[EMAIL PROTECTED] wrote: > Boaz Harrosh wrote: >> [EMAIL PROTECTED] wrote: >> >>> Boaz Harrosh wrote: >>> >>>> [EMAIL PROTECTED] wrote: >>>> >>>> >>>>> Boaz Harrosh wrote: >>>>> >>>>> >>>>>> [EMAIL PROTECTED] wrote: >>>>>> >>>>>> >>>>>> >>>>>>> Hi! >>>>>>> >>>>>>> I've compiled an UML kernel based on 2.6.25 but loading kernel modules >>>>>>> seems to be broken. No matter which module I try to load the output >>>>>>> looks similar to this: >>>>>>> >>>>>>> overflow in relocation type 11 val 80836d41 >>>>>>> 'loop' likely not compiled with -mcmodel=kernel >>>>>>> >>>>>>> After searching for a while I found some threads from 2006 discussing >>>>>>> this issue, e.g.: >>>>>>> http://www.mail-archive.com/user-mode-linux-devel@lists.sourceforge.net/msg03693.html >>>>>>> and >>>>>>> http://marc.info/?l=user-mode-linux-devel&m=115125101012707&w=2 >>>>>>> >>>>>>> As Andi Kleen has mentioned in a mail from the first thread, simply >>>>>>> appending "-mcmodel=kernel" to the KBUILD_CFLAGS does not work (I tried >>>>>>> it anyway and can confirm his statement ;) >>>>>>> >>>>>>> Since I could not find any solution I've decided to write this mail and >>>>>>> ask about the current state of this issue and of course for a solution! >>>>>>> I simply don't want to believe that there is no loadable module support >>>>>>> for UML in 2008... >>>>>>> >>>>>>> Regards >>>>>>> JK >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> Every thing is fine down here. What host Kernel-gcc-glibc / uml-gcc-glibc >>>>>> are you using? >>>>>> >>>>>> I'm using out-of-tree modules with uml for every kernel since 2.6.19. >>>>>> I have both Host and UML as x86_64 on FC7 with gcc 4.1.2 >>>>>> >>>>>> Boaz >>>>>> >>>>>> >>>>>> >>>>>> >>>>> I'm glad to here that the bug has been fixed. Anyway, it does not work >>>>> with my configuration: >>>>> >>>>> - CentOS 5.1 as host system and UML root fs >>>>> - Kernel 2.6.25.4 (vanilla, but config taken from the CentOS kernel) >>>>> - GCC 4.1.2 >>>>> - GLIBC 2.5 >>>>> >>>>> Regards >>>>> JK >>>>> >>>>> >>>>> >>>> I used to run with red-hat 4.5 so this should work. >>>> 64 bit, right? >>>> >>>> From passed experience I've seen that UML will only >>>> work if I first do "make ARCH=um defconfig" and then >>>> manually enable any needed options with make xconfig. >>>> other wise it breaks in all kind of ways. Even doing >>>> a make oldconfig on a good uml config file from older >>>> kernel will not work. Try to do defconfig and see if >>>> it loads at all. >>>> >>>> How do you compile and run the out-of-tree module >>>> or is it one of the built in modules? >>>> >>>> Boaz >>>> >>>> >>>> >>> I tried what you've suggested and did the following: >>> - make mrproper >>> - make defconfig ARCH=um >>> - make linux ARCH=um >>> - make modules ARCH=um >>> - make modules_install INSTALL_MOD_PATH=/path/to/mounted/uml_root_fs ARCH=um >>> >>> It did not work (same result). >>> >>> After that, I copied the kernel source to the uml-root-fs, started the >>> UML and did a 'make clean' and 'make modules ARCH=um' inside the running >>> UML, followed by a 'make modules_install'. Again, it did not work. >>> >>> After that, I've extracted the kernel source again (completely vanilla) >>> and restarted at 'make defconfig'. Same result. >>> No module is loadable. They all have 'invalid fomrat' an the usage of >>> the '-mcmodel=kernel' flag is suggested. >>> >>> BTW : with the same sources (and the same commands as listed above) I've >>> successfully built a fully working 32 bit UML kernel! >>> >>> I've also tried kernel 2.6.24.7 with identical results. >>> >>> Last but not least, I've tried the same with a fresh download of the >>> 2.6.26 kernel. Unfortunately, this time there was another problem: the >>> kernel exits with a panic on startup (tried to build it twice with the >>> same result). According to the stack-trace, the panic happens somewhere >>> inside "get_page_from_free_list()"... >>> >>> I'm really running out of ideas right now, does anyone have some >>> suggestions? >>> >>> Regards >>> JK >>> >>> >> >> It all works down here. Just a long shot you have installed uml_utilities >> on the host ... >> > They are installed. >> I run the uml from the root of the source tree like this: >> ......./.build_um/vmlinux ubd0=/usr0/var/local/um/Fedora7-AMD64-root_fs >> eth0=tuntap,,,192.168.0.117 mem=256M >> (The .build_um/ is because I use KBUILD_OUTPUT=.build_um so I can compile >> multiple targets from same source tree) >> >> Maybe there is some package missing from the Linux image you are using. >> You are using a 64bit Linux image with your 64bit kernel, yes? >> Try to compare the 32 bit image with the 64bit one. See if they have >> the same packages installed. I started with a ready made fedora7 uml >> image and never really touched it much except the occasional yum install >> of a library or two. >> >> Boaz >> > I already thought about the root fs being the reason for this, but I > can't imagine how a different root can affect the kernel's ability to > load modules. It should not be affected by any packages installed, isn't it? > Anyway, after taking a closer look to your starting command, I noticed > another difference: I've always been using "mem=512m" on the 64 bit > system (it's an 8 GB machine). I've tried it with "mem=256" and IT > FINALLY WORKS! All the kernels I've compiled are working correctly now, > except for the 2.6.26 which still exits with a panic on startup... > > Thank you very much for your help! But I'd really like to know why it > did not work with "m= 512m". I've always thought that this would only > alter the max. available memory inside the UML. Maybe this is a bug though? > > Regards > JK
It is certainly sounds like a bug. I also get problems with 512M but I only have 1G on my machine and I have lots of initrd configured modules so it can be lots of things. Please use gdb and try to see what fails and report. $ gdb vmlinux gdb> run ubd0=/path_to/uml-root_fs eth0=tuntap,,,192.168.0.117 mem=512M you might need a few continues: gdb> c This is expected. Try to see what happens just before those cryptic error messages of load failure, also compare the bad run with a good run of 256M I will try and do the same once I find a bit of time. Perhaps next week. Thanks Boaz ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
