l4-hackers

l4-hackers@os.inf.tu-dresden.de

2827 discussions

Re: Can't get sender from l4_ipc_wait()
by Haohui Mai 17 Apr '12

17 Apr '12

Hi, Thanks for you suggestions. I did get sources from l4_ipc_wait() -- but I still cant map it back to the thread originating the IPC. I created an IPC gate for each task to receive page faults and exceptions, where I set the label of the gate to be my task identifier. I did get my task identifier back, but it seems there's no way to get my thread identifier since the source code of L4 Fiasco suggests that l4_ipc_wait() will only return the label of the IPC gate as the source. Setting the same pager for all threads in a single task seems a reasonable thing to do but obviously it lost the information for thread identifier. In order to recover this information, does it mean that I should create an IPC gate for each thread, setting its label to thread identifier in order to recover this information? Taking a step back, am I doing the right thing? If the answer is no, what would be the suggested architecture? Your comments are highly appreciated. ~Haohui On Apr 10, 2012, at 1:55 AM, Adam Lackorzynski wrote: > Hi, > > On Sun Apr 08, 2012 at 17:08:10 -0500, Mai, Haohui wrote: >> Can you elaborate a little bit? Some code skeletons would be quite helpful. >> >> I already created a new address space through l4_factory_task_create(), and >> my own kernel can serve all page faults / exceptions / IPC for that task. >> >> This is done by mapping the capability of my own kernel, which is its >> thread id, into the newly created task. Therefore, I assume that the IPC >> gate is set up. > > Are the other tasks trusted so that you can give out your own thread > cap? That's usually no good thing to do. > >> What else should I do in order to have my kernel getting the source of the >> IPC when calling l4_ipc_wait()? > > It's basically just l4_factory_create_gate, in the same way as > l4_factory_task_create. Create it with a label of your choice and > binding to the pager, and map it instead of the thread directly. > > > > Adam > -- > Adam adam(a)os.inf.tu-dresden.de > Lackorzynski http://os.inf.tu-dresden.de/~adam/

2 1

Questions about Vcon.
by Juwon.Song 13 Apr '12

13 Apr '12

Hello l4-hackers, I will try to use the Vcon of Fiasco. But I don't know about the usage of Vcon. I want to know more information about Vcon. If you have the more information and usage of Vcon, give me the data or examples. Thank you. Song.

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Re: Fiasco.OC development status
by Robert Campbell 12 Apr '12

12 Apr '12

Thank you Bjoern. Any idea when new release will be made and what changes and improvements to expect? > Hi Robert, > >> Is Fiasco.OC being actively developed(i.e new and on going research, >> new features) or is it just being maintained (small adjustments, bug >> fixes etc...)? > > yes, it's actively being worked on and our group uses it as the basis > for research projects. To get an (incomplete) overview of our research > work, you might want to look at our publications list: > http://www.inf.tu-dresden.de/index.php?node_id=1429 > > If you have more specific questions, feel free to ask. > > Cheers, > Bjoern

2 1

Bind irq to icu failed
by Shashi Sharma 09 Apr '12

09 Apr '12

Hi, I am trying to use e1000e driver in Ankh to bring-up intel's 82574L ethernet controller. But its unable to allocate interrupt and I cant figure out the source of the problem. Here is the ankh log: ------------------------------------------------------------------------ ankh | Initialized DDELinux 2.6 ankh | Initializing DDE page cache ankh | ddekit_pci_init ankh | pci bus constructor ankh | PCI: L4 root bridge is device 4e768 ankh | init_wq_head ankh | l4dde26_register_rx_callback: New rx callback @ 0x1000270. ankh | Softirq daemon starting ankh | <6>e1000e: Intel(R) PRO/1000 Network Driver - 0.3.3.3-k6 ankh | <6>e1000e: Copyright (c) 1999-2008 Intel Corporation. ankh | unimplemented: pci_set_master ankh | <3>0000:00:01.0: 0000:00:01.0: Failed to initialize MSI-X interrupts. Falling back to MSI interrupts. ankh | <3>0000:00:01.0: 0000:00:01.0: Failed to initialize MSI interrupts. Falling back to legacy interrupts. ankh | <6>0000:00:01.0: eth0: (PCI Express:2.5GB/s:Width x1) 0x14815cM ankh | <6>0000:00:01.0: eth0: Intel(R) PRO/1000 Network Connection ankh | <6>0000:00:01.0: eth0: MAC: 3, PHY: 8, PBA No: ffffff-0ff ankh | <6>Intel(R) PRO/1000 Network Driver - version 7.3.21-k3-NAPI ankh | <6>Copyright (c) 1999-2006 Intel Corporation. ankh | <6>net_namespace: 636 bytes ankh | open_network_devices() ankh | opening lo ankh | <6>device lo entered promiscuous mode ankh | set interface to promiscuous mode. ankh | opening eth0 ankh | <6>device eth0 entered promiscuous mode ankh | set interface to promiscuous mode. ankh | Thread 0xb0 for IRQ 10 ankh | Bind irq to icu failed with -2 ankh | claim_irq: failed to attach IRQ ankh | <3>0000:00:01.0: eth0: Unable to allocate interrupt, Error: -16 ankh | error opening eth0 : -16 ankh | Opened -16 network devices. ankh | lo IRQ: 0x00 MAC: 00:00:00:00:00:00 MTU: 16436 ankh | Registered @ registry. ankh | Gooood Morning Ankh-Morpoooooork! TID = 0x57 ankh | Creating session factory. ankh | Configuration: debug,promisc,device=eth0,shm=shm,bufsize=16384,phys_mac ankh | Debug mode ON. ankh | Using promiscuous mode. ankh | Device 'eth0' requested. ankh | SHM area 'shm' requested. ankh | Buffer size: 16384 ankh | Physical MAC requested. ankh | rom/ankh: /home/shashi/Desktop/L4/src/l4/pkg/ankh/server/src/session: 159: Ankh::ServerSession::ServerSession(bool, bool, bool, const char*, const char*, unsigned int. bool): Assertion `_dev' failed. --------------------------------------------------------------------------------------- I appreciate your help. Regards, Shashi

4 8

Can't get sender from l4_ipc_wait()
by Mai, Haohui 08 Apr '12

08 Apr '12

Hi, It seems that l4_ipc_wait() will always set the sender to zero. I tested it in example at /pkg/examples/sys/ipc/ipc_example.c, in the l4re-2011081207 snapshot. Here is the patch I applied to the file (to print out label): --- a/ipc_example.c 2011-08-12 00:20:36.000000000 -0500 +++ b/ipc_example.c 2012-04-05 17:29:24.844608359 -0500 @@ -84,6 +84,7 @@ continue; } + printf ("IPC from %lx, %d\n", label, label == 0); /* So, the IPC was ok, now take the value out of message register 0 * of the UTCB and store the square of it back to it. */ l4_utcb_mr()->mr[0] = l4_utcb_mr()->mr[0] * l4_utcb_mr()->mr[0]; And here is the result I got: ... vandroid| Sending: 4 vandroid| IPC from 0, 1 vandroid| Received: 16 ... So it seems that l4_ipc_wait() doesn't return the sender. I'm writing an OS on top of Fiasco.OC. This information is important for pager because it'll need it to figure out which page it'll map in. Do you have any ideas to fix it, or any idea to work around it (at least L4Linux works)? Your comments are appreciated. ~Haohui

2 1

Tracing only write page-faults
by Ivan Bludov 08 Apr '12

08 Apr '12

Hello. I want to trace all write page-faults from an application. I use the pager that wait for page-fault and maps the fpage to thread calling l4_ipc_send_and_wait setting L4_ITEM_MAP. For tracing only write page-faults I map fpage as L4_FPAGE_RO if it was read-pf and then I map the same fpage with L4_FPAGE_RW if the next write-pf occurs. (I mean I map the same fpage with the different flags twice). But an application doesn't continue run. Also I have tried to l4_task_unmap(L4_FP_OTHER_SPACES) this fpage before mapping it as L4_FPAGE_RW. It doesn't work. What should I use to change fpage's rights to L4_FPAGE_RW for fpage that is already mapped as L4_FPAGE_RO for an application? Ivan Bludov

