linux-stable.git/include, branch v3.15.4

tracing: Fix syscall_*regfunc() vs copy_process() race

2014-07-07T01:59:12+00:00

commit 4af4206be2bd1933cae20c2b6fb2058dbc887f7c upstream.

syscall_regfunc() and syscall_unregfunc() should set/clear
TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race
with copy_process() and miss the new child which was not added to
the process/thread lists yet.

Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT
under tasklist.

Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com

Fixes: a871bd33a6c0 "tracing: Add syscall tracepoints"
Acked-by: Frederic Weisbecker 
Acked-by: Paul E. McKenney 
Signed-off-by: Oleg Nesterov 
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

ptrace,x86: force IRET path after a ptrace_stop()

2014-07-07T01:59:12+00:00

commit b9cd18de4db3c9ffa7e17b0dc0ca99ed5aa4d43a upstream.

The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values.  That is
very much part of why it's faster than 'iret'.

Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.

However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'.  Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.

Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().

Signed-off-by: Tejun Heo 
Reported-by: Andy Lutomirski 
Acked-by: Oleg Nesterov 
Suggested-by: Linus Torvalds 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Clearly distinguish mgmt LTK type from authenticated property

2014-07-01T03:14:03+00:00

commit d7b2545023ecfde94d3ea9c03c5480ac18da96c9 upstream.

On the mgmt level we have a key type parameter which currently accepts
two possible values: 0x00 for unauthenticated and 0x01 for
authenticated. However, in the internal struct smp_ltk representation we
have an explicit "authenticated" boolean value.

To make this distinction clear, add defines for the possible mgmt values
and do conversion to and from the internal authenticated value.

Signed-off-by: Johan Hedberg 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

genirq: Sanitize spurious interrupt detection of threaded irqs

2014-07-01T03:14:01+00:00

commit 1e77d0a1ed7417d2a5a52a7b8d32aea1833faa6c upstream.

Till reported that the spurious interrupt detection of threaded
interrupts is broken in two ways:

- note_interrupt() is called for each action thread of a shared
  interrupt line. That's wrong as we are only interested whether none
  of the device drivers felt responsible for the interrupt, but by
  calling multiple times for a single interrupt line we account
  IRQ_NONE even if one of the drivers felt responsible.

- note_interrupt() when called from the thread handler is not
  serialized. That leaves the members of irq_desc which are used for
  the spurious detection unprotected.

To solve this we need to defer the spurious detection of a threaded
interrupt to the next hardware interrupt context where we have
implicit serialization.

If note_interrupt is called with action_ret == IRQ_WAKE_THREAD, we
check whether the previous interrupt requested a deferred check. If
not, we request a deferred check for the next hardware interrupt and
return.

If set, we check whether one of the interrupt threads signaled
success. Depending on this information we feed the result into the
spurious detector.

If one primary handler of a shared interrupt returns IRQ_HANDLED we
disable the deferred check of irq threads on the same line, as we have
found at least one device driver who cared.

Reported-by: Till Straumann 
Signed-off-by: Thomas Gleixner 
Tested-by: Austin Schuh 
Cc: Oliver Hartkopp 
Cc: Wolfgang Grandegger 
Cc: Pavel Pisa 
Cc: Marc Kleine-Budde 
Cc: linux-can@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1303071450130.22263@ionos
Signed-off-by: Greg Kroah-Hartman

scsi_cmnd: Introduce scsi_transfer_length helper

2014-07-01T03:14:00+00:00

commit 8846bab180fa2bcfe02d4ba5288fbaba12c8f4f3 upstream.

In case protection information exists on the wire
scsi transports should include it in the transfer
byte count (even if protection information does not
exist in the host memory space). This helper will
compute the total transfer length from the scsi
command data length and protection attributes.

Signed-off-by: Sagi Grimberg 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Report correct response length for some commands

2014-07-01T03:14:00+00:00

commit 2426bd456a61407388b6e61fc5f98dbcbebc50e2 upstream.

When an initiator sends an allocation length bigger than what its
command consumes, the target should only return the actual response data
and set the residual length to the unused part of the allocation length.

Add a helper function that command handlers (INQUIRY, READ CAPACITY,
etc) can use to do this correctly, and use this code to get the correct
residual for commands that don't use the full initiator allocation in the
handlers for READ CAPACITY, READ CAPACITY(16), INQUIRY, MODE SENSE and
REPORT LUNS.

This addresses a handful of failures as reported by Christophe with
the Windows Certification Kit:

  http://permalink.gmane.org/gmane.linux.scsi.target.devel/6515

Signed-off-by: Roland Dreier 
Tested-by: Christophe Vu-Brugier 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

Target/iscsi: Fix sendtargets response pdu for iser transport

2014-07-01T03:14:00+00:00

commit 22c7aaa57e80853b4904a46c18f97db0036a3b97 upstream.

In case the transport is iser we should not include the
iscsi target info in the sendtargets text response pdu.
This causes sendtargets response to include the target
info twice.

Modify iscsit_build_sendtargets_response to filter
transport types that don't match.

Signed-off-by: Sagi Grimberg 
Reported-by: Slava Shwartsman 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

ACPI: add dynamic_debug support

2014-07-01T03:13:58+00:00

commit 45fef5b88d1f2f47ecdefae6354372d440ca5c84 upstream.

Commit 1a699476e258 ("ACPI / hotplug / PCI: Hotplug notifications
from acpi_bus_notify()") added debug messages for a few common
events. These debug messages are unconditionally enabled if
CONFIG_DYNAMIC_DEBUG is defined, contrary to the documented
meaning, making the ACPI system spew lots of unwanted noise on
any kernel with dynamic debugging.

The bug was introduced by commit fbfddae69657 ("ACPI: Add
acpi_handle_() interfaces"), which added the
CONFIG_DYNAMIC_DEBUG dependency without respecting its meaning.

Fix by adding real support for dynamic_debug.

Fixes: fbfddae69657 ("ACPI: Add acpi_handle_() interfaces")
Signed-off-by: Bjørn Mork 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

ext4: fix data integrity sync in ordered mode

2014-07-01T03:13:56+00:00

commit 1c8349a17137b93f0a83f276c764a6df1b9a116e upstream.

When we perform a data integrity sync we tag all the dirty pages with
PAGECACHE_TAG_TOWRITE at start of ext4_da_writepages.  Later we check
for this tag in write_cache_pages_da and creates a struct
mpage_da_data containing contiguously indexed pages tagged with this
tag and sync these pages with a call to mpage_da_map_and_submit.  This
process is done in while loop until all the PAGECACHE_TAG_TOWRITE
pages are synced. We also do journal start and stop in each iteration.
journal_stop could initiate journal commit which would call
ext4_writepage which in turn will call ext4_bio_write_page even for
delayed OR unwritten buffers. When ext4_bio_write_page is called for
such buffers, even though it does not sync them but it clears the
PAGECACHE_TAG_TOWRITE of the corresponding page and hence these pages
are also not synced by the currently running data integrity sync. We
will end up with dirty pages although sync is completed.

This could cause a potential data loss when the sync call is followed
by a truncate_pagecache call, which is exactly the case in
collapse_range.  (It will cause generic/127 failure in xfstests)

To avoid this issue, we can use set_page_writeback_keepwrite instead of
set_page_writeback, which doesn't clear TOWRITE tag.

Signed-off-by: Namjae Jeon 
Signed-off-by: Ashish Sangwan 
Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

ptrace: fix fork event messages across pid namespaces

2014-07-01T03:13:55+00:00

commit 4e52365f279564cef0ddd41db5237f0471381093 upstream.

When tracing a process in another pid namespace, it's important for fork
event messages to contain the child's pid as seen from the tracer's pid
namespace, not the parent's.  Otherwise, the tracer won't be able to
correlate the fork event with later SIGTRAP signals it receives from the
child.

We still risk a race condition if a ptracer from a different pid
namespace attaches after we compute the pid_t value.  However, sending a
bogus fork event message in this unlikely scenario is still a vast
improvement over the status quo where we always send bogus fork event
messages to debuggers in a different pid namespace than the forking
process.

Signed-off-by: Matthew Dempsky 
Acked-by: Oleg Nesterov 
Cc: Kees Cook 
Cc: Julien Tinnes 
Cc: Roland McGrath 
Cc: Jan Kratochvil 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman