Commit graph

1184 commits

Author SHA1 Message Date
Linus Torvalds
eee2775d99 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: (28 commits)
  rcu: Move end of special early-boot RCU operation earlier
  rcu: Changes from reviews: avoid casts, fix/add warnings, improve comments
  rcu: Create rcutree plugins to handle hotplug CPU for multi-level trees
  rcu: Remove lockdep annotations from RCU's _notrace() API members
  rcu: Add #ifdef to suppress __rcu_offline_cpu() warning in !HOTPLUG_CPU builds
  rcu: Add CPU-offline processing for single-node configurations
  rcu: Add "notrace" to RCU function headers used by ftrace
  rcu: Remove CONFIG_PREEMPT_RCU
  rcu: Merge preemptable-RCU functionality into hierarchical RCU
  rcu: Simplify rcu_pending()/rcu_check_callbacks() API
  rcu: Use debugfs_remove_recursive() simplify code.
  rcu: Merge per-RCU-flavor initialization into pre-existing macro
  rcu: Fix online/offline indication for rcudata.csv trace file
  rcu: Consolidate sparse and lockdep declarations in include/linux/rcupdate.h
  rcu: Renamings to increase RCU clarity
  rcu: Move private definitions from include/linux/rcutree.h to kernel/rcutree.h
  rcu: Expunge lingering references to CONFIG_CLASSIC_RCU, optimize on !SMP
  rcu: Delay rcu_barrier() wait until beginning of next CPU-hotunplug operation.
  rcu: Fix typo in rcu_irq_exit() comment header
  rcu: Make rcupreempt_trace.c look at offline CPUs
  ...
2009-09-11 13:20:18 -07:00
Linus Torvalds
a66a50054e Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (59 commits)
  x86/gart: Do not select AGP for GART_IOMMU
  x86/amd-iommu: Initialize passthrough mode when requested
  x86/amd-iommu: Don't detach device from pt domain on driver unbind
  x86/amd-iommu: Make sure a device is assigned in passthrough mode
  x86/amd-iommu: Align locking between attach_device and detach_device
  x86/amd-iommu: Fix device table write order
  x86/amd-iommu: Add passthrough mode initialization functions
  x86/amd-iommu: Add core functions for pd allocation/freeing
  x86/dma: Mark iommu_pass_through as __read_mostly
  x86/amd-iommu: Change iommu_map_page to support multiple page sizes
  x86/amd-iommu: Support higher level PTEs in iommu_page_unmap
  x86/amd-iommu: Remove old page table handling macros
  x86/amd-iommu: Use 2-level page tables for dma_ops domains
  x86/amd-iommu: Remove bus_addr check in iommu_map_page
  x86/amd-iommu: Remove last usages of IOMMU_PTE_L0_INDEX
  x86/amd-iommu: Change alloc_pte to support 64 bit address space
  x86/amd-iommu: Introduce increase_address_space function
  x86/amd-iommu: Flush domains if address space size was increased
  x86/amd-iommu: Introduce set_dte_entry function
  x86/amd-iommu: Add a gneric version of amd_iommu_flush_all_devices
  ...
2009-09-11 13:16:37 -07:00
James Morris
a3c8b97396 Merge branch 'next' into for-linus 2009-09-11 08:04:49 +10:00
Ingo Molnar
695a461296 Merge branch 'amd-iommu/2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu 2009-09-04 14:44:16 +02:00
Ingo Molnar
29e2035bdd Merge branch 'linus' into core/rcu
Merge reason: Avoid fuzz in init/main.c and update from rc6 to rc8.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-04 09:29:05 +02:00
David Howells
e0e817392b CRED: Add some configurable debugging [try #6]
Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking
for credential management.  The additional code keeps track of the number of
pointers from task_structs to any given cred struct, and checks to see that
this number never exceeds the usage count of the cred struct (which includes
all references, not just those from task_structs).

Furthermore, if SELinux is enabled, the code also checks that the security
pointer in the cred struct is never seen to be invalid.

This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
kernel thread on seeing cred->security be a NULL pointer (it appears that the
credential struct has been previously released):

	http://www.kerneloops.org/oops.php?number=252883

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 21:29:01 +10:00
Benjamin Herrenschmidt
4f8ee2c9cc lmb: Remove __init from lmb_end_of_DRAM()
We call lmb_end_of_DRAM() to test whether a DMA mask is ok on a machine
without IOMMU, but this function is marked as __init.

