Commit Graph

12110 Commits

Author SHA1 Message Date
Shawn Bohrer 9ea71503a8 futex: Fix regression with read only mappings
commit 7485d0d375 (futexes: Remove rw
parameter from get_futex_key()) in 2.6.33 fixed two problems:  First, It
prevented a loop when encountering a ZERO_PAGE. Second, it fixed RW
MAP_PRIVATE futex operations by forcing the COW to occur by
unconditionally performing a write access get_user_pages_fast() to get
the page.  The commit also introduced a user-mode regression in that it
broke futex operations on read-only memory maps.  For example, this
breaks workloads that have one or more reader processes doing a
FUTEX_WAIT on a futex within a read only shared file mapping, and a
writer processes that has a writable mapping issuing the FUTEX_WAKE.

This fixes the regression for valid futex operations on RO mappings by
trying a RO get_user_pages_fast() when the RW get_user_pages_fast()
fails. This change makes it necessary to also check for invalid use
cases, such as anonymous RO mappings (which can never change) and the
ZERO_PAGE which the commit referenced above was written to address.

This patch does restore the original behavior with RO MAP_PRIVATE
mappings, which have inherent user-mode usage problems and don't really
make sense.  With this patch performing a FUTEX_WAIT within a RO
MAP_PRIVATE mapping will be successfully woken provided another process
updates the region of the underlying mapped file.  However, the mmap()
man page states that for a MAP_PRIVATE mapping:

  It is unspecified whether changes made to the file after
  the mmap() call are visible in the mapped region.

So user-mode users attempting to use futex operations on RO MAP_PRIVATE
mappings are depending on unspecified behavior.  Additionally a
RO MAP_PRIVATE mapping could fail to wake up in the following case.

  Thread-A: call futex(FUTEX_WAIT, memory-region-A).
            get_futex_key() return inode based key.
            sleep on the key
  Thread-B: call mprotect(PROT_READ|PROT_WRITE, memory-region-A)
  Thread-B: write memory-region-A.
            COW happen. This process's memory-region-A become related
            to new COWed private (ie PageAnon=1) page.
  Thread-B: call futex(FUETX_WAKE, memory-region-A).
            get_futex_key() return mm based key.
            IOW, we fail to wake up Thread-A.

Once again doing something like this is just silly and users who do
something like this get what they deserve.

While RO MAP_PRIVATE mappings are nonsensical, checking for a private
mapping requires walking the vmas and was deemed too costly to avoid a
userspace hang.

This Patch is based on Peter Zijlstra's initial patch with modifications to
only allow RO mappings for futex operations that need VERIFY_READ access.

Reported-by: David Oliver <david@rgmadvisors.com>
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: peterz@infradead.org
Cc: eric.dumazet@gmail.com
Cc: zvonler@rgmadvisors.com
Cc: hughd@google.com
Link: http://lkml.kernel.org/r/1309450892-30676-1-git-send-email-sbohrer@rgmadvisors.com
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-07-26 20:59:35 +02:00
jhbird.choi@samsung.com 1dd75f91ae genirq: Fix wrong bit operation
(!msk & 0x01) should be !(msk & 0x01)

