When building linux-2.5.59 with gcc-3.3 (on s390, if that matters),
I get a warning like "warning: `__ksymtab___foo' defined but
not used" each time that EXPORT_SYMBOL is used.

by Arnd Bergmann

We support tags and TAGS already, so...

by Louis Zhuang

Yeah, the final step!
  
Now that we've got the checksums for the exported symbols and the
checksums of the unresolved symbols for the module we're loading,
let's compare and see.
  
Again, we allow to load a module which has the version info stripped,
but taint the kernel in that case.

We'll need that index to find the version checksum for the symbol in
a bit.

In the case of CONFIG_MODVERSIONING, the build step will only
generate preliminary <module>.o objects, and an additional
postprocessing step is necessary to record the versions of the unresolved
symbols and add them into the final <module>.ko
  
The version information for unresolved symbols is again recorded into
a special section, "__versions", which contains an array of symbol
name strings and checksum (struct modversion_info). Size is here not
an issue, since this section will not be stored permanently in kernel
memory.
  
Makefile.modver takes care of the following steps:
o Collect the version information for all exported symbols from vmlinux
  and all modules which export symbols.
o For each module, generate a C file which contains the modversion
  information for all unresolved symbols in that module.
o For each module, compile that C file to an object file
o Finally, link the <module>.ko using the preliminary <module.o> + the
  version information above.
  
The first two steps are currently done by not very efficient scripting,
so there's room for performance improvement using some helper C code.

With CONFIG_MODVERSIONING, we need to record the versions of the unresolved
symbols in the final <module>.ko, which we only know after we finished
the descending build. So we only build <module>.o in that case.
  
Also, keep track of the modules we built, the post-processing step needs
a list of all modules. Keeping track is done by touching
.tmp_versions/path/to/module.ko

For extracting the versions and finding the unresolved symbols, we
need multi-part modules to be linked together already, so this
patch separates the building of the modules as a .o file from generating
the .ko in the next step.

Store the information on the checksum alongside the rest of the 
information on exported symbols. To actually use them, we need
something to check them against first, though ;)

Also, fix some conditional debug code to actually compile.

Again, the license string is only used at load time, so no need
to store it permanently in kernel memory.

modprobe --force allows to load modules without a matching version
magic string. This invalidation is done by clearing the SHF_ALLOC
flag, so check it in the kernel. Also, clear the SHF_ALLOC flag
unconditionally, since we don't need to store the __vermagic section
in the kernel, it's only checked once at load time. 

Up to now, we had a way to store the checksums associated with the
exported symbols, but they were not filled in yet. This is done
with this patch, using the linker to actually do that for us.
  
The comment added with this patch explains what magic exactly is going
on.

This patch adds the new config option CONFIG_MODVERSIONING which will
be the new way of checking for ABI changes between kernel and module
code.

This and the following patches are in part based on an initial
implementation by Rusty Russell and I believe some of the ideas go back
to discussions on linux-kbuild, Keith Owens and Rusty.

though I'm not sure I think credit for the basic idea of
storing version info in sections goes to Keith Owens and Rusty.

o Rename __gpl_ksymtab to __ksymtab_gpl since that looks more consistent
  and appending _gpl instead of putting it into the middle simplifies
  sharing code for EXPORT_SYMBOL() and EXPORT_SYMBOL_GPL()
o Add CONFIG_MODVERSIONING
o If CONFIG_MODVERSIONING is set, add a section __kcrctab{,_gpl}, which
  contains the ABI checksums for the exported symbols listed in 
  __ksymtab{,_crc} Since we don't know the checksums yet at compilation
  time, just make them an unresolved symbol which gets filled in by the
  linker later.

Though the CONFIG_MODVERSIONS option was removed with rusty's module
rewrite and the associated code broken, a lot of that code was still
living on here and there. Now it's gone for good.

rusty's module rewrite removed the reference to EXPORT_SYMTAB 
from linux/module.h, and it's not used anywhere else, either.

In a discussion with Sam Ravnborg, the following problem became apparent:
Most vmlinux.lds.S (but the ARM ones) used the following construct:
  
       __start___ksymtab = .;                                          
       __ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {         
               *(__ksymtab)                                            
       }                                                               
       __stop___ksymtab = .;                                           
  
However, the link will align the beginning of the section __ksymtab
according to the requirements for the input sections. If '.' (current
location counter) wasn't sufficiently aligned before, it's possible
that __ksymtab actually starts at an address after the one
__start___ksymtab points to, which will confuse the users of
__start___ksymtab badly. The fix is to follow what the ARM Makefiles
did for this case, ie
  
       __ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) {                 
               __start___ksymtab = .;                                  
               *(__ksymtab)                                            
               __stop___ksymtab = .;                                   
       }                                                               

into home.transmeta.com:/home/torvalds/v2.5/linux

__virt_to_bus/__bus_to_virt depended on INTEGRATOR_HDR0_SDRAM_BASE
Unfortunately, this is defined in arch-integrator/platform.h, and
we really don't want to include it in memory.h.

We instead use BUS_OFFSET, which will eventually depend on the CPU
number in the system.

Only default BLK_DEV_IDEDMA on BLK_DEV_IDEDMA_ICS if ARCH_ACORN is
set, not if ARM is set.  There are PCI ARM systems out there!

Ensure that we clean up properly after initialisation error,
releasing all claimed resources in an orderly manner and
returning the correct error code.

Add cfbfillrect / cfbcopyarea / cfbimgblt objects for SA1100fb.
Remove redundant "pm" member.

Found a buglet in the marvel code -- doesn't change the number of IRQS
just the logic to get there.. This applies on top of the other marvel
code.

/jeff

into kanga.twiddle.net:/home/rth/linux/axp-2.5

to header files where they belong.

of AGP and SRMCONS patches.

From Jeff.Wiedemeier@hp.com.

(Titan / Marvel), Kconfig and headers.

From Jeff Wiedemeier.

Patch from Erich Focht

This adds a hook to rebalance globally across nodes every NODE_BALANCE_RATE
iterations of the rebalancer. This allows us to easily tune on an architecture
specific basis how often we wish to rebalance - machines with higher NUMA
ratios (more expensive off-node access) will want to do this less often.
It's currently set to 100 for NUMA-Q and 10 for other machines. If the
imbalance between nodes is > 125%, we'll rebalance them. The hook for this
is added to the NUMA definition of cpus_to_balance, so again, no impact
on non-NUMA machines.

Patch from Michael Hohnbaum

This adds a hook, sched_balance_exec(), to the exec code, to make it
place the exec'ed task on the least loaded queue. We have less state
to move at exec time than fork time, so this is the cheapest point
to cross-node migrate. Experience in Dynix/PTX and testing on Linux
has confirmed that this is the cheapest time to move tasks between nodes.

It also macro-wraps changes to nr_running, to allow us to keep track of
per-node nr_running as well. Again, no impact on non-NUMA machines.

Patch from Martin J. Bligh

This adds a small hook to the find_busiest_queue routine to allow us to
specify a mask of which CPUs to search over. In the NUMA case, it will
only balance inside the node (much cheaper to search, and stops tasks
from bouncing across nodes, which is very costly). The cpus_to_balance
routine is conditionally defined to ensure no impact to non-NUMA machines.

This is a tiny NUMA scheduler, but it needs the assistance of the second
and third patches in order to spread tasks across nodes.

Another left-over from ancient module code, it was supposed to return
non-zero if the module has a use count, but currently it always
evaluates to 0.

There are a few users of different types:
(1)  ioctl that perform a while(MOD_IN_USE) MOD_DEC_USE_COUNT loop.
     Just rip them out, we now have forced module unloading.
(2)  printk's that moan if the use-count in not zero in the exitfunc.
     Just rip them out, this can't happen.
(3)  if(MOD_IN_USE) MOD_DEC_USE_COUNT constructs in ->close of a few
     serial drivers.  Just remove the conditional, we did a
     MOD_INC_USE_COUNT in ->open.
(4)  This one is interesting:  drivers/sbus/char/display7seg.c uses
     the module use count to track openers.  Replace this with an
     atomic_t.

In addition remove tons of stale comments in network driver that aren't
understandable for anyone who doesn't know ancient Linux module semantics.

x86-64 updates for 2.5.58. Changes only x86-64 specific files.

 - Rewrote module allocation. Lots of bugs fixed. Module loading
   should work now again.
 - Kconfig help fixes from Randy Dunlap
 - Makefile cleanups from Pavel Machek and Sam Ravnborg
 - Assembly cleanups from Pavel
 - defconfig update
 - Better strlen_user/strnlen_user
 - Merge with i386: new ptrace commands, 32bit vsyscall signal trampolines
		new deactivate_mm, add asm/bug.h
 - Make sure initramfs is freed after booting (thanks to Kai for the hint)
 - User per cpu data for profile counters (Ravikiran Thirumalai)
 - 32bit compat_* updates from Stephen Rothwell
 - Fix race in context switch. The exception handler for bogus segment
   loads in __switch_to needs to keep interrupts disabled, otherwise an
   interrupt can deadlock on scheduler locks.  Also make sure they don't
   printk or set oops_in_progress during printk because printk does a
   wake_up too.
 - Disable 64bit GS base changes for processes.  I cannot get it to work
   reliably.
 - Clear IOPL on kernel entry

From Jeff.Wiedemeier@hp.com:

Add platform-specific callin for SMP.

From Jeff.Wiedemeier@hp.com:

- Only create smp_affinity /proc nodes if a set_affinity handler
  is provided.
- Limit the number of irq nodes that will be created in /proc
  to avoid overfilling the /proc inode space.

a titan specific kernel.