handle the read-only status for
+      the device once it's opened
+    <antrik> as for the naming, the idea is that devnode simply makes Mach
+      devices accessible through FS nodes... so the name seemed appropriate
+    <antrik> you may be right though that just "device" might be more
+      straightforward... I don't agree on the other variants
+    <braunr> antrik:
+      http://lists.gnu.org/archive/html/bug-hurd/2009-12/msg00155.html
+    <braunr> antrik: i agree with the general idea behind permission handling,
+      i was just referring to their thoughts about it, which probably led to
+      the hard coded READ | WRITE flags
+    <antrik> braunr: unfortunately, I don't remember the context of the
+      discussion... would take me a while to get into this again :-(
+    <antrik> the discussion seems to be about eth-multiplexer as much as about
+      devnode (if not more), and I don't remember the exact interaction
+
+
+## IRC, freenode, #hurd, 2012-01-18
+
+    <braunr> so, does anyone have an objection to getting devnode into the hurd
+      and calling it something else like e.g. device ?
+    <youpi> braunr: it's Zhengda's work, right?
+    <braunr> yes
+    <youpi> I'm completely for it, it just perhaps needs some cleanup
+    <braunr> i have a few changes to add to what already exists
+    <braunr> ok
+    <braunr> well i'm assigning myself to the task
+    <antrik> braunr: I'm still not convinced just "device" is preferable
+    <antrik> perhaps machdevice ;-)
+    <antrik> but otherwise, I'd LOVE to see it in :-)
+    <braunr> i don't know .. what if the device is actually eth-multiplexer or
+      a dde one ?
+    <braunr> it's not really "mach", is it ?
+    <braunr> or do we only refer to the interface ?
+    <youpi> that translator is only for mach devices
+    <braunr> so you consider dde devices as being mach devices too ?
+    <braunr> it's a simple proxy for device_open really
+    <youpi> will these devices use that translator?
+    <youpi> ah
+    <youpi> I thought it was using a mach-specific RPC
+    <braunr> so we can consider whatever we want
+    <antrik> braunr: yes, the translator is for Mach device interface only. it
+      might be provided by other servers, but it's still Mach devices
+    <youpi> then drop the mach, yes
+    <braunr> i'd tend to agree with antrik
+    <youpi> antrik: I'd say the device interface is part of the hur dinterfaces
+    <braunr> then machdev :p
+    <braunr> no, it's really part of the mach interface
+    <youpi> it's part of the mach interface, yes
+    <youpi> but also of the Hurd, no?
+    <antrik> DDE network servers also use the Mach device interface
+    <braunr> no
+    <youpi> can't we say it's part of it?
+    <youpi> I mean
+    <youpi> even if we change the kernel
+    <braunr> dde is the only thing that implements it besides the kernel that i
+      know of
+    <youpi> we will probably want to keep the same interface
+    <braunr> yes but that's a mach thing
+    <youpi> what we have now is not necessarily a reason
+    <antrik> as for other DDE drivers, I for my part believe they should export
+      proper Hurd (UNIX) device nodes directly... but for some reason zhengda
+      insisted on implementing it as Mach devices too :-(
+    <braunr> antrik: i agree with you on that too
+    <braunr> i was a bit surprised to see the same interface was reused
+    <braunr> youpi: we can, we just have to agree on what we'll do
+    <braunr> what do you mean by "even if we change the kernel" ?
+    <antrik> the problem with "machdev" is that it might suggest the translator
+      actually implements the device... not sure whether this would cause
+      serious confusion
+    <antrik> "devopen" might be another option
+    <antrik> or "machdevopen" to be entirely verbose ;-)
+    <braunr> an option i suggested earlier which you disagreed on :p
+    <braunr> but devopen is the one i'd choose
+    <antrik> youpi: as I already mentioned in the libburn thread, I don't
+      actually think the Mach device interface is very nice; IMHO we should get
+      rid of it as soon as we can, rather than port it to other
+      architectures...
+    <antrik> but even *if* we decided to reuse it after all, it would still be
+      the Mach device interface :-)
+    <braunr> actually, zheng da already suggested that name a long time ago
+    <braunr> http://lists.gnu.org/archive/html/bug-hurd/2008-08/msg00005.html
+    <braunr> no actually antrik did eh
+    <braunr> ok let's use devopen
+    <antrik> braunr: you suggested proxy-devopen, which I didn't like because
+      of the "proxy" part :-)
+    <braunr> not only, but i don't have the logs any more :p
+    <antrik> oh, I already suggested devopen once? didn't expect myself to be
+      that consistent... ;-)
+    <antrik> braunr: you suggested device, devproxy or proxy-devopen
+    <braunr> ah, ok
+    <braunr> devopen is better
+    <antrik> I wonder whether it's more important for clarity to have "mach" in
+      there or "open"... or whether it's really too unweildy to have both
+
+
+## IRC, freenode, #hurd, 2012-01-21
+
+    <braunr> oh btw, i made devopen run today, it shouldn't be hard getting it
+      in properly
+    <braunr> patching libpcap will be somewhat trickier
+    <braunr> i don't even really need it, but it allows having user access to
+      mach devices, which is nice for the libpcap patch and tcpdump tests
+    <braunr> permission checking is actually its only purpose
+    <braunr> well, no, not really, it also allows opening devices implemented
+      by user space servers transparently
+
+
+## IRC, freenode, #hurd, 2012-01-27
+
+    <braunr> hmm, bpf needs more work :(
+    <braunr> or we can use the userspace bpf filter in libpcap, so that it
+      works with both gnumach and dde drivers
+    <antrik> braunr: there is a userspace BPF implementation in libpcap? I'm
+      surprised that zhengda didn't notice it, and ported the one from gnumach
+      instead...
+    <antrik> what is missing in the kernel implementation?
+    <braunr> antrik: filling the bpf header
+    <braunr> frankly, i'm not sure we want to bother with the kernel
+      implementation
+    <braunr> i'd like it to work with both gnumach and dde drivers
+    <braunr> and in the long run, we'll be using userspace drivers anyway
+    <braunr> the bpf header was one of the things the defunct translator did
+    <braunr> which involved ugly memcpy()s :p
+    <antrik> braunr: well, if you want to get rid of the kernel implementation,
+      basically you would have to take up eth-multiplexer and get it into
+      mainline
+    <antrik> (and make sure it's used by default in Debian)
+    <antrik> I frankly believe it's the better design anyways... but quite a
+      major change :-)
+    <braunr> not that major to me
+    <braunr> in the meantime i'll use the libpcap embedded implementation
+    <braunr> we'll have something useful faster, with minimum work when
+      eth-multiplexer is available
+    <antrik> eth-multiplexer is ready for use, it just needs to go upstream
+    <antrik> though it's probably desirable to switch it to the BPF
+      implementation from libpcap
+    <braunr> using the libpcap implementation in libpcap and in eth-multiplexer
+      are two different things
+    <braunr> the latter is preferrable
+    <braunr> (and yes, by available, i meant upstream ofc)
+    <antrik> eth-mulitplexer is already using libpcap anyways (for compiling
+      the filters); I'm sure zhengda just didn't realize it has an actual BPF
+      implementation too...
+    <braunr> we want the filter implementation as close to the packet source as
+      possible
+    <antrik> I have been using eth-multiplexer for at least two years now
+    <braunr> hm, there is a "snoop" source type, using raw sockets
+    <braunr> too far from the packet source, but i'll try it anyway
+    <braunr> hm wrong, snoop was the solaris packet filter fyi
diff --git a/open_issues/code_analysis/discussion.mdwn b/open_issues/code_analysis/discussion.mdwn
new file mode 100644
index 00000000..f8a0657d
--- /dev/null
+++ b/open_issues/code_analysis/discussion.mdwn
@@ -0,0 +1,44 @@
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_documentation]]
+
+[[!toc]]
+
+
+# IRC, freenode, #hurd, 2011-12-04
+
+    <mcsim> has anyone used splice on hurd?
+    <mcsim> splice -> splint
+    <youpi> not that I know of
+    <mcsim> this is tool for statically checking C programs
+    <mcsim> seems I made it work
+    <braunr> hm i realli i personnally dislike such tools a lot, but sometimes
+      it might help
+    <braunr> hello hurd people
+    <mcsim> braunr: hello
+    <braunr> mcsim: duma may be helpful as replacement for the memcheck part of
+      valgrind
+    <mcsim> defpager uses it's own dynamic memory allocator, which uses
+      vm_allocate/vm_deallocate as backing store? Am I able to use duma in such
+      case?
+    <braunr> you will have to adapt it
+    <braunr> but it's already designed to handle custom allocators
+    <braunr> iirc
+    <braunr> btw, are there special flags for that memory which the pager
+      allocates ?
+    <braunr> e.g. to use wired memory ?
+    <mcsim> yes, wired memory
+    <braunr> you'll have to change that in duma then
+    <braunr> but apart from such details, it should be straightforward
+    <antrik> braunr: I have no idea about duma; but if you think it's a useful
+      tool, please add it to open_issues/code_analysis.mdwn
+    <antrik> (I guess we should have a "proper" page listing useful debugging
+      tools...)
diff --git a/open_issues/dbus.mdwn b/open_issues/dbus.mdwn
new file mode 100644
index 00000000..ec39e063
--- /dev/null
+++ b/open_issues/dbus.mdwn
@@ -0,0 +1,82 @@
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+IRC, freenode, #hurd, 2011-11-26:
+
+    <antrik> BTW, how much effort is necessary to fix dbus?
+    <pinotree> basically, have pflocal know who's the sender
+      (pid/uid/gid/groups) in the socket send op
+
+IRC, freenode, #hurd, 2011-12-16:
+
+    <braunr> pinotree: what's the problem with dbus ?
+    <pinotree> braunr: select() returning 0 changed fd's with very short (eg <
+      1ms) timeouts when there are actually events;
+
+[[select]].
+
+    <pinotree> and missing socket credentials
+
+[[sendmsg_scm_creds]].
+
+    <braunr> oh
+    <braunr> which socket creds interface ?
+    <pinotree> bsd, i.e. with SCM_CREDENTIALS payload for cmsg on
+      {recv,send}msg()
+    <braunr> ok
+    <braunr> SCM_RIGHTS too ?
+    <braunr> the select issue seems weird though
+    <pinotree> hm no, that's for passing fd's to other processes
+    <braunr> is it specific to pflocal or does dbus use pfinet too ?
+    <pinotree> iirc on very short timeouts the application has no time waiting
+      for the reply of servers
+    <braunr> i see
+    <pinotree> braunr: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=79358
+    <braunr> thanks
+    <pinotree> (the interesting messages are from #53 and on)
+    <braunr> 2000 eh ... :)
+    <braunr> hm i agree with neal, i don't understand why the timeout is given
+      to the kernel as part of the mach_msg call
+
+IRC, freenode, #hurd, 2011-12-20:
+
+    <braunr> hm, i don't see any occurrence of SCM_CREDENTIALS in dbus
+    <braunr> only SCM_RIGHTS
+    <pinotree> braunr: yes, that one
+    <braunr> oh
+    <braunr> i thought you said the opposite last time
+    <pinotree> dbus/dbus-sysdeps-unix.c, write_credentials_byte and
+      _dbus_read_credentials_socket (with #define HAVE_CMSGCRED)
+    <braunr> hm
+    <braunr> which version ?
+    <braunr> i don't see anything in 1.4.16
+    <pinotree> 1.4.16
+    <braunr> grmbl
+    <braunr> ah, i see
+    <braunr> SCM_CREDS
+    <pinotree> if you want, i have a simplier .c source with it
+    <braunr> no i'm just gathering info
+    <pinotree> ok
+    <braunr> what's the deal with SCM_CREDS and SCM_CREDENTIALS ?
+    <braunr> bsd vs sysv ?
+    <braunr> oh, http://lists.debian.org/debian-hurd/2002/03/msg00135.html
+    <braunr> so we actually do want both SCM_CREDS and SCM_RIGHTS for debus
+    <braunr> dbus
+    <pinotree> SCM_RIGHTS is a different matter, it is for passing fd's
+    <braunr> yes
+    <braunr> but it's used by dbus
+    <braunr> so if we can get it, it should help too
+    <pinotree> there's a preliminary patch for it done by emilio time ago, and
+      iirc it's applied to debian's glibc
+    <braunr> ah, he changed the libc
+    <braunr> right, that's the only sane way
+    <pinotree> iirc roland didn't like one or more parts of it (but i could be
+      wrong)
+    <braunr> ok
diff --git a/open_issues/default_pager.mdwn b/open_issues/default_pager.mdwn
index 18670c75..683dd870 100644
--- a/open_issues/default_pager.mdwn
+++ b/open_issues/default_pager.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -19,7 +19,7 @@ IRC, freenode, #hurd, 2011-08-31:
     <antrik> (and also I/O performance steadily dropping before that point is
       reached?)
 
