Implement sys_[gs]et_thread_area and the corresponding ptrace operations for
UML.  This is the main chunk, additional parts follow.  This implementation is
now well tested and has run reliably for some time, and we've understood all
the previously existing problems.

Their implementation saves the new GDT content and then forwards the call to
the host when appropriate, i.e.  immediately when the target process is
running or on context switch otherwise (i.e.  on fork and on ptrace() calls).

In SKAS mode, we must switch registers on each context switch (because SKAS
does not switches tls_array together with current->mm).

Also, added get_cpu() locking; this has been done for SKAS mode, since TT does
not need it (it does not use smp_processor_id()).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Call arch_switch also in switch_to_skas, even if it's, for now, a no-op for
that case (and mark this in the comment); this will change soon.

Also, arch_switch for TT mode is actually useless when the PT proxy (a
complicate debugging instrumentation for TT mode) is not enabled.  In fact, it
only calls update_debugregs, which checks debugregs_seq against seq (to check
if the registers are up-to-date - seq here means a "version number" of the
registers).

If the ptrace proxy is not enabled, debugregs_seq always stays 0 and
update_debugregs will be a no-op.  So, optimize this out (the compiler can't
do it).

Also, I've been disappointed by the fact that it would make a lot of sense if,
after calling a successful
update_debugregs(current->thread.arch.debugregs_seq),
current->thread.arch.debugregs_seq were updated with the new debugregs_seq.
But this is not done.  Is this a bug or a feature?  For all purposes, it seems
a bug (otherwise the whole mechanism does not make sense, which is also a
possibility to check), which causes some performance only problems (not
correctness), since we write_debugregs when not needed.

Also, as suggested by Jeff, remove a redundant enabling of SIGVTALRM,
comprised in the subsequent local_irq_enable().  I'm just a bit dubious if
ordering matters there...
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ldt-{i386,x86_64}.h is made of two different parts - some code for parsing of
LDT descriptors, which is arch-dependant, and the code to handle uml_ldt_t (an
LDT block inside UML), which is mostly arch-independant (among x86 and x86_64,
at least).

Join the common part in a single file (ldt.h) and split the rest away
(host_ldt-{i386,x86_64}.h).

This is needed because processor.h, with next patches, will start including
the LDT descriptor parsing macros in host_ldt.h, but it can't include ldt.h
because it uses semaphores (and to define semaphores one must first include
processor.h!).
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Comparing this code which is the actual body of the arch-independent
cpu_idle(), it is clear that it's unnecessary to set ->mm and ->active_mm;
beyond that, a kernel thread is not supposed to have ->mm != NULL, only
active_mm.

This showed up because I used the assumption (which is IMHO valid) that kernel
thread have their ->mm == NULL, and it failed for this thread.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

type-safe min() in arch/um/drivers/mconsole_kern.c
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Removed assignments to unused variables in arch/um/os-Linux/Makefile
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

misc sparse annotations
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kconfig sanitized around drivers/net
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

no need to add the same file twice to MRPROPER_FILES
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kills unmap magic
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kills symlinks in arch/um/sys-*
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A number of UML initcalls were improperly returning 1.  Also removed any
nearby emacs formatting comments.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The earlier printf patch missed a corresponding change in the printed
variable.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Changes since first version
	added check for MADV_REMOVE support on the host
	fixed error return botch
	shrunk sprintf array by one character

This adds hotplug memory support to UML.  The mconsole syntax is
 	config mem=[+-]n[KMG]
In other words, add or subtract some number of kilobytes, megabytes, or
gigabytes.

Unplugged pages are allocated and then madvise(MADV_TRUNCATE), which is a
currently experimental madvise extension.  These pages are tracked so they
can be plugged back in later if the admin decides to give them back.  The
first page to be unplugged is used to keep track of about 4M of other
pages.  A list_head is the first thing on this page.  The rest is filled
with addresses of other unplugged pages.  This first page is not madvised,
obviously.

When this page is filled, the next page is used in a similar way and linked
onto a list with the first page.  Etc.  This whole process reverses when
pages are plugged back in.  When a tracking page no longer tracks any
unplugged pages, then it is next in line for plugging, which is done by
freeing pages back to the kernel.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Porting the patch I posted for x86_64 to i386.

http://marc.theaimsgroup.com/?l=linux-kernel&m=114178139610707&w=2

o While using kdump, after a system crash when second kernel boots, timer
  vector gets (0x31) locked and CPU does not see timer interrupts
  travelling from IOAPIC to APIC.  Currently it does not lead to boot
  failure in second kernel as timer interrupts continues to come as ExtInt
  through LAPIC directly, but fixing it is good in case some boards do not
  support the other mode.

o After a system crash, it is not safe to service interrupts any more,
  hence interrupts are disabled.  This leads to pending interrupts at
  LAPIC.  LAPIC sends these interrupts to the CPU during early boot of
  second kernel.  Other pending interrupts are discarded saying unexpected
  trap but timer interrupt is serviced and CPU does not issue an LAPIC EOI
  because it think this interrupt came from i8259 and sends ack to 8259.
  This leads to vector 0x31 locking as LAPIC does not clear respective ISR
  and keeps on waiting for EOI.

o This patch issues extra EOI for the pending interrupts who have ISR set.

o Though today only timer seems to be the special case because in early
  boot it thinks interrupts are coming from i8259 and uses
  mask_and_ack_8259A() as ack handler and does not issue LAPIC EOI.  But
  probably doing it in generic manner for all vectors makes sense.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This adds support for the sys_splice system call. Using a pipe as a
transport, it can connect to files or sockets (latter as output only).

From the splice.c comments:

   "splice": joining two ropes together by interweaving their strands.

   This is the "extended pipe" functionality, where a pipe is used as
   an arbitrary in-memory buffer. Think of a pipe as a small kernel
   buffer that you can use to transfer data from one end to the other.

   The traditional unix read/write is extended with a "splice()" operation
   that transfers data buffers to or from a pipe buffer.

   Named by Larry McVoy, original implementation from Linus, extended by
   Jens to support splicing to files and fixing the initial implementation
   bugs.
Signed-off-by: NJens Axboe <axboe@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

With c3000_defconfig and b180_defconfig, FAT couldn't be used
because no NLS modules were built.
Signed-off-by: NStuart Brady <sdb@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Some symbols are exported both in parisc_ksyms.c, and at their
definition site. Nuke the redundant EXPORT_SYMBOL in ksyms to quiet
warnings when vmlinux is linked.
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Move ioremap/iounmap EXPORT_SYMBOL to ioremap.c where they belong.
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Fix up some ISA/EISA stuff.

(Note: isa_ accessors have been removed from asm/io.h)
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

compat_sys_getsockopt exists, so we should use that, instead of directly
using sys_getsockopt on 64-bit compiles.
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Remove CONFIG_DEBUG_IOREMAP, it's now obsolete and won't work anyway.
Remove it from lib/KConfig since it was only available on parisc.
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Enable CONFIG_HPPA_IOREMAP by default and remove all now unnecessary code.
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Instead of making it a #define in asm/io.h, allow user to select
to turn on IOREMAP from the config menu.
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

We were only copying 32-bits of the PTE/PFN, not the full 52-bits.
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

We need to do a little renaming of our original syntax because
of the difference in arguments.
Signed-off-by: NJames Bottomley <jejb@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

Addresses in F-space must be accessed uncached on most parisc machines.
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

I think it's time to enable free_initrd_mem() again...
Signed-off-by: NHelge Deller <deller@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

pdc_stable.c is explicitly licensed under GPL version 2.
Signed-off-by: NThibaut VARENE <varenet@parisc-linux.org>
Signed-off-by: NKyle McMartin <kyle@parisc-linux.org>

efi_memmap_init() collects full granules of WB memory, without
regard for whether they also support UC.  So in order for ioremap()
to work for main memory, it must prefer WB mappings when possible.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Add __mca_table to the DISCARD list for the gate.lds linker script to
avoid broken linker references when linking the final vmlinux file.

Also add comment to include/asm-ia64/asmmacros.h to avoid anyone else
hitting this problem in the future.

Credits to James Bottomley <James.Bottomley@SteelEye.com> for spotting
the DISCARD list in gate.lds.S
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Move __mca_table out of the __init section.
Signed-off-by: NTony Luck <tony.luck@intel.com>

Remove oprofile spinlock backtrace code now we have proper calltrace
support. Also make MMCRA sihv and sipr bits a variable since they may
change in future cpus. Finally, MMCRA should be a 64bit quantity.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add calltrace support for other powerpc cpus. Tested on 7450.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add oprofile calltrace support to powerpc. Disable spinlock backtracing
now we can use calltrace info.

(Updated to work on both 32bit and 64bit by me).
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>