I don't think there's a clean way to get the top of RAM max_pfn doesn't
appear to include highmem or I missed (or we have a bug :-) so for now,
let's just avoid having a broken 2.6.31 by making this function
non-__init and we can revisit later.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-27 12:25:26 -07:00
David Rientjes
b62e408c05 flex_array: convert element_nr formals to unsigned
It's problematic to allow signed element_nr's or total's to be passed as
part of the flex array API.

flex_array_alloc() allows total_nr_elements to be set to a negative
quantity, which is obviously erroneous.

flex_array_get() and flex_array_put() allows negative array indices in
dereferencing an array part, which could address memory mapped before
struct flex_array.

The fix is to convert all existing element_nr formals to be qualified as
unsigned.  Existing checks to compare it to total_nr_elements or the max
array size based on element_size need not be changed.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-26 20:06:52 -07:00
David Rientjes
105b6e8a74 flex_array: fix flex_array_free_parts comment
flex_array_free_parts() does not take `src' or `element_nr' formals, so
remove their respective comments.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-26 20:06:52 -07:00
David Rientjes
a30b595d2c flex_array: fix get function for elements in base starting at non-zero
If all array elements fit into the base structure and data is copied using
flex_array_put() starting at a non-zero index, flex_array_get() will fail
to return the data.

This fixes the bug by only checking for NULL parts when all elements do
not fit in the base structure when flex_array_get() is used.  Otherwise,
fa_element_to_part_nr() will always be 0 since there are no parts
structures needed and such element may never have been put.  Thus, it will
remain NULL due to the kzalloc() of the base.

Additionally, flex_array_put() now only checks for a NULL part when all
elements do not fit in the base structure.  This is otherwise unnecessary
since the base structure is guaranteed to exist (or we would have already
hit a NULL pointer).

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-26 20:06:52 -07:00
Linus Torvalds
87bcfa3366 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  dma-debug: Fix check_unmap null pointer dereference
2009-08-25 11:24:24 -07:00
Paul E. McKenney
6b3ef48adf rcu: Remove CONFIG_PREEMPT_RCU
Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no
further need for CONFIG_PREEMPT_RCU.  Remove it, along with
whatever subtle bugs it may (or may not) contain.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <125097461396-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23 10:32:40 +02:00
Paul E. McKenney
f41d911f8c rcu: Merge preemptable-RCU functionality into hierarchical RCU
Create a kernel/rcutree_plugin.h file that contains definitions
for preemptable RCU (or, under the #else branch of the #ifdef,
empty definitions for the classic non-preemptable semantics).
These definitions fit into plugins defined in kernel/rcutree.c
for this purpose.

This variant of preemptable RCU uses a new algorithm whose
read-side expense is roughly that of classic hierarchical RCU
under CONFIG_PREEMPT. This new algorithm's update-side expense
is similar to that of classic hierarchical RCU, and, in absence
of read-side preemption or blocking, is exactly that of classic
hierarchical RCU.  Perhaps more important, this new algorithm
has a much simpler implementation, saving well over 1,000 lines
of code compared to mainline's implementation of preemptable
RCU, which will hopefully be retired in favor of this new
algorithm.

The simplifications are obtained by maintaining per-task
nesting state for running tasks, and using a simple
lock-protected algorithm to handle accounting when tasks block
within RCU read-side critical sections, making use of lessons
learned while creating numerous user-level RCU implementations
over the past 18 months.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <12509746134003-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23 10:32:40 +02:00
Linus Torvalds
f4b0373b26 Make bitmask 'and' operators return a result code
When 'and'ing two bitmasks (where 'andnot' is a variation on it), some
cases want to know whether the result is the empty set or not.  In
particular, the TLB IPI sending code wants to do cpumask operations and
determine if there are any CPU's left in the final set.

So this just makes the bitmask (and cpumask) functions return a boolean
for whether the result has any bits set.

Cc: stable@kernel.org (2.6.30, needed by TLB shootdown fix)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-21 09:26:15 -07:00
Casey Dahlin
c7084b35eb lib/swiotlb.c: Fix strange panic message selection logic when swiotlb fills up
swiotlb_full() in lib/swiotlb.c throws one of two panic messages
based on whether the direction of transfer is from the device
or to the device. The logic around this is somewhat weird in
the case of bidirectional transfers. It appears to want to
throw both in succession, but since its a panic only the first
makes it.

This patch adds a third, separate error for DMA_BIDIRECTIONAL
to make things a bit clearer.

Signed-off-by: Casey Dahlin <cdahlin@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
[ further fixed the error message ]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <200908202327.n7KNRuqK001504@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-21 10:36:03 +02:00
Kyle McMartin
ec9c96ef3c dma-debug: Fix check_unmap null pointer dereference
While it's debatable whether or not a NULL device argument to
the DMA API functions is valid... since it certainly isn't
valid on devices with an IOMMU... dma-debug really shouldn't be
dereferencing null pointers either.

Guard against that in err_printk and the driver_filter
functions. A Fedora rawhide user was seeing this in one of the
dvb drivers resulting in an oops on boot.

[ A patch has been sent for testing to the driver, but I feel
  the dma debugging support should be fixed as well. (There's
  still a pile of legacy garbage in the kernel passing null
  pointers to dma_{alloc,free}_*. :( ]

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Cc: mchehab@infradead.org
Cc: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20090820011708.GP25206@bombadil.infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-21 10:04:24 +02:00
James Morris
8b4bfc7feb Merge branch 'master' into next 2009-08-11 08:33:01 +10:00
Albin Tonnerre
9e5cf0ca2e lib/decompress_*: only include <linux/slab.h> if STATIC is not defined
These includes were added by 079effb693
("kmemtrace, kbuild: fix slab.h dependency problem in
lib/decompress_inflate.c") to fix the build when using kmemtrace.  However
this is not necessary when used to create a compressed kernel, and
actually creates issues (brings a lot of things unavailable in the
decompression environment), so don't include it if STATIC is defined.

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-07 10:39:56 -07:00
Phillip Lougher
b1af4315d8 bzip2/lzma: remove nasty uncompressed size hack in pre-boot environment
decompress_bunzip2 and decompress_unlzma have a nasty hack that subtracts
4 from the input length if being called in the pre-boot environment.

This is a nasty hack because it relies on the fact that flush = NULL only
when called from the pre-boot environment (i.e.
arch/x86/boot/compressed/misc.c).  initramfs.c/do_mounts_rd.c pass in a
flush buffer (flush != NULL).

This hack prevents the decompressors from being used with flush = NULL by
other callers unless knowledge of the hack is propagated to them.

This patch removes the hack by making decompress (called only from the
pre-boot environment) a wrapper function that subtracts 4 from the input
length before calling the decompressor.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
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>
2009-08-07 10:39:56 -07:00
Phillip Lougher
daeb6b6fbe bzip2/lzma/gzip: fix comments describing decompressor API
Fix and improve comments in decompress/generic.h that describe the
decompressor API.  Also remove an unused definition, and rename INBUF_LEN
in lib/decompress_inflate.c to conform to bzip2/lzma naming.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
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>
2009-08-07 10:39:56 -07:00
James Morris
012a5299a2 Merge branch 'master' into next 2009-08-06 08:55:03 +10:00
Jonathan Corbet
0786820107 flex_array: remove unneeded index calculation
flex_array_get() calculates an index value, then drops it on the floor;
simply remove it.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-04 15:33:46 -07:00
Sebastian Andrzej Siewior
6de7e356fa lib/scatterlist: add a flags to signalize mapping direction
sg_miter_start() is currently unaware of the direction of the copy
process (to or from the scatter list). It is important to know the
direction because the page has to be flushed in case the data written
is seen on a different mapping in user land on cache incoherent
architectures.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
2009-07-31 12:28:45 +02:00
Dave Hansen
534acc057b lib: flexible array implementation
Once a structure goes over PAGE_SIZE*2, we see occasional allocation
failures.  Some people have chosen to switch over to things like vmalloc()
that will let them keep array-like access to such a large structures.
But, vmalloc() has plenty of downsides.

Here's an alternative.  I think it's what Andrew was suggesting here:

	http://lkml.org/lkml/2009/7/2/518

I call it a flexible array.  It does all of its work in PAGE_SIZE bits, so
never does an order>0 allocation.  The base level has
PAGE_SIZE-2*sizeof(int) bytes of storage for pointers to the second level.
 So, with a 32-bit arch, you get about 4MB (4183112 bytes) of total
storage when the objects pack nicely into a page.  It is half that on
64-bit because the pointers are twice the size.  There's a table detailing
this in the code.

There are kerneldocs for the functions, but here's an
overview:

flex_array_alloc() - dynamically allocate a base structure
flex_array_free() - free the array and all of the
		    second-level pages
flex_array_free_parts() - free the second-level pages, but
			  not the base (for static bases)
flex_array_put() - copy into the array at the given index
flex_array_get() - copy out of the array at the given index
flex_array_prealloc() - preallocate the second-level pages
			between the given indexes to
			guarantee no allocs will occur at
			put() time.

We could also potentially just pass the "element_size" into each of the
API functions instead of storing it internally.  That would get us one
more base pointer on 32-bit.

I've been testing this by running it in userspace.  The header and patch
that I've been using are here, as well as the little script I'm using to
generate the size table which goes in the kerneldocs.

	http://sr71.net/~dave/linux/flexarray/

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29 19:10:36 -07:00
Roland Dreier
3fc7b4b220 lib: export generic atomic64_t functions
The generic atomic64_t implementation in lib/ did not export the functions
it defined, which means that modules that use atomic64_t would not link on
platforms (such as 32-bit powerpc).  For example, trying to build a kernel
with CONFIG_NET_RDS on such a platform would fail with:

    ERROR: "atomic64_read" [net/rds/rds.ko] undefined!
    ERROR: "atomic64_set" [net/rds/rds.ko] undefined!

Fix this by exporting the atomic64_t functions to modules.  (I export the
entire API even if it's not all currently used by in-tree modules to avoid
having to continue fixing this in dribs and drabs)

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29 19:10:35 -07:00
Roel Kluin
4df7b3e037 Dynamic debug: fix typo: -/->
The member was intended, not the local variable.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Greg Banks <gnb@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-28 13:45:22 -07:00
FUJITA Tomonori
862d196b27 swiotlb: use phys_to_dma and dma_to_phys
This converts swiotlb to use phys_to_dma and dma_to_phys instead of
swiotlb_phys_to_bus() and swiotlb_bus_to_phys().

swiotlb_phys_to_bus() and swiotlb_bus_to_phys() are not necessary so
this patch also removes them.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
2009-07-28 14:19:20 +09:00
FUJITA Tomonori
b9394647ac swiotlb: use dma_capable()
This converts swiotlb to use dma_capable() instead of
swiotlb_arch_address_needs_mapping() and is_buffer_dma_capable().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
2009-07-28 14:19:19 +09:00
FUJITA Tomonori
02ca646e73 swiotlb: remove unnecessary swiotlb_bus_to_virt
swiotlb_bus_to_virt is unncessary; we can use swiotlb_bus_to_phys and
phys_to_virt instead.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
2009-07-28 14:19:18 +09:00
FUJITA Tomonori
cf56e3f2e8 swiotlb: remove swiotlb_arch_range_needs_mapping
Nobody uses swiotlb_arch_range_needs_mapping().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
2009-07-28 14:19:18 +09:00
FUJITA Tomonori
bb52196be3 swiotlb: remove unused swiotlb_alloc()
Nobody uses swiotlb_alloc().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
2009-07-28 14:19:18 +09:00
FUJITA Tomonori
3885123da8 swiotlb: remove unused swiotlb_alloc_boot()
Nobody uses swiotlb_alloc_boot().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Becky Bruce <beckyb@kernel.crashing.org>
2009-07-28 14:19:18 +09:00
Oleg Nesterov
967cc53711 kernel: is_current_single_threaded: don't use ->mmap_sem
is_current_single_threaded() can safely miss a freshly forked CLONE_VM
task, but in this case it must not miss its parent. That is why we take
mm->mmap_sem for writing to make sure a thread/task with the same ->mm
can't pass exit_mm() and disappear.

However we can avoid ->mmap_sem and rely on rcu/barriers:

	- if we do not see the exiting parent on thread/process list
	  we see the result of list_del_rcu(), in this case we must
	  also see the result of list_add_rcu() which does wmb().

	- if we do see the parent but its ->mm == NULL, we need rmb()
	  to make sure we can't miss the child.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-07-17 09:11:31 +10:00
Oleg Nesterov
5bb459bb45 kernel: rename is_single_threaded(task) to current_is_single_threaded(void)
- is_single_threaded(task) is not safe unless task == current,
  we can't use task->signal or task->mm.

- it doesn't make sense unless task == current, the task can
  fork right after the check.

Rename it to current_is_single_threaded() and kill the argument.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-07-17 09:10:42 +10:00
Oleg Nesterov
d2e3ee9b29 kernel: fix is_single_threaded
- Fix the comment, is_single_threaded(p) actually means that nobody shares
  ->mm with p.

  I think this helper should be renamed, and it should not have arguments.
  With or without this patch it must not be used unless p == current,
  otherwise we can't safely use p->signal or p->mm.

- "if (atomic_read(&p->signal->count) != 1)" is not right when we have a
  zombie group leader, use signal->live instead.

- Add PF_KTHREAD check to skip kernel threads which may borrow p->mm,
  otherwise we can return the wrong "false".

- Use for_each_process() instead of do_each_thread(), all threads must use
  the same ->mm.

- Use down_write(mm->mmap_sem) + rcu_read_lock() instead of tasklist_lock
  to iterate over the process list. If there is another CLONE_VM process
  it can't pass exit_mm() which takes the same mm->mmap_sem. We can miss
  a freshly forked CLONE_VM task, but this doesn't matter because we must
  see its parent and return false.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
2009-07-17 09:09:36 +10:00
Linus Torvalds
ac3f482236 Merge branch 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  dma-debug: Fix the overlap() function to be correct and readable
  oprofile: reset bt_lost_no_mapping with other stats
  x86/oprofile: rename kernel parameter for architectural perfmon to arch_perfmon
  signals: declare sys_rt_tgsigqueueinfo in syscalls.h
  rcu: Mark Hierarchical RCU no longer experimental
  dma-debug: Put all hash-chain locks into the same lock class
  dma-debug: fix off-by-one error in overlap function
2009-07-10 14:25:59 -07:00
Ingo Molnar
f39d1b9792 dma-debug: Fix the overlap() function to be correct and readable
Linus noticed how unclean and buggy the overlap() function is:

 - It uses convoluted (and bug-causing) positive checks for
   range overlap - instead of using a more natural negative
   check.

 - Even the positive checks are buggy: a positive intersection
   check has four natural cases while we checked only for three,
   missing the (addr < start && addr2 == end) case for example.

 - The variables are mis-named, making it non-obvious how the
   check was done.

 - It needlessly uses u64 instead of unsigned long. Since these
   are kernel memory pointers and we explicitly exclude highmem
   ranges anyway we cannot ever overflow 32 bits, even if we
   could. (and on 64-bit it doesnt matter anyway)

All in one, this function needs a total revamp. I used Linus's
suggestions minus the paranoid checks (we cannot overflow really
because if we get totally bad DMA ranges passed far more things
break in the systems than just DMA debugging). I also fixed a
few other small details i noticed.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-10 22:18:45 +02:00
Ingo Molnar
c222dce48c Merge branch 'dma-debug/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/urgent 2009-07-03 11:03:10 +02:00
Catalin Marinas
a9d9058aba kmemleak: Allow the early log buffer to be configurable.
(feature suggested by Sergey Senozhatsky)

Kmemleak needs to track all the memory allocations but some of these
happen before kmemleak is initialised. These are stored in an internal
buffer which may be exceeded in some kernel configurations. This patch
adds a configuration option with a default value of 400 and also removes
the stack dump when the early log buffer is exceeded.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
2009-06-25 10:16:13 +01:00
Linus Torvalds
defe910483 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: add dummy pgprot_noncached()
  lib/checksum.c: fix endianess bug
  asm-generic: hook up new system calls
  asm-generic: list Arnd as asm-generic maintainer
  asm-generic: drop HARDIRQ_BITS definition from hardirq.h
  asm-generic: uaccess: fix up local access_ok() usage
  asm-generic: uaccess: add missing access_ok() check to strnlen_user()
2009-06-23 11:34:24 -07:00
Catalin Marinas
bf96d1e3e7 kmemleak: Do not force the slab debugging Kconfig options
Selecting DEBUG_SLAB or SLUB_DEBUG by the KMEMLEAK menu entry may cause
issues with other dependencies (KMEMCHECK). These configuration options
aren't strictly needed by kmemleak but they may increase the chances of
finding leaks. This patch also updates the KMEMLEAK config entry help
text.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-06-23 14:40:27 +01:00
Linus Torvalds
8b12e2505a Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Select frame pointers on x86
  dma-debug: be more careful when building reference entries
  dma-debug: check for sg_call_ents in best-fit algorithm too
2009-06-21 13:13:53 -07:00
Peter Zijlstra
00540e5d54 lockdep: Select frame pointers on x86
x86 stack traces are a piece of crap without frame pointers, and its not
like the 'performance gain' of not having stack pointers matters when you
selected lockdep.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <new-submission>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-21 10:14:33 +02:00
Arnd Bergmann
32a9ff9cc5 lib/checksum.c: fix endianess bug
The new generic checksum code has a small dependency on endianess and
worked only on big-endian systems. I could not find a nice efficient
way to express this, so I added an #ifdef. Using
'result += le16_to_cpu(*buff);' would have worked as well, but
would be slightly less efficient on big-endian systems and IMHO
would not be clearer.

Also fix a bug that prevents this from working on 64-bit machines.
If you have a 64-bit CPU and want to use the generic checksum
code, you should probably do some more optimizations anyway, but
at least the code should not break.

Reported-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2009-06-19 14:58:13 +02:00
Florian Fainelli
d282922461 lib: add lib/gcd.c
This patch adds lib/gcd.c which contains a greatest common divider
implementation taken from sound/core/pcm_timer.c

Several usages of this new library function will be sent to subsystem
maintainers.

[akpm@linux-foundation.org: use swap() (pointed out by Joe)]
[akpm@linux-foundation.org: just add gcd.o to obj-y, remove Kconfig changes]
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julius Volz <juliusv@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:04:05 -07:00
Ingo Molnar
b0a5b83ee0 dma-debug: Put all hash-chain locks into the same lock class
Alan Cox reported that lockdep runs out of its stack-trace entries
with certain configs:

 BUG: MAX_STACK_TRACE_ENTRIES too low

This happens because there are 1024 hash buckets, each with a
separate lock. Lockdep puts each lock into a separate lock class and
tracks them independently.

But in reality we never take more than one of the buckets, so they
really belong into a single lock-class. Annotate the has bucket lock
init accordingly.

[ Impact: reduce the lockdep footprint of dma-debug ]

Reported-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2009-06-17 16:26:04 +02:00
Linus Torvalds
517d08699b Merge branch 'akpm'
* akpm: (182 commits)
  fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
  fbdev: *bfin*: fix __dev{init,exit} markings
  fbdev: *bfin*: drop unnecessary calls to memset
  fbdev: bfin-t350mcqb-fb: drop unused local variables
  fbdev: blackfin has __raw I/O accessors, so use them in fb.h
  fbdev: s1d13xxxfb: add accelerated bitblt functions
  tcx: use standard fields for framebuffer physical address and length
  fbdev: add support for handoff from firmware to hw framebuffers
  intelfb: fix a bug when changing video timing
  fbdev: use framebuffer_release() for freeing fb_info structures
  radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
  s3c-fb: CPUFREQ frequency scaling support
  s3c-fb: fix resource releasing on error during probing
  carminefb: fix possible access beyond end of carmine_modedb[]
  acornfb: remove fb_mmap function
  mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
  mb862xxfb: restrict compliation of platform driver to PPC
  Samsung SoC Framebuffer driver: add Alpha Channel support
  atmel-lcdc: fix pixclock upper bound detection
  offb: use framebuffer_alloc() to allocate fb_info struct
  ...

Manually fix up conflicts due to kmemcheck in mm/slab.c
2009-06-16 19:50:13 -07:00
Wolfram Strepp
4b324126e0 rb_tree: remove redundant if()-condition in rb_erase()
Furthermore, notice that the initial checks:

	if (!node->rb_left)
		child = node->rb_right;
	else if (!node->rb_right)
		child = node->rb_left;
	else
	{
		...
	}
guarantee that old->rb_right is set in the final else branch, therefore
we can omit checking that again.

Signed-off-by: Wolfram Strepp <wstrepp@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:56 -07:00
Wolfram Strepp
4c60117811 rb_tree: make clear distinction between two different cases in rb_erase()
There are two cases when a node, having 2 childs, is erased:
'normal case': the successor is not the right-hand-child of the node to be erased
'special case': the successor is the right-hand child of the node to be erased

Here some ascii-art, with following symbols (referring to the code):
O: node to be deleted
N: the successor of O
P: parent of N
C: child of N
L: some other node

normal case:

               O                         N
              / \                       / \
             /   \                     /   \
            L     \                   L     \
           / \     P      ---->      / \     P
                  / \                       / \
                 /                         /
                N                         C
                 \                       / \
                  \
                   C
                  / \

special case:
              O|P                        N
              / \                       / \
             /   \                     /   \
            L     \                   L     \
           / \     N      ---->      /       C
                    \                       / \
                     \
                      C
                     / \

Notice that for the special case we don't have to reconnect C to N.

Signed-off-by: Wolfram Strepp <wstrepp@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:56 -07:00
Wolfram Strepp
16c047add3 rb_tree: reorganize code in rb_erase() for additional changes
First, move some code around in order to make the next change more obvious.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wolfram Strepp <wstrepp@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:56 -07:00