-[[performance/degradation]] (?).
+[[performance/degradation]], [[ext2fs_page_cache_swapping_leak]].
 
     <antrik> hm
     <braunr> there could too many things
diff --git a/open_issues/ext2fs_page_cache_swapping_leak.mdwn b/open_issues/ext2fs_page_cache_swapping_leak.mdwn
index 075533e7..7c4cf52d 100644
--- a/open_issues/ext2fs_page_cache_swapping_leak.mdwn
+++ b/open_issues/ext2fs_page_cache_swapping_leak.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -8,7 +8,7 @@ Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
 is included in the section entitled [[GNU Free Documentation
 License|/fdl]]."]]"""]]
 
-[[!tag open_issue_hurd]]
+[[!tag open_issue_gnumach open_issue_hurd]]
 
 There is a [[!FF_project 272]][[!tag bounty]] on this task.
 
@@ -27,6 +27,7 @@ There is a [[!FF_project 272]][[!tag bounty]] on this task.
     <youpi> yes
     <youpi> the disk content, basicallyt :)
 
+
 # IRC, freenode, #hurd, 2011-04-18
 
     <antrik> damn, a cp -a simply gobbles down swap space...
@@ -257,3 +258,107 @@ There is a [[!FF_project 272]][[!tag bounty]] on this task.
     <antrik> the only way to free the memory seems to be terminating the FS
       server
     <youpi> uh :/
+
+
+# IRC, freenode, #hurd, 2011-11-30
+
+    <antrik> slpz: basically, whenever free memory goes below the paging
+      threshold (which seems to be around 6 MiB) while there is other I/O
+      happening, swap usage begins to increase continuously; and only gets
+      freed again when the filesystem translator in question exits
+    <antrik> so it sounds *very* much like pages go to swap because the
+      filesystem isn't quick enough to properly page them out
+    <antrik> slpz: I think it was you who talked about double paging a while
+      back?
+    <slpz> antrik: probably, sounds like me :-)
+    <antrik> slpz: I have some indication that the degenerating performance and
+      ultimate hang issues I'm seeing are partially or entirely caused by
+      double paging...
+    <antrik> slpz: I don't remember, did you propose some possible fix?
+    <slpz> antrik: hmm... perhaps it wasn't me, because I don't remember trying
+      to fix that problem...
+    <slpz> antrik: at which point do you think pages get duplicated?
+    <antrik> slpz: it was a question. I don't remember whether you proposed
+      something or not :-)
+    <antrik> slpz: basically, whenever free memory goes below the paging
+      threshold (which seems to be around 6 MiB) while there is other I/O
+      happening, swap usage begins to increase continuously; and only gets
+      freed again when the filesystem translator in question exits
+    <antrik> so it sounds *very* much like pages go to swap because the
+      filesystem isn't quick enough to properly page them out
+    <tschwinge>
+      http://www.bddebian.com:8888/~hurd-web/open_issues/ext2fs_page_cache_swapping_leak/
+    <slpz> tschwinge: thanks
+    <slpz> antrik: I see
+    <tschwinge> Always at your service.  ;-)
+    <slpz> antrik: I didn't addressed this problem directly, but when I've
+      modified the pageout mechanism to provide a special treatment for
+      external pages, I also removed the possibility of sending them to the
+      default pager
+    <slpz> antrik: this was in my experimental environment, of course
+    <antrik> slpz: oh, nice... so it may fix the issues I'm seeing? :-)
+    <antrik> anything testable yet?
+    <slpz> antrik: yes, only anonymous memory could be swapped with that
+    <slpz> antrik: it works, but is ugly as hell
+    <antrik> tschwinge: these is also your observation about compilations
+      getting slower on further runs, and my followups... I *suspect* it's the
+      same issue
+
+[[performance/degradation]].
+
+    <slpz> antrik: I'm thinking about establishing a repository for these
+      experimental versions, so they don't get lost with the time
+    <antrik> slpz: please do :-)
+    <slpz> antrik: perhaps in savannah's HARD project
+    <antrik> even if it's not ready for upstream, it would be nice if I could
+      test it -- right now it's bothering me more than any other Hurd issues I
+      think...
+    <slpz> also, there's another problem which causes performance degradation
+      with the simple use of the system
+    <tschwinge> slpz: Please just push to Savannah Hurd.  Under your
+      slpz/... or similar.
+    <tschwinge> antrik: Might very well be, yes.
+    <slpz> and I almost sure it is the fragmentation of the task map
+    <slpz> tschwinge: ok
+    <slpz> after playing a bit with a translator, it can easily get more than
+      3000 entries in its map
+    <antrik> slpz: yeah, other issues might play a role here as well. I
+      observed that terminating the problematic FS servers does free most of
+      the memory and remove most of the performance degradation, but in some
+      cases it's still very slow
+    <slpz> that makes vm_map_lookup a lot slower
+    <antrik> on a related note: any idea what can cause paging errors and a
+      system hang even when there is plenty of free swap?
+    <antrik> (I'm not entirely sure, but my impression is that it *might* be
+      related to the swap usage and performance degradation problems)
+    <slpz> I think this degree of fragmentation has something to do with the
+      reiterative mapping of memory objects which is done in pager-memcpy.c
+    <slpz> antrik: which kind of paging errors?
+    <antrik> hm... I don't think I ever noted down the exact message; but I
+      think it's the same you get when actually running out of swap
+    <slpz> antrik: that could be the default pager dying for some internal bug
+    <antrik> well, but it *seems* to go along with the performance degradation
+      and/or swap usage
+    <slpz> I also have the impression that we're using memory objects the wrong
+      way
+    <antrik> basically, once I get to a certain level of swap use and slowness
+      (after about a month of use), the system eventually dies
+    <slpz> antrik: I never had a system running for that time, so it could be a
+      completely different problem from what I've seen before :-/
+    <slpz> Anybody has experience with block-level caches on microkernel
+      environments?
+    <antrik> slpz: yeah, it typically happens after about a month of my normal
+      use... but I can significantly accellerate it by putting some problematic
+      load on it, such as large apt-get runs...
+    <slpz> I wonder if it would be better to put them in kernel or in user
+      space. And in the latter, if it would be better to have one per-device
+      shared for all accesing translators, or just each task should have its
+      own cache...
+    <antrik> slpz:
+      http://lists.gnu.org/archive/html/bug-hurd/2011-09/msg00041.html is where
+      I described the issue(s)
+    <antrik> (should send another update for the most recent findings I
+      guess...)
+    <antrik> slpz: well, if we move to userspace drivers, the kernel part of
+      the question is already answered ;-)
+    <antrik> but I'm not sure about per-device cache vs. caching in FS server
diff --git a/open_issues/gcc.mdwn b/open_issues/gcc.mdwn
index a3b3a2d2..71b4b2ea 100644
--- a/open_issues/gcc.mdwn
+++ b/open_issues/gcc.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2007, 2008, 2009, 2010, 2011 Free Software
+[[!meta copyright="Copyright © 2007, 2008, 2009, 2010, 2011, 2012 Free Software
 Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
@@ -206,6 +206,20 @@ Last reviewed up to the [[Git mirror's 3d83581faf4eaf52c1cf52cc0d11cc7dd1264275
     `mkdir` the directory for now, but what is really going on?  GCC has *use
     `/usr/include` patch*, but glibc still installs into `/include/`?
 
+  * `__GLIBC__`
+
+    IRC, freenode, #hurd, 2012-01-05:
+
+        <civodul> on GNU/kFreeBSD, it's GCC that defines __GLIBC__, funny
+        <youpi> ??
+        <youpi> not from features.h ?
+        <civodul> in gcc/config/kfreebsd-gnu.h
+        <civodul> :-)
+        <pinotree> correct, it's enabled in gcc's config
+        <pinotree> i discovered that after banging my head on the wall trying
+          to find out why some stuff wasn't compiling even after kfreebsd
+          porting patches adding preprocessors checks for __GLIBC__
+
 
 # Build
 
diff --git a/open_issues/gnumach_memory_management.mdwn b/open_issues/gnumach_memory_management.mdwn
index c9c3e64f..c34d1200 100644
--- a/open_issues/gnumach_memory_management.mdwn
+++ b/open_issues/gnumach_memory_management.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -2012,3 +2012,84 @@ There is a [[!FF_project 266]][[!tag bounty]] on this task.
     <mcsim> braunr: everything is ok
     <braunr> good
     <braunr> i think the branch is ready for integration
+
+
+# IRC, freenode, #hurd, 2011-12-17
+
+    <braunr> in the slab branch, there now is no use for the defines in
+      kern/mach_param.h
+    <braunr> should the file be removed or left empty as a placeholder for
+      future arbitrary limits ?
+    <braunr> (i'd tend ro remove it as a way of indicating we don't want
+      arbitrary limits but there may be a good reason to keep it around .. :))
+    <youpi> I'd just drop it
+    <braunr> ok
+    <braunr> hmm maybe we do want to keep that one :
+    <braunr> #define IMAR_MAX        (1 << 10)       /* Max number of
+      msg-accepted reqs */
+    <antrik> whatever that is...
+    <braunr> it gets returned in ipc_marequest_info
+    <braunr> but the mach_debug interface has never been used on the hurd
+    <braunr> there now is a master-slab branch in the gnumach repo, feel free
+      to test it
+
+
+# IRC, freenode, #hurd, 2011-12-22
+
+    <youpi> braunr: does the new gnumach allocator has profiling features?
+    <youpi> e.g. to easily know where memory leaks reside
+    <braunr> youpi: you mean tracking call traces to allocated blocks ?
+    <youpi> not necessarily traces
+    <youpi> but at least means to know what kind of objects is filling memory
+    <braunr> it's very close to the zone allocator
+    <braunr> but instead of zones, there are caches
+    <braunr> each named after the type they store
+    <braunr> see http://www.sceen.net/~rbraun/slabinfo.out
+    <youpi> ok, so we can know, per-type, how much memory is used
+    <braunr> yes
+    <youpi> good
+    <braunr> if backtraces can easily be forged, it wouldn't be hard to add
+      that feature too
+    <youpi> does it dump such info when memory goes short?
+    <braunr> no but it can
+    <braunr> i've done this during tests
+    <youpi> it'd be good
+    <youpi> because I don't know in advance when a buildd will crash due to
+      that :)
+    <braunr> each time slab_collect() is called for example
+    <youpi> I mean not on collect, but when it's too late
+    <youpi> and thus always enabled
+    <braunr> ok
+    <youpi> (because there's nothing better to do than at least give infos)
+    <braunr> you just have to define "when it's too late", and i can add that
+    <youpi> when there is no memory left
+    <braunr> you mean when the number of free pages strictly reaches 0 ?
+    <youpi> yes
+    <braunr> ok
+    <youpi> i.e. just before crashing the kernel
+    <braunr> i see
+
+
+# IRC, freenode, #hurdfr, 2012-01-02
+
+    <youpi> braunr: le code du slab allocator, il est écrit from scratch ?
+    <youpi> il y a encore du copyright carnegie mellon
+    <youpi> (dans slab_info.h du moins)
+    <youpi> ipc_hash_global_size = 256;
+    <youpi> il faudrait mettre 256 comme constante dans un header
+    <youpi> sinon c'est encore une valeur arbitraire cachée dans du code
+    <youpi> de même pour ipc_marequest_size etc.
+    <braunr> youpi: oui, from scratch
+    <braunr> slab_info.h est à l'origine zone_info.h
+    <braunr> pour les valeurs fixes, elles étaient déjà présentes de cette
+      façon, j'ai pensé qu'il valait mieux laisser comme ça pour faciliter la
+      lecture des diffs
+    <braunr> je ferai des macros à la place
+    <braunr> du coup il faudra peut-être remettre mach_param.h
+    <braunr> ou alors dans les .h ipc
+
+
+# IRC, freenode, #hurdfr, 2012-01-18
+
+    <braunr> does the slab branch need other reviews/reports before being
+      integrated ?
diff --git a/open_issues/libnfs.mdwn b/open_issues/libnfs.mdwn
new file mode 100644
index 00000000..8cadefa4
--- /dev/null
+++ b/open_issues/libnfs.mdwn
@@ -0,0 +1,28 @@
+[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_hurd]]
+
+IRC, freenode, #hurd, 2012-01-09:
+
+    <pinotree> https://github.com/sahlberg/libnfs ← maybe it could be used for
+      nfs support, instead of the rpc stuff "removed" in newer glibc versions
+    <antrik> pinotree: sounds like it could do much more than just the RPC
+      stuff -- definitely interesting :-)
+    <pinotree> hm but it seems to be an abstraction over either classic rpc or
+      tirpc
+    <pinotree> (anyway, it is packaged already in debian)
+    <antrik> good licensing too
+    <antrik> I guess I'll modify the GSoC task to "rework the Hurd NFS client
+      to use libnfs" :-)
+    <pinotree> the nfs translator?
+    <antrik> yes
+
+[[hurd/translator/nfs]]
diff --git a/open_issues/mach-defpager_debugging.mdwn b/open_issues/mach-defpager_debugging.mdwn
new file mode 100644
index 00000000..33e717d9
--- /dev/null
+++ b/open_issues/mach-defpager_debugging.mdwn
@@ -0,0 +1,22 @@
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_gdb]]
+
+IRC, freenode, #hurd, 2011-11-10:
+
+    <mcsim> hello. Is there any way to debug mach-defpager? When I set
+      breakpoint to any function in it, pager never breaks.
+
+IRC, freenode, #hurd, 2011-11-11:
+
+    <mcsim> hello. I've read that hde tried to debug defpager and wrote some
+      patches for debugging defpager,  but I couldn't find them. Does anybody
+      know are these patches in public?
diff --git a/open_issues/mmap_write-only.mdwn b/open_issues/mmap_write-only.mdwn
new file mode 100644
index 00000000..467274c5
--- /dev/null
+++ b/open_issues/mmap_write-only.mdwn
@@ -0,0 +1,56 @@
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_glibc]]
+
+# IRC, freenode, #hurd, 2011-12-14
+
+    <pinotree> hm, interesting mmap bug
+    <youpi> ?
+    <pinotree> youpi: http://paste.debian.net/149252/
+    #include <sys/types.h>
+    #include <sys/mman.h>
+    #include <fcntl.h>
+    #include <stdio.h>
+    #include <errno.h>
+    #include <stdlib.h>
+    #include <string.h>
+    #include <unistd.h>
+    
+    void die(int x, const char *s)
+    {
+      perror(s);
+      exit(x);
+    }
+    
+    static const char s_file[] = "foo-mmaptest";
+    
+    int main()
+    {
+      int fd;
+      void *p;
+    
+      fd = creat(s_file, 0777);
+      if (fd < 0) die(1, "creat");
+      errno = 0;
+      p = mmap(NULL, 1, PROT_READ, MAP_SHARED, fd, 0);
+      printf("> %p vs %p, %d (%s)\n", p, MAP_FAILED, errno, strerror(errno));
+      unlink(s_file);
+      return (p != MAP_FAILED);
+    }
+    <pinotree> on linux it returns 0 and fails with EACCESS (as it seems it
+      should, by reading the mmap posix docs), on hurd it returns 1 and the
+      mmap succeeds
+    <pinotree> (taken from llvm's configure)
+    <youpi> why should it? file size extension ?
+    <pinotree> creat creates a o_wronly file, while the mmap specifies only
+      read protection
+    <youpi> oh, craet is always wo
+    <youpi> I didn't know that
diff --git a/open_issues/open_symlink.mdwn b/open_issues/open_symlink.mdwn
new file mode 100644
index 00000000..20e4a4fe
--- /dev/null
+++ b/open_issues/open_symlink.mdwn
@@ -0,0 +1,18 @@
+[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!tag open_issue_glibc]]
+
+# IRC, freenode, #hurd, 2012-01-02
+
+    <pinotree> hm, is it a known issue that open("somesymlink", O_RDONLY |
+      O_NOFOLLOW) does not fail with ELOOP?
+    <youpi> pinotree: iirc there is code for it, maybe not the same behavior as
+      on linux
diff --git a/open_issues/performance/degradation.mdwn b/open_issues/performance/degradation.mdwn
index 64542af3..e520ed6a 100644
--- a/open_issues/performance/degradation.mdwn
+++ b/open_issues/performance/degradation.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -46,3 +46,6 @@ IRC, freenode, #hurd, 2011-09-02:
 # IRC, freenode, #hurd, 2011-09-22
 
 See [[/open_issues/pagers]], IRC, freenode, #hurd, 2011-09-22.
+
+
+# [[ext2fs_page_cache_swapping_leak]]
diff --git a/open_issues/select.mdwn b/open_issues/select.mdwn
index 0f750631..0b69d645 100644
--- a/open_issues/select.mdwn
+++ b/open_issues/select.mdwn
@@ -1,4 +1,5 @@
-[[!meta copyright="Copyright © 2010, 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2010, 2011, 2012 Free Software Foundation,
+Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -29,6 +30,12 @@ IRC, unknown channel, unknown date.
       respond in time?
     <paakku> Or do I just imagine this problem?
 
----
+
+# dbus
+
+See [[dbus]].
+
+
+# See Also
 
 See also [[select_bogus_fd]] and [[select_vs_signals]].
diff --git a/open_issues/sendmsg_scm_creds.mdwn b/open_issues/sendmsg_scm_creds.mdwn
index c613e21c..cf0103df 100644
--- a/open_issues/sendmsg_scm_creds.mdwn
+++ b/open_issues/sendmsg_scm_creds.mdwn
@@ -1,4 +1,5 @@
-[[!meta copyright="Copyright © 2010, 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2010, 2011, 2012 Free Software Foundation,
+Inc."]]
 
 [[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
 id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -96,4 +97,5 @@ IRC, unknown channel, unknown date.
 
 ---
 
-See also [[pflocal_socket_credentials_for_local_sockets]] and [[pflocal_reauth]].
+See also [[dbus]], [[pflocal_socket_credentials_for_local_sockets]] and
+[[pflocal_reauth]].
diff --git a/open_issues/servers_default-pager_permissions.mdwn b/open_issues/servers_default-pager_permissions.mdwn
new file mode 100644
index 00000000..58dba1cb
--- /dev/null
+++ b/open_issues/servers_default-pager_permissions.mdwn
@@ -0,0 +1,27 @@
+[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]]
+
+[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled [[GNU Free Documentation
+License|/fdl]]."]]"""]]
+
+[[!meta title="/servers/default-pager permissions"]]
+
+[[!tag open_issue_hurd]]
+
+IRC, freenode, #hurd, 2012-01-14:
+
+    <youpi> antrik: what are the permissions that are supposed to be given to
+      /servers/default-pager ?
+    <antrik> olaf@alien:~$ ls -l /servers/default-pager
+    <antrik> crw-rw-rw- 1 root root 0, 0 Sep 17  2004 /servers/default-pager
+    <antrik> oh, interesting... in the other system it's different
+    <antrik> olaf@alien:~$ ls -l /sub/servers/default-pager
+    <antrik> crw-r--r-- 1 root root 0, 0 Jul 10  2006
+      /sub/servers/default-pager
+    <antrik> both are Debian, the latter installed with crosshurd
+    <antrik> (and native-install run in a chroot or subhurd, don't remember
+      which...)