Commit Graph

1539 Commits

Author SHA1 Message Date
Andi Kleen d6f4ceb796 Kbuild: Add option to set -femit-struct-debug-baseonly
Newer gcc has a -femit-struct-debug-baseonly option that dramatically
reduces the size of object files with debug info. What it does
is to only emit type information for structures when the structures
are defined in the same file or in a header file.

This means the type information for most headers are not included.
This is not good when the type information is actually
needed (e.g. with kgdb or systemtap)

But often kernel hackers only care about line numbers and don't
need all the type information anyways. In this case setting
the option can be a big win:

A build dir for a specific x86-64 configuration with gcc 4.5
shrunk from 2.3G to 1.2G. The compilation was also nearly a minute
faster.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
[mmarek: reformatted help text]
Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-07-14 17:21:28 +02:00
Yinghai Lu 95f72d1ed4 lmb: rename to memblock
via following scripts

      FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

      sed -i \
        -e 's/lmb/memblock/g' \
        -e 's/LMB/MEMBLOCK/g' \
        $FILES

      for N in $(find . -name lmb.[ch]); do
        M=$(echo $N | sed 's/lmb/memblock/g')
        mv $N $M
      done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/

Suggested-by: Ingo Molnar <mingo@elte.hu>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-14 17:14:00 +10:00
Kulikov Vasiliy 4d45ada36b lib/devres.c: fix comment typo
'Unamp' should be 'Unmap'.

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-07-11 22:16:32 +02:00
Kenji Kaneshige ffa71f33a8 x86, ioremap: Fix incorrect physical address handling in PAE mode
Current x86 ioremap() doesn't handle physical address higher than
32-bit properly in X86_32 PAE mode. When physical address higher than
32-bit is passed to ioremap(), higher 32-bits in physical address is
cleared wrongly. Due to this bug, ioremap() can map wrong address to
linear address space.

In my case, 64-bit MMIO region was assigned to a PCI device (ioat
device) on my system. Because of the ioremap()'s bug, wrong physical
address (instead of MMIO region) was mapped to linear address space.
Because of this, loading ioatdma driver caused unexpected behavior
(kernel panic, kernel hangup, ...).

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
LKML-Reference: <4C1AE680.7090408@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-09 11:42:03 -07:00
Linus Torvalds 47a716cf0c Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rbtree: Undo augmented trees performance damage and regression
  x86, Calgary: Limit the max PHB number to 256
2010-07-06 17:16:09 -07:00
Peter Zijlstra b945d6b255 rbtree: Undo augmented trees performance damage and regression
Reimplement augmented RB-trees without sprinkling extra branches
all over the RB-tree code (which lives in the scheduler hot path).

This approach is 'borrowed' from Fabio's BFQ implementation and
relies on traversing the rebalance path after the RB-tree-op to
correct the heap property for insertion/removal and make up for
the damage done by the tree rotations.

For insertion the rebalance path is trivially that from the new
node upwards to the root, for removal it is that from the deepest
node in the path from the to be removed node that will still
be around after the removal.

[ This patch also fixes a video driver regression reported by
  Ali Gholami Rudi - the memtype->subtree_max_end was updated
  incorrectly. ]

Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Ali Gholami Rudi <ali@rudi.ir>
Cc: Fabio Checconi <fabio@gandalf.sssup.it>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1275414172.27810.27961.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-05 14:43:50 +02:00
Yehuda Sadeh ff49d74ad3 module: initialize module dynamic debug later
We should initialize the module dynamic debug datastructures
only after determining that the module is not loaded yet. This
fixes a bug that introduced in 2.6.35-rc2, where when a trying
to load a module twice, we also load it's dynamic printing data
twice which causes all sorts of nasty issues. Also handle
the dynamic debug cleanup later on failure.

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-04 20:17:22 -07:00
Joe Perches 7db6f5fb65 vsprintf: Recursive vsnprintf: Add "%pV", struct va_format
Add the ability to print a format and va_list from a structure pointer

Allows __dev_printk to be implemented as a single printk while
minimizing string space duplication.

%pV should not be used without some mechanism to verify the
format and argument use ala __attribute__(format (printf(...))).

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-04 10:40:17 -07:00
Ingo Molnar 0a54cec0c2 Merge branch 'linus' into core/rcu
Conflicts:
	fs/fs-writeback.c

Merge reason: Resolve the conflict

Note, i picked the version from Linus's tree, which effectively reverts
the fs-writeback.c bits of:

  b97181f: fs: remove all rcu head initializations, except on_stack initializations

As the upstream changes to this file changed this code heavily and the
first attempt to resolve the conflict resulted in a non-booting kernel.
It's safer to re-try this portion of the commit cleanly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-01 09:31:25 +02:00
Imre Deak e621ba9932 genalloc: fix allocation from end of pool
bitmap_find_next_zero_area requires the size of the bitmap, we instead
passed the last suitable position.  This made it impossible to allocate
from the end of the pool.

Fixes a regression introduced by 243797f59b
("genalloc: use bitmap_find_next_zero_area").

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Cc: Zygo Blaxell <zygo.blaxell@xandros.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-29 15:29:30 -07:00
Paul E. McKenney 94bfa3b669 idr: fix RCU lockdep splat in idr_get_next()
Convert to rcu_dereference_raw() given that many callers may have many
different locking models.

Located-by: Miles Lane <miles.lane@gmail.com>
Tested-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-06-23 06:50:45 -07:00
Jiri Kosina f1bbbb6912 Merge branch 'master' into for-next 2010-06-16 18:08:13 +02:00
Uwe Kleine-König 421f91d21a fix typos concerning "initiali[zs]e"
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-06-16 18:05:05 +02:00
Mathieu Desnoyers 551d55a944 tree/tiny rcu: Add debug RCU head objects
Helps finding racy users of call_rcu(), which results in hangs because list
entries are overwritten and/or skipped.

Changelog since v4:
- Bissectability is now OK
- Now generate a WARN_ON_ONCE() for non-initialized rcu_head passed to
  call_rcu(). Statically initialized objects are detected with
  object_is_static().
- Rename rcu_head_init_on_stack to init_rcu_head_on_stack.
- Remove init_rcu_head() completely.

Changelog since v3:
- Include comments from Lai Jiangshan

This new patch version is based on the debugobjects with the newly introduced
"active state" tracker.

Non-initialized entries are all considered as "statically initialized". An
activation fixup (triggered by call_rcu()) takes care of performing the debug
object initialization without issuing any warning. Since we cannot increase the
size of struct rcu_head, I don't see much room to put an identifier for
statically initialized rcu_head structures. So for now, we have to live without
"activation without explicit init" detection. But the main purpose of this debug
option is to detect double-activations (double call_rcu() use of a rcu_head
before the callback is executed), which is correctly addressed here.

This also detects potential internal RCU callback corruption, which would cause
the callbacks to be executed twice.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: David S. Miller <davem@davemloft.net>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: akpm@linux-foundation.org
CC: mingo@elte.hu
CC: laijs@cn.fujitsu.com
CC: dipankar@in.ibm.com
CC: josh@joshtriplett.org
CC: dvhltc@us.ibm.com
CC: niv@us.ibm.com
CC: tglx@linutronix.de
CC: peterz@infradead.org
CC: rostedt@goodmis.org
CC: Valdis.Kletnieks@vt.edu
CC: dhowells@redhat.com
CC: eric.dumazet@gmail.com
CC: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
2010-06-14 16:37:26 -07:00
Konrad Rzeszutek Wilk d7ef1533a9 swiotlb: Make swiotlb bookkeeping functions visible in the header file.
We put the functions dealing with the operations on
the SWIOTLB buffer in the header and make those functions non-static.
And also make the functions exported via EXPORT_SYMBOL_GPL.

See "swiotlb: swiotlb: add swiotlb_tbl_map_single library function" for
full description of patchset.

[v2: swiotlb_sync_single_range_for_* no more. Remove usage.]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Albert Herranz <albert_herranz@yahoo.es>
2010-06-07 11:59:27 -04:00
Konrad Rzeszutek Wilk 22d4826998 swiotlb: search and replace "int dir" with "enum dma_data_direction dir"
.. to catch anybody doing something funky.

See "swiotlb: swiotlb: add swiotlb_tbl_map_single library function" for
full description of patchset.

[v2: swiotlb_sync_single_range_* no more - removed usage]
[v3: enum dma_data_direction direction -> enum dma_data_direction dir]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Albert Herranz <albert_herranz@yahoo.es>
2010-06-07 11:59:26 -04:00
Konrad Rzeszutek Wilk bfc5501f6d swiotlb: Make internal bookkeeping functions have 'swiotlb_tbl' prefix.
The functions that operate on io_tlb_list/io_tlb_start/io_tlb_orig_addr
have the prefix 'swiotlb_tbl' now.

See "swiotlb: swiotlb: add swiotlb_tbl_map_single library function" for
full description of patchset.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Tested-by: Albert Herranz <albert_herranz@yahoo.es>
2010-06-07 11:59:26 -04:00
FUJITA Tomonori abbceff7d7 swiotlb: add the swiotlb initialization function with iotlb memory
This enables the caller to initialize swiotlb with its own iotlb
memory.

See "swiotlb: swiotlb: add swiotlb_tbl_map_single library function" for
full description of patchset.

[v2: changed ..with_tlb to ..with_tbl]

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Albert Herranz <albert_herranz@yahoo.es>
2010-06-07 11:59:25 -04:00
FUJITA Tomonori eb605a5754 swiotlb: add swiotlb_tbl_map_single library function
swiotlb_tbl_map_single() takes the dma address of iotlb instead of
using swiotlb_virt_to_bus().

[v2: changed swiotlb_tlb to swiotlb_tbl]
[v3: changed u64 to dma_addr_t]

This patch:

This is a set of patches that separate the address translation
(virt_to_phys, virt_to_bus, etc) and allocation of the SWIOTLB buffer
from the SWIOTLB library.

The idea behind this set of patches is to make it possible to have separate
mechanisms for translating virtual to physical or virtual to DMA addresses
on platforms which need an SWIOTLB, and where physical != PCI bus address
and also to allocate the core IOTLB memory outside SWIOTLB.

One customers of this is the pv-ops project, which can switch between
different modes of operation depending on the environment it is running in:
bare-metal or virtualized (Xen for now). Another is the Wii DMA - used to
implement the MEM2 DMA facility needed by its EHCI controller (for details:
http://lkml.org/lkml/2010/5/18/303)

On bare-metal SWIOTLB is used when there are no hardware IOMMU. In virtualized
environment it used when PCI pass-through is enabled for the guest. The problems
with PCI pass-through is that the guest's idea of PFN's is not the real thing.
To fix that, there is translation layer for PFN->machine frame number and vice-versa.
To bubble that up to the SWIOTLB layer there are two possible solutions.

One solution has been to wholesale copy the SWIOTLB, stick it in
arch/x86/xen/swiotlb.c and modify the virt_to_phys, phys_to_virt and others
to use the Xen address translation functions. Unfortunately, since the kernel can
run on bare-metal, there would be big code overlap with the real SWIOTLB.
(git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git xen/dom0/swiotlb-new)

Another approach, which this set of patches explores, is to abstract the
address translation and address determination functions away from the
SWIOTLB book-keeping functions. This way the core SWIOTLB library functions
are present in one place, while the address related functions are in
a separate library that can be loaded when running under non-bare-metal platform.

Changelog:
Since the last posting [v8.2] Konrad has done:
 - Added this changelog in the patch and referenced in the other patches
   this description.
 - 'enum dma_data_direction direction' to 'enum dma.. dir' so to be
   unified.
[v8-v8.2 changes:]
 - Rolled-up the last two patches in one.
 - Rebased against linus latest. That meant dealing with swiotlb_sync_single_range_* changes.
 - added Acked-by: Fujita Tomonori and Tested-by: Albert Herranz
[v7-v8 changes:]
 - Minimized the list of exported functions.
 - Integrated Fujita's patches and changed "swiotlb_tlb" to "swiotlb_tbl" in them.
[v6-v7 changes:]
 - Minimized the amount of exported functions/variable with a prefix of: "swiotbl_tbl".
 - Made the usage of 'int dir' to be 'enum dma_data_direction'.
[v5-v6 changes:]
 - Made the exported functions/variables have the 'swiotlb_bk' prefix.
 - dropped the checkpatches/other reworks

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Albert Herranz <albert_herranz@yahoo.es>
2010-06-07 11:59:13 -04:00
Linus Torvalds f9196e7c03 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  fix setattr error handling in sysfs, configfs
  kobject: free memory if netlink_kernel_create() fails
  lib/kobject_uevent.c: fix CONIG_NET=n warning
2010-06-04 15:27:27 -07:00
Heiko Carstens 007d08678e lib: add s390 to atomic64_dec_if_positive archs
Add s390 to list of architectures that have atomic64_dec_if_positive
implemented so we get rid of this warning:

lib/atomic64_test.c:129:2: warning: #warning Please implement
atomic64_dec_if_positive for your architecture, and add it to the IF above

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Luca Barbieri <luca@luca-barbieri.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-04 15:21:45 -07:00
Dan Carpenter 743db2d903 kobject: free memory if netlink_kernel_create() fails
There is a kfree(ue_sk) missing on the error path if
netlink_kernel_create() fails.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-04 13:27:52 -07:00
Andrew Morton c842128607 lib/kobject_uevent.c: fix CONIG_NET=n warning
lib/kobject_uevent.c:87: warning: 'kobj_bcast_filter' defined but not used

Repairs "hotplug: netns aware uevent_helper"

Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-04 13:27:52 -07:00
Linus Torvalds 021fad8b70 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, cpufeature: Unbreak compile with gcc 3.x
  x86, pat: Fix memory leak in free_memtype
  x86, k8: Fix section mismatch for powernowk8_exit()
  lib/atomic64_test: fix missing include of linux/kernel.h
  x86: remove last traces of quicklist usage
  x86, setup: Phoenix BIOS fixup is needed on Dell Inspiron Mini 1012
  x86: "nosmp" command line option should force the system into UP mode
  arch/x86/pci: use kasprintf
  x86, apic: ack all pending irqs when crashed/on kexec
2010-05-30 09:06:13 -07:00
Linus Torvalds 35926ff5fb Revert "cpusets: randomize node rotor used in cpuset_mem_spread_node()"
This reverts commit 0ac0c0d0f8, which
caused cross-architecture build problems for all the wrong reasons.
IA64 already added its own version of __node_random(), but the fact is,
there is nothing architectural about the function, and the original
commit was just badly done. Revert it, since no fix is forthcoming.

Requested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-30 09:00:03 -07:00
Linus Torvalds 9a90e09854 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (27 commits)
  ACPI: Don't let acpi_pad needlessly mark TSC unstable
  drivers/acpi/sleep.h: Checkpatch cleanup
  ACPI: Minor cleanup eliminating redundant PMTIMER_TICKS to NS conversion
  ACPI: delete unused c-state promotion/demotion data strucutures
  ACPI: video: fix acpi_backlight=video
  ACPI: EC: Use kmemdup
  drivers/acpi: use kasprintf
  ACPI, APEI, EINJ injection parameters support
  Add x64 support to debugfs
  ACPI, APEI, Use ERST for persistent storage of MCE
  ACPI, APEI, Error Record Serialization Table (ERST) support
  ACPI, APEI, Generic Hardware Error Source memory error support
  ACPI, APEI, UEFI Common Platform Error Record (CPER) header
  Unified UUID/GUID definition
  ACPI Hardware Error Device (PNP0C33) support
  ACPI, APEI, PCIE AER, use general HEST table parsing in AER firmware_first setup
  ACPI, APEI, Document for APEI
  ACPI, APEI, EINJ support
  ACPI, APEI, HEST table parsing
  ACPI, APEI, APEI supporting infrastructure
  ...
2010-05-28 14:42:18 -07:00
Cesar Eduardo Barros edcd1d843a radix-tree: fix radix_tree_prev_hole() underflow case
radix_tree_prev_hole() used LONG_MAX to detect underflow; however,
ULONG_MAX is clearly what was intended, both here and by its only user
(count_history_pages at mm/readahead.c).

Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:53 -07:00
FUJITA Tomonori 38388301b7 swiotlb: remove unnecessary swiotlb_sync_single_range_*
swiotlb_sync_single_range_for_cpu and swiotlb_sync_single_range_for_device
are unnecessary because swiotlb_sync_single_for_cpu and
swiotlb_sync_single_for_device can be used instead.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:52 -07:00
Joe Eykholt 5960164fde lib/random32: export pseudo-random number generator for modules
This patch moves the definition of struct rnd_state and the inline
__seed() function to linux/random.h.  It renames the static __random32()
function to prandom32() and exports it for use in modules.

prandom32() is useful as a privately-seeded pseudo random number generator
that can give the same result every time it is initialized.

For FCoE FC-BB-6 VN2VN mode self-selected unique FC address generation, we
need an pseudo-random number generator seeded with the 64-bit world-wide
port name.  A truly random generator or one seeded with randomness won't
do because the same sequence of numbers should be generated each time we
boot or the link comes up.

A prandom32_seed() inline function is added to the header file.  It is
inlined not for speed, but so the function won't be expanded in the base
kernel, but only in the module that uses it.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:52 -07:00
Imre Deak 2dcb22b346 idr: fix backtrack logic in idr_remove_all
Currently idr_remove_all will fail with a use after free error if
idr::layers is bigger than 2, which on 32 bit systems corresponds to items
more than 1024.  This is due to stepping back too many levels during
backtracking.  For simplicity let's assume that IDR_BITS=1 -> we have 2
nodes at each level below the root node and each leaf node stores two IDs.
 (In reality for 32 bit systems IDR_BITS=5, with 32 nodes at each sub-root
level and 32 IDs in each leaf node).  The sequence of freeing the nodes at
the moment is as follows:

layer
1 ->                       a(7)
2 ->            b(3)                  c(5)
3 ->        d(1)   e(2)           f(4)    g(6)

Until step 4 things go fine, but then node c is freed, whereas node g
should be freed first.  Since node c contains the pointer to node g we'll
have a use after free error at step 6.

How many levels we step back after visiting the leaf nodes is currently
determined by the msb of the id we are currently visiting:

Step
1.          node d with IDs 0,1 is freed, current ID is advanced to 2.
            msb of the current ID bit 1. This means we need to step back
            1 level to node b and take the next sibling, node e.
2-3.        node e with IDs 2,3 is freed, current ID is 4, msb is bit 2.
            This means we need to step back 2 levels to node a, freeing
            node b on the way.
4-5.        node f with IDs 4,5 is freed, current ID is 6, msb is still
            bit 2. This means we again need to step back 2 levels to node
            a and free c on the way.
6.          We should visit node g, but its pointer is not available as
            node c was freed.

The fix changes how we determine the number of levels to step back.
Instead of deducting this merely from the msb of the current ID, we should
really check if advancing the ID causes an overflow to a bit position
corresponding to a given layer.  In the above example overflow from bit 0
to bit 1 should mean stepping back 1 level.  Overflow from bit 1 to bit 2
should mean stepping back 2 levels and so on.

The fix was tested with IDs up to 1 << 20, which corresponds to 4 layers
on 32 bit systems.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: <stable@kernel.org>		[2.6.34.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:48 -07:00
Akinobu Mita c9d221f86e fault-injection: add CPU notifier error injection module
I used this module to test the series of modification to the cpu notifiers
code.

Example1: inject CPU offline error (-1 == -EPERM)

	# modprobe cpu-notifier-error-inject cpu_down_prepare_error=-1
	# echo 0 > /sys/devices/system/cpu/cpu1/online
	bash: echo: write error: Operation not permitted

Example2: inject CPU online error (-2 == -ENOENT)

	# modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2
	# echo 1 > /sys/devices/system/cpu/cpu1/online
	bash: echo: write error: No such file or directory

[akpm@linux-foundation.org: fix Kconfig help text]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:48 -07:00
Jack Steiner 0ac0c0d0f8 cpusets: randomize node rotor used in cpuset_mem_spread_node()
Some workloads that create a large number of small files tend to assign
too many pages to node 0 (multi-node systems).  Part of the reason is that
the rotor (in cpuset_mem_spread_node()) used to assign nodes starts at
node 0 for newly created tasks.

This patch changes the rotor to be initialized to a random node number of
the cpuset.

[akpm@linux-foundation.org: fix layout]
[Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Menage <menage@google.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:44 -07:00
Andrew Morton 0d2daf5cc8 revert "crc32: use __BYTE_ORDER macro for endian detection"
It doesn't work on big-endian - those architectures don't define
__LITTLE_ENDIAN.

Cc: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 08:19:23 -07:00
Joakim Tjernlund 4762bbc1a3 crc32: use __BYTE_ORDER macro for endian detection.
Since crc32.c contains a nifty test program that can be executed in user
space, make sure endian detection works reliably in user space too.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:06 -07:00
Joakim Tjernlund 836e2af925 crc32: major optimization
Precompute more crc32 values(0xcc00, 0xcc0000 and 0xcc000000) into tables.
 This increases the table size from 1KB to 4KB but the performance benfit
makes it worth it:

28% faster on MPC8321, 266 MHz
2x faster on Core 2 Duo, 3.1GHz

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:06 -07:00
Andy Shevchenko 903788892e lib: introduce common method to convert hex digits
hex_to_bin() is a little method which converts hex digit to its actual
value.  There are plenty of places where such functionality is needed.

[akpm@linux-foundation.org: use tolower(), saving 3 bytes, test the more common case first - it's quicker]
[akpm@linux-foundation.org: relocate tolower to make it even faster! (Joe)]
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: Duncan Sands <duncan.sands@free.fr>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "Richard Russon (FlatCap)" <ldm@flatcap.org>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:05 -07:00
Joe Perches db0fd97c27 lib/hexdump.c: reduce stack variable size and cleanups
Reduce char linebuf[200] to the actual size required., which is 32 * 3 + 2
+ 32 + 1, ie: linebuf[131].

Change examples to use bool true not int 1.

Align multiline argument indentation to open parenthesis.

Use temporary for ptr[j] so trigraph fits on single line.

Convert printk ptr from %*p, (int)(2 * sizeof(void *)) to %p as %p uses
the same calculation for size.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:05 -07:00
Florian Ragwitz 2b2f68b538 DYNAMIC_DEBUG: fix documentation errors
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Florian Ragwitz <rafl@debian.org>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:05 -07:00
Dan Carpenter ea46c8f774 dynamic_debug: small cleanup in ddebug_proc_write()
This doesn't change behavior at all.  In the original code, if nwords was
zero then ddebug_parse_query() would return -EINVAL, now we just do it
earlier.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:05 -07:00
Joe Perches cf3b429b03 vsprintf.c: use noinline_for_stack
Mark static functions with noinline_for_stack

Before:

  akpm:/usr/src/25> objdump -d lib/vsprintf.o | perl scripts/checkstack.pl
  0x00000e82 pointer [vsprintf.o]:                        344
  0x0000198c pointer [vsprintf.o]:                        344
  0x000025d6 scnprintf [vsprintf.o]:                      216
  0x00002648 scnprintf [vsprintf.o]:                      216
  0x00002565 snprintf [vsprintf.o]:                       208
  0x0000267c sprintf [vsprintf.o]:                        208
  0x000030a3 bprintf [vsprintf.o]:                        208
  0x00003b1e sscanf [vsprintf.o]:                         208
  0x00000608 number [vsprintf.o]:                         136
  0x00000937 number [vsprintf.o]:                         136

After:

  akpm:/usr/src/25> objdump -d lib/vsprintf.o | perl scripts/checkstack.pl
  0x00000a7c symbol_string [vsprintf.o]:                  248
  0x00000ae8 symbol_string [vsprintf.o]:                  248
  0x00002310 scnprintf [vsprintf.o]:                      216
  0x00002382 scnprintf [vsprintf.o]:                      216
  0x0000229f snprintf [vsprintf.o]:                       208
  0x000023b6 sprintf [vsprintf.o]:                        208
  0x00002ddd bprintf [vsprintf.o]:                        208
  0x00003858 sscanf [vsprintf.o]:                         208
  0x00000625 number [vsprintf.o]:                         136
  0x00000954 number [vsprintf.o]:                         136

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:04 -07:00
Alexey Dobriyan 4be929be34 kernel-wide: replace USHORT_MAX, SHORT_MAX and SHORT_MIN with USHRT_MAX, SHRT_MAX and SHRT_MIN
- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
  USHORT_MAX/SHORT_MAX/SHORT_MIN.

- Make SHRT_MIN of type s16, not int, for consistency.

[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:02 -07:00
Peter Huewe 0dbdd1bfe0 lib/atomic64_test: fix missing include of linux/kernel.h
Fix a build-failure
(http://kisskb.ellerman.id.au/kisskb/buildresult/2601239/) by adding the
missing include file (linux/kernel.h) for printk and KERN_INFO.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
LKML-Reference: <201005241913.o4OJDKdf010884@imap1.linux-foundation.org>
Cc: Luca Barbieri <luca@luca-barbieri.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-05-24 13:33:32 -07:00
Linus Torvalds 0961d6581c Merge git://git.infradead.org/iommu-2.6
* git://git.infradead.org/iommu-2.6:
  intel-iommu: Set a more specific taint flag for invalid BIOS DMAR tables
  intel-iommu: Combine the BIOS DMAR table warning messages
  panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I')
  panic: Allow warnings to set different taint flags
  intel-iommu: intel_iommu_map_range failed at very end of address space
  intel-iommu: errors with smaller iommu widths
  intel-iommu: Fix boot inside 64bit virtualbox with io-apic disabled
  intel-iommu: use physfn to search drhd for VF
  intel-iommu: Print out iommu seq_id
  intel-iommu: Don't complain that ACPI_DMAR_SCOPE_TYPE_IOAPIC is not supported
  intel-iommu: Avoid global flushes with caching mode.
  intel-iommu: Use correct domain ID when caching mode is enabled
  intel-iommu mistakenly uses offset_pfn when caching mode is enabled
  intel-iommu: use for_each_set_bit()
  intel-iommu: Fix section mismatch dmar_ir_support() uses dmar_tbl.
2010-05-21 17:25:01 -07:00
Linus Torvalds 90b9a32d8f Merge branch 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: (25 commits)
  kdb,debug_core: Allow the debug core to receive a panic notification
  MAINTAINERS: update kgdb, kdb, and debug_core info
  debug_core,kdb: Allow the debug core to process a recursive debug entry
  printk,kdb: capture printk() when in kdb shell
  kgdboc,kdb: Allow kdb to work on a non open console port
  kgdb: Add the ability to schedule a breakpoint via a tasklet
  mips,kgdb: kdb low level trap catch and stack trace
  powerpc,kgdb: Introduce low level trap catching
  x86,kgdb: Add low level debug hook
  kgdb: remove post_primary_code references
  kgdb,docs: Update the kgdb docs to include kdb
  kgdboc,keyboard: Keyboard driver for kdb with kgdb
  kgdb: gdb "monitor" -> kdb passthrough
  sparc,sunzilog: Add console polling support for sunzilog serial driver
  sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
  kgdb,8250,pl011: Return immediately from console poll
  kgdb: core changes to support kdb
  kdb: core for kgdb back end (2 of 2)
  kdb: core for kgdb back end (1 of 2)
  kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
  ...
2010-05-21 11:08:05 -07:00
Eric W. Biederman 417daa1e8f hotplug: netns aware uevent_helper
It only makes sense for uevent_helper to get events
in the intial namespaces.  It's invocation is not
per namespace and it is not clear how we could make
it's invocation namespace aware.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:33 -07:00
Eric W. Biederman 5f71a29629 kobj: Send hotplug events in the proper namespace.
Utilize netlink_broacast_filtered to allow sending hotplug events
in the proper namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:32 -07:00
Eric W. Biederman 07e98962fa kobject: Send hotplug events in all network namespaces
Open a copy of the uevent kernel socket in each network
namespace so we can send uevents in all network namespaces.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:32 -07:00
Serge E. Hallyn be867b194a sysfs: Comment sysfs directory tagging logic
Add some in-line comments to explain the new infrastructure, which
was introduced to support sysfs directory tagging with namespaces.
I think an overall description someplace might be good too, but it
didn't really seem to fit into Documentation/filesystems/sysfs.txt,
which appears more geared toward users, rather than maintainers, of
sysfs.

(Tejun, please let me know if I can make anything clearer or failed
altogether to comment something that should be commented.)

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
Eric W. Biederman 3ff195b011 sysfs: Implement sysfs tagged directory support.
The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
Eric W. Biederman bc451f2058 kobj: Add basic infrastructure for dealing with namespaces.
Move complete knowledge of namespaces into the kobject layer
so we can use that information when reporting kobjects to
userspace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
NeilBrown db1afffab0 kref: remove kref_set
Of the three uses of kref_set in the kernel:

 One really should be kref_put as the code is letting go of a
    reference,
 Two really should be kref_init because the kref is being
    initialised.

This suggests that making kref_set available encourages bad code.
So fix the three uses and remove kref_set completely.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:29 -07:00
Linus Torvalds 05ec7dd8dd Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6: (154 commits)
  mtd: cfi_cmdset_0002: use AMD standard command-set with Winbond flash chips
  mtd: cfi_cmdset_0002: Fix MODULE_ALIAS and linkage for new 0701 commandset ID
  mtd: mxc_nand: Remove duplicate NAND_CMD_RESET case value
  mtd: update gfp/slab.h includes
  jffs2: Stop triggering block erases from jffs2_write_super()
  jffs2: Rename jffs2_erase_pending_trigger() to jffs2_dirty_trigger()
  jffs2: Use jffs2_garbage_collect_trigger() to trigger pending erases
  jffs2: Require jffs2_garbage_collect_trigger() to be called with lock held
  jffs2: Wake GC thread when there are blocks to be erased
  jffs2: Erase pending blocks in GC pass, avoid invalid -EIO return
  jffs2: Add 'work_done' return value from jffs2_erase_pending_blocks()
  mtd: mtdchar: Do not corrupt backing device of device node inode
  mtd/maps/pcmciamtd: Fix printk format for ssize_t in debug messages
  drivers/mtd: Use kmemdup
  mtd: cfi_cmdset_0002: Fix argument order in bootloc warning
  mtd: nand: add Toshiba TC58NVG0 device ID
  pcmciamtd: add another ID
  pcmciamtd: coding style cleanups
  pcmciamtd: fixing obvious errors
  mtd: chips: add SST39WF160x NOR-flashes
  ...

Trivial conflicts due to dev_node removal in drivers/mtd/maps/pcmciamtd.c
2010-05-21 07:25:43 -07:00
Jason Wessel 5dd11d5d47 mips,kgdb: kdb low level trap catch and stack trace
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a recursive fault is
to have a low level "first opportunity handler" do_trap_or_bp() handler.

Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.

Also added was a die notification for oops such that kdb can catch an
oops for analysis.

There appeared to be no obvious way to pass the struct pt_regs from
the original exception back to the stack back tracer, so a special
case was added to show_stack() for when kdb is active because you
generally desire to generally look at the back trace of the original
exception.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
2010-05-20 21:04:26 -05:00
Jason Wessel f503b5ae53 x86,kgdb: Add low level debug hook
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a triple fault is
to have a low level "first opportunity handler" in the int3 exception
handler.

Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.

CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:25 -05:00
Jason Wessel ada64e4c98 kgdboc,keyboard: Keyboard driver for kdb with kgdb
This patch adds in the kdb PS/2 keyboard driver.  This was mostly a
direct port from the original kdb where I cleaned up the code against
checkpatch.pl and added the glue to stitch it into kgdb.

This patch also enables early kdb debug via kgdbwait and the keyboard.

All the access to configure kdb using either a serial console or the
keyboard is done via kgdboc.

If you want to use only the keyboard and want to break in early you
would add to your kernel command arguments:

    kgdboc=kbd kgdbwait

If you wanted serial and or the keyboard access you could use:

    kgdboc=kbd,ttyS0

You can also configure kgdboc as a kernel module or at run time with
the sysfs where you can activate and deactivate kgdb.

Turn it on:
    echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc

Turn it off:
    echo "" > /sys/module/kgdboc/parameters/kgdboc

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2010-05-20 21:04:24 -05:00
Jason Wessel dcc7871128 kgdb: core changes to support kdb
These are the minimum changes to the kgdb core in order to enable an
API to connect a new front end (kdb) to the debug core.

This patch introduces the dbg_kdb_mode variable controls where the
user level I/O is routed.  It will be routed to the gdbstub (kgdb) or
to the kdb front end which is a simple shell available over the kgdboc
connection.

You can switch back and forth between kdb or the gdb stub mode of
operation dynamically.  From gdb stub mode you can blindly type
"$3#33", or from the kdb mode you can enter "kgdb" to switch to the
gdb stub.

The logic in the debug core depends on kdb to look for the typical gdb
connection sequences and return immediately with KGDB_PASS_EVENT if a
gdb serial command sequence is detected.  That should allow a
reasonably seamless transition between kdb -> gdb without leaving the
kernel exception state.  The two gdb serial queries that kdb is
responsible for detecting are the "?" and "qSupported" packets.

CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
2010-05-20 21:04:21 -05:00
Huang Ying fab1c23242 Unified UUID/GUID definition
There are many different UUID/GUID definitions in kernel, such as that
in EFI, many file systems, some drivers, etc. Every kernel components
need UUID/GUID has its own definition. This patch provides a unified
definition for UUID/GUID.

UUID is defined via typedef. This makes that UUID appears more like a
preliminary type, and makes the data type explicit (comparing with
implicit "u8 uuid[16]").

The binary representation of UUID/GUID can be little-endian (used by
EFI, etc) or big-endian (defined by RFC4122), so both is defined.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-05-19 22:40:47 -04:00
Frederic Weisbecker e35e7fb0e9 lockup_detector: Don't enable the lockup detector by default
The lockup detector is a new feature that now involves the
nmi watchdog. Drop the default y and let the user choose.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
2010-05-19 11:36:49 +02:00
Ben Hutchings b2be05273a panic: Allow warnings to set different taint flags
WARN() is used in some places to report firmware or hardware bugs that
are then worked-around.  These bugs do not affect the stability of the
kernel and should not set the flag for TAINT_WARN.  To allow for this,
add WARN_TAINT() and WARN_TAINT_ONCE() macros that take a taint number
as argument.

Architectures that implement warnings using trap instructions instead
of calls to warn_slowpath_*() now implement __WARN_TAINT(taint)
instead of __WARN().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Helge Deller <deller@gmx.de>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2010-05-19 08:36:48 +01:00
Linus Torvalds c4fd308ed6 Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, pat: Update the page flags for memtype atomically instead of using memtype_lock
  x86, pat: In rbt_memtype_check_insert(), update new->type only if valid
  x86, pat: Migrate to rbtree only backend for pat memtype management
  x86, pat: Preparatory changes in pat.c for bigger rbtree change
  rbtree: Add support for augmented rbtrees
2010-05-18 09:28:04 -07:00
Linus Torvalds cb41838bbc Merge branch 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-hweight-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, hweight: Use a 32-bit popcnt for __arch_hweight32()
  arch, hweight: Fix compilation errors
  x86: Add optimized popcnt variants
  bitops: Optimize hweight() by making use of compile-time evaluation
2010-05-18 09:17:01 -07:00
Linus Torvalds 93c9d7f60c Merge branch 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix LOCK_PREFIX_HERE for uniprocessor build
  x86, atomic64: In selftest, distinguish x86-64 from 586+
  x86-32: Fix atomic64_inc_not_zero return value convention
  lib: Fix atomic64_inc_not_zero test
  lib: Fix atomic64_add_unless return value convention
  x86-32: Fix atomic64_add_unless return value convention
  lib: Fix atomic64_add_unless test
  x86: Implement atomic[64]_dec_if_positive()
  lib: Only test atomic64_dec_if_positive on archs having it
  x86-32: Rewrite 32-bit atomic64 functions in assembly
  lib: Add self-test for atomic64_t
  x86-32: Allow UP/SMP lock replacement in cmpxchg64
  x86: Add support for lock prefix in alternatives
2010-05-18 08:40:05 -07:00
Linus Torvalds f262af3d08 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  rcu: remove all rcu head initializations, except on_stack initializations
  rcu head introduce rcu head init on stack
  Debugobjects transition check
  rcu: fix build bug in RCU_FAST_NO_HZ builds
  rcu: RCU_FAST_NO_HZ must check RCU dyntick state
  rcu: make SRCU usable in modules
  rcu: improve the RCU CPU-stall warning documentation
  rcu: reduce the number of spurious RCU_SOFTIRQ invocations
  rcu: permit discontiguous cpu_possible_mask CPU numbering
  rcu: improve RCU CPU stall-warning messages
  rcu: print boot-time console messages if RCU configs out of ordinary
  rcu: disable CPU stall warnings upon panic
  rcu: enable CPU_STALL_VERBOSE by default
  rcu: slim down rcutiny by removing rcu_scheduler_active and friends
  rcu: refactor RCU's context-switch handling
  rcu: rename rcutiny rcu_ctrlblk to rcu_sched_ctrlblk
  rcu: shrink rcutiny by making synchronize_rcu_bh() be inline
  rcu: fix now-bogus rcu_scheduler_active comments.
  rcu: Fix bogus CONFIG_PROVE_LOCKING in comments to reflect reality.
  rcu: ignore offline CPUs in last non-dyntick-idle CPU check
  ...
2010-05-18 08:17:58 -07:00
Linus Torvalds 06ee772043 Merge branch 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: Section mismatch cleanup
2010-05-18 07:20:19 -07:00
Frederic Weisbecker 23637d477c lockup_detector: Introduce CONFIG_HARDLOCKUP_DETECTOR
This new config is deemed to simplify even more the lockup detector
dependencies and can make it easier to bring a smooth sorting
between archs that support the new generic lockup detector and those
that still have their own, especially for those that are in the
middle of this migration.

Instead of checking whether we have CONFIG_LOCKUP_DETECTOR +
CONFIG_PERF_EVENTS_NMI each time an arch wants to know if it needs
to build its own lockup detector, take a shortcut with this new
config. It is enabled only if the hardlockup detection part of
the whole lockup detector is on.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
2010-05-16 01:57:42 +02:00
Frederic Weisbecker e16bb1d7fe lockup_detector: Update some config
We kept CONFIG_DETECT_SOFTLOCKUP around for compatibility with
older configs. But it was enabled by default if CONFIG_DEBUG_KERNEL.

So if we want to enable CONFIG_LOCKUP_DETECTOR on configs that had
CONFIG_DETECT_SOFTLOCKUP, all we need is to have the same enabling
by default if CONFIG_DEBUG_KERNEL. We can then remove
CONFIG_DETECT_SOFTLOCKUP directly.

So tag CONFIG_LOCKUP_DETECTOR as default y. This is what we want for
most serious kernel debugging anyway.

And also forbid the lockup detector in S390 as it was for the
previous softlockup detector, event though the true reason for that
is not outlined.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
2010-05-16 01:57:27 +02:00
kirjanov@gmail.com 43aa7ac736 lib/btree: fix possible NULL pointer dereference
mempool_alloc() can return null in atomic case.

Signed-off-by: Denis Kirjanov <kirjanov@gmail.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-15 12:48:10 -07:00
Michel Lespinasse 91af708141 rwsem: Test for no active locks in __rwsem_do_wake undo code
If there are no active threasd using a semaphore, it is always correct
to unqueue blocked threads.  This seems to be what was intended in the
undo code.

What was done instead, was to look for a sem count of zero - this is an
impossible situation, given that at least one thread is known to be
queued on the semaphore.  The code might be correct as written, but it's
hard to reason about and it's not what was intended (otherwise the goto
out would have been unconditional).

Go for checking the active count - the alternative is not worth the
headache.

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-12 18:23:34 -07:00
Frederic Weisbecker 89d7ce2a21 lockup_detector: Make BOOTPARAM_SOFTLOCKUP_PANIC depend on LOCKUP_DETECTOR
Panic on softlockups was still depending on the softlockup detector.
But the latter has been merged into the lockup detector now.

Let's update this config dependency.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
2010-05-13 00:27:20 +02:00
Don Zickus 58687acba5 lockup_detector: Combine nmi_watchdog and softlockup detector
The new nmi_watchdog (which uses the perf event subsystem) is very
similar in structure to the softlockup detector.  Using Ingo's
suggestion, I combined the two functionalities into one file:
kernel/watchdog.c.

Now both the nmi_watchdog (or hardlockup detector) and softlockup
detector sit on top of the perf event subsystem, which is run every
60 seconds or so to see if there are any lockups.

To detect hardlockups, cpus not responding to interrupts, I
implemented an hrtimer that runs 5 times for every perf event
overflow event.  If that stops counting on a cpu, then the cpu is
most likely in trouble.

To detect softlockups, tasks not yielding to the scheduler, I used the
previous kthread idea that now gets kicked every time the hrtimer fires.
If the kthread isn't being scheduled neither is anyone else and the
warning is printed to the console.

I tested this on x86_64 and both the softlockup and hardlockup paths
work.

V2:
- cleaned up the Kconfig and softlockup combination
- surrounded hardlockup cases with #ifdef CONFIG_PERF_EVENTS_NMI
- seperated out the softlockup case from perf event subsystem
- re-arranged the enabling/disabling nmi watchdog from proc space
- added cpumasks for hardlockup failure cases
- removed fallback to soft events if no PMU exists for hard events

V3:
- comment cleanups
- drop support for older softlockup code
- per_cpu cleanups
- completely remove software clock base hardlockup detector
- use per_cpu masking on hard/soft lockup detection
- #ifdef cleanups
- rename config option NMI_WATCHDOG to LOCKUP_DETECTOR
- documentation additions

V4:
- documentation fixes
- convert per_cpu to __get_cpu_var
- powerpc compile fixes

V5:
- split apart warn flags for hard and soft lockups

TODO:
- figure out how to make an arch-agnostic clock2cycles call
  (if possible) to feed into perf events as a sample period

[fweisbec: merged conflict patch]

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <1273266711-18706-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-05-12 23:55:33 +02:00
Frederic Weisbecker a9aa1d02de Merge commit 'v2.6.34-rc7' into perf/nmi
Merge reason: catch up with latest softlockup detector changes.
2010-05-12 23:20:33 +02:00
Mathieu Desnoyers a5d8e467f8 Debugobjects transition check
Implement a basic state machine checker in the debugobjects.

This state machine checker detects races and inconsistencies within the "active"
life of a debugobject. The checker only keeps track of the current state; all
the state machine logic is kept at the object instance level.

The checker works by adding a supplementary "unsigned int astate" field to the
debug_obj structure. It keeps track of the current "active state" of the object.

The only constraints that are imposed on the states by the debugobjects system
is that:

- activation of an object sets the current active state to 0,
- deactivation of an object expects the current active state to be 0.

For the rest of the states, the state mapping is determined by the specific
object instance. Therefore, the logic keeping track of the state machine is
within the specialized instance, without any need to know about it at the
debugobject level.

The current object active state is changed by calling:

debug_object_active_state(addr, descr, expect, next)

where "expect" is the expected state and "next" is the next state to move to if
the expected state is found. A warning is generated if the expected is not
found.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: akpm@linux-foundation.org
CC: mingo@elte.hu
CC: laijs@cn.fujitsu.com
CC: dipankar@in.ibm.com
CC: josh@joshtriplett.org
CC: dvhltc@us.ibm.com
CC: niv@us.ibm.com
CC: peterz@infradead.org
CC: rostedt@goodmis.org
CC: Valdis.Kletnieks@vt.edu
CC: dhowells@redhat.com
CC: eric.dumazet@gmail.com
CC: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-05-10 16:08:01 -07:00
Paul E. McKenney 55ec936ff4 rcu: enable CPU_STALL_VERBOSE by default
The CPU_STALL_VERBOSE kernel configuration parameter was added to
2.6.34 to identify any preempted/blocked tasks that were preventing
the current grace period from completing when running preemptible
RCU.  As is conventional for new configurations parameters, this
defaulted disabled.  It is now time to enable it by default.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-05-10 11:08:34 -07:00
Lai Jiangshan 2b3fc35f69 rcu: optionally leave lockdep enabled after RCU lockdep splat
There is no need to disable lockdep after an RCU lockdep splat,
so remove the debug_lockdeps_off() from lockdep_rcu_dereference().
To avoid repeated lockdep splats, use a static variable in the inlined
rcu_dereference_check() and rcu_dereference_protected() macros so that
a given instance splats only once, but so that multiple instances can
be detected per boot.

This is controlled by a new config variable CONFIG_PROVE_RCU_REPEATEDLY,
which is disabled by default.  This provides the normal lockdep behavior
by default, but permits people who want to find multiple RCU-lockdep
splats per boot to easily do so.

Requested-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Tested-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-05-10 11:08:31 -07:00
David Woodhouse 0ae28a35bc Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
	drivers/mtd/mtdcore.c

Pull in the bdi fixes and ARM platform changes that other outstanding
patches depend on.
2010-05-10 14:32:46 +01:00
H. Peter Anvin d9c5841e22 Merge branch 'x86/asm' into x86/atomic
Merge reason:
	Conflict between LOCK_PREFIX_HERE and relative alternatives
	pointers

Resolved Conflicts:
	arch/x86/include/asm/alternative.h
	arch/x86/kernel/alternative.c

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-29 16:53:17 -07:00
Hans Verkuil 98d5ce0d00 lib/vsprintf.c: add missing EXPORT_SYMBOL(simple_strtoll)
Add a missing EXPORT_SYMBOL.

I must be the first person that wants to use this function :-)

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:26 -07:00
Albin Tonnerre ccdb40048b lib: fix the use of LZO to decompress initramfs images
This patch fixes 2 issues with the LZO decompressor:

- It doesn't handle the case where a block isn't compressed at all.  In
  this case, calling lzo1x_decompress_safe will fail, so we need to just
  use memcpy() instead (the upstream LZO code does something similar)

- Since commit 54291362d2 ("initramfs: add
  missing decompressor error check") , the decompressor return code is
  checked in the init/initramfs.c The LZO decompressor didn't return the
  expected value, causing the initramfs code to falsely believe a
  decompression error occured

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Tested-by: bert schulze <spambemyguest@googlemail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:25 -07:00
Changli Gao e59464c735 flex_array: fix the panic when calling flex_array_alloc() without __GFP_ZERO
memset() is called with the wrong address and the kernel panics.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-24 11:31:24 -07:00
Linus Torvalds dc57da3875 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/gart: Disable GART explicitly before initialization
  dma-debug: Cleanup for copy-loop in filter_write()
  x86/amd-iommu: Remove obsolete parameter documentation
  x86/amd-iommu: use for_each_pci_dev
  Revert "x86: disable IOMMUs on kernel crash"
  x86/amd-iommu: warn when issuing command to uninitialized cmd buffer
  x86/amd-iommu: enable iommu before attaching devices
  x86/amd-iommu: Use helper function to destroy domain
  x86/amd-iommu: Report errors in acpi parsing functions upstream
  x86/amd-iommu: Pt mode fix for domain_destroy
  x86/amd-iommu: Protect IOMMU-API map/unmap path
  x86/amd-iommu: Remove double NULL check in check_device
2010-04-15 12:20:56 -07:00
Joe Perches 4e310fda91 vsprintf: Change struct printf_spec.precision from s8 to s16
Commit ef0658f3de changed precision
from int to s8.

There is existing kernel code that uses a larger precision.

An example from the audit code:
	vsnprintf(...,..., " msg='%.1024s'", (char *)data);
which overflows precision and truncates to nothing.

Extending precision size fixes the audit system issue.

Other changes:

Change the size of the struct printf_spec.type from u16 to u8 so
sizeof(struct printf_spec) stays as small as possible.
Reorder the struct members so sizeof(struct printf_spec) remains 64 bits
without alignment holes.
Document the struct members a bit more.

Original-patch-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-14 10:32:35 -07:00
Ingo Molnar 2b2f862ee6 Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2010-04-13 13:24:54 +02:00
David S. Miller 9343af084c Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
	lib/Kconfig.debug
2010-04-13 00:28:45 -07:00
David S. Miller 8b8d8e2840 sparc64: Support kmemleak.
Only missing thing was an _sdata marker in vmlinux.lds.S

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-12 23:46:17 -07:00
Linus Torvalds 2f4084209a Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits)
  cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch
  loop: Update mtime when writing using aops
  block: expose the statistics in blkio.time and blkio.sectors for the root cgroup
  backing-dev: Handle class_create() failure
  Block: Fix block/elevator.c elevator_get() off-by-one error
  drbd: lc_element_by_index() never returns NULL
  cciss: unlock on error path
  cfq-iosched: Do not merge queues of BE and IDLE classes
  cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging
  i2o: Remove the dangerous kobj_to_i2o_device macro
  block: remove 16 bytes of padding from struct request on 64bits
  cfq-iosched: fix a kbuild regression
  block: make CONFIG_BLK_CGROUP visible
  Remove GENHD_FL_DRIVERFS
  block: Export max number of segments and max segment size in sysfs
  block: Finalize conversion of block limits functions
  block: Fix overrun in lcm() and move it to lib
  vfs: improve writeback_inodes_wb()
  paride: fix off-by-one test
  drbd: fix al-to-on-disk-bitmap for 4k logical_block_size
  ...
2010-04-09 11:50:29 -07:00
David Howells ce82653d6c radix_tree_tag_get() is not as safe as the docs make out [ver #2]
radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set()
or radix_tree_tag_clear().  The problem is that the double tag_get() in
radix_tree_tag_get():

		if (!tag_get(node, tag, offset))
			saw_unset_tag = 1;
		if (height == 1) {
			int ret = tag_get(node, tag, offset);

may see the value change due to the action of set/clear.  RCU is no protection
against this as no pointers are being changed, no nodes are being replaced
according to a COW protocol - set/clear alter the node directly.

The documentation in linux/radix-tree.h, however, says that
radix_tree_tag_get() is an exception to the rule that "any function modifying
the tree or tags (...) must exclude other modifications, and exclude any
functions reading the tree".

The problem is that the next statement in radix_tree_tag_get() checks that the
tag doesn't vary over time:

			BUG_ON(ret && saw_unset_tag);

This has been seen happening in FS-Cache:

	https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html

To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various
comments that the value of the tag may change whilst the RCU read lock is held,
and thus that the return value of radix_tree_tag_get() may not be relied upon
unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from
running concurrently with it.

Reported-by: Romain DEGEZ <romain.degez@smartjog.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-09 10:12:03 -07:00
Kevin Hilman 3eac4abaa6 rwsem generic spinlock: use IRQ save/restore spinlocks
rwsems can be used with IRQs disabled, particularily in early boot
before IRQs are enabled.  Currently the spin_unlock_irq() usage in the
slow-patch will unconditionally enable interrupts and cause problems
since interrupts are not yet initialized or enabled.

This patch uses save/restore versions of IRQ spinlocks in the slowpath
to ensure interrupts are not unintentionally disabled.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 16:15:05 -07:00
Linus Torvalds addb2d6c13 Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze
* 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Remove unused variable from ptrace
  microblaze: io.h: Add io big-endian function
  microblaze: Enable memory leak detector
  microblaze: Fix futex code
  microblaze: Fix ftrace_update_ftrace_func panic
2010-04-07 08:48:39 -07:00
Yong Zhang 57119c34e5 ratelimit: fix the return value when __ratelimit() fails to acquire the lock
The log of commit edaac8e316 ("ratelimit:
Fix/allow use in atomic contexts"), indicates that we want to suppress the
callback when the trylock fails.

Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:04 -07:00
Yong Zhang 2a7268abc4 ratelimit: annotate ___ratelimit()
To prevent from wrongly using the return value.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-07 08:38:04 -07:00
Dan Carpenter 39a37ce1cc dma-debug: Cleanup for copy-loop in filter_write()
Earlier in this function we set the last byte of "buf" to NULL so we
always hit the break statement and "i" is never equal to NAME_MAX_LEN.
This patch doesn't change how the driver works but it silences a Smatch
warning and it makes it clearer that we don't write past the end of the
array.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-04-07 14:36:27 +02:00
Michal Simek 47c4c864af microblaze: Enable memory leak detector
Enable DEBUG_KMEMLEAK for microblaze

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-04-07 07:27:26 +02:00
Borislav Petkov d61931d89b x86: Add optimized popcnt variants
Add support for the hardware version of the Hamming weight function,
popcnt, present in CPUs which advertize it under CPUID, Function
0x0000_0001_ECX[23]. On CPUs which don't support it, we fallback to the
default lib/hweight.c sw versions.

A synthetic benchmark comparing popcnt with __sw_hweight64 showed almost
a 3x speedup on a F10h machine.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100318112015.GC11152@aftab>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-06 15:52:11 -07:00
Peter Zijlstra 1527bc8b92 bitops: Optimize hweight() by making use of compile-time evaluation
Rename the extisting runtime hweight() implementations to
__arch_hweight(), rename the compile-time versions to __const_hweight()
and then have hweight() pick between them.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100318111929.GB11152@aftab>
Acked-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1265028224.24455.154.camel@laptop>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-06 15:52:11 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Henrik Kretzschmar 1fb2f77c03 debugobjects: Section mismatch cleanup
This patch marks two functions, which only get called at
initialization, as __init.

Here is also interesting, that modpost doesn't catch here the right
function name.

WARNING: lib/built-in.o(.text+0x585f): Section mismatch in reference
from the function T.506() to the variable .init.data:obj
The function T.506() references the variable __initdata obj.
This is often because T.506 lacks a __initdata annotation or the 
annotation of obj is wrong.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
LKML-Reference: <1269632315-19403-1-git-send-email-henne@nachtwindheim.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-26 21:52:29 +01:00
David Woodhouse 329f9052db Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
	drivers/mtd/nand/sh_flctl.c

Maxim's patch to initialise sysfs attributes depends on the patch which
actually adds sysfs_attr_init().
2010-03-26 14:55:59 +00:00
Mike Frysinger 1d53661d26 blackfin: enable DEBUG_SECTION_MISMATCH
We see only one section mismatch now after thousands of randconfigs, and a
bug has been filed about that one.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:20 -07:00
Jens Axboe b4b7a4ef09 Merge branch 'master' into for-linus
Conflicts:
	block/Kconfig

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-03-19 08:05:10 +01:00
Martin K. Petersen 2cda2728aa block: Fix overrun in lcm() and move it to lib
lcm() was defined to take integer-sized arguments.  The supplied
arguments are multiplied, however, causing us to overflow given
sufficiently large input.  That in turn led to incorrect optimal I/O
size reporting in some cases (RAID over RAID).

Switch lcm() over to unsigned long similar to gcd() and move the
function from blk-settings.c to lib.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-03-15 12:47:59 +01:00