openwrt/staging/blogic.git
11 years agoset_task_comm: kill the pointless memset() + wmb()
Oleg Nesterov [Tue, 30 Apr 2013 22:28:19 +0000 (15:28 -0700)]
set_task_comm: kill the pointless memset() + wmb()

set_task_comm() does memset() + wmb() before strlcpy().  This buys
nothing and to add to the confusion, the comment is wrong.

- We do not need memset() to be "safe from non-terminating string
  reads", the final char is always zero and we never change it.

- wmb() is paired with nothing, it cannot prevent from printing
  the mixture of the old/new data unless the reader takes the lock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agofs, proc: truncate /proc/pid/comm writes to first TASK_COMM_LEN bytes
David Rientjes [Tue, 30 Apr 2013 22:28:18 +0000 (15:28 -0700)]
fs, proc: truncate /proc/pid/comm writes to first TASK_COMM_LEN bytes

Currently, a write to a procfs file will return the number of bytes
successfully written.  If the actual string is longer than this, the
remainder of the string will not be be written and userspace will
complete the operation by issuing additional write()s.

Hence

$ echo -n "abcdefghijklmnopqrs" > /proc/self/comm

results in

$ cat /proc/$$/comm
pqrs

since the final four bytes were written with a second write() since
TASK_COMM_LEN == 16.  This is obviously an undesired result and not
equivalent to prctl(PR_SET_NAME).  The implementation should not need to
know the definition of TASK_COMM_LEN.

This patch truncates the string to the first TASK_COMM_LEN bytes and
returns the bytes written as the length of the string written so the
second write() is suppressed.

$ cat /proc/$$/comm
abcdefghijklmno

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: change wait_for_dump_helpers() to use wait_event_interruptible()
Oleg Nesterov [Tue, 30 Apr 2013 22:28:17 +0000 (15:28 -0700)]
coredump: change wait_for_dump_helpers() to use wait_event_interruptible()

wait_for_dump_helpers() calls wake_up/kill_fasync from inside the
wait_event-like loop.  This is not needed and in fact this is not
strictly correct, we can/should do this only once after we change
pipe->writers.  We could even check if it becomes zero.

Change this code to use use wait_event_interruptible(), this can also
help to make this wait freezable.

With this patch we check pipe->readers without pipe_lock(), this is
fine.  Once we see pipe->readers == 1 we know that the handler
decremented the counter, this is all we need.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: factor out the setting of PF_DUMPCORE
Oleg Nesterov [Tue, 30 Apr 2013 22:28:16 +0000 (15:28 -0700)]
coredump: factor out the setting of PF_DUMPCORE

Cleanup.  Every linux_binfmt->core_dump() sets PF_DUMPCORE, move this into
zap_threads() called by do_coredump().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: introduce dump_interrupted()
Oleg Nesterov [Tue, 30 Apr 2013 22:28:15 +0000 (15:28 -0700)]
coredump: introduce dump_interrupted()

By discussion with Mandeep.

Change dump_write(), dump_seek() and do_coredump() to check
signal_pending() and abort if it is true.  dump_seek() does this only
before f_op->llseek(), otherwise it relies on dump_write().

We need this change to ensure that the coredump won't delay suspend, and
to ensure it reacts to SIGKILL "quickly enough", a core dump can take a
lot of time.  In particular this can help oom-killer.

We add the new trivial helper, dump_interrupted() to add the comments and
to simplify the potential freezer changes.  Perhaps it will have more
callers.

Ideally it should do try_to_freeze() but then we need the unpleasant
changes in dump_write() and wait_for_dump_helpers().  It is not trivial to
change dump_write() to restart if f_op->write() fails because of
freezing().  We need to handle the short writes, we need to clear
TIF_SIGPENDING (and we can't rely on recalc_sigpending() unless we change
it to check PF_DUMPCORE).  And if the buggy f_op->write() sets
TIF_SIGPENDING we can not distinguish this case from the race with
freeze_task() + __thaw_task().

So we simply accept the fact that the freezer can truncate a core-dump but
at least you can reliably suspend.  Hopefully we can tolerate this
unlikely case and the necessary complications doesn't worth a trouble.
But if we decide to make the coredumping freezable later we can do this on
top of this change.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: sanitize the setting of signal->group_exit_code
Oleg Nesterov [Tue, 30 Apr 2013 22:28:13 +0000 (15:28 -0700)]
coredump: sanitize the setting of signal->group_exit_code

Now that the coredumping process can be SIGKILL'ed, the setting of
->group_exit_code in do_coredump() can race with complete_signal() and
SIGKILL or 0x80 can be "lost", or wait(status) can report status ==
SIGKILL | 0x80.

But the main problem is that it is not clear to me what should we do if
binfmt->core_dump() succeeds but SIGKILL was sent, that is why this patch
comes as a separate change.

This patch adds 0x80 if ->core_dump() succeeds and the process was not
killed.  But perhaps we can (should?) re-set ->group_exit_code changed by
SIGKILL back to "siginfo->si_signo |= 0x80" in case when core_dumped == T.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: ensure that SIGKILL always kills the dumping thread
Oleg Nesterov [Tue, 30 Apr 2013 22:28:12 +0000 (15:28 -0700)]
coredump: ensure that SIGKILL always kills the dumping thread

prepare_signal() blesses SIGKILL sent to the dumping process but this
signal can be "lost" anyway.  The problems is, complete_signal() sees
SIGNAL_GROUP_EXIT and skips the "kill them all" logic.  And even if the
dumping process is single-threaded (so the target is always "correct"),
the group-wide SIGKILL is not recorded in task->pending and thus
__fatal_signal_pending() won't be true.  A multi-threaded case has even
more problems.

And even ignoring all technical details, SIGNAL_GROUP_EXIT doesn't look
right to me.  This coredumping process is not exiting yet, it can do a lot
of work dumping the core.

With this patch the dumping process doesn't have SIGNAL_GROUP_EXIT, we set
signal->group_exit_task instead.  This makes signal_group_exit() true and
thus this should equally close the races with exit/exec/stop but allows to
kill the dumping thread reliably.

Notes:
- It is not clear what should we do with ->group_exit_code
  if the dumper was killed, see the next change.

- we need more (hopefully straightforward) changes to ensure
  that SIGKILL actually interrupts the coredump. Basically we
  need to check __fatal_signal_pending() in dump_write() and
  dump_seek().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: only SIGKILL should interrupt the coredumping task
Oleg Nesterov [Tue, 30 Apr 2013 22:28:10 +0000 (15:28 -0700)]
coredump: only SIGKILL should interrupt the coredumping task

There are 2 well known and ancient problems with coredump/signals, and a
lot of related bug reports:

- do_coredump() clears TIF_SIGPENDING but of course this can't help
  if, say, SIGCHLD comes after that.

  In this case the coredump can fail unexpectedly. See for example
  wait_for_dump_helper()->signal_pending() check but there are other
  reasons.

- At the same time, dumping a huge core on the slow media can take a
  lot of time/resources and there is no way to kill the coredumping
  task reliably. In particular this is not oom_kill-friendly.

This patch tries to fix the 1st problem, and makes the preparation for the
next changes.

We add the new SIGNAL_GROUP_COREDUMP flag set by zap_threads() to indicate
that this process dumps the core.  prepare_signal() checks this flag and
nacks any signal except SIGKILL.

Note that this check tries to be conservative, in the long term we should
probably treat the SIGNAL_GROUP_EXIT case equally but this needs more
discussion.  See marc.info/?l=linux-kernel&m=120508897917439

Notes:
- recalc_sigpending() doesn't check SIGNAL_GROUP_COREDUMP.
  The patch assumes that dump_write/etc paths should never
  call it, but we can change it as well.

- There is another source of TIF_SIGPENDING, freezer. This
  will be addressed separately.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokmod: remove call_usermodehelper_fns()
Lucas De Marchi [Tue, 30 Apr 2013 22:28:09 +0000 (15:28 -0700)]
kmod: remove call_usermodehelper_fns()

This function suffers from not being able to determine if the cleanup is
called in case it returns -ENOMEM.  Nobody is using it anymore, so let's
remove it.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agousermodehelper: split remaining calls to call_usermodehelper_fns()
Lucas De Marchi [Tue, 30 Apr 2013 22:28:07 +0000 (15:28 -0700)]
usermodehelper: split remaining calls to call_usermodehelper_fns()

These are the only users of call_usermodehelper_fns().  This function
suffers from not being able to determine if the cleanup is called.  Even
if in this places the cleanup pointer is NULL, convert them to use the
separate call_usermodehelper_setup() + call_usermodehelper_exec()
functions so we can remove the _fns variant.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocoredump: remove trailling whitespace
Lucas De Marchi [Tue, 30 Apr 2013 22:28:06 +0000 (15:28 -0700)]
coredump: remove trailling whitespace

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoKEYS: split call to call_usermodehelper_fns()
Lucas De Marchi [Tue, 30 Apr 2013 22:28:05 +0000 (15:28 -0700)]
KEYS: split call to call_usermodehelper_fns()

Use call_usermodehelper_setup() + call_usermodehelper_exec() instead of
calling call_usermodehelper_fns().  In case there's an OOM in this last
function the cleanup function may not be called - in this case we would
miss a call to key_put().

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokmod: split call to call_usermodehelper_fns()
Lucas De Marchi [Tue, 30 Apr 2013 22:28:03 +0000 (15:28 -0700)]
kmod: split call to call_usermodehelper_fns()

Use call_usermodehelper_setup() + call_usermodehelper_exec() instead of
calling call_usermodehelper_fns().  In case the latter returns -ENOMEM the
cleanup function may had not been called - in this case we would not free
argv and module_name.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agousermodehelper: export call_usermodehelper_exec() and call_usermodehelper_setup()
Lucas De Marchi [Tue, 30 Apr 2013 22:28:02 +0000 (15:28 -0700)]
usermodehelper: export call_usermodehelper_exec() and call_usermodehelper_setup()

call_usermodehelper_setup() + call_usermodehelper_exec() need to be
called instead of call_usermodehelper_fns() when the cleanup function
needs to be called even when an ENOMEM error occurs.  In this case using
call_usermodehelper_fns() the user can't distinguish if the cleanup
function was called or not.

[akpm@linux-foundation.org: export call_usermodehelper_setup() to modules]
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoselftest: add a test case for PTRACE_PEEKSIGINFO
Andrey Vagin [Tue, 30 Apr 2013 22:28:00 +0000 (15:28 -0700)]
selftest: add a test case for PTRACE_PEEKSIGINFO

* Dump signals from process-wide and per-thread queues with
  different sizes of buffers.
* Check error paths for buffers with restricted permissions. A part of
  buffer or a whole buffer is for read-only.
* Try to get nonexistent signal.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pedro Alves <palves@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoptrace: add ability to retrieve signals without removing from a queue (v4)
Andrey Vagin [Tue, 30 Apr 2013 22:27:59 +0000 (15:27 -0700)]
ptrace: add ability to retrieve signals without removing from a queue (v4)

This patch adds a new ptrace request PTRACE_PEEKSIGINFO.

This request is used to retrieve information about pending signals
starting with the specified sequence number.  Siginfo_t structures are
copied from the child into the buffer starting at "data".

The argument "addr" is a pointer to struct ptrace_peeksiginfo_args.
struct ptrace_peeksiginfo_args {
u64 off; /* from which siginfo to start */
u32 flags;
s32 nr; /* how may siginfos to take */
};

"nr" has type "s32", because ptrace() returns "long", which has 32 bits on
i386 and a negative values is used for errors.

Currently here is only one flag PTRACE_PEEKSIGINFO_SHARED for dumping
signals from process-wide queue.  If this flag is not set, signals are
read from a per-thread queue.

The request PTRACE_PEEKSIGINFO returns a number of dumped signals.  If a
signal with the specified sequence number doesn't exist, ptrace returns
zero.  The request returns an error, if no signal has been dumped.

Errors:
EINVAL - one or more specified flags are not supported or nr is negative
EFAULT - buf or addr is outside your accessible address space.

A result siginfo contains a kernel part of si_code which usually striped,
but it's required for queuing the same siginfo back during restore of
pending signals.

This functionality is required for checkpointing pending signals.  Pedro
Alves suggested using it in "gdb" to peek at pending signals.  gdb already
uses PTRACE_GETSIGINFO to get the siginfo for the signal which was already
dequeued.  This functionality allows gdb to look at the pending signals
which were not reported yet.

The prototype of this code was developed by Oleg Nesterov.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pedro Alves <palves@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agohfsplus: remove duplicated message prefix in hfsplus_block_free()
Vyacheslav Dubeyko [Tue, 30 Apr 2013 22:27:58 +0000 (15:27 -0700)]
hfsplus: remove duplicated message prefix in hfsplus_block_free()

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agohfsplus: add error propagation to __hfsplus_ext_write_extent()
Alexey Khoroshilov [Tue, 30 Apr 2013 22:27:56 +0000 (15:27 -0700)]
hfsplus: add error propagation to __hfsplus_ext_write_extent()

__hfsplus_ext_write_extent() suppresses errors coming from
hfs_brec_find().  The patch implements error code propagation.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agohfs/hfsplus: convert printks to pr_<level>
Joe Perches [Tue, 30 Apr 2013 22:27:55 +0000 (15:27 -0700)]
hfs/hfsplus: convert printks to pr_<level>

Use a more current logging style.

Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
hfsplus now uses "hfsplus: " for all messages.
Coalesce formats.
Prefix debugging messages too.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agohfs/hfsplus: convert dprint to hfs_dbg
Joe Perches [Tue, 30 Apr 2013 22:27:54 +0000 (15:27 -0700)]
hfs/hfsplus: convert dprint to hfs_dbg

Use a more current logging style.

Rename macro and uses.
Add do {} while (0) to macro.
Add DBG_ to macro.
Add and use hfs_dbg_cont variant where appropriate.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agohfsplus: fix warnings in fs/hfsplus/bfind.c
Vyacheslav Dubeyko [Tue, 30 Apr 2013 22:27:53 +0000 (15:27 -0700)]
hfsplus: fix warnings in fs/hfsplus/bfind.c

fs/hfsplus/bfind.c: In function 'hfs_find_1st_rec_by_cnid':
(1) include/uapi/linux/swab.h:60:2: warning: 'search_cnid' may be used uninitialized in this function [-Wmaybe-uninitialized]
(2) include/uapi/linux/swab.h:60:2: warning: 'cur_cnid' may be used uninitialized in this function [-Wmaybe-uninitialized]

[akpm@linux-foundation.org: make the workaround more explicit]
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agohfs: add error checking for hfs_find_init()
Alexey Khoroshilov [Tue, 30 Apr 2013 22:27:52 +0000 (15:27 -0700)]
hfs: add error checking for hfs_find_init()

hfs_find_init() may fail with ENOMEM, but there are places, where the
returned value is not checked.  The consequences can be very unpleasant,
e.g.  kfree uninitialized pointer and inappropriate mutex unlocking.

The patch adds checks for errors in hfs_find_init().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agonilfs2: remove unneeded test in nilfs_writepage()
Vyacheslav Dubeyko [Tue, 30 Apr 2013 22:27:51 +0000 (15:27 -0700)]
nilfs2: remove unneeded test in nilfs_writepage()

page->mapping->host cannot be NULL in nilfs_writepage(), so remove the
unneeded test.

The fixes the smatch warning: "fs/nilfs2/inode.c:211 nilfs_writepage()
error: we previously assumed 'inode' could be null (see line 195)".

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agonilfs2: fix using of PageLocked() in nilfs_clear_dirty_page()
Vyacheslav Dubeyko [Tue, 30 Apr 2013 22:27:50 +0000 (15:27 -0700)]
nilfs2: fix using of PageLocked() in nilfs_clear_dirty_page()

Change test_bit(PG_locked, &page->flags) to PageLocked().

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agonilfs2: fix issue with flush kernel thread after remount in RO mode because of driver...
Vyacheslav Dubeyko [Tue, 30 Apr 2013 22:27:48 +0000 (15:27 -0700)]
nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption

The NILFS2 driver remounts itself in RO mode in the case of discovering
metadata corruption (for example, discovering a broken bmap).  But
usually, this takes place when there have been file system operations
before remounting in RO mode.

Thereby, NILFS2 driver can be in RO mode with presence of dirty pages in
modified inodes' address spaces.  It results in flush kernel thread's
infinite trying to flush dirty pages in RO mode.  As a result, it is
possible to see such side effects as: (1) flush kernel thread occupies
50% - 99% of CPU time; (2) system can't be shutdowned without manual
power switch off.

SYMPTOMS:
(1) System log contains error message: "Remounting filesystem read-only".
(2) The flush kernel thread occupies 50% - 99% of CPU time.
(3) The system can't be shutdowned without manual power switch off.

REPRODUCTION PATH:
(1) Create volume group with name "unencrypted" by means of vgcreate utility.
(2) Run script (prepared by Anthony Doggett <Anthony2486@interfaces.org.uk>):

  ----------------[BEGIN SCRIPT]--------------------
  #!/bin/bash

  VG=unencrypted
  #apt-get install nilfs-tools darcs
  lvcreate --size 2G --name ntest $VG
  mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest
  mkdir /var/tmp/n
  mkdir /var/tmp/n/ntest
  mount /dev/mapper/$VG-ntest /var/tmp/n/ntest
  mkdir /var/tmp/n/ntest/thedir
  cd /var/tmp/n/ntest/thedir
  sleep 2
  date
  darcs init
  sleep 2
  dmesg|tail -n 5
  date
  darcs whatsnew || true
  date
  sleep 2
  dmesg|tail -n 5
  ----------------[END SCRIPT]--------------------

(3) Try to shutdown the system.

REPRODUCIBILITY: 100%

FIX:

This patch implements checking mount state of NILFS2 driver in
nilfs_writepage(), nilfs_writepages() and nilfs_mdt_write_page()
methods.  If it is detected the RO mount state then all dirty pages are
simply discarded with warning messages is written in system log.

[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Anthony Doggett <Anthony2486@interfaces.org.uk>
Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp>
Cc: Piotr Szymaniak <szarpaj@grubelek.pl>
Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com>
Cc: Elmer Zhang <freeboy6716@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoi2o: check copy_from_user() size parameter
Dan Carpenter [Tue, 30 Apr 2013 22:27:47 +0000 (15:27 -0700)]
i2o: check copy_from_user() size parameter

Limit the size of the copy so we don't corrupt memory.  Hopefully this
can only be called by root, but fixing this makes the static checkers
happier.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Masanari Iida <standby24x7@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()
Ben Hutchings [Tue, 30 Apr 2013 22:27:46 +0000 (15:27 -0700)]
dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()

Move the calls to memcpy_fromio() up into the loop in
dmi_scan_machine(), and move the signature checks back down into
dmi_decode().  We need to check at 16-byte intervals but keep a 32-byte
buffer for an SMBIOS entry, so shift the buffer after each iteration.

Merge smbios_present() into dmi_present(), so we look for an SMBIOS
signature at the beginning of the given buffer and then for a DMI
signature at an offset of 16 bytes.

[artem.savkov@gmail.com: use proper buf type in dmi_present()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: Tim McGrath <tmhikaru@gmail.com>
Tested-by: Tim Mcgrath <tmhikaru@gmail.com>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Artem Savkov <artem.savkov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agobinfmt_elf: PIE: make PF_RANDOMIZE check comment more accurate
Jiri Kosina [Tue, 30 Apr 2013 22:27:45 +0000 (15:27 -0700)]
binfmt_elf: PIE: make PF_RANDOMIZE check comment more accurate

The comment I originally added in commit a3defbe5c337 ("binfmt_elf: fix
PIE execution with randomization disabled") is not really 100% accurate
-- sysctl is not the only way how PF_RANDOMIZE could be forcibly unset
in runtime.

Another option of course is direct modification of personality flags
(i.e.  running through setarch wrapper).

Make the comment more explicit and accurate.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agofs: make binfmt support for #! scripts modular and removable
Josh Triplett [Tue, 30 Apr 2013 22:27:44 +0000 (15:27 -0700)]
fs: make binfmt support for #! scripts modular and removable

Add a new configuration option CONFIG_BINFMT_SCRIPT to configure support
for interpreted scripts starting with "#!"; allow compiling out that
support, or building it as a module.  Embedded systems running exclusively
compiled binaries could leave this support out, and systems that don't
need scripts before mounting the root filesystem can build this as a
module.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoepoll: cleanup: use RCU_INIT_POINTER when nulling
Eric Wong [Tue, 30 Apr 2013 22:27:43 +0000 (15:27 -0700)]
epoll: cleanup: use RCU_INIT_POINTER when nulling

It is always safe to use RCU_INIT_POINTER to NULL a pointer.  This results
in slightly smaller/faster code.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoepoll: cleanup: hoist out f_op->poll calls
Eric Wong [Tue, 30 Apr 2013 22:27:42 +0000 (15:27 -0700)]
epoll: cleanup: hoist out f_op->poll calls

This reduces the amount of code inside the ready list iteration loops for
better readability IMHO.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoepoll: lock ep->mtx in ep_free to silence lockdep
Eric Wong [Tue, 30 Apr 2013 22:27:40 +0000 (15:27 -0700)]
epoll: lock ep->mtx in ep_free to silence lockdep

Technically we do not need to hold ep->mtx during ep_free since we are
certain there are no other users of ep at that point.  However, lockdep
complains with a "suspicious rcu_dereference_check() usage!" message; so
lock the mutex before ep_remove to silence the warning.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: NeilBrown <neilb@suse.de>,
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoepoll: use RCU to protect wakeup_source in epitem
Eric Wong [Tue, 30 Apr 2013 22:27:39 +0000 (15:27 -0700)]
epoll: use RCU to protect wakeup_source in epitem

This prevents wakeup_source destruction when a user hits the item with
EPOLL_CTL_MOD while ep_poll_callback is running.

Tested with CONFIG_SPARSE_RCU_POINTER=y and "make fs/eventpoll.o C=2"

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: NeilBrown <neilb@suse.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoepoll: trim epitem by one cache line
Eric Wong [Tue, 30 Apr 2013 22:27:38 +0000 (15:27 -0700)]
epoll: trim epitem by one cache line

It is common for epoll users to have thousands of epitems, so saving a
cache line on every allocation leads to large memory savings.

Since epitem allocations are cache-aligned, reducing sizeof(struct
epitem) from 136 bytes to 128 bytes will allow it to squeeze under a
cache line boundary on x86_64.

Via /sys/kernel/slab/eventpoll_epi, I see the following changes on my
x86_64 Core2 Duo (which has 64-byte cache alignment):

object_size  :  192 => 128
objs_per_slab:   21 =>  32

Also, add a BUILD_BUG_ON() to check for future accidental breakage.

[akpm@linux-foundation.org: use __packed, for all architectures]
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/timer.c: move some non timer related syscalls to kernel/sys.c
Stephen Rothwell [Tue, 30 Apr 2013 22:27:37 +0000 (15:27 -0700)]
kernel/timer.c: move some non timer related syscalls to kernel/sys.c

Andrew Morton noted:

akpm3:/usr/src/25> grep SYSCALL kernel/timer.c
SYSCALL_DEFINE1(alarm, unsigned int, seconds)
SYSCALL_DEFINE0(getpid)
SYSCALL_DEFINE0(getppid)
SYSCALL_DEFINE0(getuid)
SYSCALL_DEFINE0(geteuid)
SYSCALL_DEFINE0(getgid)
SYSCALL_DEFINE0(getegid)
SYSCALL_DEFINE0(gettid)
SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)

Only one of those should be in kernel/timer.c.  Who wrote this thing?

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/timer.c: convert compat_sys_sysinfo to COMPAT_SYSCALL_DEFINE
Stephen Rothwell [Tue, 30 Apr 2013 22:27:35 +0000 (15:27 -0700)]
kernel/timer.c: convert compat_sys_sysinfo to COMPAT_SYSCALL_DEFINE

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/compat.c: make do_sysinfo() static
Stephen Rothwell [Tue, 30 Apr 2013 22:27:34 +0000 (15:27 -0700)]
kernel/compat.c: make do_sysinfo() static

The only use outside of kernel/timer.c was in kernel/compat.c, so move
compat_sys_sysinfo() next to sys_sysinfo() in kernel/timer.c.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agobinfmt_misc: reuse string_unescape_inplace()
Andy Shevchenko [Tue, 30 Apr 2013 22:27:33 +0000 (15:27 -0700)]
binfmt_misc: reuse string_unescape_inplace()

There is string_unescape_inplace() function which decodes strings in generic
way. Let's use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodynamic_debug: reuse generic string_unescape function
Andy Shevchenko [Tue, 30 Apr 2013 22:27:32 +0000 (15:27 -0700)]
dynamic_debug: reuse generic string_unescape function

There is kernel function to do the job in generic way. Let's use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agostaging: speakup: remove custom string_unescape_any_inplace
Andy Shevchenko [Tue, 30 Apr 2013 22:27:31 +0000 (15:27 -0700)]
staging: speakup: remove custom string_unescape_any_inplace

There is generic implementation of the function to unescape strings.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@braille.uwo.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agolib/string_helpers: introduce generic string_unescape
Andy Shevchenko [Tue, 30 Apr 2013 22:27:30 +0000 (15:27 -0700)]
lib/string_helpers: introduce generic string_unescape

There are several places in kernel where modules unescapes input to convert
C-Style Escape Sequences into byte codes.

The patch provides generic implementation of such approach. Test cases are
also included into the patch.

[akpm@linux-foundation.org: clarify comment]
[akpm@linux-foundation.org: export get_random_int() to modules]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@braille.uwo.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/smp.c: cleanups
Andrew Morton [Tue, 30 Apr 2013 22:27:28 +0000 (15:27 -0700)]
kernel/smp.c: cleanups

We sometimes use "struct call_single_data *data" and sometimes "struct
call_single_data *csd".  Use "csd" consistently.

We sometimes use "struct call_function_data *data" and sometimes "struct
call_function_data *cfd".  Use "cfd" consistently.

Also, avoid some 80-col layout tricks.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoinclude/linux/fs.h: disable preempt when acquire i_size_seqcount write lock
Fan Du [Tue, 30 Apr 2013 22:27:27 +0000 (15:27 -0700)]
include/linux/fs.h: disable preempt when acquire i_size_seqcount write lock

Two rt tasks bind to one CPU core.

The higher priority rt task A preempts a lower priority rt task B which
has already taken the write seq lock, and then the higher priority rt
task A try to acquire read seq lock, it's doomed to lockup.

rt task A with lower priority: call write
i_size_write                                        rt task B with higher priority: call sync, and preempt task A
  write_seqcount_begin(&inode->i_size_seqcount);    i_size_read
  inode->i_size = i_size;                             read_seqcount_begin <-- lockup here...

So disable preempt when acquiring every i_size_seqcount *write* lock will
cure the problem.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/smp.c: remove 'priv' of call_single_data
liguang [Tue, 30 Apr 2013 22:27:26 +0000 (15:27 -0700)]
kernel/smp.c: remove 'priv' of call_single_data

The 'priv' field is redundant; we can pass data via 'info'.

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/smp.c: use '|=' for csd_lock
liguang [Tue, 30 Apr 2013 22:27:25 +0000 (15:27 -0700)]
kernel/smp.c: use '|=' for csd_lock

csd_lock() uses assignment to data->flags rather than |=.  That is not
buggy at present because only one bit (CSD_FLAG_LOCK) is defined in
call_single_data.flags.

But it will become buggy if we later add another flag, so fix it now.

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agowriteback: set worker desc to identify writeback workers in task dumps
Tejun Heo [Tue, 30 Apr 2013 22:27:24 +0000 (15:27 -0700)]
writeback: set worker desc to identify writeback workers in task dumps

Writeback has been recently converted to use workqueue instead of its
private thread pool implementation.  One negative side effect of this
conversion is that there's no easy to tell which backing device a
writeback work item was working on at the time of task dump, be it
sysrq-t, BUG, WARN or whatever, which, according to our writeback
brethren, is important in tracking down issues with a lot of mounted
file systems on a lot of different devices.

This patch restores that information using the new worker description
facility.  bdi_writeback_workfn() calls set_work_desc() to identify
which bdi it's working on.  The description is printed out together with
the worqueue name and worker function as in the following example dump.

 WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0()
 Modules linked in:
 Pid: 28, comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ #24 empty empty/S3992
 Workqueue: writeback bdi_writeback_workfn (flush-8:16)
  ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8
  ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0
  ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08
 Call Trace:
  [<ffffffff81c61855>] dump_stack+0x19/0x1b
  [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
  [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff81200144>] bdi_writeback_workfn+0x2b4/0x3c0
  [<ffffffff810b4c87>] process_one_work+0x1d7/0x660
  [<ffffffff810b5c72>] worker_thread+0x122/0x380
  [<ffffffff810bdfea>] kthread+0xea/0xf0
  [<ffffffff81c6cedc>] ret_from_fork+0x7c/0xb0

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoworkqueue: include workqueue info when printing debug dump of a worker task
Tejun Heo [Tue, 30 Apr 2013 22:27:22 +0000 (15:27 -0700)]
workqueue: include workqueue info when printing debug dump of a worker task

One of the problems that arise when converting dedicated custom
threadpool to workqueue is that the shared worker pool used by workqueue
anonimizes each worker making it more difficult to identify what the
worker was doing on which target from the output of sysrq-t or debug
dump from oops, BUG() and friends.

This patch implements set_worker_desc() which can be called from any
workqueue work function to set its description.  When the worker task is
dumped for whatever reason - sysrq-t, WARN, BUG, oops, lockdep assertion
and so on - the description will be printed out together with the
workqueue name and the worker function pointer.

The printing side is implemented by print_worker_info() which is called
from functions in task dump paths - sched_show_task() and
dump_stack_print_info().  print_worker_info() can be safely called on
any task in any state as long as the task struct itself is accessible.
It uses probe_*() functions to access worker fields.  It may print
garbage if something went very wrong, but it wouldn't cause (another)
oops.

The description is currently limited to 24bytes including the
terminating \0.  worker->desc_valid and workder->desc[] are added and
the 64 bytes marker which was already incorrect before adding the new
fields is moved to the correct position.

Here's an example dump with writeback updated to set the bdi name as
worker desc.

 Hardware name: Bochs
 Modules linked in:
 Pid: 7, comm: kworker/u9:0 Not tainted 3.9.0-rc1-work+ #1
 Workqueue: writeback bdi_writeback_workfn (flush-8:0)
  ffffffff820a3ab0 ffff88000f6e9cb8 ffffffff81c61845 ffff88000f6e9cf8
  ffffffff8108f50f 0000000000000000 0000000000000000 ffff88000cde16b0
  ffff88000cde1aa8 ffff88001ee19240 ffff88000f6e9fd8 ffff88000f6e9d08
 Call Trace:
  [<ffffffff81c61845>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff81200150>] bdi_writeback_workfn+0x2a0/0x3b0
 ...

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokthread: implement probe_kthread_data()
Tejun Heo [Tue, 30 Apr 2013 22:27:21 +0000 (15:27 -0700)]
kthread: implement probe_kthread_data()

One of the problems that arise when converting dedicated custom threadpool
to workqueue is that the shared worker pool used by workqueue anonimizes
each worker making it more difficult to identify what the worker was doing
on which target from the output of sysrq-t or debug dump from oops, BUG()
and friends.

For example, after writeback is converted to use workqueue instead of
priviate thread pool, there's no easy to tell which backing device a
writeback work item was working on at the time of task dump, which,
according to our writeback brethren, is important in tracking down issues
with a lot of mounted file systems on a lot of different devices.

This patchset implements a way for a work function to mark its execution
instance so that task dump of the worker task includes information to
indicate what the work item was doing.

An example WARN dump would look like the following.

 WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0()
 Modules linked in:
 CPU: 0 Pid: 28 Comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ #24
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 Workqueue: writeback bdi_writeback_workfn (flush-8:16)
  ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8
  ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0
  ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08
 Call Trace:
  [<ffffffff81c61855>] dump_stack+0x19/0x1b
  [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
  ...

This patch:

Implement probe_kthread_data() which returns kthread_data if accessible.
The function is equivalent to kthread_data() except that the specified
@task may not be a kthread or its vfork_done is already cleared rendering
struct kthread inaccessible.  In the former case, probe_kthread_data() may
return any value.  In the latter, NULL.

This will be used to safely print debug information without affecting
synchronization in the normal paths.  Workqueue debug info printing on
dump_stack() and friends will make use of it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoarc, print-fatal-signals: reduce duplicated information
Vineet Gupta [Tue, 30 Apr 2013 22:27:19 +0000 (15:27 -0700)]
arc, print-fatal-signals: reduce duplicated information

After the recent generic debug info on dump_stack() and friends, arc
is printing duplicate information on debug dumps.

 [ARCLinux]$ ./crash
 crash/50: potentially unexpected fatal signal 11. <-- [1]
 /sbin/crash, TGID 50 <-- [2]
 Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132  <-- [3]
 ...

Remove them.

[tj@kernel.org: updated patch desc]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodump_stack: unify debug information printed by show_regs()
Tejun Heo [Tue, 30 Apr 2013 22:27:17 +0000 (15:27 -0700)]
dump_stack: unify debug information printed by show_regs()

show_regs() is inherently arch-dependent but it does make sense to print
generic debug information and some archs already do albeit in slightly
different forms.  This patch introduces a generic function to print debug
information from show_regs() so that different archs print out the same
information and it's much easier to modify what's printed.

show_regs_print_info() prints out the same debug info as dump_stack()
does plus task and thread_info pointers.

* Archs which didn't print debug info now do.

  alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
  metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
  um, xtensa

* Already prints debug info.  Replaced with show_regs_print_info().
  The printed information is superset of what used to be there.

  arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* s390 is special in that it used to print arch-specific information
  along with generic debug info.  Heiko and Martin think that the
  arch-specific extra isn't worth keeping s390 specfic implementation.
  Converted to use the generic version.

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

 kernel BUG at /work/os/work/kernel/workqueue.c:4841!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
 RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
 RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
 RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
  0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
  ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
 Call Trace:
  [<ffffffff81000312>] do_one_initcall+0x122/0x170
  [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  [<ffffffff81c4776e>] kernel_init+0xe/0xf0
  [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  ...

v2: Typo fix in x86-32.

v3: CPU number dropped from show_regs_print_info() as
    dump_stack_print_info() has been updated to print it.  s390
    specific implementation dropped as requested by s390 maintainers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile bits]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodump_stack: implement arch-specific hardware description in task dumps
Tejun Heo [Tue, 30 Apr 2013 22:27:15 +0000 (15:27 -0700)]
dump_stack: implement arch-specific hardware description in task dumps

x86 and ia64 can acquire extra hardware identification information
from DMI and print it along with task dumps; however, the usage isn't
consistent.

* x86 show_regs() collects vendor, product and board strings and print
  them out with PID, comm and utsname.  Some of the information is
  printed again later in the same dump.

* warn_slowpath_common() explicitly accesses the DMI board and prints
  it out with "Hardware name:" label.  This applies to both x86 and
  ia64 but is irrelevant on all other archs.

* ia64 doesn't show DMI information on other non-WARN dumps.

This patch introduces arch-specific hardware description used by
dump_stack().  It can be set by calling dump_stack_set_arch_desc()
during boot and, if exists, printed out in a separate line with
"Hardware name:" label.

dmi_set_dump_stack_arch_desc() is added which sets arch-specific
description from DMI data.  It uses dmi_ids_string[] which is set from
dmi_present() used for DMI debug message.  It is superset of the
information x86 show_regs() is using.  The function is called from x86
and ia64 boot code right after dmi_scan_machine().

This makes the explicit DMI handling in warn_slowpath_common()
unnecessary.  Removed.

show_regs() isn't yet converted to use generic debug information
printing and this patch doesn't remove the duplicate DMI handling in
x86 show_regs().  The next patch will unify show_regs() handling and
remove the duplication.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #3
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a08e
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
  [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a0c3>] init_workqueues+0x35/0x505
  ...

v2: Use the same string as the debug message from dmi_present() which
    also contains BIOS information.  Move hardware name into its own
    line as warn_slowpath_common() did.  This change was suggested by
    Bjorn Helgaas.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodmi: morph dmi_dump_ids() into dmi_format_ids() which formats into a buffer
Tejun Heo [Tue, 30 Apr 2013 22:27:14 +0000 (15:27 -0700)]
dmi: morph dmi_dump_ids() into dmi_format_ids() which formats into a buffer

We're goning to use DMI identification for other purposes too.  Morph
dmi_dump_ids() which is used to print DMI identification as a debug
message during boot into dmi_format_ids() which formats the same
information sans the leading "DMI:" tag into a string buffer.

dmi_present() is updated to format the information into dmi_ids_string[]
using the new function and print it with "DMI:" prefix.

dmi_ids_string[] will be used for another purpose by a future patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodump_stack: consolidate dump_stack() implementations and unify their behaviors
Tejun Heo [Tue, 30 Apr 2013 22:27:12 +0000 (15:27 -0700)]
dump_stack: consolidate dump_stack() implementations and unify their behaviors

Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a071>] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agosparc32: make show_stack() acquire %fp if @_ksp is not specified
Tejun Heo [Tue, 30 Apr 2013 22:27:10 +0000 (15:27 -0700)]
sparc32: make show_stack() acquire %fp if @_ksp is not specified

show_stack(current or NULL, NULL) is used by arch-independent code to dump
backtrace of the current task; however, sparc32 show_stack() doesn't
implement it and wouldn't print any backtrace when NULL @_ksp is specfied.

Make show_stack() acquire and use %fp if @tsk is NULL or current and @_ksp
is NULL.  This makes %fp fetching in dump_stack() unnecessary.  Make it
use NULL for @_ksp instead.

Only compile tested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agox86: don't show trace beyond show_stack(NULL, NULL)
Tejun Heo [Tue, 30 Apr 2013 22:27:09 +0000 (15:27 -0700)]
x86: don't show trace beyond show_stack(NULL, NULL)

There are multiple ways a task can be dumped - explicit call to
dump_stack(), triggering WARN() or BUG(), through sysrq-t and so on.
Most of what gets printed is upto each architecture and the current
state is not particularly pretty.  Different pieces of information are
presented differently depending on which path the dump takes and which
architecture it's running on.  This is messy for no good reason and
makes it exceedingly difficult to add or modify debug information to
task dumps.

In all archs except for s390, there's nothing arch-specific about the
printed debug information.  This patchset updates all those archs to use
the same helpers to consistently print out the same debug information.

An example WARN dump after this patchset.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #3
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a08e
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
  [<ffffffff8108f54a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a0c3>] init_workqueues+0x35/0x505
  ...

And BUG dump.

 kernel BUG at kernel/workqueue.c:4841!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
 RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
 RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
 RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
  0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
  ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
 Call Trace:
  [<ffffffff81000312>] do_one_initcall+0x122/0x170
  [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  [<ffffffff81c4776e>] kernel_init+0xe/0xf0
  [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  ...

This patchset contains the following seven patches.

 0001-x86-don-t-show-trace-beyond-show_stack-NULL-NULL.patch
 0002-sparc32-make-show_stack-acquire-fp-if-_ksp-is-not-sp.patch
 0003-dump_stack-consolidate-dump_stack-implementations-an.patch
 0004-dmi-morph-dmi_dump_ids-into-dmi_format_ids-which-for.patch
 0005-dump_stack-implement-arch-specific-hardware-descript.patch
 0006-dump_stack-unify-debug-information-printed-by-show_r.patch
 0007-arc-print-fatal-signals-reduce-duplicated-informatio.patch

0001-0002 update stack dumping functions in x86 and sparc32 in
preparation.

0003 makes all arches except blackfin use generic dump_stack().
blackfin still uses the generic helper to print the same info.

0004-0005 properly abstract DMI identifier printing in WARN() and
show_regs() so that all dumps print out the information.  This enables
show_regs() to use the same debug info message.

0006 updates show_regs() of all arches to use a common generic helper
to print debug info.

0007 removes somem duplicate information from arc dumps.

While this patchset changes how debug info is printed on some archs,
the printed information is always superset of what used to be there.

This patchset makes task dump debug messages consistent and enables
adding more information.  Workqueue is scheduled to add worker
information including the workqueue in use and work item specific
description.

While this patch touches a lot of archs, it isn't too likely to cause
non-trivial conflicts with arch-specfic changes and would probably be
best to route together either through -mm.

x86 is tested but other archs are either only compile tested or not
tested at all.  Changes to most archs are generally trivial.

This patch:

show_stack(current or NULL, NULL) is used to print the backtrace of the
current task.  As trace beyond the function itself isn't of much
interest to anyone, don't show it by determining sp and bp in
show_stack()'s frame and passing them to show_stack_log_lvl().

This brings show_stack(NULL, NULL)'s behavior in line with
dump_stack().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agokernel/range.c: subtract_range: fix the broken phrase issued by printk
Lin Feng [Tue, 30 Apr 2013 22:27:07 +0000 (15:27 -0700)]
kernel/range.c: subtract_range: fix the broken phrase issued by printk

Also replace deprecated printk(KERN_ERR...) with pr_err() as suggested
by Yinghai, attaching the function name to provide plenty info.

Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoselftest: add simple test for soft-dirty bit
Pavel Emelyanov [Tue, 30 Apr 2013 22:27:06 +0000 (15:27 -0700)]
selftest: add simple test for soft-dirty bit

It creates a mapping of 3 pages and checks that reads, writes and
clear-refs result in present and soft-dirt bits reported from pagemap2
set as expected.

[akpm@linux-foundation.org: alphasort the Makefile TARGETS to reduce rejects]
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agostaging: zcache: enable zcache to be built/loaded as a module
Dan Magenheimer [Tue, 30 Apr 2013 22:27:05 +0000 (15:27 -0700)]
staging: zcache: enable zcache to be built/loaded as a module

Allow zcache to be built/loaded as a module.  Note runtime dependency
disallows loading if cleancache/frontswap lazy initialization patches
are not present.  Zsmalloc support has not yet been merged into zcache
but, once merged, could now easily be selected via a module_param.

If built-in (not built as a module), the original mechanism of enabling
via a kernel boot parameter is retained, but this should be considered
deprecated.

Note that module unload is explicitly not yet supported.

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Rebased with different order of patches]
[v2: Removed [CLEANCACHE|FRONTSWAP]_HAS_LAZY_INIT ifdef]
[v3: Rebased on top of ramster->zcache move]
[v4: Redid the Makefile]
[v5: s/ZCACHE2/ZCACHE/]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agostaging: zcache: enable ramster to be built/loaded as a module
Dan Magenheimer [Tue, 30 Apr 2013 22:27:03 +0000 (15:27 -0700)]
staging: zcache: enable ramster to be built/loaded as a module

Enable module support for ramster.  Note runtime dependency disallows
loading if cleancache/frontswap lazy initialization patches are not
present.

If built-in (not built as a module), the original mechanism of enabling
via a kernel boot parameter is retained, but this should be considered
deprecated.

Note that module unload is explicitly not yet supported.

[v1: Fixed compile issues since ramster_init now has four arguments]
[v2: Fixed rebase on ramster->zcache move]
[akpm@linux-foundation.org: use_frontswap_selfshrink cannot be __initdata]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agozcache/tmem: Better error checking on frontswap_register_ops return value.
Konrad Rzeszutek Wilk [Tue, 30 Apr 2013 22:27:01 +0000 (15:27 -0700)]
zcache/tmem: Better error checking on frontswap_register_ops return value.

In the past it either used to be NULL or the "older" backend. Now we
also return -Exx error codes.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoxen: tmem: enable Xen tmem shim to be built/loaded as a module
Dan Magenheimer [Tue, 30 Apr 2013 22:27:00 +0000 (15:27 -0700)]
xen: tmem: enable Xen tmem shim to be built/loaded as a module

Allow Xen tmem shim to be built/loaded as a module.  Xen self-ballooning
and frontswap-selfshrinking are now also "lazily" initialized when the
Xen tmem shim is loaded as a module, unless explicitly disabled by
module parameters.

Note runtime dependency disallows loading if cleancache/frontswap lazy
initialization patches are not present.

If built-in (not built as a module), the original mechanism of enabling
via a kernel boot parameter is retained, but this should be considered
deprecated.

Note that module unload is explicitly not yet supported.

[v1: Removed the [CLEANCACHE|FRONTSWAP]_HAS_LAZY_INIT ifdef]
[v2: Squashed the xen/tmem: Remove the subsys call patch in]
[akpm@linux-foundation.org: fix build (disable_frontswap_selfshrinking undeclared)]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agomm: cleancache: clean up cleancache_enabled
Bob Liu [Tue, 30 Apr 2013 22:26:58 +0000 (15:26 -0700)]
mm: cleancache: clean up cleancache_enabled

cleancache_ops is used to decide whether backend is registered.
So now cleancache_enabled is always true if defined CONFIG_CLEANCACHE.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agocleancache: Make cleancache_init use a pointer for the ops
Konrad Rzeszutek Wilk [Tue, 30 Apr 2013 22:26:57 +0000 (15:26 -0700)]
cleancache: Make cleancache_init use a pointer for the ops

Instead of using a backend_registered to determine whether a backend is
enabled.  This allows us to remove the backend_register check and just
do 'if (cleancache_ops)'

[v1: Rebase on top of b97c4b430b0a (ramster->zcache move]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agomm: cleancache: lazy initialization to allow tmem backends to build/run as modules
Dan Magenheimer [Tue, 30 Apr 2013 22:26:56 +0000 (15:26 -0700)]
mm: cleancache: lazy initialization to allow tmem backends to build/run as modules

With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to
be built/loaded as modules rather than built-in and enabled by a boot
parameter, this patch provides "lazy initialization", allowing backends
to register to cleancache even after filesystems were mounted.  Calls to
init_fs and init_shared_fs are remembered as fake poolids but no real
tmem_pools created.  On backend registration the fake poolids are mapped
to real poolids and respective tmem_pools.

Signed-off-by: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Florian Schmaus <fschmaus@gmail.com>
Signed-off-by: Andor Daam <andor.daam@googlemail.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Minor fixes: used #define for some values and bools]
[v2: Removed CLEANCACHE_HAS_LAZY_INIT]
[v3: Added more comments, added a lock for [shared_|]fs_poolid_map]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agofrontswap: get rid of swap_lock dependency
Minchan Kim [Tue, 30 Apr 2013 22:26:54 +0000 (15:26 -0700)]
frontswap: get rid of swap_lock dependency

Frontswap initialization routine depends on swap_lock, which want to be
atomic about frontswap's first appearance.  IOW, frontswap is not present
and will fail all calls OR frontswap is fully functional but if new
swap_info_struct isn't registered by enable_swap_info, swap subsystem
doesn't start I/O so there is no race between init procedure and page I/O
working on frontswap.

So let's remove unnecessary swap_lock dependency.

Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
[v1: Rebased on my branch, reworked to work with backends loading late]
[v2: Added a check for !map]
[v3: Made the invalidate path follow the init path]
[v4: Address comments by Wanpeng Li <liwanp@linux.vnet.ibm.com>]
Signed-off-by: Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agomm: frontswap: cleanup code
Bob Liu [Tue, 30 Apr 2013 22:26:53 +0000 (15:26 -0700)]
mm: frontswap: cleanup code

After allowing tmem backends to build/run as modules, frontswap_enabled
always true if defined CONFIG_FRONTSWAP.  But frontswap_test() depends on
whether backend is registered, mv it into frontswap.c using fronstswap_ops
to make the decision.

frontswap_set/clear are not used outside frontswap, so don't export them.

Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agofrontswap: make frontswap_init use a pointer for the ops
Konrad Rzeszutek Wilk [Tue, 30 Apr 2013 22:26:51 +0000 (15:26 -0700)]
frontswap: make frontswap_init use a pointer for the ops

This simplifies the code in the frontswap - we can get rid of the
'backend_registered' test and instead check against frontswap_ops.

[v1: Rebase on top of 703ba7fe5e0 (ramster->zcache move]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agomm: frontswap: lazy initialization to allow tmem backends to build/run as modules
Dan Magenheimer [Tue, 30 Apr 2013 22:26:50 +0000 (15:26 -0700)]
mm: frontswap: lazy initialization to allow tmem backends to build/run as modules

With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to
be built/loaded as modules rather than built-in and enabled by a boot
parameter, this patch provides "lazy initialization", allowing backends
to register to frontswap even after swapon was run.  Before a backend
registers all calls to init are recorded and the creation of tmem_pools
delayed until a backend registers or until a frontswap store is
attempted.

Signed-off-by: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Florian Schmaus <fschmaus@gmail.com>
Signed-off-by: Andor Daam <andor.daam@googlemail.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Fixes per Seth Jennings suggestions]
[v2: Removed FRONTSWAP_HAS_.. ]
[v3: Fix up per Bob Liu <lliubbo@gmail.com> recommendations]
[v4: Fix up per Andrew's comments]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agofs/dcache.c: add cond_resched() to shrink_dcache_parent()
Greg Thelen [Tue, 30 Apr 2013 22:26:48 +0000 (15:26 -0700)]
fs/dcache.c: add cond_resched() to shrink_dcache_parent()

Call cond_resched() in shrink_dcache_parent() to maintain interactivity.

Before this patch:

void shrink_dcache_parent(struct dentry * parent)
{
while ((found = select_parent(parent, &dispose)) != 0)
shrink_dentry_list(&dispose);
}

select_parent() populates the dispose list with dentries which
shrink_dentry_list() then deletes.  select_parent() carefully uses
need_resched() to avoid doing too much work at once.  But neither
shrink_dcache_parent() nor its called functions call cond_resched().  So
once need_resched() is set select_parent() will return single dentry
dispose list which is then deleted by shrink_dentry_list().  This is
inefficient when there are a lot of dentry to process.  This can cause
softlockup and hurts interactivity on non preemptable kernels.

This change adds cond_resched() in shrink_dcache_parent().  The benefit
of this is that need_resched() is quickly cleared so that future calls
to select_parent() are able to efficiently return a big batch of dentry.

These additional cond_resched() do not seem to impact performance, at
least for the workload below.

Here is a program which can cause soft lockup if other system activity
sets need_resched().

int main()
{
        struct rlimit rlim;
        int i;
        int f[100000];
        char buf[20];
        struct timeval t1, t2;
        double diff;

        /* cleanup past run */
        system("rm -rf x");

        /* boost nfile rlimit */
        rlim.rlim_cur = 200000;
        rlim.rlim_max = 200000;
        if (setrlimit(RLIMIT_NOFILE, &rlim))
                err(1, "setrlimit");

        /* make directory for files */
        if (mkdir("x", 0700))
                err(1, "mkdir");

        if (gettimeofday(&t1, NULL))
                err(1, "gettimeofday");

        /* populate directory with open files */
        for (i = 0; i < 100000; i++) {
                snprintf(buf, sizeof(buf), "x/%d", i);
                f[i] = open(buf, O_CREAT);
                if (f[i] == -1)
                        err(1, "open");
        }

        /* close some of the files */
        for (i = 0; i < 85000; i++)
                close(f[i]);

        /* unlink all files, even open ones */
        system("rm -rf x");

        if (gettimeofday(&t2, NULL))
                err(1, "gettimeofday");

        diff = (((double)t2.tv_sec * 1000000 + t2.tv_usec) -
                ((double)t1.tv_sec * 1000000 + t1.tv_usec));

        printf("done: %g elapsed\n", diff/1e6);
        return 0;
}

Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agofs/block_dev.c: no need to check inode->i_bdev in bd_forget()
Yan Hong [Tue, 30 Apr 2013 22:26:47 +0000 (15:26 -0700)]
fs/block_dev.c: no need to check inode->i_bdev in bd_forget()

Its only caller evict() has promised a non-NULL inode->i_bdev.

Signed-off-by: Yan Hong <clouds.yan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoinotify: invalid mask should return a error number but not set it
Zhao Hongjiang [Tue, 30 Apr 2013 22:26:46 +0000 (15:26 -0700)]
inotify: invalid mask should return a error number but not set it

When we run the crackerjack testsuite, the inotify_add_watch test is
stalled.

This is caused by the invalid mask 0 - the task is waiting for the event
but it never comes.  inotify_add_watch() should return -EINVAL as it did
before commit 676a0675cf92 ("inotify: remove broken mask checks causing
unmount to be EINVAL").  That commit removes the invalid mask check, but
that check is needed.

Check the mask's ALL_INOTIFY_BITS before the inotify_arg_to_mask() call.
If none are set, just return -EINVAL.

Because IN_UNMOUNT is in ALL_INOTIFY_BITS, this change will not trigger
the problem that above commit fixed.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Acked-by: Jim Somerville <Jim.Somerville@windriver.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agomemory hotplug: fix warnings
Vincent Stehlé [Tue, 30 Apr 2013 22:26:45 +0000 (15:26 -0700)]
memory hotplug: fix warnings

Fix the following compilation warnings:

  mm/slab.c: In function `kmem_cache_init_late':
  mm/slab.c:1778:2: warning: statement with no effect [-Wunused-value]

  mm/page_cgroup.c: In function `page_cgroup_init':
  mm/page_cgroup.c:305:2: warning: statement with no effect [-Wunused-value]

Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agodrivers/usb/storage/realtek_cr.c: fix build
Andrew Morton [Tue, 30 Apr 2013 22:26:44 +0000 (15:26 -0700)]
drivers/usb/storage/realtek_cr.c: fix build

Remove unused local `us', which broke the build.  Also nuke an unneeded
cast.

Repairs commit 191648d03d20 ("usb: storage: Convert US_DEBUGP to
usb_stor_dbg").

Cc: Joe Perches <joe@perches.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoMerge tag 'arm64-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas...
Linus Torvalds [Tue, 30 Apr 2013 17:10:48 +0000 (10:10 -0700)]
Merge tag 'arm64-for-linus' of git://git./linux/kernel/git/cmarinas/linux-aarch64

Pull arm64 update from Catalin Marinas:
 "Main features:

   - Versatile Express SoC (model) support - DT files and Kconfig
     entries (there are no arch/arm64/mach-* directories).  The bulk of
     the code has already been moved to drivers/ as part of the ARM SoC
     clean-up.

   - Basic multi-cluster support (CPU logical map initialised from the
     DT)

   - Simple earlyprintk support for UART 8250/16550 and FastModel
     console output

   - Optimised kernel library bitops and string functions.

   - Automatic initialisation of the irqchip and clocks via DT"

* tag 'arm64-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64: (26 commits)
  arm64: Use acquire/release semantics instead of explicit DMB
  arm64: klib: bitops: fix unpredictable stxr usage
  arm64: vexpress: Enable ARMv8 RTSM model (SoC) support
  arm64: vexpress: Add dts files for the ARMv8 RTSM models
  arm64: Survive invalid cpu enable-methods
  arm64: mm: Correct show_pte behaviour
  arm64: Fix compat types affecting struct compat_stat
  arm64: Execute DSB during thread switching for TLB/cache maintenance
  arm64: compiling issue, need add include/asm/vga.h file
  arm64: smp: honour #address-size when parsing CPU reg property
  arm64: Define cmpxchg64 and cmpxchg64_local for outside use
  arm64: Define readq and writeq for driver module using
  arm64: Fix task tracing
  arm64: add explicit symbols to ESR_EL1 decoding
  arm64: Use irqchip_init() for interrupt controller initialisation
  arm64: psci: Use the MPIDR values from cpu_logical_map for cpu ids.
  arm64: klib: Optimised atomic bitops
  arm64: klib: Optimised string functions
  arm64: klib: Optimised memory functions
  arm64: head: match all affinity levels in the pen of the secondaries
  ...

11 years agoMerge tag 'metag-for-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 17:09:39 +0000 (10:09 -0700)]
Merge tag 'metag-for-v3.10-rc1' of git://git./linux/kernel/git/jhogan/metag

Pull arch/metag update from James Hogan:

 - Various fixes for the interrupting perf counter handling in metag's
   perf backend.

 - Add OProfile support based on perf.

 - Sets up cache partitions for SMP so bootloader doesn't have to.

 - Patch from Paul Bolle to remove ARCH_POPULATES_NODE_MAP again
   (touches microblaze too).

 - Add TLS pointer regset to metag ptrace api.

 - Add exported metag DSP extended context handling header <asm/ech.h>.

 - Increase defconfig log buffer size to 128KiB.

 - Various fixes, typos, missing exports.

* tag 'metag-for-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
  metag: defconfigs: increase log buffer 8KiB => 128KiB
  metag: avoid unnecessary builtin dtb rebuilds
  metag: add exported <asm/ech.h> for extended context handling
  metag: export _metag_da_present and cpu_2_hwthread_id
  metag: ptrace: Implement NT_METAG_TLS
  memblock: Kill ARCH_POPULATES_NODE_MAP once more
  metag: cachepart: fix get_global_dcache_size() typo
  metag: cachepart: take into account small cache bits
  metag: smp: copy cache partition and enable GCOn
  metag: OProfile support
  metag: perf: prepare for use by oprofile
  metag: perf: don't reset TXTACTCYC
  metag: perf: use hard_processor_id() to get thread
  metag: perf: fix frequency sampling (dynamic period)
  metag: perf: add missing prev_count updates
  metag: perf: fixes for interrupting perf counters
  metag: perf: fix wrap handling in delta calculation
  metag: perf: fix core internal / perf channel mux

11 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux...
Linus Torvalds [Tue, 30 Apr 2013 17:08:44 +0000 (10:08 -0700)]
Merge branch 'for-linus' of git://git./linux/kernel/git/geert/linux-m68k

Pull m68k update from Geert Uytterhoeven.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Remove inline strlen() implementation
  m68k/atari: USB - add platform devices for EtherNAT/NetUSBee ISP1160 HCD
  m68k: Implement ndelay() based on the existing udelay() logic
  m68k/atari: EtherNAT - add interrupt chip definition for CPLD interrupts
  m68k/atari: EtherNEC - add platform device support
  m68k/atari: EtherNAT - platform device and IRQ support code
  m68k/atari: use dedicated irq_chip for timer D interrupts
  m68k/atari: ROM port ISA adapter support
  m68k: Add missing cmpxchg64() if CONFIG_RMW_INSNS=y

11 years agoMerge branch 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
Linus Torvalds [Tue, 30 Apr 2013 17:00:49 +0000 (10:00 -0700)]
Merge branch 'linux_next' of git://git./linux/kernel/git/mchehab/linux-edac

Pull edac fixes from Mauro Carvalho Chehab:
 "Two edac fixes:

   - i7300_edac currently reports a wrong number of DIMMs when the
     memory controller is in single channel mode

   - on some Sandy Bridge machines, the EDAC driver bails out as one of
     the PCI IDs used by the driver is hidden by BIOS.  As the driver
     uses it only to detect the type of memory, make it optional at the
     driver"

* 'linux_next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac:
  edac: sb_edac.c should not require prescence of IMC_DDRIO device
  i7300_edac: Fix memory detection in single mode

11 years agoMerge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
Linus Torvalds [Tue, 30 Apr 2013 16:58:16 +0000 (09:58 -0700)]
Merge branch 'v4l_for_linus' of git://git./linux/kernel/git/mchehab/linux-media

Pull media update from Mauro Carvalho Chehab:

 - OF documentation and patches at core and drivers, to be used by for
   embedded media systems

 - some I2C drivers used on go7007 were rewritten/promoted from staging:
   sony-btf-mpx, tw2804, tw9903, tw9906, wis-ov7640, wis-uda1342

 - add fimc-is driver (Exynos)

 - add a new radio driver: radio-si476x

 - add a two new tuners: r820t and tuner_it913x

 - split camera code on em28xx driver and add more models

 - the cypress firmware load is used outside dvb usb drivers.  So, move
   it to a common directory to make easier to re-use it

 - siano media driver updated to work with sms2270 devices

 - several work done in order to promote go7007 and solo6x1x out of
   staging (still, there are some pending issues)

 - several API compliance fixes at v4l2 drivers that don't behave as
   expected

 - as usual, lots of driver fixes, improvements, cleanups and new device
   addition at the existing drivers.

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (831 commits)
  [media] cx88: make core less verbose
  [media] em28xx: fix oops at em28xx_dvb_bus_ctrl()
  [media] s5c73m3: fix indentation of the help section in Kconfig
  [media] cx25821-alsa: get rid of a __must_check warning
  [media] cx25821-video: declare cx25821_vidioc_s_std as static
  [media] cx25821-video: remove maxw from cx25821_vidioc_try_fmt_vid_cap
  [media] r820t: Remove a warning for an unused value
  [media] dib0090: Fix a warning at dib0090_set_EFUSE
  [media] dib8000: fix a warning
  [media] dib8000: Fix sub-channel range
  [media] dib8000: store dtv_property_cache in a temp var
  [media] dib8000: warning fix: declare internal functions as static
  [media] r820t: quiet gcc warning on n_ring
  [media] r820t: memory leak in release()
  [media] r820t: precendence bug in r820t_xtal_check()
  [media] videodev2.h: Remove the unused old V4L1 buffer types
  [media] anysee: Grammar s/report the/report to/
  [media] anysee: Initialize ret = 0 in anysee_frontend_attach()
  [media] media: videobuf2: fix the length check for mmap
  [media] em28xx: save isoc endpoint number for DVB only if endpoint has alt settings with xMaxPacketSize != 0
  ...

11 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Linus Torvalds [Tue, 30 Apr 2013 16:37:55 +0000 (09:37 -0700)]
Merge branch 'for-linus' of git://git./linux/kernel/git/jikos/hid

Pull HID updates from Jiri Kosina:

 - hid driver transport cleanup, finalizing the long-desired decoupling
   of core from transport layers, by Benjamin Tissoires and Henrik
   Rydberg

 - support for hybrid finger/pen multitouch HID devices, by Benjamin
   Tissoires

 - fix for long-standing issue in Logitech unifying driver sometimes not
   inializing properly due to device specifics, by Andrew de los Reyes

 - Wii remote driver updates to support 2nd generation of devices, by
   David Herrmann

 - support for Apple IR remote

 - roccat driver now supports new devices (Roccat Kone Pure, IskuFX), by
   Stefan Achatz

 - debugfs locking fixes in hid debug interface, by Jiri Kosina

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (43 commits)
  HID: protect hid_debug_list
  HID: debug: break out hid_dump_report() into hid-debug
  HID: Add PID for Japanese version of NE4K keyboard
  HID: hid-lg4ff add support for new version of DFGT wheel
  HID: icade: u16 which never < 0
  HID: clarify Magic Mouse Kconfig description
  HID: appleir: add support for Apple ir devices
  HID: roccat: added media key support for Kone
  HID: hid-lenovo-tpkbd: remove doubled hid_get_drvdata
  HID: i2c-hid: fix length for set/get report in i2c hid
  HID: wiimote: parse reduced status reports
  HID: wiimote: add 2nd generation Wii Remote IDs
  HID: wiimote: use unique battery names
  HID: hidraw: warn if userspace headers are outdated
  HID: multitouch: force BTN_STYLUS for pen devices
  HID: multitouch: append " Pen" to the name of the stylus input
  HID: multitouch: add handling for pen in dual-sensors device
  HID: multitouch: change touch sensor detection in mt_input_configured()
  HID: multitouch: do not map usage from non used reports
  HID: multitouch: breaks out touch handling in specific functions
  ...

11 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Linus Torvalds [Tue, 30 Apr 2013 16:36:50 +0000 (09:36 -0700)]
Merge branch 'for-linus' of git://git./linux/kernel/git/jikos/trivial

Pull trivial tree updates from Jiri Kosina:
 "Usual stuff, mostly comment fixes, typo fixes, printk fixes and small
  code cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits)
  mm: Convert print_symbol to %pSR
  gfs2: Convert print_symbol to %pSR
  m32r: Convert print_symbol to %pSR
  iostats.txt: add easy-to-find description for field 6
  x86 cmpxchg.h: fix wrong comment
  treewide: Fix typo in printk and comments
  doc: devicetree: Fix various typos
  docbook: fix 8250 naming in device-drivers
  pata_pdc2027x: Fix compiler warning
  treewide: Fix typo in printks
  mei: Fix comments in drivers/misc/mei
  treewide: Fix typos in kernel messages
  pm44xx: Fix comment for "CONFIG_CPU_IDLE"
  doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP"
  mmzone: correct "pags" to "pages" in comment.
  kernel-parameters: remove outdated 'noresidual' parameter
  Remove spurious _H suffixes from ifdef comments
  sound: Remove stray pluses from Kconfig file
  radio-shark: Fix printk "CONFIG_LED_CLASS"
  doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE
  ...

11 years agoMerge branch 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 15:42:45 +0000 (08:42 -0700)]
Merge branch 'x86-ras-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 RAS changes from Ingo Molnar:

 - Add an Intel CMCI hotplug fix

 - Add AMD family 16h EDAC support

 - Make the AMD MCE banks code more flexible for virtual environments

* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  amd64_edac: Add Family 16h support
  x86/mce: Rework cmci_rediscover() to play well with CPU hotplug
  x86, MCE, AMD: Use MCG_CAP MSR to find out number of banks on AMD
  x86, MCE, AMD: Replace shared_bank array with is_shared_bank() helper

11 years agoMerge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Tue, 30 Apr 2013 15:42:11 +0000 (08:42 -0700)]
Merge branch 'x86-platform-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 platform changes from Ingo Molnar:
 "Small fixes and cleanups all over the map"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/setup: Drop unneeded include <asm/dmi.h>
  x86/olpc/xo1/sci: Don't call input_free_device() after input_unregister_device()
  x86/platform/intel/mrst: Remove cast for kmalloc() return value
  x86/platform/uv: Replace kmalloc() & memset with kzalloc()

11 years agoMerge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Tue, 30 Apr 2013 15:41:21 +0000 (08:41 -0700)]
Merge branch 'x86-paravirt-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 paravirt update from Ingo Molnar:
 "Various paravirtualization related changes - the biggest one makes
  guest support optional via CONFIG_HYPERVISOR_GUEST"

* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, wakeup, sleep: Use pvops functions for changing GDT entries
  x86, xen, gdt: Remove the pvops variant of store_gdt.
  x86-32, gdt: Store/load GDT for ACPI S3 or hibernation/resume path is not needed
  x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.
  x86: Make Linux guest support optional
  x86, Kconfig: Move PARAVIRT_DEBUG into the paravirt menu

11 years agoMerge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 15:40:35 +0000 (08:40 -0700)]
Merge branch 'x86-mm-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 mm changes from Ingo Molnar:
 "Misc smaller changes all over the map"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/iommu/dmar: Remove warning for HPET scope type
  x86/mm/gart: Drop unnecessary check
  x86/mm/hotplug: Put kernel_physical_mapping_remove() declaration in CONFIG_MEMORY_HOTREMOVE
  x86/mm/fixmap: Remove unused FIX_CYCLONE_TIMER
  x86/mm/numa: Simplify some bit mangling
  x86/mm: Re-enable DEBUG_TLBFLUSH for X86_32
  x86/mm/cpa: Cleanup split_large_page() and its callee
  x86: Drop always empty .text..page_aligned section

11 years agoMerge branch 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 15:37:24 +0000 (08:37 -0700)]
Merge branch 'x86-kaslr-for-linus' of git://git./linux/kernel/git/tip/tip

Pull perparatory x86 kasrl changes from Ingo Molnar:
 "This contains changes from the ongoing KASLR work, by Kees Cook.

  The main changes are the use of a read-only IDT on x86 (which
  decouples the userspace visible virtual IDT address from the physical
  address), and a rework of ELF relocation support, in preparation of
  random, boot-time kernel image relocation."

* 'x86-kaslr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, relocs: Refactor the relocs tool to merge 32- and 64-bit ELF
  x86, relocs: Build separate 32/64-bit tools
  x86, relocs: Add 64-bit ELF support to relocs tool
  x86, relocs: Consolidate processing logic
  x86, relocs: Generalize ELF structure names
  x86: Use a read-only IDT alias on all CPUs

11 years agoMerge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 15:35:20 +0000 (08:35 -0700)]
Merge branch 'x86-debug-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 debug update from Ingo Molnar:
 "Two small changes: a documentation update and a constification"

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, early-printk: Update earlyprintk documentation (and kill x86 copy)
  x86: Constify a few items

11 years agoMerge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 15:34:38 +0000 (08:34 -0700)]
Merge branch 'x86-cpu-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 cpuid changes from Ingo Molnar:
 "The biggest change is x86 CPU bug handling refactoring and cleanups,
  by Borislav Petkov"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, CPU, AMD: Drop useless label
  x86, AMD: Correct {rd,wr}msr_amd_safe warnings
  x86: Fold-in trivial check_config function
  x86, cpu: Convert AMD Erratum 400
  x86, cpu: Convert AMD Erratum 383
  x86, cpu: Convert Cyrix coma bug detection
  x86, cpu: Convert FDIV bug detection
  x86, cpu: Convert F00F bug detection
  x86, cpu: Expand cpufeature facility to include cpu bugs

11 years agoMerge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Tue, 30 Apr 2013 15:34:07 +0000 (08:34 -0700)]
Merge branch 'x86-cleanups-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 cleanups from Ingo Molnar:
 "Misc smaller cleanups"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/lib: Fix spelling, put space between a numeral and its units
  x86/lib: Fix spelling in the comments
  x86, quirks: Shut-up a long-standing gcc warning
  x86, msr: Unify variable names
  x86-64, docs, mm: Add vsyscall range to virtual address space layout
  x86: Drop KERNEL_IMAGE_START
  x86_64: Use __BOOT_DS instead_of __KERNEL_DS for safety

11 years agoMerge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 15:32:16 +0000 (08:32 -0700)]
Merge branch 'x86-asm-for-linus' of git://git./linux/kernel/git/tip/tip

Pull extable dmesg fixlet from Ingo Molnar:
 "Small tweak to reduce kmsg boot time spam"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  extable: Flip the sorting message

11 years agoMerge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Tue, 30 Apr 2013 15:15:40 +0000 (08:15 -0700)]
Merge branch 'timers-core-for-linus' of git://git./linux/kernel/git/tip/tip

Pull core timer updates from Ingo Molnar:
 "The main changes in this cycle's merge are:

   - Implement shadow timekeeper to shorten in kernel reader side
     blocking, by Thomas Gleixner.

   - Posix timers enhancements by Pavel Emelyanov:

   - allocate timer ID per process, so that exact timer ID allocations
     can be re-created be checkpoint/restore code.

   - debuggability and tooling (/proc/PID/timers, etc.) improvements.

   - suspend/resume enhancements by Feng Tang: on certain new Intel Atom
     processors (Penwell and Cloverview), there is a feature that the
     TSC won't stop in S3 state, so the TSC value won't be reset to 0
     after resume.  This can be taken advantage of by the generic via
     the CLOCK_SOURCE_SUSPEND_NONSTOP flag: instead of using the RTC to
     recover/approximate sleep time, the main (and precise) clocksource
     can be used.

   - Fix /proc/timer_list for 4096 CPUs by Nathan Zimmer: on so many
     CPUs the file goes beyond 4MB of size and thus the current
     simplistic seqfile approach fails.  Convert /proc/timer_list to a
     proper seq_file with its own iterator.

   - Cleanups and refactorings of the core timekeeping code by John
     Stultz.

   - International Atomic Clock time is managed by the NTP code
     internally currently but not exposed externally.  Separate the TAI
     code out and add CLOCK_TAI support and TAI support to the hrtimer
     and posix-timer code, by John Stultz.

   - Add deep idle support enhacement to the broadcast clockevents core
     timer code, by Daniel Lezcano: add an opt-in CLOCK_EVT_FEAT_DYNIRQ
     clockevents feature (which will be utilized by future clockevents
     driver updates), which allows the use of IRQ affinities to avoid
     spurious wakeups of idle CPUs - the right CPU with an expiring
     timer will be woken.

   - Add new ARM bcm281xx clocksource driver, by Christian Daudt

   - ... various other fixes and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  clockevents: Set dummy handler on CPU_DEAD shutdown
  timekeeping: Update tk->cycle_last in resume
  posix-timers: Remove unused variable
  clockevents: Switch into oneshot mode even if broadcast registered late
  timer_list: Convert timer list to be a proper seq_file
  timer_list: Split timer_list_show_tickdevices
  posix-timers: Show sigevent info in proc file
  posix-timers: Introduce /proc/PID/timers file
  posix timers: Allocate timer id per process (v2)
  timekeeping: Make sure to notify hrtimers when TAI offset changes
  hrtimer: Fix ktime_add_ns() overflow on 32bit architectures
  hrtimer: Add expiry time overflow check in hrtimer_interrupt
  timekeeping: Shorten seq_count region
  timekeeping: Implement a shadow timekeeper
  timekeeping: Delay update of clock->cycle_last
  timekeeping: Store cycle_last value in timekeeper struct as well
  ntp: Remove ntp_lock, using the timekeeping locks to protect ntp state
  timekeeping: Simplify tai updating from do_adjtimex
  timekeeping: Hold timekeepering locks in do_adjtimex and hardpps
  timekeeping: Move ADJ_SETOFFSET to top level do_adjtimex()
  ...

11 years agoarm64: Use acquire/release semantics instead of explicit DMB
Catalin Marinas [Tue, 30 Apr 2013 14:58:37 +0000 (15:58 +0100)]
arm64: Use acquire/release semantics instead of explicit DMB

This patch changes the test_and_*_bit functions to use the
load-acquire/store-release instructions instead of explicit DMB.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
11 years agoarm64: klib: bitops: fix unpredictable stxr usage
Mark Rutland [Tue, 30 Apr 2013 10:11:15 +0000 (11:11 +0100)]
arm64: klib: bitops: fix unpredictable stxr usage

We're currently relying on unpredictable behaviour in our testops
(test_and_*_bit), as stxr is unpredictable when the status register and
the source register are the same

This patch changes reallocates the status register so as to bring us back into
the realm of predictable behaviour. Boot tested on an AEMv8 model.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
11 years agoMerge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Tue, 30 Apr 2013 14:50:17 +0000 (07:50 -0700)]
Merge branch 'smp-hotplug-for-linus' of git://git./linux/kernel/git/tip/tip

Pull SMP/hotplug changes from Ingo Molnar:
 "This is a pretty large, multi-arch series unifying and generalizing
  the various disjunct pieces of idle routines that architectures have
  historically copied from each other and have grown in random, wildly
  inconsistent and sometimes buggy directions:

   101 files changed, 455 insertions(+), 1328 deletions(-)

  this went through a number of review and test iterations before it was
  committed, it was tested on various architectures, was exposed to
  linux-next for quite some time - nevertheless it might cause problems
  on architectures that don't read the mailing lists and don't regularly
  test linux-next.

  This cat herding excercise was motivated by the -rt kernel, and was
  brought to you by Thomas "the Whip" Gleixner."

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  idle: Remove GENERIC_IDLE_LOOP config switch
  um: Use generic idle loop
  ia64: Make sure interrupts enabled when we "safe_halt()"
  sparc: Use generic idle loop
  idle: Remove unused ARCH_HAS_DEFAULT_IDLE
  bfin: Fix typo in arch_cpu_idle()
  xtensa: Use generic idle loop
  x86: Use generic idle loop
  unicore: Use generic idle loop
  tile: Use generic idle loop
  tile: Enter idle with preemption disabled
  sh: Use generic idle loop
  score: Use generic idle loop
  s390: Use generic idle loop
  powerpc: Use generic idle loop
  parisc: Use generic idle loop
  openrisc: Use generic idle loop
  mn10300: Use generic idle loop
  mips: Use generic idle loop
  microblaze: Use generic idle loop
  ...

11 years agoMerge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Tue, 30 Apr 2013 14:43:28 +0000 (07:43 -0700)]
Merge branch 'sched-core-for-linus' of git://git./linux/kernel/git/tip/tip

Pull scheduler changes from Ingo Molnar:
 "The main changes in this development cycle were:

   - full dynticks preparatory work by Frederic Weisbecker

   - factor out the cpu time accounting code better, by Li Zefan

   - multi-CPU load balancer cleanups and improvements by Joonsoo Kim

   - various smaller fixes and cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  sched: Fix init NOHZ_IDLE flag
  sched: Prevent to re-select dst-cpu in load_balance()
  sched: Rename load_balance_tmpmask to load_balance_mask
  sched: Move up affinity check to mitigate useless redoing overhead
  sched: Don't consider other cpus in our group in case of NEWLY_IDLE
  sched: Explicitly cpu_idle_type checking in rebalance_domains()
  sched: Change position of resched_cpu() in load_balance()
  sched: Fix wrong rq's runnable_avg update with rt tasks
  sched: Document task_struct::personality field
  sched/cpuacct/UML: Fix header file dependency bug on the UML build
  cgroup: Kill subsys.active flag
  sched/cpuacct: No need to check subsys active state
  sched/cpuacct: Initialize cpuacct subsystem earlier
  sched/cpuacct: Initialize root cpuacct earlier
  sched/cpuacct: Allocate per_cpu cpuusage for root cpuacct statically
  sched/cpuacct: Clean up cpuacct.h
  sched/cpuacct: Remove redundant NULL checks in cpuacct_acount_field()
  sched/cpuacct: Remove redundant NULL checks in cpuacct_charge()
  sched/cpuacct: Add cpuacct_acount_field()
  sched/cpuacct: Add cpuacct_init()
  ...

11 years agoMerge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 14:41:01 +0000 (07:41 -0700)]
Merge branch 'perf-core-for-linus' of git://git./linux/kernel/git/tip/tip

Pull perf updates from Ingo Molnar:
 "Features:

   - Add "uretprobes" - an optimization to uprobes, like kretprobes are
     an optimization to kprobes.  "perf probe -x file sym%return" now
     works like kretprobes.  By Oleg Nesterov.

   - Introduce per core aggregation in 'perf stat', from Stephane
     Eranian.

   - Add memory profiling via PEBS, from Stephane Eranian.

   - Event group view for 'annotate' in --stdio, --tui and --gtk, from
     Namhyung Kim.

   - Add support for AMD NB and L2I "uncore" counters, by Jacob Shin.

   - Add Ivy Bridge-EP uncore support, by Zheng Yan

   - IBM zEnterprise EC12 oprofile support patchlet from Robert Richter.

   - Add perf test entries for checking breakpoint overflow signal
     handler issues, from Jiri Olsa.

   - Add perf test entry for for checking number of EXIT events, from
     Namhyung Kim.

   - Add perf test entries for checking --cpu in record and stat, from
     Jiri Olsa.

   - Introduce perf stat --repeat forever, from Frederik Deweerdt.

   - Add --no-demangle to report/top, from Namhyung Kim.

   - PowerPC fixes plus a couple of cleanups/optimizations in uprobes
     and trace_uprobes, by Oleg Nesterov.

  Various fixes and refactorings:

   - Fix dependency of the python binding wrt libtraceevent, from
     Naohiro Aota.

   - Simplify some perf_evlist methods and to allow 'stat' to share code
     with 'record' and 'trace', by Arnaldo Carvalho de Melo.

   - Remove dead code in related to libtraceevent integration, from
     Namhyung Kim.

   - Revert "perf sched: Handle PERF_RECORD_EXIT events" to get 'perf
     sched lat' back working, by Arnaldo Carvalho de Melo

   - We don't use Newt anymore, just plain libslang, by Arnaldo Carvalho
     de Melo.

   - Kill a bunch of die() calls, from Namhyung Kim.

   - Fix build on non-glibc systems due to libio.h absence, from Cody P
     Schafer.

   - Remove some perf_session and tracing dead code, from David Ahern.

   - Honor parallel jobs, fix from Borislav Petkov

   - Introduce tools/lib/lk library, initially just removing duplication
     among tools/perf and tools/vm.  from Borislav Petkov

  ... and many more I missed to list, see the shortlog and git log for
  more details."

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (136 commits)
  perf/x86/intel/P4: Robistify P4 PMU types
  perf/x86/amd: Fix AMD NB and L2I "uncore" support
  perf/x86/amd: Remove old-style NB counter support from perf_event_amd.c
  perf/x86: Check all MSRs before passing hw check
  perf/x86/amd: Add support for AMD NB and L2I "uncore" counters
  perf/x86/intel: Add Ivy Bridge-EP uncore support
  perf/x86/intel: Fix SNB-EP CBO and PCU uncore PMU filter management
  perf/x86: Avoid kfree() in CPU_{STARTING,DYING}
  uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty
  uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()
  uprobes/tracing: Change create_trace_uprobe() to support uretprobes
  uprobes/tracing: Make seq_printf() code uretprobe-friendly
  uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendly
  uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendly
  uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()
  uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpers
  uprobes/tracing: Generalize struct uprobe_trace_entry_head
  uprobes/tracing: Kill the pointless local_save_flags/preempt_count calls
  uprobes/tracing: Kill the pointless seq_print_ip_sym() call
  uprobes/tracing: Kill the pointless task_pt_regs() calls
  ...

11 years agoMerge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 14:39:01 +0000 (07:39 -0700)]
Merge branch 'core-rcu-for-linus' of git://git./linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "The main changes in this cycle are mostly related to preparatory work
  for the full-dynticks work:

   - Remove restrictions on no-CBs CPUs, make RCU_FAST_NO_HZ take
     advantage of numbered callbacks, do callback accelerations based on
     numbered callbacks.  Posted to LKML at
        https://lkml.org/lkml/2013/3/18/960

   - RCU documentation updates.  Posted to LKML at
        https://lkml.org/lkml/2013/3/18/570

   - Miscellaneous fixes.  Posted to LKML at
        https://lkml.org/lkml/2013/3/18/594"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  rcu: Make rcu_accelerate_cbs() note need for future grace periods
  rcu: Abstract rcu_start_future_gp() from rcu_nocb_wait_gp()
  rcu: Rename n_nocb_gp_requests to need_future_gp
  rcu: Push lock release to rcu_start_gp()'s callers
  rcu: Repurpose no-CBs event tracing to future-GP events
  rcu: Rearrange locking in rcu_start_gp()
  rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks
  rcu: Accelerate RCU callbacks at grace-period end
  rcu: Export RCU_FAST_NO_HZ parameters to sysfs
  rcu: Distinguish "rcuo" kthreads by RCU flavor
  rcu: Add event tracing for no-CBs CPUs' grace periods
  rcu: Add event tracing for no-CBs CPUs' callback registration
  rcu: Introduce proper blocking to no-CBs kthreads GP waits
  rcu: Provide compile-time control for no-CBs CPUs
  rcu: Tone down debugging during boot-up and shutdown.
  rcu: Add softirq-stall indications to stall-warning messages
  rcu: Documentation update
  rcu: Make bugginess of code sample more evident
  rcu: Fix hlist_bl_set_first_rcu() annotation
  rcu: Delete unused rcu_node "wakemask" field
  ...

11 years agotracing: Fix small merge bug
Steven Rostedt [Tue, 30 Apr 2013 00:08:14 +0000 (20:08 -0400)]
tracing: Fix small merge bug

During the 3.10 merge, a conflict happened and the resolution was
almost, but not quite, correct. An if statement was reversed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[ Duh. That was just silly of me  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
11 years agoMerge tag 'localmodconfig-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Tue, 30 Apr 2013 14:20:33 +0000 (07:20 -0700)]
Merge tag 'localmodconfig-v3.10' of git://git./linux/kernel/git/rostedt/linux-kconfig

Pull localmodconfig changes from Steven Rostedt:
 "A bug was recently found in the make localmodconfig where it would
  miss dependencies of config files are include in other config files
  inside an if statement.

  Also added a debug print that helped in solving this bug."

* tag 'localmodconfig-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-kconfig:
  localmodconfig: Process source kconfig files as they are found
  localmodconfig: Add debug prints for dependencies of module configs

11 years agoMerge branch 'devel-for-v3.10' into v4l_for_linus
Mauro Carvalho Chehab [Tue, 30 Apr 2013 12:01:04 +0000 (09:01 -0300)]
Merge branch 'devel-for-v3.10' into v4l_for_linus

* patchwork: (831 commits)
  [media] cx88: make core less verbose
  [media] em28xx: fix oops at em28xx_dvb_bus_ctrl()
  [media] s5c73m3: fix indentation of the help section in Kconfig
  [media] cx25821-alsa: get rid of a __must_check warning
  [media] cx25821-video: declare cx25821_vidioc_s_std as static
  [media] cx25821-video: remove maxw from cx25821_vidioc_try_fmt_vid_cap
  [media] r820t: Remove a warning for an unused value
  [media] dib0090: Fix a warning at dib0090_set_EFUSE
  [media] dib8000: fix a warning
  [media] dib8000: Fix sub-channel range
  [media] dib8000: store dtv_property_cache in a temp var
  [media] dib8000: warning fix: declare internal functions as static
  [media] r820t: quiet gcc warning on n_ring
  [media] r820t: memory leak in release()
  [media] r820t: precendence bug in r820t_xtal_check()
  [media] videodev2.h: Remove the unused old V4L1 buffer types
  [media] anysee: Grammar s/report the/report to/
  [media] anysee: Initialize ret = 0 in anysee_frontend_attach()
  [media] media: videobuf2: fix the length check for mmap
  [media] em28xx: save isoc endpoint number for DVB only if endpoint has alt settings with xMaxPacketSize != 0
  ...

Conflicts:
drivers/media/pci/cx25821/cx25821-video.c
drivers/media/platform/Kconfig

11 years agoMerge tag 'v3.9' into v4l_for_linus
Mauro Carvalho Chehab [Tue, 30 Apr 2013 12:00:33 +0000 (09:00 -0300)]
Merge tag 'v3.9' into v4l_for_linus

Linux 3.9

* tag 'v3.9': (1099 commits)
  Linux 3.9
  vm: add no-mmu vm_iomap_memory() stub
  efivars: only check for duplicates on the registered list
  TTY: fix atime/mtime regression
  aio: fix possible invalid memory access when DEBUG is enabled
  parisc: use spin_lock_irqsave/spin_unlock_irqrestore for PTE updates
  parisc: disable -mlong-calls compiler option for kernel modules
  parisc: uaccess: fix compiler warnings caused by __put_user casting
  parisc: Change kunmap macro to static inline function
  parisc: Provide __ucmpdi2 to resolve undefined references in 32 bit builds.
  sparc64: Fix missing put_cpu_var() in tlb_batch_add_one() when not batching.
  Revert "gpio: pxa: set initcall level to module init"
  efi: Check EFI revision in setup_efi_vars
  x86, efi: Fix a build warning
  Revert "MIPS: page.h: Provide more readable definition for PAGE_MASK."
  kernel/hz.bc: ignore.
  Linux 3.9-rc8
  events: Protect access via task_subsys_state_check()
  net: fix incorrect credentials passing
  x86, microcode: Verify the family before dispatching microcode patching
  ...