linux-toradex.git/include/linux, branch v3.2.6

usb: ch9.h: usb_endpoint_maxp() uses __le16_to_cpu()

2012-02-13T19:17:03+00:00

commit 9c0a835a9d9aed41bcf9c287f5069133a6e2a87b upstream.

The usb/ch9.h will be installed to /usr/include/linux,
and be used from user space.
But le16_to_cpu() is only defined for kernel code.
Without this patch, user space compile will be broken.
Special thanks to Stefan Becker

Reported-by: Stefan Becker 
Signed-off-by: Kuninori Morimoto 
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman

PM / QoS: CPU C-state breakage with PM Qos change

2012-02-13T19:16:55+00:00

commit d020283dc694c9ec31b410f522252f7a8397e67d upstream.

Looks like change "PM QoS: Move and rename the implementation files"
merged during the 3.2 development cycle made PM QoS depend on
CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME).

That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs
to spend time in Polling loop idle instead of going into deep C-states,
consuming way way more power. This is with either acpi idle or intel idle
enabled.

Either CONFIG_PM should be enabled with any pm_qos users or
the !CONFIG_PM pm_qos_request() should return sane defaults not to break
the existing users. Here's is the patch for the latter option.

[rjw: Modified the changelog slightly.]

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: Fix s2disk regression related to freezing workqueues

2012-02-13T19:16:55+00:00

commit 181e9bdef37bfcaa41f3ab6c948a2a0d60a268b5 upstream.

Commit 2aede851ddf08666f68ffc17be446420e9d2a056

  PM / Hibernate: Freeze kernel threads after preallocating memory

introduced a mechanism by which kernel threads were frozen after
the preallocation of hibernate image memory to avoid problems with
frozen kernel threads not responding to memory freeing requests.
However, it overlooked the s2disk code path in which the
SNAPSHOT_CREATE_IMAGE ioctl was run directly after SNAPSHOT_FREE,
which caused freeze_workqueues_begin() to BUG(), because it saw
that worqueues had been already frozen.

Although in principle this issue might be addressed by removing
the relevant BUG_ON() from freeze_workqueues_begin(), that would
reintroduce the very problem that commit 2aede851ddf08666f68ffc17be4
attempted to avoid into that particular code path.  For this reason,
to fix the issue at hand, introduce thaw_kernel_threads() and make
the SNAPSHOT_FREE ioctl execute it.

Special thanks to Srivatsa S. Bhat for detailed analysis of the
problem.

Reported-and-tested-by: Jiri Slaby 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Srivatsa S. Bhat 
Signed-off-by: Greg Kroah-Hartman

PCI: Rework ASPM disable code

2012-02-06T17:41:06+00:00

commit 3c076351c4027a56d5005a39a0b518a4ba393ce2 upstream.

Right now we forcibly clear ASPM state on all devices if the BIOS indicates
that the feature isn't supported. Based on the Microsoft presentation
"PCI Express In Depth for Windows Vista and Beyond", I'm starting to think
that this may be an error. The implication is that unless the platform
grants full control via _OSC, Windows will not touch any PCIe features -
including ASPM. In that case clearing ASPM state would be an error unless
the platform has granted us that control.

This patch reworks the ASPM disabling code such that the actual clearing
of state is triggered by a successful handoff of PCIe control to the OS.
The general ASPM code undergoes some changes in order to ensure that the
ability to clear the bits isn't overridden by ASPM having already been
disabled. Further, this theoretically now allows for situations where
only a subset of PCIe roots hand over control, leaving the others in the
BIOS state.

It's difficult to know for sure that this is the right thing to do -
there's zero public documentation on the interaction between all of these
components. But enough vendors enable ASPM on platforms and then set this
bit that it seems likely that they're expecting the OS to leave them alone.

Measured to save around 5W on an idle Thinkpad X220.

Signed-off-by: Matthew Garrett 
Signed-off-by: Jesse Barnes 
Signed-off-by: Greg Kroah-Hartman

SHM_UNLOCK: fix Unevictable pages stranded after swap

2012-01-26T00:13:59+00:00

commit 245132643e1cfcd145bbc86a716c1818371fcb93 upstream.

Commit cc39c6a9bbde ("mm: account skipped entries to avoid looping in
find_get_pages") correctly fixed an infinite loop; but left a problem
that find_get_pages() on shmem would return 0 (appearing to callers to
mean end of tree) when it meets a run of nr_pages swap entries.

The only uses of find_get_pages() on shmem are via pagevec_lookup(),
called from invalidate_mapping_pages(), and from shmctl SHM_UNLOCK's
scan_mapping_unevictable_pages().  The first is already commented, and
not worth worrying about; but the second can leave pages on the
Unevictable list after an unusual sequence of swapping and locking.

Fix that by using shmem_find_get_pages_and_swap() (then ignoring the
swap) instead of pagevec_lookup().

But I don't want to contaminate vmscan.c with shmem internals, nor
shmem.c with LRU locking.  So move scan_mapping_unevictable_pages() into
shmem.c, renaming it shmem_unlock_mapping(); and rename
check_move_unevictable_page() to check_move_unevictable_pages(), looping
down an array of pages, oftentimes under the same lock.

Leave out the "rotate unevictable list" block: that's a leftover from
when this was used for /proc/sys/vm/scan_unevictable_pages, whose flawed
handling involved looking at pages at tail of LRU.

Was there significance to the sequence first ClearPageUnevictable, then
test page_evictable, then SetPageUnevictable here? I think not, we're
under LRU lock, and have no barriers between those.