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Link: http://lkml.kernel.org/r/1311229754-6003-1-git-send-email-jhbird.choi@samsung.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2011-07-26 16:24:02 +02:00
Linus Torvalds 45b583b10a Merge 'akpm' patch series
* Merge akpm patch series: (122 commits)
  drivers/connector/cn_proc.c: remove unused local
  Documentation/SubmitChecklist: add RCU debug config options
  reiserfs: use hweight_long()
  reiserfs: use proper little-endian bitops
  pnpacpi: register disabled resources
  drivers/rtc/rtc-tegra.c: properly initialize spinlock
  drivers/rtc/rtc-twl.c: check return value of twl_rtc_write_u8() in twl_rtc_set_time()
  drivers/rtc: add support for Qualcomm PMIC8xxx RTC
  drivers/rtc/rtc-s3c.c: support clock gating
  drivers/rtc/rtc-mpc5121.c: add support for RTC on MPC5200
  init: skip calibration delay if previously done
  misc/eeprom: add eeprom access driver for digsy_mtc board
  misc/eeprom: add driver for microwire 93xx46 EEPROMs
  checkpatch.pl: update $logFunctions
  checkpatch: make utf-8 test --strict
  checkpatch.pl: add ability to ignore various messages
  checkpatch: add a "prefer __aligned" check
  checkpatch: validate signature styles and To: and Cc: lines
  checkpatch: add __rcu as a sparse modifier
  checkpatch: suggest using min_t or max_t
  ...

Did this as a merge because of (trivial) conflicts in
 - Documentation/feature-removal-schedule.txt
 - arch/xtensa/include/asm/uaccess.h
that were just easier to fix up in the merge than in the patch series.
2011-07-25 21:00:19 -07:00
Stephen Boyd 626a031251 kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n
If CONFIG_IKCONFIG=m but CONFIG_IKCONFIG_PROC=n we get a module that has
no MODULE_LICENSE definition.  Move the MODULE_*() definitions outside the
CONFIG_IKCONFIG_PROC #ifdef to prevent this configuration from tainting
the kernel.

Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:15 -07:00
Amerigo Wang c5f41752fd notifiers: sys: move reboot notifiers into reboot.h
It is not necessary to share the same notifier.h.

This patch already moves register_reboot_notifier() and
unregister_reboot_notifier() from kernel/notifier.c to kernel/sys.c.

[amwang@redhat.com: make allyesconfig succeed on ppc64]
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:14 -07:00
Maxin B John ae891a1b93 devres: fix possible use after free
devres uses the pointer value as key after it's freed, which is safe but
triggers spurious use-after-free warnings on some static analysis tools.
Rearrange code to avoid such warnings.

Signed-off-by: Maxin B. John <maxin.john@gmail.com>
Reviewed-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:14 -07:00
Benjamin Herrenschmidt 2efaca927f mm/futex: fix futex writes on archs with SW tracking of dirty & young
I haven't reproduced it myself but the fail scenario is that on such
machines (notably ARM and some embedded powerpc), if you manage to hit
that futex path on a writable page whose dirty bit has gone from the PTE,
you'll livelock inside the kernel from what I can tell.

It will go in a loop of trying the atomic access, failing, trying gup to
"fix it up", getting succcess from gup, go back to the atomic access,
failing again because dirty wasn't fixed etc...

So I think you essentially hang in the kernel.

The scenario is probably rare'ish because affected architecture are
embedded and tend to not swap much (if at all) so we probably rarely hit
the case where dirty is missing or young is missing, but I think Shan has
a piece of SW that can reliably reproduce it using a shared writable
mapping & fork or something like that.

On archs who use SW tracking of dirty & young, a page without dirty is
effectively mapped read-only and a page without young unaccessible in the
PTE.

Additionally, some architectures might lazily flush the TLB when relaxing
write protection (by doing only a local flush), and expect a fault to
invalidate the stale entry if it's still present on another processor.

The futex code assumes that if the "in_atomic()" access -EFAULT's, it can
"fix it up" by causing get_user_pages() which would then be equivalent to
taking the fault.

However that isn't the case.  get_user_pages() will not call
handle_mm_fault() in the case where the PTE seems to have the right
permissions, regardless of the dirty and young state.  It will eventually
update those bits ...  in the struct page, but not in the PTE.

Additionally, it will not handle the lazy TLB flushing that can be
required by some architectures in the fault case.

Basically, gup is the wrong interface for the job.  The patch provides a
more appropriate one which boils down to just calling handle_mm_fault()
since what we are trying to do is simulate a real page fault.

The futex code currently attempts to write to user memory within a
pagefault disabled section, and if that fails, tries to fix it up using
get_user_pages().

This doesn't work on archs where the dirty and young bits are maintained
by software, since they will gate access permission in the TLB, and will
not be updated by gup().

In addition, there's an expectation on some archs that a spurious write
fault triggers a local TLB flush, and that is missing from the picture as
well.

I decided that adding those "features" to gup() would be too much for this
already too complex function, and instead added a new simpler
fixup_user_fault() which is essentially a wrapper around handle_mm_fault()
which the futex code can call.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix some nits Darren saw, fiddle comment layout]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: Shan Hai <haishan.bai@gmail.com>
Tested-by: Shan Hai <haishan.bai@gmail.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Darren Hart <darren.hart@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:11 -07:00
Linus Torvalds 154dd78d30 Merge branches 'kbuild', 'packaging' and 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
  genksyms: Use same type in loop comparison
  kbuild: silence generated makefile message
  kernel: prevent unnecessary rebuilding due to config_data.gz
  headers_install: fix __packed in exported kernel headers
  dtc: regen parser
  dtc: migrate parser to implicit rules
  kconfig: regen parser
  kconfig: migrate parser to implicit rules
  kconfig/zconf.l: do not ask to generate backup
  kconfig: kill no longer needed reference to YYDEBUG
  kconfig: constify `kconf_id_lookup'
  genksym: regen parser
  genksyms: migrate parser to implicit rules
  genksyms: drop -Wno-uninitialized from HOSTCFLAGS_parse.tab.o
  genksyms: pass hash and lookup functions name and target language though the input file
  kbuild: simplify the %_shipped rule
  kbuild: add implicit rules for parser generation
  kbuild: add `baseprereq'
  kbuild: Fix reference to vermagic.h

* 'packaging' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
  package: Makefile: fix perf target bug

* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
  gitignore: ignore debian build directory
2011-07-25 20:01:57 -07:00
Linus Torvalds d3ec4844d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  fs: Merge split strings
  treewide: fix potentially dangerous trailing ';' in #defined values/expressions
  uwb: Fix misspelling of neighbourhood in comment
  net, netfilter: Remove redundant goto in ebt_ulog_packet
  trivial: don't touch files that are removed in the staging tree
  lib/vsprintf: replace link to Draft by final RFC number
  doc: Kconfig: `to be' -> `be'
  doc: Kconfig: Typo: square -> squared
  doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
  drivers/net: static should be at beginning of declaration
  drivers/media: static should be at beginning of declaration
  drivers/i2c: static should be at beginning of declaration
  XTENSA: static should be at beginning of declaration
  SH: static should be at beginning of declaration
  MIPS: static should be at beginning of declaration
  ARM: static should be at beginning of declaration
  rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
  Update my e-mail address
  PCIe ASPM: forcedly -> forcibly
  gma500: push through device driver tree
  ...

Fix up trivial conflicts:
 - arch/arm/mach-ep93xx/dma-m2p.c (deleted)
 - drivers/gpio/gpio-ep93xx.c (renamed and context nearby)
 - drivers/net/r8169.c (just context changes)
2011-07-25 13:56:39 -07:00
Linus Torvalds 096a705bbc Merge branch 'for-3.1/core' of git://git.kernel.dk/linux-block
* 'for-3.1/core' of git://git.kernel.dk/linux-block: (24 commits)
  block: strict rq_affinity
  backing-dev: use synchronize_rcu_expedited instead of synchronize_rcu
  block: fix patch import error in max_discard_sectors check
  block: reorder request_queue to remove 64 bit alignment padding
  CFQ: add think time check for group
  CFQ: add think time check for service tree
  CFQ: move think time check variables to a separate struct
  fixlet: Remove fs_excl from struct task.
  cfq: Remove special treatment for metadata rqs.
  block: document blk_plug list access
  block: avoid building too big plug list
  compat_ioctl: fix make headers_check regression
  block: eliminate potential for infinite loop in blkdev_issue_discard
  compat_ioctl: fix warning caused by qemu
  block: flush MEDIA_CHANGE from drivers on close(2)
  blk-throttle: Make total_nr_queued unsigned
  block: Add __attribute__((format(printf...) and fix fallout
  fs/partitions/check.c: make local symbols static
  block:remove some spare spaces in genhd.c
  block:fix the comment error in blkdev.h
  ...
2011-07-25 10:33:36 -07:00
Jesper Juhl f629299b54 trace events: Update version number reference to new 3.x scheme for EVENT_POWER_TRACING_DEPRECATED
What was scheduled to be 2.6.41 is now going to be 3.1 .

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1107250929370.8080@swampdragon.chaosbits.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-25 09:37:21 +02:00
Linus Torvalds fcda12e7f6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  modpost: Fix modpost's license checking V3
  module: add /sys/module/<name>/uevent files
  module: change attr callbacks to take struct module_kobject
  modules: make arch's use default loader hooks
  modules: add default loader hook implementations
  param: fix return value handling in param_set_*
2011-07-24 09:54:54 -07:00
Linus Torvalds 5fabc487c9 Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (143 commits)
  KVM: IOMMU: Disable device assignment without interrupt remapping
  KVM: MMU: trace mmio page fault
  KVM: MMU: mmio page fault support
  KVM: MMU: reorganize struct kvm_shadow_walk_iterator
  KVM: MMU: lockless walking shadow page table
  KVM: MMU: do not need atomicly to set/clear spte
  KVM: MMU: introduce the rules to modify shadow page table
  KVM: MMU: abstract some functions to handle fault pfn
  KVM: MMU: filter out the mmio pfn from the fault pfn
  KVM: MMU: remove bypass_guest_pf
  KVM: MMU: split kvm_mmu_free_page
  KVM: MMU: count used shadow pages on prepareing path
  KVM: MMU: rename 'pt_write' to 'emulate'
  KVM: MMU: cleanup for FNAME(fetch)
  KVM: MMU: optimize to handle dirty bit
  KVM: MMU: cache mmio info on page fault path
  KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code
  KVM: MMU: do not update slot bitmap if spte is nonpresent
  KVM: MMU: fix walking shadow page table
  KVM guest: KVM Steal time registration
  ...
2011-07-24 09:07:03 -07:00
Kay Sievers 88bfa32479 module: add /sys/module/<name>/uevent files
Userspace wants to manage module parameters with udev rules.
This currently only works for loaded modules, but not for
built-in ones.

To allow access to the built-in modules we need to
re-trigger all module load events that happened before any
userspace was running. We already do the same thing for all
devices, subsystems(buses) and drivers.

This adds the currently missing /sys/module/<name>/uevent files
to all module entries.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split & trivial fix)
2011-07-24 22:06:04 +09:30
Kay Sievers 4befb026cf module: change attr callbacks to take struct module_kobject
This simplifies the next patch, where we have an attribute on a
builtin module (ie. module == NULL).

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split into 2)
2011-07-24 22:06:04 +09:30
Jonas Bonn 74e08fcf7b modules: add default loader hook implementations
The module loader code allows architectures to hook into the code by
providing a small number of entry points that each arch must implement.
This patch provides __weakly linked generic implementations of these
entry points for architectures that don't need to do anything special.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-24 22:06:04 +09:30
Satoru Moriya 81c7413650 param: fix return value handling in param_set_*
In STANDARD_PARAM_DEF, param_set_* handles the case in which strtolfn
returns -EINVAL but it may return -ERANGE. If it returns -ERANGE,
param_set_* may set uninitialized value to the paramerter. We should handle
both cases.

