l4-hackers

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

2827 discussions

RE: Re: Keeping track of the CPU time for a thread
by Mohammad A Haque 27 Jun '12

27 Jun '12

Thank you for your reply. Just to test the functionality, I tried a very simple thread. It computes a factorial for some number of iterations. void entry_point(void * param) { int num_run = 1000000; int number = 15; int fact; thread_t self = env()->self(); for(int i=0;i<num_run;i++) { fact = 1; for(int j = 2; j<= number; j++) { fact = fact * j; } } printf("Factorial of %d is : %d\n", number, fact); l4_thread_stats_time(self.cap()); printf("Consumed time: %llu\n",l4_utcb_mr()->mr[0]); } What I found is - the consumed time does not depend on the number of iterations (num_run) - I tried from 1 to a very large number. It does vary with the number. Am I missing something? Thanks again. ---------------------------------------------------------------------- Date: Sun, 24 Jun 2012 23:29:25 +0200 From: Adam Lackorzynski <adam(a)os.inf.tu-dresden.de> To: l4-hackers(a)os.inf.tu-dresden.de Subject: Re: Keeping track of the CPU time for a thread Message-ID: <20120624212925.GC1246(a)os.inf.tu-dresden.de> Content-Type: text/plain; charset=iso-8859-1 Hi, On Thu Jun 21, 2012 at 17:44:25 +0000, Mohammad A Haque wrote: > I want to measure how much CPU time a thread has consumed. When the > CPU time consumption exceeds a certain limit (specific to that > thread), I want to raise an interrupt. Please suggest me how can I do > it efficiently? The L4::Thread interface has the stats_time function to get the consumed time of a thread (FINE_GRAINED_CPUTIME in the kernel might be of interest here). Triggering an interrupt goes with its trigger function. Then it's just about plugging this together. Adam -- Adam adam(a)os.inf.tu-dresden.de Lackorzynski http://os.inf.tu-dresden.de/~adam/

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l4con
by Valery V. Sedletski 25 Jun '12

25 Jun '12

Hi again I forgot to ask, can l4con directly access video hardware? I knew that it supports some video acceleration features with, for example, Matrox cards (I have Matrox Millenium G400). So, can I use it with l4con video acceleration? If so, how to enable it? Is it detected automatically? Have you any plans for enancing fb_drv to support the video acceleration? There were some libraries used in Linux to support framebuffer acceleration. They could be ported to l4re... WBR, valery

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how to build L4android for ARM?
by Jay Yao 24 Jun '12

24 Jun '12

Hi , I'm a rookie. And I'm very interest in L4Android. I want to use L4android in arm platform, but I don't know how to build L4android for arm , is there any build tutorials?

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l4linux build failure, and a few questions
by Ryan Brown 24 Jun '12

24 Jun '12

I tried building l4linux for x86 and got this error: MODPOST vmlinux.o WARNING: modpost: Found 1 section mismatch(es). To see full details build your kernel with: 'make CONFIG_DEBUG_SECTION_MISMATCH=y' GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o LD init/built-in.o LD .tmp_vmlinux1 drivers/built-in.o: In function `pnp_register_irq_resource': /home/ribrdb/fiasco/src/l4linux/drivers/pnp/resource.c:70: undefined reference to `pcibios_penalize_isa_irq' make[1]: *** [.tmp_vmlinux1] Error 1 make: *** [sub-make] Error 2 Has anyone seen this before? Also I had a few questions about configuring l4linux: I see that the paravirtualization options are not supported. Is there a specific reason for this? I'd like to be able to use virtio devices from l4linux when running in a VM. Neither x86_64 or highmem is supported. Is there any way to run an l4 linux with more than 1G of memory? Can 32 bit l4linux run on a 64 bit fiasco kernel? Does 32 bit fiasco support more than 1G of physical memory? What would be involved if I wanted to port l4linux to x86_64? Thanks, and sorry for so many questions. Ryan Brown

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Re: l4-hackers Digest, Vol 110, Issue 18
by Robert Campbell 24 Jun '12

24 Jun '12

> There's one thing to add, though: By running device drivers in dedicated > user-level processes, a crashing driver in the common case only takes > down its own process, but the rest of the system continues to run. > That's a major advantage, because you can have a monitoring process that > then restarts the driver [1] this way. > However, even a user space driver can still crash the system if it goes > rampant by misprogramming the DMA engine and you don't use an IOMMU. > Bjoern Are there plans to provide IOMMU support in Fiasco.OC?

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Keeping track of the CPU time for a thread
by Mohammad A Haque 24 Jun '12

24 Jun '12

Hi, I want to measure how much CPU time a thread has consumed. When the CPU time consumption exceeds a certain limit (specific to that thread), I want to raise an interrupt. Please suggest me how can I do it efficiently? Thanks.

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Re: l4linux GPU direct access
by Abhishek Gupta 21 Jun '12

21 Jun '12

Hi Adam, I was just trying to change the config file of l4linux to enable support for MTRRs because my Xserver log file had a warning (WW) System lacks support for changing MTRRs I was wondering why it is not allowed to enable to support for MTRRs? Below is the complete X.org log file: X.Org X Server 1.7.7 Release Date: 2010-05-04 X Protocol Version 11, Revision 0 Build Operating System: Linux 2.6.32.29-dsa-ia32 i686 Debian Current Operating System: Linux moarhost 3.0.0-l4-svn23 #72 SMP Thu Mar 8 18:05:24 CET 2012 i686 Kernel command line: mem=400M root=/dev/hda Build Date: 19 February 2011 02:37:36PM xorg-server 2:1.7.7-13 (Cyril Brulebois <kibi(a)debian.org>) Current version of pixman: 0.16.4 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan 1 00:00:27 1970 (==) Using system config directory "/usr/share/X11/xorg.conf.d" (==) No Layout section. Using the first Screen section. (==) No screen section available. Using defaults. (**) |-->Screen "Default Screen Section" (0) (**) | |-->Monitor "<default monitor>" (==) No monitor specified for screen "Default Screen Section". Using a default monitor configuration. (==) Automatically adding devices (==) Automatically enabling devices (WW) The directory "/usr/share/fonts/X11/misc" does not exist. Entry deleted from font path. (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist. Entry deleted from font path. (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist. Entry deleted from font path. (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist. Entry deleted from font path. (WW) The directory "/usr/share/fonts/X11/Type1" does not exist. Entry deleted from font path. (WW) The directory "/usr/share/fonts/X11/100dpi" does not exist. Entry deleted from font path. (WW) The directory "/usr/share/fonts/X11/75dpi" does not exist. Entry deleted from font path. (WW) The directory "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType" does not exist. Entry deleted from font path. (==) FontPath set to: built-ins (==) ModulePath set to "/usr/lib/xorg/modules" (II) The server relies on udev to provide the list of input devices. If no devices become available, reconfigure udev or disable AutoAddDevices. (II) Loader magic: 0x81ecca0 (II) Module ABI versions: X.Org ANSI C Emulation: 0.4 X.Org Video Driver: 6.0 X.Org XInput driver : 7.0 X.Org Server Extension : 2.0 (--) using VT number 7 (--) PCI:*(0:0:1:0) 1234:1111:1af4:1100 Technical Corp. rev 0, Mem @ 0xf0000000/16777216 (WW) Open ACPI failed (/var/run/acpid.socket) (No such file or directory) (II) LoadModule: "extmod" (II) Loading /usr/lib/xorg/modules/extensions/libextmod.so (II) Module extmod: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.0.0 Module class: X.Org Server Extension ABI class: X.Org Server Extension, version 2.0 (II) Loading extension SELinux (II) Loading extension MIT-SCREEN-SAVER (II) Loading extension XFree86-VidModeExtension (II) Loading extension XFree86-DGA (II) Loading extension DPMS (II) Loading extension XVideo (II) Loading extension XVideo-MotionCompensation (II) Loading extension X-Resource (II) LoadModule: "dbe" (II) Loading /usr/lib/xorg/modules/extensions/libdbe.so (II) Module dbe: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.0.0 Module class: X.Org Server Extension ABI class: X.Org Server Extension, version 2.0 (II) Loading extension DOUBLE-BUFFER (II) LoadModule: "glx" (II) Loading /usr/lib/xorg/modules/extensions/libglx.so (II) Module glx: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.0.0 ABI class: X.Org Server Extension, version 2.0 (==) AIGLX enabled (II) Loading extension GLX (II) LoadModule: "record" (II) Loading /usr/lib/xorg/modules/extensions/librecord.so (II) Module record: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.13.0 Module class: X.Org Server Extension ABI class: X.Org Server Extension, version 2.0 (II) Loading extension RECORD (II) LoadModule: "dri" (II) Loading /usr/lib/xorg/modules/extensions/libdri.so (II) Module dri: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.0.0 ABI class: X.Org Server Extension, version 2.0 (II) Loading extension XFree86-DRI (II) LoadModule: "dri2" (II) Loading /usr/lib/xorg/modules/extensions/libdri2.so (II) Module dri2: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.1.0 ABI class: X.Org Server Extension, version 2.0 (II) Loading extension DRI2 (==) Matched vesa as autoconfigured driver 0 (==) Matched fbdev as autoconfigured driver 1 (==) Assigned the driver to the xf86ConfigLayout (II) LoadModule: "vesa" (II) Loading /usr/lib/xorg/modules/drivers/vesa_drv.so (II) Module vesa: vendor="X.Org Foundation" compiled for 1.7.7, module version = 2.3.0 Module class: X.Org Video Driver ABI class: X.Org Video Driver, version 6.0 (II) LoadModule: "fbdev" (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so (II) Module fbdev: vendor="X.Org Foundation" compiled for 1.7.6.901, module version = 0.4.2 ABI class: X.Org Video Driver, version 6.0 (II) VESA: driver for VESA chipsets: vesa (II) FBDEV: driver for framebuffer: fbdev (II) Primary Device is: PCI 00@00:01:0 (WW) Falling back to old probe method for fbdev (II) Loading sub module "fbdevhw" (II) LoadModule: "fbdevhw" (II) Loading /usr/lib/xorg/modules/linux/libfbdevhw.so (II) Module fbdevhw: vendor="X.Org Foundation" compiled for 1.7.7, module version = 0.0.2 ABI class: X.Org Video Driver, version 6.0 (II) Loading sub module "vbe" (II) LoadModule: "vbe" (II) Loading /usr/lib/xorg/modules/libvbe.so (II) Module vbe: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.1.0 ABI class: X.Org Video Driver, version 6.0 (II) Loading sub module "int10" (II) LoadModule: "int10" (II) Loading /usr/lib/xorg/modules/libint10.so (II) Module int10: vendor="X.Org Foundation" compiled for 1.7.7, module version = 1.0.0 ABI class: X.Org Video Driver, version 6.0 (II) VESA(0): initializing int10 (WW) System lacks support for changing MTRRs (II) VESA(0): Primary V_BIOS segment is: 0xc000

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L4 Driver Security
by Tobias Fink 20 Jun '12

20 Jun '12

Hey List, me again with one (hopefully final) question. I'm learning about Driver Security in L4Re. I have some statements which I would like to have confirmed to understand the underlying principles: 1. L4 Drivers use DMA and are therefore able to write directly to the device memory and thus can cause crashes or damage if not carefully implemented. 2. While the L4Re Io-Server manages the access of drivers to the hardware's address spaces, it doesn't prevent drivers to write "bad" things into the device memory. 3. Untrusted, untested drivers can cause system crashes. best regards Tobi

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Re: l4linux GPU direct access
by Abhishek Gupta 19 Jun '12

19 Jun '12

Hi Adam, Where can I add x86emu inside L4Linux to switch modes??

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Re: L4Android on Pandaboard
by Matthias Lange 19 Jun '12

19 Jun '12

On 19.06.2012, at 15:49, ZhangEditing wrote: > android_bus => new System_bus() > { > sys => wrap(hw-root.sys); > prcm => wrap(hw-root.prcm); > sysdma => wrap(hw-root.sysdma); > gic => wrap(hw-root.gic); > hsmmc1 => wrap(hw-root.hsmmc1); > hsmmc2 => wrap(hw-root.hsmmc2); > hsmmc3 => wrap(hw-root.hsmmc3); > hsmmc4 => wrap(hw-root.hsmmc4); > hsmmc5 => wrap(hw-root.hsmmc5); > } The gic shouldn't be assigned to L4Android as it is driven by Fiasco. > In addition, I don't know how to assign registers that affect global configuration of the platform (e.g., the system control registers), although I don't think it is appropriate to assign such registers to only one OS. You can write a L4Re server which configures those registers. Then L4Android can access those registers via the server interface. Matthias. -- Dipl.-Inf. Matthias Lange <mlange(a)sec.t-labs.tu-berlin.de> Security in Telecommunications TU Berlin / Deutsche Telekom Laboratories Ernst-Reuter-Platz 7, 10587 Berlin Phone: +49 - 30 - 8353 58 553 Mobile: +49 - 160 - 587 28 07 Web: http://www.t-labs.tu-berlin.de/sect

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