Changes to the base kprobes infrastructure to use RCU for synchronization
during kprobe registration and unregistration.  These changes coupled with the
arch kprobe changes (next in series):

a. serialize registration and unregistration of kprobes.
b. enable lockless execution of handlers. Handlers can now run in parallel.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

x86_64 changes to track kprobe execution on a per-cpu basis.  We now track the
kprobe state machine independently on each cpu using a arch specific kprobe
control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Sparc64 changes to track kprobe execution on a per-cpu basis.  We now track
the kprobe state machine independently on each cpu using an arch specific
kprobe control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

PPC64 changes to track kprobe execution on a per-cpu basis.  We now track the
kprobe state machine independently on each cpu using an arch specific kprobe
control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

IA64 changes to track kprobe execution on a per-cpu basis.  We now track the
kprobe state machine independently on each cpu using an arch specific kprobe
control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I386 changes to track kprobe execution on a per-cpu basis.  We now track the
kprobe state machine independently on each cpu, using an arch specific kprobe
control block.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Changes to the base kprobe infrastructure to track kprobe execution on a
per-cpu basis.
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The following set of patches are aimed at improving kprobes scalability.  We
currently serialize kprobe registration, unregistration and handler execution
using a single spinlock - kprobe_lock.

With these changes, kprobe handlers can run without any locks held.  It also
allows for simultaneous kprobe handler executions on different processors as
we now track kprobe execution on a per processor basis.  It is now necessary
that the handlers be re-entrant since handlers can run concurrently on
multiple processors.

All changes have been tested on i386, ia64, ppc64 and x86_64, while sparc64
has been compile tested only.

The patches can be viewed as 3 logical chunks:

patch 1: 	Reorder preempt_(dis/en)able calls
patches 2-7: 	Introduce per_cpu data areas to track kprobe execution
patches 8-9: 	Use RCU to synchronize kprobe (un)registration and handler
		execution.

Thanks to Maneesh Soni, James Keniston and Anil Keshavamurthy for their
review and suggestions. Thanks again to Anil, Hien Nguyen and Kevin Stafford
for testing the patches.

This patch:

Reorder preempt_disable/enable() calls in arch kprobes files in preparation to
introduce locking changes.  No functional changes introduced by this patch.
Signed-off-by: NAnanth N Mavinakayahanalli <ananth@in.ibm.com>
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If a panic came from the IPMI watchdog pretimeout and that was reported via
an NMI, it would also be reported via the standard IPMI flags, which would
get picked up when reporting panic events and cause another panic.  This
adds an atomic to avoid calling panic twice.
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use rcu_read_lock for the cmd_rcvrs list, since that was what what
intended, anyway.  This means that all the users of the cmd_rcvrs_lock are
tasks, so the irq disables are no longer required for that lock and it can
become a semaphore.
Signed-off-by: NCorey Minyard <minyard@acm.org>
Acked-by: N"Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Convert ipmi driver thread to kthread API, only sleep when interface is
idle.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Cc: Corey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We must poll for responses to commands when interrupts aren't in use.  The
default poll interval is based on using a kernel timer, which varies with HZ.
For character-based interfaces like KCS and SMIC though, that can be way too
slow (>15 minutes to flash a new firmware with KCS, >20 seconds to retrieve
the sensor list).

This creates a low-priority kernel thread to poll more often.  If the state
machine is idle, so is the kernel thread.  But if there's an active command,
it polls quite rapidly.  This decrease a firmware flash time from 15 minutes
to 1.5 minutes, and the sensor list time to 4.5 seconds, on a Dell PowerEdge
x8x system.

The timer-based polling remains, to ensure some amount of responsiveness even
under high user process CPU load.

Checking for a stopped timer at rmmod now uses atomics and del_timer_sync() to
ensure safe stoppage.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

BMCs can get into ERROR0 state while flashing new firmware, particularly while
the BMC is erasing the next flash block, which may take a just under 2 seconds
on a Dell PowerEdge 2800 (1.75 seconds typical), during which time the
single-threaded firmware may not be able to process new commands.  In
particular, clearing OBF may not take effect immediately.

We want it to delay in ERROR0 after clearing OBF a bit waiting for OBF to
actually be clear before proceeding.

This introduces a new return value from the LLDD's event loop,
SI_SM_CALL_WITH_TICK_DELAY.  This means the calling thread/timer should
schedule_timeout() at least 1 tick, rather than busy-wait.  This is a longer
delay than SI_SM_CALL_WITH_DELAY, which is typically a 250us busy-wait.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The current BT retry/reset mechanism fails to succeed on a PowerEdge 1650,
when the controller is wedged with B2H_ATN asserted at XACTION_START.  If this
occurs, no further commands will ever succeed unless the state of the
controller is first cleared out.

Furthermore, the soft reset would only occur if the first command after insmod
was the one that timed out, not if a later command timed out.

This patch changes the retry/reset mechanism to be as follows:

Before retrying a command, clear the state of the BT controller such that the
flags represent ready for a new transaction.  This increases the chance of
success of the restarted transaction.

After 2 retries, issue a soft reset and retry one more time before giving up
and reporting back a failure.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Acked-by: NRocky Craig <rocky.craig@hp.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some commands, on some system BMCs, don't respond at at all.  This is seen on
Dell PowerEdge x6xx and x7xx systems with IPMI 1.0 BT controllers when a "Get
SDR" command is issued, with a length field of 0x3A, which happens to be the
length of about SDR entries.  If another length is passed, this command
succeeds.

This patch adds general infrastructure for receiving commands before they're
passed down to the low-level drivers, such that they can be completed
immediately, or modified, prior to being sent to ->start_transaction().
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make SMIC driver ignore EVT_AVAIL and SMS_ATN bits in flags register, as
they're used by systems management interrupts, not the host OS.

Make the OEM0 Data Available handler work for pre-IPMI 1.5 systems from Dell
too.

Without these two fixes, PowerEdge 2650 and other similar systems with SMIC
may hang a process (modprobe or anything using /dev/ipmi0).
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make module_param and MODULE_PARAM_DESC agree on poweroff_powercycle name.

There was an extraneous ifdef in the IPMI poweroff code that prevented it from
working if PROC_FS was disabled.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Modify the IPMI watchdog parameters (the ones that make sense) to be exported
from sysfs.  This is somewhat complicated because these parameters have
side-effects that must be handled.
Signed-off-by: NCorey Minyard <minyard@acm.org>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A number of small changes for the various system interface drivers,
consolidated from a number of patches from Matt Domsch.

Clear B2H_ATN and drain the BMC message buffer on command timeout.  This
prevents further commands from failing after a timeout.

Add bt_debug and smic_debug module parameters, expose them in sysfs.  This
lets you enable and disable debugging messages at runtime.

Unsigned jiffies math in ipmi_si_intf.c causes a too-large value to be passed
to ->event() after jiffies wrap-around.  The BT driver had caught this, but
didn't know how to fix it.  Now all calls to ->event() use a sane value for
time.

Increase timeout for commands handed to the BT driver from 2 seconds to 5
seconds.  This is necessary particularly when the previous command was a
"Clear SEL", as that command completes, yet the BMC isn't really ready to
handle another command yet.

Silence BT debugging messages which were being printed on the console.

Increase SMIC timeout form 1/10s to 2s.  This is needed on Dell PowerEdge 2650
and PowerEdge 750 with ERA/O cards to allow commands to complete without
timing out.

Adds kcs_debug module param, to match behavior of BT and SMIC.  This also
prevents messages from being sent to the console unless explicitly requested.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch is rather large, but it really can't be done in smaller chunks
easily and I believe it is an important change.  This has been out and tested
for a while in the latest IPMI driver release.  There are no functional
changes, just changes as necessary to convert the locking over (and a few
minor style updates).

The IPMI driver uses read/write locks to ensure that things exist while they
are in use.  This is bad from a number of points of view.  This patch removes
the rwlocks and uses refcounts and RCU lists to manage what the locks did.
Signed-off-by: NCorey Minyard <minyard@acm.org>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce the notion of cooperating processes (those that submit requests
close to one another), and use these statistics to make better choices about
whether or not to do anticipatory waiting.

Help and analysis from Seetharami Seelam <seelam@cs.utep.edu>

Performance testing from Seelam:

I set up my system and executed a couple of tests that I used for OLS.  I
tested with AS, cooperative process patch merged in -mm tree (which I called
Nick, below) and the cooperative patch with modifications to as_update_iohist
(which I called Seelam).

I used a dual-processor (2.28GHz Pentium 4 Xeon) system, with 1 GB main memory
and 1 MB L2 cache, running Linux 2.6.9.  Only a single processor is used for
the experiments.  I used 7.2K RPM Maxtor 10GB drive configured with ext2 file
system.

Experiment 1 (ex1) consists of reading  one Linux source trees using

  find . -type f -exec cat '{}' ';' > /dev/null.

Experiment 2 (ex2) consists of reading two disjoint Linux source trees
using

  find . -type f -exec cat '{}' ';' > /dev/null.

Experiment 3 (ex3) consists of streaming read of a 2GB file in the background
and 1 instance of the chunk reads in Experiment 1.

Timings for reading the Linux source are shown below:

             AS                     Nick          Seelam
ex1:      0m25.813s               0m27.859s      0m27.640s
ex2:      1m11.468s               1m13.918s      1m5.869s
ex3:      81m44.352s             10m38.572s      6m47.994s

The difference between the numbers in Experiment 3 must be due to the code in
as_update_iohist.  (akpm: that's not part of this patch.  So this patch is
"Nick").
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch passes the file handle supplied in iattr to userspace, in case the
->setattr() was invoked from sys_ftruncate().  This solves the permission
checking (or lack thereof) in ftruncate() for the class of filesystems served
by an unprivileged userspace process.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds an atomic create+open operation.  This does not yet work if
the file type changes between lookup and create+open, but solves the
permission checking problems for the separte create and open methods.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add a new access call, which will only be called if ->permission is invoked
from sys_access().  In all other cases permission checking is delayed until
the actual filesystem operation.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Though the following changes are all backward compatible (from the kernel's as
well as the library's POV) change the minor version, so interested
applications can detect new features.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch extends the iattr structure with a file pointer memeber, and adds
an ATTR_FILE validity flag for this member.

This is set if do_truncate() is invoked from ftruncate() or from
do_coredump().

The change is source and binary compatible.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.

Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations.  For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NPaul Mackerras <paulus@samba.org>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Acked-By: NDavid Howells <dhowells@redhat.com>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Both AFFS and HPFS update the ctime and mtime in the write path, after
generic_file_write returned and marked the inode dirty.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NRoman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

afs actually had a write method that returned different errors depending on
whether some flag was set - better return the standard EINVAL errno.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

No need to duplicate a generic readonly file ops table in befs.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

No need to duplicate a generic readonly file ops table in befs.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch.  This should now allow not to include sched.h
from module.h, which is done by a followup patch.
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is a memory leak possible in dentry_open().  If get_empty_filp()
fails, then the references to dentry and mnt need to be released.  The
attached patch adds the calls to dput() and mntput() to release these two
references.
Signed-off-by: NPeter Staubach <staubach@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Updates to Documentation/vm/hugetlbpage.txt:

- there's no need to select HUGETLB_PAGE manually and it's no longer
  under the processor menu.  Update the text accordingly.

- fix typos and trim trailing whitespace.
Signed-Off-By: NMuli Ben-Yehuda <mulix@mulix.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Get rid of the `int unused' parameter of __find_get_block_slow().
Signed-off-by: NCoywolf Qi Hunt <qiyong@fc-cn.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Data allocated with "__getname()" should always be free'd with "__putname()"
because of the AUDITSYSCALL code.
Signed-off-by: NDavi Arnaut <davi.arnaut@gmail.com>
Cc: Urban Widmark <urban@teststation.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Data allocated with "__getname()" should always be free'd with "__putname()"
because of the AUDITSYSCALL code.
Signed-off-by: NDavi Arnaut <davi.arnaut@gmail.com>
Cc: <rminnich@lanl.gov>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- "extern inline" -> "static inline"

- every file should #include the headers containing the prototypes for
  it's global functions
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Mikael Pettersson <mikpe@csd.uu.se> noted that the current 2.6-git (and 2.4)
patch to disallow KDSKBSENT for unpriviledged users should be less restrictive
allowing reading of current function key string entry, but not writing.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The code for FUTEX_WAKE_OP calls an arch callback,
futex_atomic_op_inuser().  That callback can return an error code, but
currently the caller assumes any error is EFAULT, and will try various
things to resolve the fault before eventually giving up with EFAULT
(regardless of the original error code).  This is not a theoretical case -
arch callbacks currently return -ENOSYS if the opcode they are given is
bogus.

This patch alters the code to detect non-EFAULT errors and return them
directly to the user.

Of course, whether -ENOSYS is the correct return value for the bogus opcode
case, or whether EINVAL would be more appropriate is another question.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jamie Lokier <jamie@shareable.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>