As ftrace function tracing would require modifying code that could
be executed in NMI context, which is not stopped with stop_machine(),
ftrace had to do a complex algorithm with various stages of setup
and memory barriers to make it work.

With the new breakpoint method, this is no longer required. The changes
to the code can be done without any problem in NMI context, as well as
without stop machine altogether. Remove the complex code as it is
no longer needed.

Also, a lot of the notrace annotations could be removed from the
NMI code as it is now safe to trace them. With the exception of
do_nmi itself, which does some special work to handle running in
the debug stack. The breakpoint method can cause NMIs to double
nest the debug stack if it's not setup properly, and that is done
in do_nmi(), thus that function must not be traced.

(Note the arch sh may want to do the same)

Cc: Paul Mundt <lethal@linux-sh.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

This method changes x86 to add a breakpoint to the mcount locations
instead of calling stop machine.

Now that iret can be handled by NMIs, we perform the following to
update code:

1) Add a breakpoint to all locations that will be modified

2) Sync all cores

3) Update all locations to be either a nop or call (except breakpoint
   op)

4) Sync all cores

5) Remove the breakpoint with the new code.

6) Sync all cores

[
  Added updates that Masami suggested:
   Use unlikely(modifying_ftrace_code) in int3 trap to keep kprobes efficient.
   Don't use NOTIFY_* in ftrace handler in int3 as it is not a notifier.
]

Cc: H. Peter Anvin <hpa@zytor.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

I have a new optimized x86 "strncpy_from_user()" that will use these
same helper functions for all the same reasons the name lookup code uses
them.  This is preparation for that.

This moves them into an architecture-specific header file.  It's
architecture-specific for two reasons:

 - some of the functions are likely to want architecture-specific
   implementations.  Even if the current code happens to be "generic" in
   the sense that it should work on any little-endian machine, it's
   likely that the "multiply by a big constant and shift" implementation
   is less than optimal for an architecture that has a guaranteed fast
   bit count instruction, for example.

 - I expect that if architectures like sparc want to start playing
   around with this, we'll need to abstract out a few more details (in
   particular the actual unaligned accesses).  So we're likely to have
   more architecture-specific stuff if non-x86 architectures start using
   this.

   (and if it turns out that non-x86 architectures don't start using
   this, then having it in an architecture-specific header is still the
   right thing to do, of course)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is an extra and unnecessary call to smp_processor_id()
in cpu_bringup(). Remove it.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The above mentioned patch checks the IOAPIC and if it contains
-1, then it unmaps said IOAPIC. But under Xen we get this:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
IP: [<ffffffff8134e51f>] xen_irq_init+0x1f/0xb0
PGD 0
Oops: 0002 [#1] SMP
CPU 0
Modules linked in:

Pid: 1, comm: swapper/0 Not tainted 3.2.10-3.fc16.x86_64 #1 Dell Inc. Inspiron
1525                  /0U990C
RIP: e030:[<ffffffff8134e51f>]  [<ffffffff8134e51f>] xen_irq_init+0x1f/0xb0
RSP: e02b: ffff8800d42cbb70  EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000ffffffef RCX: 0000000000000001
RDX: 0000000000000040 RSI: 00000000ffffffef RDI: 0000000000000001
RBP: ffff8800d42cbb80 R08: ffff8800d6400000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffef
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000010
FS:  0000000000000000(0000) GS:ffff8800df5fe000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0:000000008005003b
CR2: 0000000000000040 CR3: 0000000001a05000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/0 (pid: 1, threadinfo ffff8800d42ca000, task ffff8800d42d0000)
Stack:
 00000000ffffffef 0000000000000010 ffff8800d42cbbe0 ffffffff8134f157
 ffffffff8100a9b2 ffffffff8182ffd1 00000000000000a0 00000000829e7384
 0000000000000002 0000000000000010 00000000ffffffff 0000000000000000
Call Trace:
 [<ffffffff8134f157>] xen_bind_pirq_gsi_to_irq+0x87/0x230
 [<ffffffff8100a9b2>] ? check_events+0x12+0x20
 [<ffffffff814bab42>] xen_register_pirq+0x82/0xe0
 [<ffffffff814bac1a>] xen_register_gsi.part.2+0x4a/0xd0
 [<ffffffff814bacc0>] acpi_register_gsi_xen+0x20/0x30
 [<ffffffff8103036f>] acpi_register_gsi+0xf/0x20
 [<ffffffff8131abdb>] acpi_pci_irq_enable+0x12e/0x202
 [<ffffffff814bc849>] pcibios_enable_device+0x39/0x40
 [<ffffffff812dc7ab>] do_pci_enable_device+0x4b/0x70
 [<ffffffff812dc878>] __pci_enable_device_flags+0xa8/0xf0
 [<ffffffff812dc8d3>] pci_enable_device+0x13/0x20

The reason we are dying is b/c the call acpi_get_override_irq() is used,
which returns the polarity and trigger for the IRQs. That function calls
mp_find_ioapics to get the 'struct ioapic' structure - which along with the
mp_irq[x] is used to figure out the default values and the polarity/trigger
overrides. Since the mp_find_ioapics now returns -1 [b/c the IOAPIC is filled
with 0xffffffff], the acpi_get_override_irq() stops trying to lookup in the
mp_irq[x] the proper INT_SRV_OVR and we can't install the SCI interrupt.

The proper fix for this is going in v3.5 and adds an x86_io_apic_ops
struct so that platforms can override it. But for v3.4 lets carry this
work-around. This patch does that by providing a slightly different variant
of the fake IOAPIC entries.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"Page ready" async PF can kick vcpu out of idle state much like IRQ.
We need to tell RCU about this.
Reported-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

vmx_set_cr0 is called from vcpu run context, therefore it expects
kvm->srcu to be held (for setting up the real-mode TSS).
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NSasikantha babu <sasikanth.v19@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Now the helper function from filter.c for negative offsets is exported,
it can be used it in the jit to handle negative offsets.

First modify the asm load helper functions to handle:
- know positive offsets
- know negative offsets
- any offset

then the compiler can be modified to explicitly use these helper
when appropriate.

This fixes the case of a negative X register and allows to lift
the restriction that bpf programs with negative offsets can't
be jited.
Signed-of-by: NJan Seiffert <kaffeemonster@googlemail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Steven reported his P4 not booting properly, the missing format
attributes cause a NULL ptr deref. Cure this by adding the
missing format specification.

I took the format description out of the comment near
p4_config_pack*() and hope that comment is still relatively
accurate.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Reported-by: NBruno Prémont <bonbons@linux-vserver.org>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1332859842.16159.227.camel@twinsSigned-off-by: NIngo Molnar <mingo@kernel.org>

s2ram broke due to this KVM commit:

  b74f05d6 x86: kvmclock: abstract save/restore sched_clock_state

restore_sched_clock_state() methods use percpu data, therefore
they must run after %gs is initialized, but before mtrr_bp_restore()
(due to lockstat using sched_clock).

Move it to the correct place.
Reported-and-tested-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

On gccs that support AVX it's a good idea to disable that too, similar to
how SSE2, SSE1 etc. are already disabled. This prevents the compiler
from generating AVX ever implicitely.

No failure observed, just from review.

[ hpa: Marking this for urgent and stable, simply because the patch
  will either have absolutely no effect *or* it will avoid potentially
  very hard to debug failures. ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1332960678-11879-1-git-send-email-andi@firstfloor.orgSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>

When processor is being hot-added to the system, acpi_map_lsapic invokes
ACPI _MAT method to find APIC ID and flags, verifies that returned structure
is indeed ACPI's local APIC structure, and that flags contain MADT_ENABLED
bit.  Then saves APIC ID, frees structure - and accesses structure when
computing arguments for acpi_register_lapic call.  Which sometime leads
to acpi_register_lapic call being made with second argument zero, failing
to bring processor online with error 'Unable to map lapic to logical cpu
number'.

