kprobes: Fix to free gone and unused optprobes

Fix to free gone and unused optprobes. This bug will
cause a kernel panic if the user reuses the killed and
unused probe.

Reported at:

  http://sourceware.org/ml/systemtap/2013-q2/msg00142.html

In the normal path, an optprobe on an init function is
unregistered when a module goes live.

unregister_kprobe(kp)
 -> __unregister_kprobe_top
   ->__disable_kprobe
     ->disarm_kprobe(ap == op)
       ->__disarm_kprobe
        ->unoptimize_kprobe : the op is queued
                              on unoptimizing_list
and do nothing in __unregister_kprobe_bottom

After a while (usually wait 5 jiffies), kprobe_optimizer
runs to unoptimize and free optprobe.

kprobe_optimizer
 ->do_unoptimize_kprobes
   ->arch_unoptimize_kprobes : moved to free_list
 ->do_free_cleaned_kprobes
   ->hlist_del: the op is removed
   ->free_aggr_kprobe
     ->arch_remove_optimized_kprobe
     ->arch_remove_kprobe
     ->kfree: the op is freed

Here, if kprobes_module_callback is called and the delayed
unoptimizing probe is picked BEFORE kprobe_optimizer runs,

kprobes_module_callback
 ->kill_kprobe
   ->kill_optimized_kprobe : dequeued from unoptimizing_list <=!!!
     ->arch_remove_optimized_kprobe
   ->arch_remove_kprobe
   (but op is not freed, and on the kprobe hash table)

This doesn't happen if the probe unregistration is done AFTER
kprobes_module_callback is called (because at that time the op
is gone), and kprobe-tracer does it.

To fix this bug, this patch changes kprobes_module_callback to
enqueue the op to freeing_list at kill_optimized_kprobe only
if the op is unused. The unused probes on freeing_list will
be freed in do_free_cleaned_kprobes.

Note that this calls arch_remove_*kprobe twice on the
same probe. Thus those functions have to check the double free.
Fortunately, most of arch codes already checked that except
for mips. This will be fixed in the next patch.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Timo Juhani Lindfors <timo.lindfors@iki.fi>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: systemtap@sourceware.org
Cc: yrl.pp-manager.tt@hitachi.com
Cc: David S. Miller <davem@davemloft.net>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20130522093409.9084.63554.stgit@mhiramat-M0-7522
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf: Fix perf mmap bugs

Vince reported a problem found by his perf specific trinity
fuzzer.

Al noticed 2 problems with perf's mmap():

 - it has issues against fork() since we use vma->vm_mm for accounting.
 - it has an rb refcount leak on double mmap().

We fix the issues against fork() by using VM_DONTCOPY; I don't
think there's code out there that uses this; we didn't hear
about weird accounting problems/crashes. If we do need this to
work, the previously proposed VM_PINNED could make this work.

Aside from the rb reference leak spotted by Al, Vince's example
prog was indeed doing a double mmap() through the use of
perf_event_set_output().

This exposes another problem, since we now have 2 events with
one buffer, the accounting gets screwy because we account per
event. Fix this by making the buffer responsible for its own
accounting.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20130528085548.GA12193@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
vtime: Use consistent clocks among nohz accounting

While computing the cputime delta of dynticks CPUs,
we are mixing up clocks of differents natures:

* local_clock() which takes care of unstable clock
sources and fix these if needed.

* sched_clock() which is the weaker version of
local_clock(). It doesn't compute any fixup in case
of unstable source.

If the clock source is stable, those two clocks are the
same and we can safely compute the difference against
two random points.

Otherwise it results in random deltas as sched_clock()
can randomly drift away, back or forward, from local_clock().

As a consequence, some strange behaviour with unstable tsc
has been observed such as non progressing constant zero cputime.
(The 'top' command showing no load).

Fix this by only using local_clock(), or its irq safe/remote
equivalent, in vtime code.

Reported-by: Mike Galbraith <efault@gmx.de>
Suggested-by: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kvm: Move guest entry/exit APIs to context_tracking

The kvm_host.h header file doesn't handle well
inclusion when archs don't support KVM.

This results in build crashes for such archs when they
want to implement context tracking because this subsystem
includes kvm_host.h in order to implement the
guest_enter/exit APIs but it doesn't handle KVM off case.

To fix this, move the guest_enter()/guest_exit()
declarations and generic implementation to the context
tracking headers. These generic APIs actually belong to
this subsystem, besides other domains boundary tracking
like user_enter() et al.

KVM now properly becomes a user of this library, not the
other buggy way around.

Reported-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
nohz: Fix notifier return val that enforce timekeeping

In tick_nohz_cpu_down_callback() if the cpu is the one handling
timekeeping, we must return something that stops the CPU_DOWN_PREPARE
notifiers and then start notify CPU_DOWN_FAILED on the already called
notifier call backs.

However traditional errno values are not handled by the notifier unless
these are encapsulated using errno_to_notifier().

Hence the current -EINVAL is misinterpreted and converted to junk after
notifier_to_errno(), leaving the notifier subsystem to random behaviour
such as eventually allowing the cpu to go down.

Fix this by using the standard NOTIFY_BAD instead.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/x86: Construct all sibling maps if smt

Commit 316ad248307fb ("sched/x86: Rewrite
set_cpu_sibling_map()") broke the construction of sibling maps,
which also broke the booted_cores accounting.

Before the rewrite, if smt was present, then each map was
updated for each smt sibling. After the rewrite only
cpu_sibling_mask gets updated, as the llc and core maps depend
on 'has_mc = x86_max_cores > 1' instead. This leads to problems
with topologies like the following

(qemu -smp sockets=2,cores=1,threads=2)

  processor       : 0
  physical id     : 0
  siblings        : 1    <= should be 2
  core id         : 0
  cpu cores       : 1

  processor       : 1
  physical id     : 0
  siblings        : 1    <= should be 2
  core id         : 0
  cpu cores       : 0    <= should be 1

  processor       : 2
  physical id     : 1
  siblings        : 1    <= should be 2
  core id         : 0
  cpu cores       : 1

  processor       : 3
  physical id     : 1
  siblings        : 1    <= should be 2
  core id         : 0
  cpu cores       : 0    <= should be 1

This patch restores the former construction by defining has_mc
as (has_smt || x86_max_cores > 1). This should be fine as there
were no (has_smt && !has_mc) conditions in the context.

Aso rename has_mc to has_mp now that it's not just for cores.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: a.p.zijlstra@chello.nl
Cc: fenghua.yu@intel.com
Link: http://lkml.kernel.org/r/1369831695-11970-1-git-send-email-drjones@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
tick: Remove useless timekeeping duty attribution to broadcast source

Since 7300711e ("clockevents: broadcast fixup possible waiters"),
the timekeeping duty is assigned to the CPU that handles the tick
broadcast clock device by the time it is set in one shot mode.

This is an issue in full dynticks mode where the timekeeping duty
must stay handled by the boot CPU for now. Otherwise it prevents
secondary CPUs from offlining and this breaks
suspend/shutdown/reboot/...

As it appears there is no reason for this timekeeping duty to be
moved to the broadcast CPU, besides nothing prevent it from being
later re-assigned to another target, let's simply remove it.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
idle: Add the stack canary init to cpu_startup_entry()

Moving x86 to the generic idle implementation (commit 7d1a9417 "x86:
Use generic idle loop") wreckaged the stack protector.

I stupidly missed that boot_init_stack_canary() must be inlined from a
function which never returns, but I put that call into
arch_cpu_idle_prepare() which of course returns.

I pondered to play tricks with arch_cpu_idle_prepare() first, but then
I noticed, that the other archs which have implemented the
stackprotector (ARM and SH) do not initialize the canary for the
non-boot cpus.

So I decided to move the boot_init_stack_canary() call into
cpu_startup_entry() ifdeffed with an CONFIG_X86 for now. This #ifdef
is just a temporary measure as I don't want to inflict the
boot_init_stack_canary() call on ARM and SH that late in the cycle.

I'll queue a patch for 3.11 which removes the #ifdef if the ARM/SH
maintainers have no objection.

Reported-by: Wouter van Kesteren <woutershep@gmail.com>
Cc: x86@kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
drm/radeon: do not try to uselessly update virtual memory pagetable

If a buffer is never bound to a virtual memory pagetable than don't try
to unbind it. Only drawback is that we don't update the pagetable when
unbinding the ib pool buffer which is fine because it only happens at
suspend or module unload/shutdown.

Fixes spurious messages about buffers without VM mappings. E.g.:
radeon 0000:01:00.0: bo ffff88020afac400 don't has a mapping in vm ffff88021ca2b900

Cc: stable@kernel.org
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/radeon: fix write back suspend regression with uvd v2

UVD ring can't use scratch thus it does need writeback buffer to keep
a valid address or radeon_ring_backup will trigger a kernel fault.

It's ok to not unpin the write back buffer on suspend as it leave in
gtt and thus does not need eviction.

v2: Fix the uvd case.

Reported and tracked by Wojtek <wojtask9@wp.pl>

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
crypto: aesni_intel - fix accessing of unaligned memory

The new XTS code for aesni_intel uses input buffers directly as memory operands
for pxor instructions, which causes crash if those buffers are not aligned to
16 bytes.

Patch changes XTS code to handle unaligned memory correctly, by loading memory
with movdqu instead.

Reported-by: Dave Jones <davej@redhat.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
rbd: use the correct length for format 2 object names

Format 2 objects use 16 characters for the object name suffix to be
able to express the full 64-bit range of object numbers. Format 1
images only use 12 characters for this. Using 12-character names for
format 2 caused userspace and kernel rbd clients to read differently
named objects, which made an image written by one client look empty to
the other client.

CC: stable@vger.kernel.org  # 3.9+
Reported-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
target/iscsi: don't corrupt bh_count in iscsit_stop_time2retain_timer()

Here is a fun one.  Bug seems to have been introduced by commit 140854cb,
almost two years ago.  I have no idea why we only started seeing it now,
but we did.

Rough callgraph:
core_tpg_set_initiator_node_queue_depth()
`-> spin_lock_irqsave(&tpg->session_lock, flags);
`-> lio_tpg_shutdown_session()
    `-> iscsit_stop_time2retain_timer()
        `-> spin_unlock_bh(&se_tpg->session_lock);
        `-> spin_lock_bh(&se_tpg->session_lock);
`-> spin_unlock_irqrestore(&tpg->session_lock, flags);

core_tpg_set_initiator_node_queue_depth() used to call spin_lock_bh(),
but 140854cb changed that to spin_lock_irqsave().  However,
lio_tpg_shutdown_session() still claims to be called with spin_lock_bh()
held, as does iscsit_stop_time2retain_timer():
 *      Called with spin_lock_bh(&struct se_portal_group->session_lock) held

Stale documentation is mostly annoying, but in this case the dropping
the lock with the _bh variant is plain wrong.  It is also wrong to drop
locks two functions below the lock-holder, but I will ignore that bit
for now.

