This also includes a change so that if an instruction is being single-stepped
and it turns out to need to be emulated (e.g. because of an alignment
exception, or because we are emulating floating-point instructions), then
we need to deliver a SIGTRAP after successfully emulating the instruction
and advancing NIP.

The main thing here is that the signal delivery/return code for real-time
signals has been changed so that the layout of the registers corresponds
with the new ucontext_t definition being used by glibc.  The old ucontext_t
didn't have space to actually store the registers, just a pointer to them,
which made it impossible to implement set/getcontext et al.  The new
ucontext_t includes a mcontext_t which actually contains space to store
all of the general, floating pointer and vector registers.

We now also save the altivec registers on signal delivery and restore them
on return from the signal if the process has ever used altivec (since the
last exec).

Finally this adds a swapcontext system call.  Swapcontext really needs to be
done in the kernel since on PPC, only privileged code can set all three of
CTR, LR and NIA (next instruction address) to arbitrary values.  Also the kernel
know if the process currently owns the FP and altivec units and can optimize
in the case where it doesn't.

I should have stayed in bed.

Cleanup ikconfig
	- use single_open for built_with file.
	- get rid of unneeded globals
	- use copy_to_user instead of char at a time
	- only need the read routine, proc defaults to correct behaviour
	  for the rest.

When mmap MAP_SHARED is done on a file, it gets marked with VM_MAYSHARE
and, if it's read/write, VM_SHARED.  However, if it is remapped with
mremap(), the MAP_SHARED is only passed into the new mapping based on
VM_SHARED.  This means that remapped read only MAP_SHARED mappings lose
VM_MAYSHARE.  This is causing us a problem on parisc because we have to
align all shared mappings carefully to mitigate cache aliasing problems.

The fix is to key passing the MAP_SHARED flag back into the remapped are
off VM_MAYSHARE not VM_SHARED.

driver->supports_dma was used together with CONFIG_IDEDMA_ONLYDISK to limit
DMA access to disk devices only.  However Alan introduced new scheme in 2.5.63
and this field is not needed any longer because all ide drivers support DMA.

From Benjamin Herrenschmidt <benh@kernel.crashing.org>

into home.osdl.org:/home/torvalds/v2.5/linux

into raven.il.steeleye.com:/home/jejb/BK/scsi-for-linus-2.6

Some references to irq_stat[] snuck into generic code.  It doesn't work on
several architectures.

So revert that little improvement to the original version.

It seems that changing CONFIG_BLK_DEV_INITRD causes the whole kernel to
rebuild due to an inappropriate ifdef in linux/fs.h - we should not
conditionalise prototypes.

In addition, real_root_dev is only used by two files (kernel/sysctl.c
and init/do_mounts_initrd.c) so it makes even less sense that it was in
linux/fs.h

into home.osdl.org:/home/torvalds/v2.5/linux

into kernel.bkbits.net:/home/davem/net-2.5

This patch fixes a logic bug in NAT range calculations, which also
causes a large slowdown when ICMP floods go through NAT.

Author: Karlis Peisenieks

From: Rusty Russell <rusty@rustcorp.com.au>

Rather than hardcoded names in modprobe, modules can offer their own
aliases (which can be overridden by the config file).

Here are the tty-ldisc ones.

From: mike.miller@hp.com

Clean up the error handling in cciss_init_one().

From: Michael Pruznick <michael_pruznick@mvista.com>

build errors:
  hermes.h: In function `hermes_set_irqmask':
  hermes.h:337: parse error before "do"
  hermes.h:337: parse error before ';' token
  hermes.h: In function `hermes_write_words':

In mips, outw_p() is a #define do...while(0) which, in the case of ?:,
results in a statement being used where an expression is required.

From: Rusty Russell <rusty@rustcorp.com.au>

Please delete Documentation/kmod.txt: it's entirely outdated and misleading.

I thought about rewriting it, but there's not much to add beyond what's in
the CONFIG_KMOD's help text.

The same address `i8042_request_irq_cookie' is used in three places for the
i8042 request_irq() argument.  This means that if someone calls
i8042_check_mux() or i8042_check_aux() while the IRQ is in use, the
free_irq() call in there will free the wrong IRQ handler.

So give all three instances of request_irq() in i8042.c a distinct address by
which to identify the IRQ instance.

(This is probably a non-bug, because the `check' functions are not called
when the device is open, but it is better this way).

From: Andrew Lunn <andrew@lunn.ch>

Create the pty slaves on init so the behaviour is consistant with 2.4 and 2.6
without devfs.

From: James Morris <jmorris@redhat.com>

This patch adds an 'selinux' boot parameter which must be used to actually
enable SELinux.

It follows some internal discussion about deployment issues, where a vendor
would want to ship a single kernel image with SELinux built-in, without
requiring the user to use it.

Without specifying selinux=1 as a boot parameter, SELinux will not register
with LSM and selinuxfs will not be registered as a filesystem.  This causes
SELinux to be bypassed entirely from then on, and no performance overhead
is imposed.  Other security modules may then also be loaded if needed.

From: Ravikiran G Thirumalai <kiran@in.ibm.com>

The routine disk_round_stats showed up considerably under oprofile for high
disk io load (four processes doing dd to the same disk (different
partitions) on a 4 way).

This is because the counter in_flight which is per-cpu right now gets read
every time disk_round_stats gets called.  Per cpu counters like disk
statistics improve write speed, but reads are slow (since all cpus' local
counter values have to be read and summed up).  Considering the fact that
in_flight counter is modified post disk_round_stats (which reads the
in_flight counter) it is better not to per-cpu this counter.

Following patch does just that.  Below is the profile comparison before and
after the change.  This was on a 4 way PIII Xeon, 1G ram, 2.6.0-test4-mm2. 

Before:
c010aa60 2910109  92.2249     poll_idle
c0275340 23208    0.73549     __copy_to_user_ll
c02753b0 11191    0.354657    __copy_from_user_ll
c0114aa0 7168     0.227163    mark_offset_tsc
c011ad10 6767     0.214455    schedule
c011a2b0 6741     0.213631    load_balance
c0138890 6710     0.212648    __generic_file_aio_write_nolock
c011d302 4683     0.14841     .text.lock.sched
c02e4b50 4533     0.143656    ahc_linux_isr
c029cec0 3582     0.113518    disk_round_stats
c0119b40 3509     0.111205    try_to_wake_up
c029d320 3306     0.104771    __make_request
c01567d0 3300     0.104581    __block_write_full_page
c0156c00 3299     0.104549    __block_prepare_write

After:
c010aa60 2777940  92.1302     poll_idle
c0275340 23479    0.778679    __copy_to_user_ll
c02753b0 10943    0.362924    __copy_from_user_ll
c0114aa0 7022     0.232884    mark_offset_tsc
c0138890 6988     0.231757    __generic_file_aio_write_nolock
c011ad10 6607     0.219121    schedule
c011d302 5771     0.191395    .text.lock.sched
c02e4a60 4458     0.147849    ahc_linux_isr
c011a2b0 3921     0.13004     load_balance
c01567d0 3569     0.118366    __block_write_full_page
c029d2a0 3540     0.117404    __make_request
...
c029ceb0 311      0.0103143   disk_round_stats
c011d5b0 299      0.00991631  remove_wait_queue

From: Rusty Russell <rusty@rustcorp.com.au>

Previously, default aliases were hardwired into modutils.  Now they should
be inside the modules, using MODULE_ALIAS() (they will be overridden by any
user alias).

From: Rusty Russell <rusty@rustcorp.com.au>

Previously, default aliases were hardwired into modutils.  Now they should
be inside the modules, using MODULE_ALIAS() (they will be overridden by any
user alias).

From: Mitchell Blank Jr <mitch@sfgoth.com>

This patch makes the following improvements to might_sleep():

 o Add a "might_sleep_if()" macro for when we might sleep only if some
   condition is met.  It's a bit tidier, and has an unlikely() in it.

 o Add might_sleep checks to skb_share_check() and skb_unshare() which
   sometimes need to allocate memory.

 o Make all architectures call might_sleep() in both down() and
   down_interruptible().  Before only ppc, ppc64, and i386 did this check.
   (sh did the check on down() but not down_interruptible())

Add checks for kfree() of a page which was allocated with __alloc_pages(),
and for free_pages() of a page which was allocated with kmalloc().

fs/proc/proc_misc.c: In function `show_stat':
fs/proc/proc_misc.c:423: `irq_desc' undeclared (first use in this function)

From: Dmitry Torokhov <dtor_core@ameritech.net>

8250_acpi module does not have MODULE_LICENSE specified.  8250_gsc does not
have it either but as I can't compile it I did not touch it.

From: Nick Piggin <piggin@cyberone.com.au>

This fixes a bug in deadline and AS that causes insert_here to be ignored on
blk_fs_requests. This has been causing problems with SCSI requeueing code.
It makes elevator insertion more correct as advertised wrt insert_here and
REQ_SOFTBARRIER.

It also fixes a buglet in the as_requeue code where the request wasn't being
put into the front of the list (in rare cases).

From: Andrey Panin <pazke@donpac.ru>

Add a config option which allows ioport/mmio selection for QLA1280 SCSI
driver.

With this patch applied QLA1280 can be used on Visws again.

The new HPET RTC emulation code uses a function in rtc.c, get_rtc_time().

So that function was made non-static.  Problem is, the same function name is
used elsewhere by some architectures, so there will be linkage problems.

And rtc_get_time() is used too, so I renamed it to rtc_get_rtc_time().

Also, the HPET code was setting CONFIG_HPET_EMULATE_RTC by hand in a header
file.  Fix it to use the Kconfig system properly.

From: "Randy.Dunlap" <rddunlap@osdl.org>

Anton needs this for ppc64.  Things overflow with a huge number of CPUs.

From: Neil Brown <neilb@cse.unsw.edu.au>

With the current code in bio_add_page, if fail_segments is ever set, it
stays set, so bio_add_page will eventually fail having recounted the
segmentation once.

I don't think this is intended.  This patch changes the code to allow
success if the recounting the segments helps.

(Jens has acked this)

- non_fatal.c comment fix (Zwane Mwaikambo <zwane@linuxpower.ca>)

- s/elevator/io scheduler/ in ll_rw_blk.c (Jens)

- update KJ mailing list address ("Randy.Dunlap" <rddunlap@osdl.org>)

- unused var in riscom8.c (Adrian Bunk <bunk@fs.tum.de>)

- add help texts to two OSS drivers (Adrian Bunk <bunk@fs.tum.de>)

- "PCMCIA SCSI adapter support" requires CONFIG_MODULES (Adrian Bunk
  <bunk@fs.tum.de>)