As lapic->lapic_flags & ACPI_MADT_ENABLED was already confirmed to be non-zero
few lines above, we can just pass unconditional ACPI_MADT_ENABLED to the
acpi_register_lapic.
Signed-off-by: NPetr Vandrovec <petr@vmware.com>
Signed-off-by: NAlok N Kataria <akataria@vmware.com>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Currently when a CPU is off-lined it enters either MWAIT-based idle or,
if MWAIT is not desired or supported, HLT-based idle (which places the
processor in C1 state). This patch allows processors without MWAIT
support to stay in states deeper than C1.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The X86_32-only disable_hlt/enable_hlt mechanism was used by the
32-bit floppy driver. Its effect was to replace the use of the
HLT instruction inside default_idle() with cpu_relax() - essentially
it turned off the use of HLT.

This workaround was commented in the code as:

 "disable hlt during certain critical i/o operations"

 "This halt magic was a workaround for ancient floppy DMA
  wreckage. It should be safe to remove."

H. Peter Anvin additionally adds:

 "To the best of my knowledge, no-hlt only existed because of
  flaky power distributions on 386/486 systems which were sold to
  run DOS.  Since DOS did no power management of any kind,
  including HLT, the power draw was fairly uniform; when exposed
  to the much hhigher noise levels you got when Linux used HLT
  caused some of these systems to fail.

  They were by far in the minority even back then."

Alan Cox further says:

 "Also for the Cyrix 5510 which tended to go castors up if a HLT
  occurred during a DMA cycle and on a few other boxes HLT during
  DMA tended to go astray.

  Do we care ? I doubt it. The 5510 was pretty obscure, the 5520
  fixed it, the 5530 is probably the oldest still in any kind of
  use."

So, let's finally drop this.
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NJosh Boyer <jwboyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Acked-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Stephen Hemminger <shemminger@vyatta.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org
[ If anyone cares then alternative instruction patching could be
  used to replace HLT with a one-byte NOP instruction. Much simpler. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

There has long been a limitation using software breakpoints with a
kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For
this particular patch, it will apply cleanly and has been tested all
the way back to 2.6.36.

The kprobes code uses the text_poke() function which accommodates
writing a breakpoint into a read-only page.  The x86 kgdb code can
solve the problem similarly by overriding the default breakpoint
set/remove routines and using text_poke() directly.

The x86 kgdb code will first attempt to use the traditional
probe_kernel_write(), and next try using a the text_poke() function.
The break point install method is tracked such that the correct break
point removal routine will get called later on.

Cc: x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org # >= 2.6.36
Inspried-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

When K >= 0xFFFF0000, AND needs the two least significant bytes of K as
its operand, but EMIT2() gives it the least significant byte of K and
0x2. EMIT() should be used here to replace EMIT2().
Signed-off-by: NFeiran Zhuang  <zhuangfeiran@ict.ac.cn>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The default irq_disable() sematics are to mark the interrupt disabled,
but keep it unmasked. If the interrupt is delivered while marked
disabled, the low level interrupt handler masks it and marks it
pending. This is important for detecting wakeup interrupts during
suspend and for edge type interrupts to avoid losing interrupts.

fixup_irqs() moves the interrupts away from an offlined cpu. For
certain interrupt types it needs to mask the interrupt line before
changing the affinity. After affinity has changed the interrupt line
is unmasked again, but only if it is not marked disabled.

This breaks the lazy irq disable semantics and causes problems in
suspend as the interrupt can be lost or wakeup functionality is
broken.

Check irqd_irq_masked() instead of irqd_irq_disabled() because
irqd_irq_masked() is only set, when the core code actually masked the
interrupt line. If it's not set, we unmask the interrupt and let the
lazy irq disable logic deal with an eventually incoming interrupt.

[ tglx: Massaged changelog and added a comment ]
Signed-off-by: Nliu chuansheng <chuansheng.liu@intel.com>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Link: http://lkml.kernel.org/r/27240C0AC20F114CBF8149A2696CBE4A05DFB3@SHSMSX101.ccr.corp.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This has been obsolescent for a while, fix documentation and
misc comments.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

crashkernel reservation need know the total memory size.  Current
get_total_mem simply use max_pfn - min_low_pfn.  It is wrong because it
will including memory holes in the middle.

Especially for kvm guest with memory > 0xe0000000, there's below in qemu
code: qemu split memory as below:

    if (ram_size >= 0xe0000000 ) {
        above_4g_mem_size = ram_size - 0xe0000000;
        below_4g_mem_size = 0xe0000000;
    } else {
        below_4g_mem_size = ram_size;
    }

So for 4G mem guest, seabios will insert a 512M usable region beyond of
4G.  Thus in above case max_pfn - min_low_pfn will be more than original
memsize.

Fixing this issue by using memblock_phys_mem_size() to get the total
memsize.
Signed-off-by: NDave Young <dyoung@redhat.com>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Reviewed-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add information about LVT offset assignments to better debug firmware
bugs related to this. See following examples.

 # dmesg | grep -i 'offset\|ibs'
 LVT offset 0 assigned for vector 0xf9
 [Firmware Bug]: cpu 0, try to use APIC500 (LVT offset 0) for vector 0x10400, but the register is already in use for vector 0xf9 on another cpu
 [Firmware Bug]: cpu 0, IBS interrupt offset 0 not available (MSRC001103A=0x0000000000000100)
 Failed to setup IBS, -22

In this case the BIOS assigns both offsets for MCE (0xf9) and IBS
(0x400) vectors to offset 0, which is why the second APIC setup (IBS)
failed.

With correct setup you get:

 # dmesg | grep -i 'offset\|ibs'
 LVT offset 0 assigned for vector 0xf9
 LVT offset 1 assigned for vector 0x400
 IBS: LVT offset 1 assigned
 perf: AMD IBS detected (0x00000007)
 oprofile: AMD IBS detected (0x00000007)

Note: The vector includes also the message type to handle also NMIs
(0x400). In the firmware bug message the format is the same as of the
APIC500 register and includes the mask bit (bit 16) in addition.
Signed-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Delete all instances of asm/system.h as they should be redundant by this
point.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Move all declarations of free_initmem() to linux/mm.h so that there's only one
and it's used by everything.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-c6x-dev@linux-c6x.org
cc: microblaze-uclinux@itee.uq.edu.au
cc: linux-sh@vger.kernel.org
cc: sparclinux@vger.kernel.org
cc: x86@kernel.org
cc: linux-mm@kvack.org

Disintegrate asm/system.h for X86.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
cc: x86@kernel.org

These are used as offsets into an array of GDT_ENTRY_TLS_ENTRIES members
so GDT_ENTRY_TLS_ENTRIES is one past the end of the array.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Link: http://lkml.kernel.org/r/20120324075250.GA28258@elgon.mountain
Cc: <stable@vger.kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Adapt core x86 and IA64 architecture code for dma_map_ops changes: replace
alloc/free_coherent with generic alloc/free methods.
Signed-off-by: NAndrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
[removed swiotlb related changes and replaced it with wrappers,
 merged with IA64 patch to avoid inter-patch dependences in intel-iommu code]
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NTony Luck <tony.luck@intel.com>

Xen dom0 needs to paravirtualize IO operations to the IO APIC,
so add a io_apic_ops for it to intercept.  Do this as ops
structure because there's at least some chance that another
paravirtualized environment may want to intercept these.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: jwboyer@redhat.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/1332385090-18056-2-git-send-email-konrad.wilk@oracle.com
[ Made all the affected code easier on the eyes ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Add a debugfs interface for sending commands to the OLPC
Embedded Controller (EC) and reading the responses.  The EC
provides functionality for machine identification, battery and
AC control, wakeup control, etc.

Having a debugfs interface available is useful for EC
development and debugging.

Based on code by Paul Fox (who also approves of the end result).
Signed-off-by: NDaniel Drake <dsd@laptop.org>
Acked-by: NPaul Fox <pgf@laptop.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andres Salomon <dilinger@queued.net>
Link: http://lkml.kernel.org/r/20120327150740.667D09D401E@zog.reactivated.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

We should not ever enable IRQs until we're fully set up. This opens up
a window where interrupts can hit the cpu and interrupts can do
wakeups, wakeups need state that isn't set-up yet, in particular this
cpu isn't elegible to run tasks, so if any cpu-affine task that got
created in CPU_UP_PREPARE manages to get a wakeup, its affinity mask
will get broken and we'll run into lots of 'interesting' problems.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-yaezmlbriluh166tfkgni22m@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Both functions are mostly identical.
The differences are:

- x86_32's cpu_idle() makes use of check_pgt_cache(), which is a
  nop on both x86_32 and x86_64.

- x86_64's cpu_idle() uses enter/__exit_idle/(), on x86_32 these
  function are a nop.

- In contrast to x86_32, x86_64 calls rcu_idle_enter/exit() in
  the innermost loop because idle notifications need RCU.
  Calling these function on x86_32 also in the innermost loop
  does not hurt.

So we can merge both functions.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: paulmck@linux.vnet.ibm.com
Cc: josh@joshtriplett.org
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/1332709204-22496-1-git-send-email-richard@nod.atSigned-off-by: NIngo Molnar <mingo@kernel.org>

nicked from patch by dwmw2 back in July
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
[richard@nod.at: Re-export SUBARCH in arch/um/Makefile]
Signed-off-by: NRichard Weinberger <richard@nod.at>

just provide get_current_pid() to the userland side of things
instead of get_current() + manual poking in its results
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRichard Weinberger <richard@nod.at>

Sigh, warnings are there for a reason.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: John Stultz <john.stultz@linaro.org>

Remove CONFIG_TR=y from the x86 defconfigs since
token ring support is antiquated and obsolete.

( I reviewed both x86 defconfigs - I didn't come up with
  anything else that obviously should be removed. )
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Link: http://lkml.kernel.org/r/4F6D05CA.2050801@xenotime.net
[ Twiddled the changelog a bit ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

After printing out the first line of a stack backtrace,
print_context_stack() calls print_ftrace_graph_addr() to check
if it's making a graph of function calls, usually not the case.

But unfortunate ordering of assignments causes this to oops if
an earlier stack overflow corrupted threadinfo->task.  Reorder
to avoid that irritation.

( The fact that there was a stack overflow may often be more
  interesting than the stack that can now be shown; but
  integrating that information with this stacktrace is awkward,
  so leave it to overflow reporting. )
Signed-off-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20120323225648.15DD5A033B@akpm.mtv.corp.google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The motivation for this patchset was that I was looking at a way for a
qemu-kvm process, to exclude the guest memory from its core dump, which
can be quite large.  There are already a number of filter flags in
/proc/<pid>/coredump_filter, however, these allow one to specify 'types'
of kernel memory, not specific address ranges (which is needed in this
case).

Since there are no more vma flags available, the first patch eliminates
the need for the 'VM_ALWAYSDUMP' flag.  The flag is used internally by
the kernel to mark vdso and vsyscall pages.  However, it is simple
enough to check if a vma covers a vdso or vsyscall page without the need
for this flag.

The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new
'VM_NODUMP' flag, which can be set by userspace using new madvise flags:
'MADV_DONTDUMP', and unset via 'MADV_DODUMP'.  The core dump filters
continue to work the same as before unless 'MADV_DONTDUMP' is set on the
region.

The qemu code which implements this features is at:

  http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch

In my testing the qemu core dump shrunk from 383MB -> 13MB with this
patch.

I also believe that the 'MADV_DONTDUMP' flag might be useful for
security sensitive apps, which might want to select which areas are
dumped.

This patch:

The VM_ALWAYSDUMP flag is currently used by the coredump code to
indicate that a vma is part of a vsyscall or vdso section.  However, we
can determine if a vma is in one these sections by checking it against
the gate_vma and checking for a non-NULL return value from
arch_vma_name().  Thus, freeing a valuable vma bit.
Signed-off-by: NJason Baron <jbaron@redhat.com>
Acked-by: NRoland McGrath <roland@hack.frob.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use for_each_clear_bit() to iterate over all the cleared bit in a
memory region.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>