From: John M. Choi (johnchoi_at_its_dot_caltech_dot_edu)
Date: Tue May 16 2006 - 14:37:25 PDT
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 System.map 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 configure.ac,
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
_____________________________________________
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 kernel.org. 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
> System.map 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/System.map', 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
>