Signed-off-by: Hugh Dickins 
Reviewed-by: KOSAKI Motohiro 
Cc: Minchan Kim 
Cc: Rik van Riel 
Cc: Shaohua Li 
Cc: Eric Dumazet 
Cc: Johannes Weiner 
Cc: Michel Lespinasse 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

block: fail SCSI passthrough ioctls on partition devices

2012-01-26T00:13:42+00:00

commit 0bfc96cb77224736dfa35c3c555d37b3646ef35e upstream.

[ Changes with respect to 3.3: return -ENOTTY from scsi_verify_blk_ioctl
  and -ENOIOCTLCMD from sd_compat_ioctl. ]

Linux allows executing the SG_IO ioctl on a partition or LVM volume, and
will pass the command to the underlying block device.  This is
well-known, but it is also a large security problem when (via Unix
permissions, ACLs, SELinux or a combination thereof) a program or user
needs to be granted access only to part of the disk.

This patch lets partitions forward a small set of harmless ioctls;
others are logged with printk so that we can see which ioctls are
actually sent.  In my tests only CDROM_GET_CAPABILITY actually occurred.
Of course it was being sent to a (partition on a) hard disk, so it would
have failed with ENOTTY and the patch isn't changing anything in
practice.  Still, I'm treating it specially to avoid spamming the logs.

In principle, this restriction should include programs running with
CAP_SYS_RAWIO.  If for example I let a program access /dev/sda2 and
/dev/sdb, it still should not be able to read/write outside the
boundaries of /dev/sda2 independent of the capabilities.  However, for
now programs with CAP_SYS_RAWIO will still be allowed to send the
ioctls.  Their actions will still be logged.

This patch does not affect the non-libata IDE driver.  That driver
however already tests for bd != bd->bd_contains before issuing some
ioctl; it could be restricted further to forbid these ioctls even for
programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO.

Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe 
Cc: James Bottomley 
Signed-off-by: Paolo Bonzini 
[ Make it also print the command name when warning - Linus ]
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

block: add and use scsi_blk_cmd_ioctl

2012-01-26T00:13:42+00:00

commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream.

Introduce a wrapper around scsi_cmd_ioctl that takes a block device.

The function will then be enhanced to detect partition block devices
and, in that case, subject the ioctls to whitelisting.

Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe 
Cc: James Bottomley 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fix shrink_dcache_parent() livelock

2012-01-26T00:13:35+00:00

commit eaf5f9073533cde21c7121c136f1c3f072d9cf59 upstream.

Two (or more) concurrent calls of shrink_dcache_parent() on the same dentry may
cause shrink_dcache_parent() to loop forever.

Here's what appears to happen:

1 - CPU0: select_parent(P) finds C and puts it on dispose list, returns 1

2 - CPU1: select_parent(P) locks P->d_lock

3 - CPU0: shrink_dentry_list() locks C->d_lock
   dentry_kill(C) tries to lock P->d_lock but fails, unlocks C->d_lock

4 - CPU1: select_parent(P) locks C->d_lock,
         moves C from dispose list being processed on CPU0 to the new
dispose list, returns 1

5 - CPU0: shrink_dentry_list() finds dispose list empty, returns

6 - Goto 2 with CPU0 and CPU1 switched

Basically select_parent() steals the dentry from shrink_dentry_list() and thinks
it found a new one, causing shrink_dentry_list() to think it's making progress
and loop over and over.

One way to trigger this is to make udev calls stat() on the sysfs file while it
is going away.

Having a file in /lib/udev/rules.d/ with only this one rule seems to the trick:

ATTR{vendor}=="0x8086", ATTR{device}=="0x10ca", ENV{PCI_SLOT_NAME}="%k", ENV{MATCHADDR}="$attr{address}", RUN+="/bin/true"

Then execute the following loop:

while true; do
        echo -bond0 > /sys/class/net/bonding_masters
        echo +bond0 > /sys/class/net/bonding_masters
        echo -bond1 > /sys/class/net/bonding_masters
        echo +bond1 > /sys/class/net/bonding_masters
done

One fix would be to check all callers and prevent concurrent calls to
shrink_dcache_parent().  But I think a better solution is to stop the
stealing behavior.

This patch adds a new dentry flag that is set when the dentry is added to the
dispose list.  The flag is cleared in dentry_lru_del() in case the dentry gets a
new reference just before being pruned.

If the dentry has this flag, select_parent() will skip it and let
shrink_dentry_list() retry pruning it.  With select_parent() skipping those
dentries there will not be the appearance of progress (new dentries found) when
there is none, hence shrink_dcache_parent() will not loop forever.

Set the flag is also set in prune_dcache_sb() for consistency as suggested by
Linus.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

svcrpc: destroy server sockets all at once

2012-01-26T00:13:31+00:00

commit 2fefb8a09e7ed251ae8996e0c69066e74c5aa560 upstream.

There's no reason I can see that we need to call sv_shutdown between
closing the two lists of sockets.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy()

2012-01-26T00:13:29+00:00

commit 6c06108be53ca5e94d8b0e93883d534dd9079646 upstream.

If ctrls->count is too high the multiplication could overflow and
array_size would be lower than expected.  Mauro and Hans Verkuil
suggested that we cap it at 1024.  That comes from the maximum
number of controls with lots of room for expantion.

$ grep V4L2_CID include/linux/videodev2.h | wc -l
211

Signed-off-by: Dan Carpenter 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman