L4Linux: pagefault at the beginning of BSS area

[Adam Lackorzynski]

Hi,

On Sat Mar 08, 2008 at 00:44:46 +1200, Valery V. Sedletski wrote:
> I compiled myself l4linux and tried to start it, but something goes wrong. When the linux server starts, a page 
> fault occurs at the beginning of its BSS area. The log is the following:
> 
> exec    | vmlinuz26: Packed 1868352 bytes of lines
> loader  | vmlinuz26,#f: Continue at l4env_init (00016640, libloader.s.so)
> l4lx    | ======> L4Linux 2.6 starting... <========
> l4lx    | Linux version 2.6.17-l4 (root at umas1) (gcc version 3.3.1 (Mandrake Lin
> l4lx    : ux 9.2 3.3.1-2mdk)) #1 Thu Feb 7 22:57:26 UTC 2008
> l4lx    | Binary name: vmlinuz26
> l4lx    | Kernel command line (5 args): mem=128M load_ramdisk=1 ramdisk_size=40
> l4lx    : 96 root=/dev/ram l4env_rd=(nd)/tftpboot/drops/bin/rd/initrd.gz
> l4lx    | Image: 00400000 - 0071c000 [3184 KiB].
> l4lx    | Areas: Text:     00400000 - 00631000 [2244kB] (a bit longer)
> l4lx    |        Data:     00631000 - 0067b5ac [297kB]
> l4lx    |        Initdata: 0067e000 - 006af000 [196kB]
> l4lx    |        BSS:      006b0000 - 0071aac0 [426kB]
> l4lx    | L4RM: [PF] read at 0x006b0000, ip 004019e0, src F.02
> l4lx    | [F.0] l4rm/lib/src/pagefault.c:78:__unknown_pf():
> l4lx    |  unhandled page fault
> l4lx    | 
> l4lx    | Exiting with -1
> simplets| Exit F.00
> [===============================================]
> 
> What must be mapped to the BSS area and why it may be unsuccessful? These page faults, as I understand, 
> are handled by l4rm library and dm_phys dataspace manager, but what here can be wrong?
> 
> 
> as you can probably see, I use a bit old l4linux and l4env sources
> (downloaded a year or more ago). I think I 
> missed something simple, but I can't understand what. Please help.

Quite old but anyway. It would be interesting to know where 0x004019e0
is in the vmlinux binary. So please look up the address with
objdump -ld vmlinux
and see what .c files and which line in there are mentioned around the
address. Then please look it up in the source and show me the function
where this happens. As 2.6.17 is quite old it probably won't match with
the current source I use.



Adam
-- 
Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/