CR_FIND_KSYM help? (was: kernel >2.4.29 problems?)

From: John M. Choi (johnchoi_at_its_dot_caltech_dot_edu)
Date: Tue May 16 2006 - 14:37:25 PDT

  • Next message: Paul H. Hargrove: "Re: CR_FIND_KSYM help?"
    So I've traced the problem, which is I guess not really a problem. The
    function 'rw_verify_area' is *not* exported (I'm guessing by the absence
    of EXPORT_SYMBOL in the kernel source?) so everything is actually working
    correctly. It looks like you (the developers) get around this by looking
    it up in using CR_FIND_KSYM. However, I can't figure out (yet)
    what 'type' is in CR_FIND_KSYM([kernel function],[type]), type =
    {DATA,CODE}, and what purpose blcr_imports/imports.c has.
    Would someone please help with what I should do to get this to work? I
    know I need to add CR_FIND_KSYM([rw_verify_area],[type]) to,
    but I don't know what 'type' to use, and what to do to
    blcr_imports/imports.c. (Or if there's anything else I need to do.) Any
    help would be much appreciated...
    John Choi, Caltech 136-93, Pasadena, CA 91125
    Tel: 626-395-4829 Fax: 626-405-0928
    On Tue, 16 May 2006, John M. Choi wrote:
    > Hi,
    > I'm trying to install blcr-0.4.2 against linux-2.4.32. However, blcr uses
    > locks_verify_area in 2 files:
    >   cr_module/cr_io.c
    >   vmadump/vmadump.c
    > The first time I tried to install this, the module blcr_vmadump complained of
    > unresolved symbol locks_verify_area. I believe that the function no longer
    > exists in linux version > 2.4.29 except in arch/mips from looking at
    > patch-2.4.30 from The new function seems to be rw_verify_area.
    > So, I copied the function calls in
    >   linux-2.4.32/fs/read_write.c:sys_read/sys_write
    >   (as per the comments in cr_io.c)
    > and changed the references in blcr. I then recompiled, but now the vmadump
    > module complains:
    >   unresolved symbol rw_verify_area.
    > So, just to make sure, I recompiled the kernel, and made sure that
    > and bzImage was self-consistent, copied the freshly compiled
    > versions to /boot, re-ran lilo and rebooted. I then 'make distclean', and
    > re-configure and re-make blcr, but I still get the unresolved symbol
    > error.
    > If I do 'grep rw_verify_area /boot/', I get
    >   c014d5f0 T rw_verify_area
    > but if I look in /proc/ksyms, the symbol does not exist. However, this
    > symbol does exist in linux-2.4.32/vmlinux, which is used to create
    > bzImage. (I'm confused about what's going on here.)
    > I realize, that most of the people reading this are probably much more
    > familiar with kernel internals than I (I'm basically guessing here), but
    > I've tried to err on the side of verbosity in what I've tried for
    > clarity's sake.
    > Would anyone please be willing to offer any hints? It would be much
    > appreciated.
    > Thanks,
    > John
    > _____________________________________________
    > John Choi, Caltech 136-93, Pasadena, CA 91125
    > Tel: 626-395-4829 Fax: 626-405-0928

  • Next message: Paul H. Hargrove: "Re: CR_FIND_KSYM help?"