Stephen Warren [Thu, 25 Oct 2012 01:14:44 +0000 (12:14 +1100)]
block: store partition_meta_info.uuid as a string
This will allow other types of UUID to be stored here, aside from true
UUIDs. This also simplifies code that uses this field, since it's usually
constructed from a, used as a, or compared to other, strings.
Note: A simplistic approach here would be to set uuid_str[36]=0 whenever a
/PARTNROFF option was found to be present. However, this modifies the
input string, and causes subsequent calls to devt_from_partuuid() not to
see the /PARTNROFF option, which causes different results. In order to
avoid misleading future maintainers, this parameter is marked const.
Signed-off-by: Stephen Warren <swarren@nvidia.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Will Drewry <wad@chromium.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Thu, 25 Oct 2012 01:14:44 +0000 (12:14 +1100)]
cciss: use check_signature()
Use check_signature() to find a signature in the mmio address.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Akinobu Mita [Thu, 25 Oct 2012 01:14:43 +0000 (12:14 +1100)]
cciss: cleanup bitops usage
- Remove unnecessary correction of bit and address
- Use BITS_TO_LONGS macro to calculate bitmap size
- Use bitmap_zero()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The block control group, infiniband, xfs, crypto, 802.11, netfilter.
Nothing quite so fundamental as fs/namespace.c but definitely in
multiplatform-code that should work, and is already broken on those
architecutres.
Looking at the implementation of atomic64_add_return in lib/atomic64.c the
code looks as efficient as these kinds of things get.
Which leads me to the conclusion that we need atomic64 support on all
architectures.
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hannes Reinecke [Thu, 25 Oct 2012 01:14:42 +0000 (12:14 +1100)]
fs/pstore/ram.c: fix up section annotations
The compiler complained about missing section annotations. Fix it.
Signed-off-by: Hannes Reinecke <hare@suse.de> Cc: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Colin Cross <ccross@android.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
How is the compiler even handling exported functions that are marked
inline? Anyway, these shouldn't be inline because of that, so remove that
marking.
Based on a larger patch by Mark Charlebois to get LLVM to build the
kernel.
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Charlebois <mcharleb@qualcomm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: hank <pyu@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The use of defined() on arrays and hashes has been deprecated since perl
5.6, but until 5.17.6 it only warned on lexicals, not package globals.
Signed-off-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jean Delvare [Thu, 25 Oct 2012 01:14:41 +0000 (12:14 +1100)]
drm/i915: optimize DIV_ROUND_CLOSEST() call
DIV_ROUND_CLOSEST is faster if the compiler knows it will only be dealing
with unsigned dividends.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pcmcia: move unbind/rebind into dev_pm_ops.complete
Move the device rebind procedures for cardbus devices from the pm.resume
into the pm.complete callback.
The reason for moving the code is: "[...] The PM code needs to send
suspend and resume messages to every device in the right order, and it
can't do that if new devices are being added at the same time. [...]"
However the situation really isn't quite that rigid. In particular,
adding new children during a resume callback shouldn't cause much of
problem because the children don't need to be resumed anyway (since they
were never suspended). On the other hand, if you do it you will get a
dev_warn() from the PM core, something like 'parent should not be
sleeping'.
Still, it is considered bad form and should be avoided if possible."
(Alan Stern's full comment about the topic can
be found here: <https://lkml.org/lkml/2012/7/10/254>)
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Greg KH <greg@kroah.com> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Randy Dunlap [Thu, 25 Oct 2012 01:14:41 +0000 (12:14 +1100)]
olpc: fix olpc-xo1-sci.c build errors
Fix build errors when CONFIG_INPUT=m. This is not pretty, but all of the
OLPC kconfig options are bool instead of tristate.
arch/x86/built-in.o: In function `send_lid_state':
olpc-xo1-sci.c:(.text+0x1d323): undefined reference to `input_event'
olpc-xo1-sci.c:(.text+0x1d338): undefined reference to `input_event'
arch/x86/built-in.o: In function `free_ebook_switch':
olpc-xo1-sci.c:(.text+0x1d529): undefined reference to `input_unregister_device'
olpc-xo1-sci.c:(.text+0x1d533): undefined reference to `input_free_device'
arch/x86/built-in.o: In function `free_power_button':
olpc-xo1-sci.c:(.text+0x1d549): undefined reference to `input_unregister_device'
olpc-xo1-sci.c:(.text+0x1d553): undefined reference to `input_free_device'
arch/x86/built-in.o: In function `send_ebook_state':
olpc-xo1-sci.c:(.text+0x1d632): undefined reference to `input_event'
olpc-xo1-sci.c:(.text+0x1d647): undefined reference to `input_event'
arch/x86/built-in.o: In function `xo1_sci_intr':
olpc-xo1-sci.c:(.text+0x1d78e): undefined reference to `input_event'
olpc-xo1-sci.c:(.text+0x1d7a3): undefined reference to `input_event'
olpc-xo1-sci.c:(.text+0x1d7be): undefined reference to `input_event'
arch/x86/built-in.o:olpc-xo1-sci.c:(.text+0x1d7d3): more undefined references to `input_event' follow
arch/x86/built-in.o: In function `free_lid_switch':
olpc-xo1-sci.c:(.text+0x1d7fd): undefined reference to `input_unregister_device'
olpc-xo1-sci.c:(.text+0x1d807): undefined reference to `input_free_device'
arch/x86/built-in.o: In function `setup_lid_switch':
olpc-xo1-sci.c:(.devinit.text+0x155): undefined reference to `input_allocate_device'
olpc-xo1-sci.c:(.devinit.text+0x1a4): undefined reference to `input_register_device'
olpc-xo1-sci.c:(.devinit.text+0x1ce): undefined reference to `input_unregister_device'
olpc-xo1-sci.c:(.devinit.text+0x1d8): undefined reference to `input_free_device'
arch/x86/built-in.o: In function `xo1_sci_probe':
olpc-xo1-sci.c:(.devinit.text+0x235): undefined reference to `input_allocate_device'
olpc-xo1-sci.c:(.devinit.text+0x285): undefined reference to `input_register_device'
olpc-xo1-sci.c:(.devinit.text+0x299): undefined reference to `input_free_device'
olpc-xo1-sci.c:(.devinit.text+0x2e1): undefined reference to `input_register_device'
olpc-xo1-sci.c:(.devinit.text+0x2f5): undefined reference to `input_free_device'
olpc-xo1-sci.c:(.devinit.text+0x54c): undefined reference to `input_allocate_device'
In the long run, fixing this driver kconfig to be tristate instead of bool
would be a very good change.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Andres Salomon <dilinger@queued.net> Cc: Chris Ball <cjb@laptop.org> Cc: Jon Nettleton <jon.nettleton@gmail.com> Cc: Daniel Drake <dsd@laptop.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alex Shi [Thu, 25 Oct 2012 01:14:40 +0000 (12:14 +1100)]
arch/x86/platform/uv: fix incorrect tlb flush all issue
The flush tlb optimization code has logical issue on UV platform. It
doesn't flush the full range at all, since it simply ignores its 'end'
parameter (and hence also the "all" indicator) in uv_flush_tlb_others()
function.
Cliff's notes:
: I tested the patch on a UV. It has the effect of either clearing 1 or all
: TLBs in a cpu. I added some debugging to test for the cases when clearing
: all TLBs is overkill, and in practice it happens very seldom.
Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Cliff Wickman <cpw@sgi.com> Tested-by: Cliff Wickman <cpw@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andrew Morton [Thu, 25 Oct 2012 01:14:40 +0000 (12:14 +1100)]
arch/x86/tools/insn_sanity.c: identify source of messages
The kernel build prints:
Building modules, stage 2.
TEST posttest
MODPOST 3821 modules
TEST posttest
Success: decoded and checked 1000000 random instructions with 0 errors (seed:0xaac4bc47)
CC arch/x86/boot/a20.o
CC arch/x86/boot/cmdline.o
AS arch/x86/boot/copy.o
HOSTCC arch/x86/boot/mkcpustr
CC arch/x86/boot/cpucheck.o
CC arch/x86/boot/early_serial_console.o
which is irritating because you don't know what program is proudly
pronouncing its success.
So, as described in "console mode programming user interface guidelines
version 101" which doesn't exist, change this program to identify the
source of its messages.
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wen Congyang [Thu, 25 Oct 2012 01:14:40 +0000 (12:14 +1100)]
x86 numa: don't check if node is NUMA_NO_NODE
If we aren't debugging per_cpu maps, the cpu's node is stored in per_cpu
variable numa_node. If `node' is NUMA_NO_NODE, it means the caller wants
to clear the cpu's node. So we should also call set_cpu_numa_node() in
this case.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Shérab [Thu, 25 Oct 2012 01:14:39 +0000 (12:14 +1100)]
arch/x86/platform/iris/iris.c: register a platform device and a platform driver
This makes the iris driver use the platform API, so it is properly exposed
in /sys.
[akpm@linux-foundation.org: remove commented-out code, add missing space to printk, clean up code layout] Signed-off-by: Shérab <Sebastien.Hinderer@ens-lyon.org> Cc: Len Brown <lenb@kernel.org> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wen Congyang [Thu, 25 Oct 2012 01:14:39 +0000 (12:14 +1100)]
acpi_memhotplug.c: auto bind the memory device which is hotplugged before the driver is loaded
If the memory device is hotplugged before the driver is loaded, the user
cannot see this device under the directory /sys/bus/acpi/devices/, and the
user cannot bind it by hand after the driver is loaded. This patch
introduces a new feature to bind such device when the driver is being
loaded.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Len Brown <lenb@kernel.org> Cc: "Brown, Len" <len.brown@intel.com> Cc: Yasuaki ISIMATU <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wen Congyang [Thu, 25 Oct 2012 01:14:39 +0000 (12:14 +1100)]
acpi_memhotplug.c: bind the memory device when the driver is being loaded
We had introduced acpi_hotmem_initialized to avoid strange add_memory fail
message. But the memory device may not be used by the kernel, and the
device should be bound when the driver is being loaded. Remove
acpi_hotmem_initialized to allow that the device can be bound when the
driver is being loaded.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Len Brown <lenb@kernel.org> Cc: "Brown, Len" <len.brown@intel.com> Cc: Yasuaki ISIMATU <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wen Congyang [Thu, 25 Oct 2012 01:14:38 +0000 (12:14 +1100)]
acpi_memhotplug.c: free memory device if acpi_memory_enable_device() failed
If acpi_memory_enable_device() fails, acpi_memory_enable_device() will
return a non-zero value, which means we fail to bind the memory device to
this driver. So we should free memory device before
acpi_memory_device_add() returns.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Len Brown <lenb@kernel.org> Cc: "Brown, Len" <len.brown@intel.com> Cc: Yasuaki ISIMATU <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wen Congyang [Thu, 25 Oct 2012 01:14:37 +0000 (12:14 +1100)]
x86 cpu_hotplug: unmap cpu2node when the cpu is hotremoved
When a cpu is hotplugged, we call acpi_map_cpu2node() in
_acpi_map_lsapic() to store the cpu's node. But we don't clear the cpu's
node in acpi_unmap_lsapic() when this cpu is hotremoved. If the node is
also hotremoved, We will get the following messages:
The reason is that: the cpu's node is not NUMA_NO_NODE, we will call
alloc_pages_exact_node() to alloc memory on the node, but the node is
offlined.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
MITSUNARI Shigeo [Thu, 25 Oct 2012 01:14:36 +0000 (12:14 +1100)]
fs/block_dev.c: page cache wrongly left invalidated after revalidate_disk()
We found that bdev->bd_invalidated was left set once revalidate_disk() is
called, which results in page cache flush every time that device is open.
Specifically, we found this problem in MD block device. Once we resize a
MD device, mdadm --monitor periodically flush all page cache for that
device every 60 or 1000 seconds when it opens the device.
This bug lies since at least 3.2.0 till the latest kernel(3.6.2).
Patch is attached.
The following steps will reproduce the problem.
1. prepair a block device(ex. /dev/sdb).
2. create two partitions.
NeilBrown [Thu, 25 Oct 2012 01:14:36 +0000 (12:14 +1100)]
vfs: d_obtain_alias() needs to use "/" as default name.
NFS appears to use d_obtain_alias() to create the root dentry rather than
d_make_root. This can cause 'prepend_path()' to complain that the root
has a weird name if an NFS filesystem is lazily unmounted. e.g. if
"/mnt" is an NFS mount then
{ cd /mnt; umount -l /mnt ; ls -l /proc/self/cwd; }
will cause a WARN message like
WARNING: at /home/git/linux/fs/dcache.c:2624 prepend_path+0x1d7/0x1e0()
...
Root dentry has weird name <>
to appear in kernel logs.
So change d_obtain_alias() to use "/" rather than "" as the anonymous
name.
Signed-off-by: NeilBrown <neilb@suse.de> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch below does what Paul McKenney suggested in the previous thread.
Signed-off-by: Dave Jones <davej@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: Eric Paris <eparis@parisplace.org> Cc: James Morris <jmorris@namei.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Corey Minyard [Thu, 25 Oct 2012 01:14:36 +0000 (12:14 +1100)]
CRIS: Fix I/O macros
The inb/outb macros for CRIS are broken from a number of points of view,
missing () around parameters and they have an unprotected if statement in
them. This was breaking the compile of IPMI on CRIS and thus I was being
annoyed by build regressions, so I fixed them.
Plus I don't think they would have worked at all, since the data values
were missing "&" and the outsl had a "3" instead of a "4" for the size.
From what I can tell, this stuff is not used at all, so this can't be any
more broken than it was before, anyway.
Maxim Levitsky [Thu, 25 Oct 2012 01:14:35 +0000 (12:14 +1100)]
memstick: ms_block: fix compile issue
As suggested by Geert Uytterhoeven:
: http://kisskb.ellerman.id.au/kisskb/buildresult/7280352/
: arch/m68k/include/asm/hardirq.h:23:20: error: expected ')' before 'DRIVER_NAME'
: make[4]: *** [drivers/memstick/core/ms_block.o] Error 1
:
: The reason for this is that pr_fmt() references DRIVER_NAME and is defined
: before the first include, while DRIVER_NAME is only defined in ms_block.h,
: which is the last included file. If any subsequent include file uses
: pr_fmt() (e.g. the call to pr_crit() in arch/m68k/include/asm/hardirq.h),
: this causes a build failure.
:
: I suggest moving the DRIVER_NAME define to ms_block.c. Cfr. memstick.c
: and mspro_block.c, who already have their own definition.
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Alex Dubov <oakad@yahoo.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
7b540d0646ce ("proc_map_files_readdir(): don't bother with grabbing
files") switched proc_map_files_readdir() to use @f_mode directly instead of
grabbing @file reference, but same time the test for @vm_file presence was
lost leading to nil dereference. The patch brings the test back.
The all proc_map_files feature is CONFIG_\10CHECKPOINT_RESTORE wrapped
(which is set to 'n' by default) so the bug doesn't affect regular
kernels.
The regression is 3.7-rc1 only as far as I can tell.
[gorcunov@openvz.org: provided changelog] Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mel Gorman [Thu, 25 Oct 2012 01:14:33 +0000 (12:14 +1100)]
mm: vmscan: scale number of pages reclaimed by reclaim/compaction only in direct reclaim
Jiri Slaby reported the following:
(It's an effective revert of "mm: vmscan: scale number of pages
reclaimed by reclaim/compaction based on failures".)
Given kswapd had hours of runtime in ps/top output yesterday in the
morning and after the revert it's now 2 minutes in sum for the last 24h,
I would say, it's gone.
The intention of the patch in question was to compensate for the loss of
lumpy reclaim. Part of the reason lumpy reclaim worked is because it
aggressively reclaimed pages and this patch was meant to be a sane
compromise.
When compaction fails, it gets deferred and both compaction and
reclaim/compaction is deferred avoid excessive reclaim. However, since
commit c6543459 ("mm: remove __GFP_NO_KSWAPD"), kswapd is woken up each
time and continues reclaiming which was not taken into account when the
patch was developed.
As it is not taking deferred compaction into account in this path it scans
aggressively before falling out and making the compaction_deferred check
in compaction_ready. This patch avoids kswapd scaling pages for reclaim
and leaves the aggressive reclaim to the process attempting the THP
allocation.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-by: Jiri Slaby <jslaby@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
epoll: support for disabling items, and a self-test app
Pending resolution of the issues identifier by Michael Kerrisk:
: I've taken a look at this patch as it currently stands in 3.7-rc1, and
: done a bit of testing. (By the way, the test program
: tools/testing/selftests/epoll/test_epoll.c does not compile...)
:
: There are one or two places where the behavior seems a little strange,
: so I have a question or two at the end of this mail. But other than
: that, I want to check my understanding so that the interface can be
: correctly documented.
:
: Just to go though my understanding, the problem is the following
: scenario in a multithreaded application:
:
: 1. Multiple threads are performing epoll_wait() operations,
: and maintaining a user-space cache that contains information
: corresponding to each file descriptor being monitored by
: epoll_wait().
:
: 2. At some point, a thread wants to delete (EPOLL_CTL_DEL)
: a file descriptor from the epoll interest list, and
: delete the corresponding record from the user-space cache.
:
: 3. The problem with (2) is that some other thread may have
: previously done an epoll_wait() that retrieved information
: about the fd in question, and may be in the middle of using
: information in the cache that relates to that fd. Thus,
: there is a potential race.
:
: 4. The race can't solved purely in user space, because doing
: so would require applying a mutex across the epoll_wait()
: call, which would of course blow thread concurrency.
:
: Right?
:
: Your solution is the EPOLL_CTL_DISABLE operation. I want to
: confirm my understanding about how to use this flag, since
: the description that has accompanied the patches so far
: has been a bit sparse
:
: 0. In the scenario you're concerned about, deleting a file
: descriptor means (safely) doing the following:
: (a) Deleting the file descriptor from the epoll interest list
: using EPOLL_CTL_DEL
: (b) Deleting the corresponding record in the user-space cache
:
: 1. It's only meaningful to use this EPOLL_CTL_DISABLE in
: conjunction with EPOLLONESHOT.
:
: 2. Using EPOLL_CTL_DISABLE without using EPOLLONESHOT in
: conjunction is a logical error.
:
: 3. The correct way to code multithreaded applications using
: EPOLL_CTL_DISABLE and EPOLLONESHOT is as follows:
:
: a. All EPOLL_CTL_ADD and EPOLL_CTL_MOD operations should
: should EPOLLONESHOT.
:
: b. When a thread wants to delete a file descriptor, it
: should do the following:
:
: [1] Call epoll_ctl(EPOLL_CTL_DISABLE)
: [2] If the return status from epoll_ctl(EPOLL_CTL_DISABLE)
: was zero, then the file descriptor can be safely
: deleted by the thread that made this call.
: [3] If the epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY,
: then the descriptor is in use. In this case, the calling
: thread should set a flag in the user-space cache to
: indicate that the thread that is using the descriptor
: should perform the deletion operation.
:
: Is all of the above correct?
:
: The implementation depends on checking on whether
: (events & ~EP_PRIVATE_BITS) == 0
: This replies on the fact that EPOLL_CTL_AD and EPOLL_CTL_MOD always
: set EPOLLHUP and EPOLLERR in the 'events' mask, and EPOLLONESHOT
: causes those flags (as well as all others in ~EP_PRIVATE_BITS) to be
: cleared.
:
: A corollary to the previous paragraph is that using EPOLL_CTL_DISABLE
: is only useful in conjunction with EPOLLONESHOT. However, as things
: stand, one can use EPOLL_CTL_DISABLE on a file descriptor that does
: not have EPOLLONESHOT set in 'events' This results in the following
: (slightly surprising) behavior:
:
: (a) The first call to epoll_ctl(EPOLL_CTL_DISABLE) returns 0
: (the indicator that the file descriptor can be safely deleted).
: (b) The next call to epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY.
:
: This doesn't seem particularly useful, and in fact is probably an
: indication that the user made a logic error: they should only be using
: epoll_ctl(EPOLL_CTL_DISABLE) on a file descriptor for which
: EPOLLONESHOT was set in 'events'. If that is correct, then would it
: not make sense to return an error to user space for this case?
Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paton J. Lewis" <palewis@adobe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The compat ioctl for VIDEO_SET_SPU_PALETTE was missing an error check
while converting ioctl arguments. This could lead to leaking kernel stack
contents into userspace.
Patch extracted from existing fix in grsecurity.
Signed-off-by: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Cc: Brad Spengler <spender@grsecurity.net> Cc: PaX Team <pageexec@freemail.hu> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kees Cook [Thu, 25 Oct 2012 01:13:58 +0000 (12:13 +1100)]
gen_init_cpio: avoid stack overflow when expanding
Fix possible overflow of the buffer used for expanding environment
variables when building file list. In the extremely unlikely case of an
attacker having control over the environment variables visible to
gen_init_cpio, control over the contents of the file gen_init_cpio parses,
and gen_init_cpio was built without compiler hardening, the attacker can
gain arbitrary execution control via a stack buffer overflow.
Signed-off-by: Jan Luebbe <jlu@pengutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Roland Stigge <stigge@antcom.de> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Rientjes [Thu, 25 Oct 2012 01:13:57 +0000 (12:13 +1100)]
mm, numa: avoid setting zone_reclaim_mode unless a node is sufficiently distant
Commit 957f822a0ab9 ("mm, numa: reclaim from all nodes within reclaim
distance") caused zone_reclaim_mode to be set for all systems where two
nodes are within RECLAIM_DISTANCE of each other. This is the opposite of
what we actually want: zone_reclaim_mode should be set if two nodes are
sufficiently distant.
Andrew Vagin [Thu, 25 Oct 2012 01:13:57 +0000 (12:13 +1100)]
pidns: limit the nesting depth of pid namespaces
'struct pid' is a "variable sized struct" - a header with an array of
upids at the end.
The size of the array depends on a level (depth) of pid namespaces. Now a
level of pidns is not limited, so 'struct pid' can be more than one page.
Looks reasonable, that it should be less than a page. MAX_PIS_NS_LEVEL is
not calculated from PAGE_SIZE, because in this case it depends on
architectures, config options and it will be reduced, if someone adds a
new fields in struct pid or struct upid.
I suggest to set MAX_PIS_NS_LEVEL = 32, because it saves ability to expand
"struct pid" and it's more than enough for all known for me use-cases.
When someone finds a reasonable use case, we can add a config option or a
sysctl parameter.
In addition it will reduce the effect of another problem, when we have
many nested namespaces and the oldest one starts dying.
zap_pid_ns_processe will be called for each namespace and find_vpid will
be called for each process in a namespace. find_vpid will be called
minimum max_level^2 / 2 times. The reason of that is that when we found a
bit in pidmap, we can't determine this pidns is top for this process or it
isn't.
vpid is a heavy operation, so a fork bomb, which create many nested
namespace, can make a system inaccessible for a long time. For example my
system becomes inaccessible for a few minutes with 4000 processes.
Signed-off-by: Andrew Vagin <avagin@openvz.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hein Tibosch [Thu, 25 Oct 2012 01:13:56 +0000 (12:13 +1100)]
drivers/dma/dw_dmac: make driver's endianness configurable
The dw_dmac driver was originally developed for avr32 to be used with the
Synopsys DesignWare AHB DMA controller. Starting from 2.6.38, access to
the device's i/o memory was done with the little-endian readl/writel
functions(1)
This broke the driver for the avr32 platform, because it needs big
(native) endian accessors. This patch makes the endianness configurable
using 'DW_DMAC_BIG_ENDIAN_IO', which will default be true for AVR32
I submitted this patch before(2) but then waited for Andy to finish other
changes to the same module(3).
Gavin Shan [Thu, 25 Oct 2012 01:13:56 +0000 (12:13 +1100)]
mm/mmu_notifier: allocate mmu_notifier in advance
While allocating mmu_notifier with parameter GFP_KERNEL, swap would start
to work in case of tight available memory. Eventually, that would lead to
a deadlock while the swap deamon swaps anonymous pages. It was caused by
commit e0f3c3f78da29b ("mm/mmu_notifier: init notifier if necessary").
Latest Linus head run of "make selftests" in the tools directory failed
with references to undefined variables. Reference was to
'write_thread_data' which is the name of a struct that is being used, not
the variable itself. Change reference so it points to the variable.
Signed-off-by: Daniel Hazelton <dshadowwolf@gmail.com> Cc: "Paton J. Lewis" <palewis@adobe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Howells [Thu, 25 Oct 2012 01:13:55 +0000 (12:13 +1100)]
UAPI: fix tools/vm/page-types.c
Fix tools/vm/page-types.c to use the UAPI variant of linux/kernel-page-flags.h
lest the following error appear:
In file included from page-types.c:38:0:
../../include/linux/kernel-page-flags.h:4:42: fatal error:
uapi/linux/kernel-page-flags.h: No such file or directory
Reported-by: Daniel Hazelton <dshadowwolf@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Daniel Hazelton <dshadowwolf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Bob Liu [Thu, 25 Oct 2012 01:13:55 +0000 (12:13 +1100)]
mm/page_alloc.c:alloc_contig_range(): return early for err path
If start_isolate_page_range() failed, unset_migratetype_isolate() has been
done inside it.
Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Ni zhan Chen <nizhan.chen@gmail.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Will Deacon [Thu, 25 Oct 2012 01:13:54 +0000 (12:13 +1100)]
rbtree: include linux/compiler.h for definition of __always_inline
rb_erase_augmented() is a static function annotated with __always_inline.
This causes a compile failure when attempting to use the rbtree
implementation as a library (e.g. kvm tool):
rbtree_augmented.h:125:24: error: expected `=', `,', `;', `asm' or `__attribute__' before `void'
Include linux/compiler.h in rbtree_augmented.h so that the __always_inline
macro is resolved correctly.
Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Pekka Enberg <penberg@kernel.org> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
genalloc: stop crashing the system when destroying a pool
The genalloc code uses the bitmap API from include/linux/bitmap.h and
lib/bitmap.c, which is based on long values. Both bitmap_set from
lib/bitmap.c and bitmap_set_ll, which is the lockless version from
genalloc.c, use BITMAP_LAST_WORD_MASK to set the first bits in a long in
the bitmap.
That one uses (1 << bits) - 1, 0b111, if you are setting the first three
bits. This means that the API counts from the least significant bits
(LSB from now on) to the MSB. The LSB in the first long is bit 0, then.
The same works for the lookup functions.
The genalloc code uses longs for the bitmap, as it should. In
include/linux/genalloc.h, struct gen_pool_chunk has unsigned long
bits[0] as its last member. When allocating the struct, genalloc should
reserve enough space for the bitmap. This should be a proper number of
longs that can fit the amount of bits in the bitmap.
However, genalloc allocates an integer number of bytes that fit the
amount of bits, but may not be an integer amount of longs. 9 bytes, for
example, could be allocated for 70 bits.
This is a problem in itself if the Least Significat Bit in a long is in
the byte with the largest address, which happens in Big Endian machines.
This means genalloc is not allocating the byte in which it will try to
set or check for a bit.
This may end up in memory corruption, where genalloc will try to set the
bits it has not allocated. In fact, genalloc may not set these bits
because it may find them already set, because they were not zeroed
since they were not allocated. And that's what causes a BUG when
gen_pool_destroy is called and check for any set bits.
What really happens is that genalloc uses kmalloc_node with __GFP_ZERO
on gen_pool_add_virt. With SLAB and SLUB, this means the whole slab will
be cleared, not only the requested bytes. Since struct gen_pool_chunk
has a size that is a multiple of 8, and slab sizes are multiples of 8,
we get lucky and allocate and clear the right amount of bytes.
Hower, this is not the case with SLOB or with older code that did memset
after allocating instead of using __GFP_ZERO.
So, a simple module as this (running 3.6.0), will cause a crash when
rmmod'ed.
Jingoo Han [Thu, 25 Oct 2012 01:13:54 +0000 (12:13 +1100)]
backlight: ili9320: add missing SPI dependency
Add this missing SPI dependency and prevent the driver from building
without SPI, because functions of the spi driver are used in this driver.
drivers/video/backlight/ili9320.c:51: undefined reference to `spi_sync'
Also, a prompt string for CONFIG_LCD_ILI9320 is added for explicit
selection.
Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Aristeu Rozanski [Thu, 25 Oct 2012 01:13:53 +0000 (12:13 +1100)]
device_cgroup: stop using simple_strtoul()
Convert the code to use kstrtou32() instead of simple_strtoul() which is
deprecated. The real size of the variables are u32, so use kstrtou32
instead of kstrtoul
Signed-off-by: Aristeu Rozanski <aris@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: James Morris <jmorris@namei.org> Cc: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Aristeu Rozanski [Thu, 25 Oct 2012 01:13:53 +0000 (12:13 +1100)]
device_cgroup: rename deny_all to behavior
This was done in a v2 patch but v1 ended up being committed. The variable
name is less confusing and stores the default behavior when no matching
exception exists.
Signed-off-by: Aristeu Rozanski <aris@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: James Morris <jmorris@namei.org> Cc: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jiri Slaby [Thu, 25 Oct 2012 01:13:52 +0000 (12:13 +1100)]
cgroup: fix invalid rcu dereference
Commit ad676077a2ae ("device_cgroup: convert device_cgroup internally to
policy + exceptions") removed rcu locks which are needed in task_devcgroup
called in this chain: devcgroup_inode_mknod OR
__devcgroup_inode_permission -> __devcgroup_inode_permission ->
task_devcgroup -> task_subsys_state -> task_subsys_state_check.
Change the code so that task_devcgroup is safely called with rcu read
lock held.
Jan Kara [Thu, 25 Oct 2012 01:13:52 +0000 (12:13 +1100)]
mm: fix XFS oops due to dirty pages without buffers on s390
On s390 any write to a page (even from kernel itself) sets architecture
specific page dirty bit. Thus when a page is written to via buffered
write, HW dirty bit gets set and when we later map and unmap the page,
page_remove_rmap() finds the dirty bit and calls set_page_dirty().
Dirtying of a page which shouldn't be dirty can cause all sorts of
problems to filesystems. The bug we observed in practice is that buffers
from the page get freed, so when the page gets later marked as dirty and
writeback writes it, XFS crashes due to an assertion
BUG_ON(!PagePrivate(page)) in page_buffers() called from
xfs_count_page_state().
Similar problem can also happen when zero_user_segment() call from
xfs_vm_writepage() (or block_write_full_page() for that matter) set the
hardware dirty bit during writeback, later buffers get freed, and then
page unmapped.
Fix the issue by ignoring s390 HW dirty bit for page cache pages of
mappings with mapping_cap_account_dirty(). This is safe because for such
mappings when a page gets marked as writeable in PTE it is also marked
dirty in do_wp_page() or do_page_fault(). When the dirty bit is cleared
by clear_page_dirty_for_io(), the page gets writeprotected in
page_mkclean(). So pagecache page is writeable if and only if it is
dirty.
Thanks to Hugh Dickins for pointing out mapping has to have
mapping_cap_account_dirty() for things to work and proposing a cleaned up
variant of the patch.
The patch has survived about two hours of running fsx-linux on tmpfs while
heavily swapping and several days of running on out build machines where
the original problem was triggered.
Signed-off-by: Jan Kara <jack@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: <stable@vger.kernel.org> [3.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log