linux-toradex.git, branch v2.6.27.59

Linux 2.6.27.59

2011-04-30T14:53:51+00:00

mptsas: fix hangs caused by ATA pass-through

2011-04-30T14:53:40+00:00

commit 2a1b7e575b80ceb19ea50bfa86ce0053ea57181d upstream.

I may have an explanation for the LSI 1068 HBA hangs provoked by ATA
pass-through commands, in particular by smartctl.

First, my version of the symptoms.  On an LSI SAS1068E B3 HBA running
01.29.00.00 firmware, with SATA disks, and with smartd running, I'm seeing
occasional task, bus, and host resets, some of which lead to hard faults of
the HBA requiring a reboot.  Abusively looping the smartctl command,

    # while true; do smartctl -a /dev/sdb > /dev/null; done

dramatically increases the frequency of these failures to nearly one per
minute.  A high IO load through the HBA while looping smartctl seems to
improve the chance of a full scsi host reset or a non-recoverable hang.

I reduced what smartctl was doing down to a simple test case which
causes the hang with a single IO when pointed at the sd interface.  See
the code at the bottom of this e-mail.  It uses an SG_IO ioctl to issue
a single pass-through ATA identify device command.  If the buffer
userspace gives for the read data has certain alignments, the task is
issued to the HBA but the HBA fails to respond.  If run against the sg
interface, neither the test code nor smartctl causes a hang.

sd and sg handle the SG_IO ioctl slightly differently.  Unless you
specifically set a flag to do direct IO, sg passes a buffer of its own,
which is page-aligned, to the block layer and later copies the result
into the userspace buffer regardless of its alignment.  sd, on the other
hand, always does direct IO unless the userspace buffer fails an
alignment test at block/blk-map.c line 57, in which case a page-aligned
buffer is created and used for the transfer.

The alignment test currently checks for word-alignment, the default
setup by scsi_lib.c; therefore, userspace buffers of almost any
alignment are given directly to the HBA as DMA targets.  The LSI 1068
hardware doesn't seem to like at least a couple of the alignments which
cross a page boundary (see the test code below).  Curiously, many
page-boundary-crossing alignments do work just fine.

So, either the hardware has an bug handling certain alignments or the
hardware has a stricter alignment requirement than the driver is
advertising.  If stricter alignment is required, then in no case should
misaligned buffers from userspace be allowed through without being
bounced or at least causing an error to be returned.

It seems the mptsas driver could use blk_queue_dma_alignment() to advertise
a stricter alignment requirement.  If it does, sd does the right thing and
bounces misaligned buffers (see block/blk-map.c line 57).  The following
patch to 2.6.34-rc5 makes my symptoms go away.  I'm sure this is the wrong
place for this code, but it gets my idea across.

Acked-by: "Desai Kashyap" 
Signed-off-by: James Bottomley

net: Fix oops from tcp_collapse() when using splice()

2011-04-30T14:53:40+00:00

commit baff42ab1494528907bf4d5870359e31711746ae upstream.

tcp_read_sock() can have a eat skbs without immediately advancing copied_seq.
This can cause a panic in tcp_collapse() if it is called as a result
of the recv_actor dropping the socket lock.

A userspace program that splices data from a socket to either another
socket or to a file can trigger this bug.

Signed-off-by: Steven J. Magnani 
Signed-off-by: David S. Miller

net: ax25: fix information leak to userland harder

2011-04-30T14:53:40+00:00

commit 5b919f833d9d60588d026ad82d17f17e8872c7a9 upstream.

Commit fe10ae53384e48c51996941b7720ee16995cbcb7 adds a memset() to clear
the structure being sent back to userspace, but accidentally used the
wrong size.

Reported-by: Brad Spengler 
Signed-off-by: Kees Cook 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

USB: EHCI: unlink unused QHs when the controller is stopped

2011-04-30T14:53:39+00:00

commit 94ae4976e253757e9b03a44d27d41b20f1829d80 upstream.

This patch (as1458) fixes a problem affecting ultra-reliable systems:
When hardware failover of an EHCI controller occurs, the data
structures do not get released correctly.  This is because the routine
responsible for removing unused QHs from the async schedule assumes
the controller is running properly (the frame counter is used in
determining how long the QH has been idle) -- but when a failover
causes the controller to be electronically disconnected from the PCI
bus, obviously it stops running.

The solution is simple: Allow scan_async() to remove a QH from the
async schedule if it has been idle for long enough _or_ if the
controller is stopped.

Signed-off-by: Alan Stern 
Reported-and-Tested-by: Dan Duval 
Signed-off-by: Greg Kroah-Hartman

proc: do proper range check on readdir offset

2011-04-30T14:53:38+00:00

commit d8bdc59f215e62098bc5b4256fd9928bf27053a1 upstream.

Rather than pass in some random truncated offset to the pid-related
functions, check that the offset is in range up-front.

This is just cleanup, the previous commit fixed the real problem.

Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

next_pidmap: fix overflow condition

2011-04-30T14:53:38+00:00

commit c78193e9c7bcbf25b8237ad0dec82f805c4ea69b upstream.

next_pidmap() just quietly accepted whatever 'last' pid that was passed
in, which is not all that safe when one of the users is /proc.

Admittedly the proc code should do some sanity checking on the range
(and that will be the next commit), but that doesn't mean that the
helper functions should just do that pidmap pointer arithmetic without
checking the range of its arguments.

So clamp 'last' to PID_MAX_LIMIT.  The fact that we then do "last+1"
doesn't really matter, the for-loop does check against the end of the
pidmap array properly (it's only the actual pointer arithmetic overflow
case we need to worry about, and going one bit beyond isn't going to
overflow).

[ Use PID_MAX_LIMIT rather than pid_max as per Eric Biederman ]

Reported-by: Tavis Ormandy 
Analyzed-by: Robert Święcki 
Cc: Eric W. Biederman 
Cc: Pavel Emelyanov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

UBIFS: fix oops when R/O file-system is fsync'ed

2011-04-30T14:53:38+00:00

commit 78530bf7f2559b317c04991b52217c1608d5a58d upstream.

This patch fixes severe UBIFS bug: UBIFS oopses when we 'fsync()' an
file on R/O-mounter file-system. We (the UBIFS authors) incorrectly
thought that VFS would not propagate 'fsync()' down to the file-system
if it is read-only, but this is not the case.

It is easy to exploit this bug using the following simple perl script:

use strict;
use File::Sync qw(fsync sync);

die "File path is not specified" if not defined $ARGV[0];
my $path = $ARGV[0];

open FILE, "<", "$path" or die "Cannot open $path: $!";
fsync(\*FILE) or die "cannot fsync $path: $!";
close FILE or die "Cannot close $path: $!";

Thanks to Reuben Dowle  for reporting about this
issue.

Signed-off-by: Artem Bityutskiy 
Reported-by: Reuben Dowle 
Signed-off-by: Greg Kroah-Hartman

MAINTAINERS: update STABLE BRANCH info

2011-04-30T14:53:38+00:00

commit d00ebeac5f24f290636f7a895dafc124b2930a08 upstream.

Drop Chris Wright from STABLE maintainers.  He hasn't done STABLE release
work for quite some time.

Signed-off-by: Randy Dunlap 
Acked-by: Chris Wright 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

nommu: ramfs: pages allocated to an inode's pagecache may get wrongly discarded

2011-04-30T14:53:37+00:00

commit 020fe22ff14320927f394de222cbb11708bcc7a8 upstream.

The pages attached to a ramfs inode's pagecache by truncation from nothing
- as done by SYSV SHM for example - may get discarded under memory
pressure.

The problem is that the pages are not marked dirty.  Anything that creates
data in an MMU-based ramfs will cause the pages holding that data will
cause the set_page_dirty() aop to be called.

For the NOMMU-based mmap, set_page_dirty() may be called by write(), but
it won't be called by page-writing faults on writable mmaps, and it isn't
called by ramfs_nommu_expand_for_mapping() when a file is being truncated
from nothing to allocate a contiguous run.

The solution is to mark the pages dirty at the point of allocation by the
truncation code.

Signed-off-by: Enrik Berkhan 
Signed-off-by: David Howells 
Cc: Peter Zijlstra 
Cc: Nick Piggin 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds