We started to see patches enabling this - so explain why
it is disabled and the condition to enable it again.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Ingo Molnar wrote:
>
> i've got a build log from a weird build error below:
>
>   LD      init/built-in.o
> distcc[12023] ERROR: compile (null) on localhost failed
> make: *** [vmlinux.o] Error 1
> make: *** Waiting for unfinished jobs....
>   LD      .tmp_vmlinux1
>

Building vmlinux.o were moved up in the dependency chain so we started
to build it before the kallsym stuff. This was done to let modpost
report section mismatch bugs even when the final link failed.

Originally I had expected the dependency of $(kallsyms.o) to
cover this but it turns out that we need to be even more explicit.
Fix this by adding a conditional dependency on firat target
used in the kallsyms serie of builds.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>

Arjan van de Ven <arjan@infradead.org> wrote:
===
I just read the excellent LWN writeup of the vmsplice
security thing, and that got me wondering why this attack
wasn't stopped by the CONFIG_CC_STACKPROTECTOR option...
because it plain should have been...

Some analysis later.. it turns out that the following line
in the top level Makefile, added by you in October 2007,
entirely disables CONFIG_CC_STACKPROTECTOR ;(
With this line removed the exploit will be nicely stopped.

CFLAGS          += $(call cc-option, -fno-stack-protector)

Now I realize that certain distros have patched gcc to
compensate for their lack of distro wide CFLAGS, and it's
great to work around that... but would there be a way to NOT
disable this for CONFIG_CC_STACKPROTECTOR please?
It would have made this exploit not possible for those kernels
that enable this feature (and that includes distros like Fedora)
===

Move the assignment to KBUILD_CFLAGS up before including
the arch specific Makefile so arch makefiles may override
the setting.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: stable@kernel.org

> The attached .config (with current -git) results in a compile
> error since it contains:
>
> CONFIG_X86=y
> # CONFIG_EMBEDDED is not set
> CONFIG_SERIO=m
> CONFIG_SERIO_I8042=y
>
> Looking at drivers/input/serio/Kconfig I simply don't get how this
> can happen.

You've hit the rather subtle rules of select vs default. What happened is
that SERIO is selected to m, but SERIO_I8042 isn't selected so the default
of y is used instead.
We already had the problem in the past that select and default don't work
well together, so this patch cleans this up and makes the rule hopefully
more straightforward. Basically now the value is calculated like this:

	(value && dependency) || select

where the value is the user choice (if available and the symbol is
visible) or default.

In this case it means SERIO and SERIO_I8042 are both set to y due to their
default and if SERIO didn't had the default, then the SERIO_I8042 value
would be limited to m due to the dependency.

I tested this patch with more 10000 random configs and above case is the
only the difference that showed up, so I hope there is nothing that
depended on the old more complex and subtle rules.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Tested-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

The raw_pci_read() interface (as the raw_pci_ops->read() before it)
unconditionally fills in a 32-bit integer return value regardless of the
size of the operation requested.

So claiming to take a "void *" is wrong, as is passing in a pointer to
just a byte variable.

Noticed by pageexec when enabling -fstack-protector (which needs other
patches too to actually work, but that's a separate issue).
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix up parse error in FRV linker script, presumably introduced through changes
to the INIT_TEXT and EXIT_TEXT macros.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: rt-group: refure unrunnable tasks
  sched: rt-group: clean up the ifdeffery
  sched: rt-group: make rt groups scheduling configurable
  sched: rt-group: interface
  sched: rt-group: deal with PI
  sched: fix incorrect irq lock usage in normalize_rt_tasks()
  sched: fair-group: separate tg->shares from task_group_lock
  hrtimer: more hrtimer_init_sleeper() fallout.

* git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: pit_clockevent can be static
  x86: EFI runtime code mapping enhancement
  x86: EFI: fix use of unitialized variable and the cache logic
  x86: CPA: fix gbpages support in try_preserve_large_page
  xen: unpin initial Xen pagetable once we're finished with it
  x86/early_ioremap: don't assume we're using swapper_pg_dir
  x86: fixup machine_ops reboot_{32|64}.c unification fallout
  x86: fix sigcontext.h user export

writel(sock + ...) that should've been writel(sock->addr + ...)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_and_set_bit() on address of uint32_t is a Bad Idea(tm)...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/i8253.c:98:27: warning: symbol 'pit_clockevent' was not declared. Should it be static?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

This patch enhances EFI runtime code memory mapping as following:

- Move __supported_pte_mask & _PAGE_NX checking before invoking
  runtime_code_page_mkexec(). This makes it possible for compiler to
  eliminate runtime_code_page_mkexec() on machine without NX support.

- Use set_memory_x/nx in early_mapping_set_exec(). This eliminates the
  duplicated implementation.

This patch has been tested on Intel x86_64 platform with EFI64/32
firmware.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Andi Kleen pointed out that the cache attribute logic is reverse in
efi_enter_virtual_mode(). This problem alone is harmless as we do not
(yet) do cache attribute conflict resolution. (This bug was not present
in the original EFI submission - I introduced it while fixing up rejects.)

While reviewing this code I noticed a second, worse problem: the use of
uninitialized md->virt_addr.

Fix both problems.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[ mingo@elte.hu: while gbpages cannot be enabled on mainline currently,
  keep the code uptodate and this fix is easy enough. ]

Use correct page sizes and masks for GB pages in try_preserve_large_page()

This prevents a boot hang on a GB capable system with CONFIG_DIRECT_GBPAGES
enabled.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Unpin the Xen-provided pagetable once we've finished with it, so it
doesn't cause stray references which cause later swapper_pg_dir
pagetable updates to fail.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Tested-by: Jody Belka <knew-linux@pimb.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

At the early stages of boot, before the kernel pagetable has been
fully initialized, a Xen kernel will still be running off the
Xen-provided pagetables rather than swapper_pg_dir[].  Therefore,
readback cr3 to determine the base of the pagetable rather than
assuming swapper_pg_dir[].
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Tested-by: Jody Belka <knew-linux@pimb.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

When reboot_32.c and reboot_64.c were unified (commit 4d022e35...),
the machine_ops code was broken, leading to xen pvops kernels failing
to properly halt/poweroff/reboot etc. This fixes that up.
Signed-off-by: Jody Belka <knew-linux@pimb.org>
Cc: Miguel Boton <mboton@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Jakub Jelinek reported that some user-space code that relies on
kernel headers has built dependency on the sigcontext->eip/rip
register names - which have been unified in commit:

  commit 742fa54a
  Author: H. Peter Anvin <hpa@zytor.com>
  Date:   Wed Jan 30 13:30:56 2008 +0100

      x86: use generic register names in struct sigcontext

so give the old layout to user-space. This is not particularly
pretty, but it's an ABI so there's no danger of the two definitions
getting out of sync.
Reported-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Refuse to accept or create RT tasks in groups that can't run them.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Clean up some of the excessive ifdeffery introduces in the last patch.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Make the rt group scheduler compile time configurable.
Keep it experimental for now.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Change the rt_ratio interface to rt_runtime_us, to match rt_period_us.
This avoids picking a granularity for the ratio.

Extend the /sys/kernel/uids/<uid>/ interface to allow setting
the group's rt_runtime.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Steven mentioned the fun case where a lock holding task will be throttled.

Simple fix: allow groups that have boosted tasks to run anyway.

If a runnable task in a throttled group gets boosted the dequeue/enqueue
done by rt_mutex_setprio() is enough to unthrottle the group.

This is ofcourse not quite correct. Two possible ways forward are:
  - second prio array for boosted tasks
  - boost to a prio ceiling (this would also work for deadline scheduling)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

lockdep spotted this bogus irq locking. normalize_rt_tasks() can be called
from hardirq context through sysrq-n
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

On Mon, 2008-02-11 at 15:09 +0300, Denis V. Lunev wrote:
> BUG: sleeping function called from invalid context
> at /home/den/src/linux-netns26/kernel/mutex.c:209
> in_atomic():1, irqs_disabled():0
> no locks held by swapper/0.
> Pid: 0, comm: swapper Not tainted 2.6.24 #304
>
> Call Trace:
>  <IRQ>  [<ffffffff80252d1e>] ? __debug_show_held_locks+0x15/0x27
>  [<ffffffff8022c2a8>] __might_sleep+0xc0/0xdf
>  [<ffffffff8049f1df>] mutex_lock_nested+0x28/0x2a9
>  [<ffffffff80231294>] sched_destroy_group+0x18/0xea
>  [<ffffffff8023e835>] sched_destroy_user+0xd/0xf
>  [<ffffffff8023e8c1>] free_uid+0x8a/0xab
>  [<ffffffff80233e24>] __put_task_struct+0x3f/0xd3
>  [<ffffffff80236708>] delayed_put_task_struct+0x23/0x25
>  [<ffffffff8026fda7>] __rcu_process_callbacks+0x8d/0x215
>  [<ffffffff8026ff52>] rcu_process_callbacks+0x23/0x44
>  [<ffffffff8023a2ae>] __do_softirq+0x79/0xf8
>  [<ffffffff8020f8c3>] ? profile_pc+0x2a/0x67
>  [<ffffffff8020d38c>] call_softirq+0x1c/0x30
>  [<ffffffff8020f689>] do_softirq+0x61/0x9c
>  [<ffffffff8023a233>] irq_exit+0x51/0x53
>  [<ffffffff8021bd1a>] smp_apic_timer_interrupt+0x77/0xad
>  [<ffffffff8020ce3b>] apic_timer_interrupt+0x6b/0x70
>  <EOI>  [<ffffffff8020b0dd>] ? default_idle+0x43/0x76
>  [<ffffffff8020b0db>] ? default_idle+0x41/0x76
>  [<ffffffff8020b09a>] ? default_idle+0x0/0x76
>  [<ffffffff8020b186>] ? cpu_idle+0x76/0x98

separate the tg->shares protection from the task_group lock.
Reported-by: Denis V. Lunev <den@openvz.org>
Tested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Missed an instance...

  futex_lock_pi()
    hrtimer_init_sleeper()
    rt_mutex_timed_lock()
      rt_mutex_timed_fastlock()
        rt_mutex_slowlock()
          hrtimer_start()
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

The USEC_TO_HZ and HZ_TO_USEC constant sets were mislabelled, with
seriously incorrect results.  This among other things manifested
itself as cpufreq not working when a tickless kernel was configured.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: Carlos R. Mafra <crmafra@ift.unesp.br>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Even if we don't want to register the WMI driver, we should initialize
the wmi_blocks list to be empty, since we don't want the wmi helper
functions to oops just because that basic list has not even been set up.

With this, "find_guid()" will happily return "not found" rather than
oopsing all over the place, and the callers will then just automatically
return false or AE_NOT_FOUND as appropriate.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The makefile magic for installing the 32-bit vdso images on disk had a
little error.  A single-line change would fix that bug, but this does a
little more to reduce the error-prone duplication of this bit of
makefile variable magic.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Kosaki Motohito noted that "numactl --interleave=all ..." failed in the
presence of memoryless nodes.  This patch attempts to fix that problem.

Some background:

numactl --interleave=all calls set_mempolicy(2) with a fully populated
[out to MAXNUMNODES] nodemask.  set_mempolicy() [in do_set_mempolicy()]
calls contextualize_policy() which requires that the nodemask be a
subset of the current task's mems_allowed; else EINVAL will be returned.

A task's mems_allowed will always be a subset of node_states[N_HIGH_MEMORY]
i.e., nodes with memory.  So, a fully populated nodemask will be
declared invalid if it includes memoryless nodes.

  NOTE:  the same thing will occur when running in a cpuset
         with restricted mem_allowed--for the same reason:
         node mask contains dis-allowed nodes.

mbind(2), on the other hand, just masks off any nodes in the nodemask
that are not included in the caller's mems_allowed.

In each case [mbind() and set_mempolicy()], mpol_check_policy() will
complain [again, resulting in EINVAL] if the nodemask contains any
memoryless nodes.  This is somewhat redundant as mpol_new() will remove
memoryless nodes for interleave policy, as will bind_zonelist()--called
by mpol_new() for BIND policy.

Proposed fix:

1) modify contextualize_policy logic to:
   a) remember whether the incoming node mask is empty.
   b) if not, restrict the nodemask to allowed nodes, as is
      currently done in-line for mbind().  This guarantees
      that the resulting mask includes only nodes with memory.

      NOTE:  this is a [benign, IMO] change in behavior for
             set_mempolicy().  Dis-allowed nodes will be
             silently ignored, rather than returning an error.

   c) fold this code into mpol_check_policy(), replace 2 calls to
      contextualize_policy() to call mpol_check_policy() directly
      and remove contextualize_policy().

2) In existing mpol_check_policy() logic, after "contextualization":
   a) MPOL_DEFAULT:  require that in coming mask "was_empty"
   b) MPOL_{BIND|INTERLEAVE}:  require that contextualized nodemask
      contains at least one node.
   c) add a case for MPOL_PREFERRED:  if in coming was not empty
      and resulting mask IS empty, user specified invalid nodes.
      Return EINVAL.
   c) remove the now redundant check for memoryless nodes

3) remove the now redundant masking of policy nodes for interleave
   policy from mpol_new().

4) Now that mpol_check_policy() contextualizes the nodemask, remove
   the in-line nodes_and() from sys_mbind().  I believe that this
   restores mbind() to the behavior before the memoryless-nodes
   patch series.  E.g., we'll no longer treat an invalid nodemask
   with MPOL_PREFERRED as local allocation.

[ Patch history:

  v1 -> v2:
   - Communicate whether or not incoming node mask was empty to
     mpol_check_policy() for better error checking.
   - As suggested by David Rientjes, remove the now unused
     cpuset_nodes_subset_current_mems_allowed() from cpuset.h

  v2 -> v3:
   - As suggested by Kosaki Motohito, fold the "contextualization"
     of policy nodemask into mpol_check_policy().  Looks a little
     cleaner. ]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Fix build for sim_defconfig

So I spent a while pounding my head against my monitor trying to figure
out the vmsplice() vulnerability - how could a failure to check for
*read* access turn into a root exploit? It turns out that it's a buffer
overflow problem which is made easy by the way get_user_pages() is
coded.

In particular, "len" is a signed int, and it is only checked at the
*end* of a do {} while() loop.  So, if it is passed in as zero, the loop
will execute once and decrement len to -1.  At that point, the loop will
proceed until the next invalid address is found; in the process, it will
likely overflow the pages array passed in to get_user_pages().

I think that, if get_user_pages() has been asked to grab zero pages,
that's what it should do.  Thus this patch; it is, among other things,
enough to block the (already fixed) root exploit and any others which
might be lurking in similar code.  I also think that the number of pages
should be unsigned, but changing the prototype of this function probably
requires some more careful review.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  mlx4_core: Fix build break (missing include)

Matt is already the maintainer of SLOB which is one of the "SLAB" allocators in
the kernel so add him to MAINTAINERS.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  sata_mv: platform driver allocs dma without create
  pata_ninja32: setup changes
  pata_legacy: typo fix
  pata_amd: Note in the module description it handles Nvidia
  sata_mv: fix loop with last port
  libata: ignore deverr on SETXFER if mode is configured
  pata_via: fix SATA cable detection on cx700

This avoids warnings with unreferenced variables in the !NUMA case.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 313abe55 ("mlx4_core: For 64-bit systems, vmap() kernel queue
buffers") caused this to pop up on powerpc allyesconfig, looks like a
missing include file:

    drivers/net/mlx4/alloc.c: In function 'mlx4_buf_alloc':
    drivers/net/mlx4/alloc.c:162: error: implicit declaration of function 'vmap'
    drivers/net/mlx4/alloc.c:162: error: 'VM_MAP' undeclared (first use in this function)
    drivers/net/mlx4/alloc.c:162: error: (Each undeclared identifier is reported only once
    drivers/net/mlx4/alloc.c:162: error: for each function it appears in.)
    drivers/net/mlx4/alloc.c:162: warning: assignment makes pointer from integer without a cast
    drivers/net/mlx4/alloc.c: In function 'mlx4_buf_free':
    drivers/net/mlx4/alloc.c:187: error: implicit declaration of function 'vunmap'
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

Commit bdc80787 broke the build
for this config because the sim_defconfig selects CONFIG_HZ=250
but include/asm-ia64/param.h has an ifdef for the simulator to
force HZ to 32.  So we ended up with a kernel/timeconst.h set
for HZ=250 ... which then failed the check for the right HZ
value and died with:

Drop the #ifdef magic from param.h and make force CONFIG_HZ=32
directly for the simulator.
Signed-off-by: Tony Luck <tony.luck@intel.com>

When the sata_mv driver is used as a platform driver,
mv_create_dma_pools() is never called so it fails when trying
to alloc in mv_pool_start().
Signed-off-by: Byron Bradley <byron.bbradley@gmail.com>
Acked-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>