After some more locking and unlocking we eventually hit this backtrace:
------------[ cut here ]------------
WARNING: at kernel/softirq.c:159 local_bh_enable_ip+0xe8/0x100()
Pid: 24645, comm: lio_helper.py Tainted: G           O 3.6.11+
Call Trace:
 [<ffffffff8103e5ff>] warn_slowpath_common+0x7f/0xc0
 [<ffffffffa040ae37>] ? iscsit_inc_conn_usage_count+0x37/0x50 [iscsi_target_mod]
 [<ffffffff8103e65a>] warn_slowpath_null+0x1a/0x20
 [<ffffffff810472f8>] local_bh_enable_ip+0xe8/0x100
 [<ffffffff815b8365>] _raw_spin_unlock_bh+0x15/0x20
 [<ffffffffa040ae37>] iscsit_inc_conn_usage_count+0x37/0x50 [iscsi_target_mod]
 [<ffffffffa041149a>] iscsit_stop_session+0xfa/0x1c0 [iscsi_target_mod]
 [<ffffffffa0417fab>] lio_tpg_shutdown_session+0x7b/0x90 [iscsi_target_mod]
 [<ffffffffa033ede4>] core_tpg_set_initiator_node_queue_depth+0xe4/0x290 [target_core_mod]
 [<ffffffffa0409032>] iscsit_tpg_set_initiator_node_queue_depth+0x12/0x20 [iscsi_target_mod]
 [<ffffffffa0415c29>] lio_target_nacl_store_cmdsn_depth+0xa9/0x180 [iscsi_target_mod]
 [<ffffffffa0331b49>] target_fabric_nacl_base_attr_store+0x39/0x40 [target_core_mod]
 [<ffffffff811b857d>] configfs_write_file+0xbd/0x120
 [<ffffffff81148f36>] vfs_write+0xc6/0x180
 [<ffffffff81149251>] sys_write+0x51/0x90
 [<ffffffff815c0969>] system_call_fastpath+0x16/0x1b
---[ end trace 3747632b9b164652 ]---

As a pure band-aid, this patch drops the _bh.

Signed-off-by: Joern Engel <joern@logfs.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
tcm_qla2xxx: Fix residual for underrun commands that fail

Suppose an initiator sends a DATA IN command with an allocation length
shorter than the FC transfer length -- we get a target message like

    TARGET_CORE[qla2xxx]: Expected Transfer Length: 256 does not match SCSI CDB Length: 0 for SAM Opcode: 0x12

In that case, the target core adjusts the data_length and sets
se_cmd->residual_count for the underrun.  But now suppose that command
fails and we end up in tcm_qla2xxx_queue_status() -- that function
unconditionally overwrites residual_count with the already adjusted
data_length, and the initiator will burp with a message like

    qla2xxx [0000:00:06.0]-301d:0: Dropped frame(s) detected (0x100 of 0x100 bytes).

Fix this by adding on to the existing underflow residual count instead.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
idle: Enable interrupts in the weak arch_cpu_idle() implementation

PARISC bootup triggers the warning at kernel/cpu/idle.c:96. That's
caused by the weak arch_cpu_idle() implementation, which is provided
to avoid that architectures implement idle_poll over and over.

The switchover to polling mode happens in the first call of the weak
arch_cpu_idle() implementation, but that code fails to reenable
interrupts and therefor triggers the warning.

Fix this by enabling interrupts in the weak arch_cpu_idle() code.

[ tglx: Made the changelog match the patch ]

Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1371236142.2726.43.camel@dabdike
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
drm/radeon: fix UVD on big endian

This fixes the kernel side so that the ring should come
up and ring and IB tests should work.  The userspace
UVD drivers will also need big endian fixes.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
tilepro: work around module link error with gcc 4.7

gcc 4.7.x is emitting calls to __ffsdi2 where previously
it used to inline the appropriate ctz instructions.
While this needs to be fixed in gcc, it's also easy to avoid
having it cause build failures when building with those
compilers by exporting __ffsdi2 to modules.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: stable@kernel.org
ARM: 7752/1: errata: LoUIS bit field in CLIDR register is incorrect

On Cortex-A9 before version r1p0, the LoUIS bit field of the CLIDR
register returns zero when it should return one. This leads to cache
maintenance operations which rely on this value to not function as
intended, causing data corruption.

The workaround for this errata is to detect affected CPUs and correct
the LoUIS value read.

Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7753/1: map_init_section flushes incorrect pmd

This bug was introduced in commit e651eab0.
Some v4/v5 platforms failed to boot due to this.

Signed-off-by: Po-Yu Chuang <ratbert.chuang@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7754/1: Fix the CPU ID and the mask associated to the PJ4B

This commit fixes the ID and mask for the PJ4B which was too
restrictive and didn't match the CPU of the Armada 370 SoC.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>