It's more efficient for sendfile() emulation. Basically we cache an
internal private pipe and just use that as the intermediate area for
pages. Direct splicing is not available from sys_splice(), it is only
meant to be used for sendfile() emulation.

Additional patch from Ingo Molnar to avoid the PIPE_BUFFERS loop at
exit for the normal fast path.
Signed-off-by: NJens Axboe <axboe@suse.de>

add optional input and output offsets to sys_splice(), for seekable file
descriptors:

 asmlinkage long sys_splice(int fd_in, loff_t __user *off_in,
                            int fd_out, loff_t __user *off_out,
                            size_t len, unsigned int flags);

semantics are straightforward: f_pos will be updated with the offset
provided by user-space, before the splice transfer is about to begin.
Providing a NULL offset pointer means the existing f_pos will be used
(and updated in situ).  Providing an offset for a pipe results in
-ESPIPE. Providing an invalid offset pointer results in -EFAULT.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NJens Axboe <axboe@suse.de>

separate out the 'internal pipe object' abstraction, and make it
usable to splice. This cleans up and fixes several aspects of the
internal splice APIs and the pipe code:

 - pipes: the allocation and freeing of pipe_inode_info is now more symmetric
   and more streamlined with existing kernel practices.

 - splice: small micro-optimization: less pointer dereferencing in splice
   methods
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Update XFS for the ->splice_read/->splice_write changes.
Signed-off-by: NJens Axboe <axboe@suse.de>

We don't want to call into the read-ahead logic unless we are at the
start of a page, _or_ we have multiple pages to read.
Signed-off-by: NJens Axboe <axboe@suse.de>

We don't really need to lock down the pages, just make sure they
are uptodate.
Signed-off-by: NJens Axboe <axboe@suse.de>

The whole shadow/pages logic got overly complex, and this simpler
approach is actually faster in testing.
Signed-off-by: NJens Axboe <axboe@suse.de>

__wake_up_common() is pretty heavy in the kernel profiles, this brings
it down to a more acceptable level.
Signed-off-by: NJens Axboe <axboe@suse.de>

We can get to out: with a NULL page, which we probably
don't want to be calling page_cache_release() on.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NJens Axboe <axboe@suse.de>

We should do that, since we do the LRU manipulation ourselves now. Suggested
by Nick Piggin.
Signed-off-by: NJens Axboe <axboe@suse.de>

    security/selinux/xfrm.c: In function 'selinux_socket_getpeer_dgram':
    security/selinux/xfrm.c:284: error: 'struct sec_path' has no member named 'x'
    security/selinux/xfrm.c: In function 'selinux_xfrm_sock_rcv_skb':
    security/selinux/xfrm.c:317: error: 'struct sec_path' has no member named 'x'
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This effectively undoes the PCI resource allocation changes done in
commit b408cbc7, but leaves the cleanups
of that commit in place.

We're going back to marking the resources reported by e820 busy _before_
doing PCI probing, so that any PCI resource that clashes with the BIOS-
reported memory map will be reloacted to a non-clashing area.

The reason? Larry Finger reports that his laptop has the cardbus
controller set up by the BIOS so that it conflicts with the e820 memory
map, and needs to be relocated. See

   http://bugzilla.kernel.org/show_bug.cgi?id=6337

for more details.

We'll have to work out how to handle the fbcon problem that caused that
commit in the first place in some other way.

Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Antonino A. Daplas <adaplas@pol.net>
Cc: <bjk@luxsci.net>
Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Or rather compute it based on the table length automatically.

This also has the intended side effect of not warning for new system calls
anymore.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix CONFIG_REORDER.

The value of cflags-y was assined to CFLAGS before cflags-y was assigned
the value used for CONFIG_REORDER.

Use cflags-y for all CFLAGS options in the Makefile to avoid this
happening again.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In linux-2.6.16, we have noticed a problem where the gs base value
returned from an arch_prtcl(ARCH_GET_GS, ...) call will be incorrect if:

   - the current/calling task has NOT set its own gs base yet to a
     non-zero value,

   - some other task that ran on the same processor previously set their
     own gs base to a non-zero value.

In this situation, the ARCH_GET_GS code will read and return the
MSR_KERNEL_GS_BASE msr register.

However, since the __switch_to() code does NOT load/zero the
MSR_KERNEL_GS_BASE register when the task that is switched IN has a zero
next->gs value, the caller of arch_prctl(ARCH_GET_GS, ...) will get back
the value of some previous tasks's gs base value instead of 0.

    Change the arch_prctl() ARCH_GET_GS code to only read and return
    the MSR_KERNEL_GS_BASE msr register if the 'gs' register of the calling
    task is non-zero.

    Side note: Since in addition to using arch_prctl(ARCH_SET_GS, ...),
    a task can also setup a gs base value by using modify_ldt() and write
    an index value into 'gs' from user space, the patch below reads
    'gs' instead of using thread.gs, since in the modify_ldt() case,
    the thread.gs value will be 0, and incorrect value would be returned
    (the task->thread.gs value).

    When the user has not set its own gs base value and the 'gs'
    register is zero, then the MSR_KERNEL_GS_BASE register will not be
    read and a value of zero will be returned by reading and returning
    'task->thread.gs'.

    The first patch shown below is an attempt at implementing this
    approach.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Printk doesn't have any value
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If the HPET timer is enabled, the clock can drift by ~3 seconds a day.
This is due to the HPET timer not being initialized with the correct
setting (still using PIT count).

If HZ changes, this drift can become even more pronounced.

HPET patch initializes tick_nsec with correct tick_nsec settings for
HPET timer.

Vojtech comments:

  "It's not entirely correct (it assumes the HPET ticks totally
   exactly), but it's significantly better than assuming the PIT error
   there."
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Mostly to get better handling when a extended config space
access has to fallback to Type1.

Cc: gregkh@suse.de
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Previously only the first bus would be checked against Type 1.

Why 16? Checking all would need too much memory and we
can assume that systems with more than 16 busses have better than
average quality BIOS.

This is an additional defense against bad MCFG tables.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fixup the read mostly section to start at internode cacheline boundary.
Signed-off-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NShai Fultheim <shai@scalex86.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix

  WARNING: vmlinux: 'strlen' exported twice. Previous export was in vmlinux

Reported by Mats Johannesson
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Intel EM64T CPUs handle uncanonical return addresses differently
from AMD CPUs.

The exception is reported in the SYSRET, not the next instruction.
This leads to the kernel exception handler running on the user stack
with the wrong GS because the kernel didn't expect exceptions
on this instruction.

This version of the patch has the teething problems that plagued an earlier
version fixed.

This is CVE-2006-0744

Thanks to Ernie Petrides and Asit B. Mallick for analysis and initial
patches.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Machine checks can stall the machine for a long time and
it's not good to trigger the nmi watchdog during that.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The generic linux/numa.h file defines NODES_SHIFT to 0 in case
the architecture did not.

Every architecture which has a NUMA config option defines
NODES_SHIFT in its asm-$ARCH headers, but only if NUMA is
enabled, except for x86_64.

This should make it like all the rest.
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This prevents crashes on dual core system when enough ticks are lost.

Replaces earlier patch by me.

Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

AMD systems have a modern APIC that supports 8 bit IDs, but
don't have a XAPIC version number.  Add a new "modern_apic"
subfunction that handles this correctly and use it (nearly)
everywhere where XAPIC is tested for.

I removed one wart: the code specified that external APICs
would use an 8bit APIC ID. But I checked a real 82093 data sheet
and it says clearly that they only use 4bit. So I removed
this special case since it would a bit awkward to implement now.

I removed the valid APIC tests in mptable parsing completely. On any modern
system they only check against the full field width (8bit) anyways
and are no-ops. This also fixes them doing the wrong thing
on >8 core Opterons.

This makes i386 boot again on 16 core Opterons.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Needed for other checks later in ACPI.

Pointed out by Len Brown
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When nolapic was passed or the local APIC was disabled
for another reason ACPI would still parse the IO-APICs
until these were explicitely disabled with noapic.

Usually this resulted in a non booting configuration unless
"nolapic noapic" was used.

I also disabled the local APIC parsing in this case, although
that's only cosmetic (suppresses a few printks)

This hopefully makes nolapic work in all cases.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Horus systems don't have anything on bus 0 which makes
the Type 1 sanity checks fail.  Use the DMI BIOS year to
check for newer systems and always assume Type 1 works on them.
I used 2001 as an pretty arbitary cutoff year.

Cc: gregkh@suse.de
Cc: Navin Boppuri <navin.boppuri@newisys.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch introduces a user for the e820_all_mapped function:

There have been several machines that don't have a working MMCONFIG,
often because of a buggy MCFG table in the ACPI bios.  This patch adds a
simple sanity check that detects a whole bunch of these cases, and when
it detects it, linux now boots rather than crash-and-burns.

The accuracy of this detection can in principle be improved if there was
a "is this entire range in e820 with THIS attribute", but no such
function exist and the complexity needed for this is not really worth
it; this simple check already catches most cases anyway.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce a e820_all_mapped() function which checks if the entire range
<start,end> is mapped with type.

This is done by moving the local start variable to the end of each
known-good region; if at the end of the function the start address is
still before end, there must be a part that's not of the correct type;
otherwise it's a good region.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rename e820_mapped to e820_any_mapped since it tests if any part of the
range is mapped according to the type.

Later steps will introduce e820_all_mapped which will check if the
entire range is mapped with the type.  Both have their merit.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The node setup code would try to allocate the node metadata in the node
itself, but that fails if there is no memory in there.

This can happen with memory hotplug when the hotplug area defines an so
far empty node.

Now use bootmem to try to allocate the mem_map in other nodes.

And if it fails don't panic, but just ignore the node.

To make this work I added a new __alloc_bootmem_nopanic function that
does what its name implies.

TBD should try to use nearby nodes here.  Currently we just use any.
It's hard to do it better because bootmem doesn't have proper fallback
lists yet.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

From: Keith Mannthey, Andi Kleen

Implement memory hotadd without sparsemem. The memory in the SRAT
hotadd area is just preserved instead and can be activated later.

There are a few restrictions:
- Only one continuous hotadd area allowed per node

The main problem is dealing with the many buggy SRAT tables
that are out there. The strategy here is to reject anything
suspicious.

Originally from Keith Mannthey, with several hacks and changes by AK
and also contributions from Andrew Morton

[ TBD: Problems pointed out by KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>:

 1) Goto's rebuild_zonelist patch will not work if CONFIG_MEMORY_HOTPLUG=n.

    Rebuilding zonelist is necessary when the system has just memory <
    4G at boot, and hot add memory > 4G.  because x86_64 has DMA32,
    ZONE_NORAML is not included into zonelist at boot time if system
    doesn't have memory >4G at boot.

    [AK: should just force the higher zones at boot time when SRAT tells us]

 2) zone and node's spanned_pages and present_pages are not incremented.
    They should be.

    For example, our server (ia64/Fujitsu PrimeQuest) can equip memory
    from 4G to 1T(maybe 2T in future), and SRAT will *always* say we have
    possible 1T +memory.  (Microsoft requires "write all possible memory
    in SRAT") When we reserve memmap for possible 1T memory, Linux will
    not work well in +minimum 4G configuraion ;)

    [AK: needs limiting to 5-10% of max memory]
 ]
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Memory hotadd doesn't need SPARSEMEM, but can be handled by just preallocating
mem_maps. This only needs some untangling of ifdefs to enable the necessary
code even without SPARSEMEM.

Originally from Keith Mannthey, hacked by AK.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Just call IRET always, no need for any special cases.

Needed for the next bug fix.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>