2 1

support for multi-core in Fiasco.OC
by K M 05 Apr '12

05 Apr '12

I am using Fiasco.OC with VirtualBox and have successfully booted and run some demos. However, I am unable to get the kernel to use more than one core on my quad-core machine. I have enabled all 4 processors within the VirtualBox L4 machine, but when I run the "thread_migrate" example, only one CPU is ever recognized and used. What am I doing wrong? Thanks, Kevin

2 1

libgendep on Ubuntu 11.10
by Christian Helmuth 03 Apr '12

03 Apr '12

Hi, with current SVN (r38) I get the following error: gcc -fPIC -Wall -pedantic -g -m64 -c /plain/krishna/src/genode/genode.git/base-foc/contrib/l4/tool/gendep/deptrack.c -o /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/deptrack.64.o gcc -fPIC -Wall -pedantic -g -m64 -c /plain/krishna/src/genode/genode.git/base-foc/contrib/l4/tool/gendep/syscall.c -o /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/syscall.64.o mkdir -p /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/64 gcc -m64 -shared -Wl,-soname,/plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/64/libgendep.so -ldl -o /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/64/libgendep.so /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/deptrack.64.o /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/syscall.64.o /usr/local/genode-gcc/bin/genode-x86-gcc: symbol lookup error: /plain/krishna/build/genode.foc_x86_32/l4/tool/gendep/64/libgendep.so: undefined symbol: dlsym The attached patch fixed the issue for me and I'd like to share it here ;-) Greets -- Christian Helmuth Genode Labs http://www.genode-labs.com/ · http://genode.org/ · /ˈdʒiː.nəʊd/ Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth

2 3

L4Android kernel didn't intialize L4 stack for the server thread.
by Mai, Haohui 03 Apr '12

03 Apr '12

Hi, It seems that I found a bug in the latest version of L4Android kernel. I'm familiar enough with the code base so your comments are highly appreciated. The main thread for L4Linux (i.e., the thread running l4x_server_loop()) didn't initialize l4x_stack before execution. Therefore, this thread crashes whenever it calls cli() / sti(). Calling vmalloc() and kmalloc() can reproduce this bug reliably. Here is a patch to fix this problem. ~Haohui --- a/arch/l4/kernel/main.c +++ b/arch/l4/kernel/main.c @@ -2501,6 +2501,8 @@ int __init_refok L4_CV main(int argc, char **argv) * for these areas so far */ //l4x_register_pointer_section(&_edata, 0, "data"); + l4x_stack_setup(current_thread_info(), l4_utcb(), 0); + /* Send start message to main thread. */ l4_ipc_send(l4lx_thread_get_cap(main_id), l4_utcb(), l4_msgtag(0, 0, 0, 0), L4_IPC_NEVER);

3 3

Question on sending capability through IPC
by Mai, Haohui 02 Apr '12

02 Apr '12

Hi, I'm a little bit confused by how Fiasco.OC sending capabilities through IPC. Particularly, it seems that one has to pack the capability in message register, rather than buffer register. Here is a code sending some capability to the client, which works with Fiasco.OC: l4_utcb_t * u = l4_utcb(); l4_utcb_mr_u(u)->mr[0] = ipc_id; l4_utcb_mr_u(u)->mr[1] = L4_ITEM_MAP; l4_utcb_mr_u(u)->mr[2] = l4_obj_fpage(cap, 0, L4_FPAGE_RWX).raw; l4_utcb_br_u(u)->bdr = 0; tag = l4_msgtag(label, 1, 1, 0); ipc_call(...); Notice that the capability is assigned into mr[1] and mr[2], but not br[1] and br[2]. It seems that this behavior is controlled by the constructor of L4_snd_item_iter, at kern/l4_buf_iter.cpp:52 explicit L4_snd_item_iter(Utcb const *utcb, unsigned offset) : _buf(&utcb->values[offset]), _max(&utcb->values[Utcb::Max_words]) {} My question is that whether this is the desired behavior? I didn't find any specification on this. ~Haohui

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