The one of the cases in which strtolfn() returns -ERANGE is following:

 *Type of module parameter is long
 *Set the parameter more than LONG_MAX

Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-07-24 22:06:03 +09:30
Linus Torvalds bbd9d6f7fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Linus Torvalds dc43d9fa73 Merge branch 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mtrr: Use pci_dev->revision
  x86, mtrr: use stop_machine APIs for doing MTRR rendezvous
  stop_machine: implement stop_machine_from_inactive_cpu()
  stop_machine: reorganize stop_cpus() implementation
  x86, mtrr: lock stop machine during MTRR rendezvous sequence
2011-07-22 17:04:04 -07:00
Linus Torvalds 112ec46966 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  time: Fix stupid KERN_WARN compile issue
  rtc: Avoid accumulating time drift in suspend/resume
  time: Avoid accumulating time drift in suspend/resume
  time: Catch invalid timespec sleep values in __timekeeping_inject_sleeptime
2011-07-22 16:52:18 -07:00
Linus Torvalds bdc7ccfc06 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair
  sched: Replace use of entity_key()
  sched: Separate group-scheduling code more clearly
  sched: Reorder root_domain to remove 64 bit alignment padding
  sched: Do not attempt to destroy uninitialized rt_bandwidth
  sched: Remove unused function cpu_cfs_rq()
  sched: Fix (harmless) typo 'CONFG_FAIR_GROUP_SCHED'
  sched, cgroup: Optimize load_balance_fair()
  sched: Don't update shares twice on on_rq parent
  sched: update correct entity's runtime in check_preempt_wakeup()
  xtensa: Use generic config PREEMPT definition
  h8300: Use generic config PREEMPT definition
  m32r: Use generic PREEMPT config
  sched: Skip autogroup when looking for all rt sched groups
  sched: Simplify mutex_spin_on_owner()
  sched: Remove rcu_read_lock() from wake_affine()
  sched: Generalize sleep inside spinlock detection
  sched: Make sleeping inside spinlock detection working in !CONFIG_PREEMPT
  sched: Isolate preempt counting in its own config option
  sched: Remove pointless in_atomic() definition check
  ...
2011-07-22 16:45:02 -07:00
Linus Torvalds 4d4abdcb1d Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (123 commits)
  perf: Remove the nmi parameter from the oprofile_perf backend
  x86, perf: Make copy_from_user_nmi() a library function
  perf: Remove perf_event_attr::type check
  x86, perf: P4 PMU - Fix typos in comments and style cleanup
  perf tools: Make test use the preset debugfs path
  perf tools: Add automated tests for events parsing
  perf tools: De-opt the parse_events function
  perf script: Fix display of IP address for non-callchain path
  perf tools: Fix endian conversion reading event attr from file header
  perf tools: Add missing 'node' alias to the hw_cache[] array
  perf probe: Support adding probes on offline kernel modules
  perf probe: Add probed module in front of function
  perf probe: Introduce debuginfo to encapsulate dwarf information
  perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
  perf probe: Remove redundant dwarf functions
  perf probe: Move strtailcmp to string.c
  perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
  tracing/kprobe: Update symbol reference when loading module
  tracing/kprobes: Support module init function probing
  kprobes: Return -ENOENT if probe point doesn't exist
  ...
2011-07-22 16:44:39 -07:00
Linus Torvalds 0342cbcfce Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: Fix wrong check in list_splice_init_rcu()
  net,rcu: Convert call_rcu(xt_rateest_free_rcu) to kfree_rcu()
  sysctl,rcu: Convert call_rcu(free_head) to kfree
  vmalloc,rcu: Convert call_rcu(rcu_free_vb) to kfree_rcu()
  vmalloc,rcu: Convert call_rcu(rcu_free_va) to kfree_rcu()
  ipc,rcu: Convert call_rcu(ipc_immediate_free) to kfree_rcu()
  ipc,rcu: Convert call_rcu(free_un) to kfree_rcu()
  security,rcu: Convert call_rcu(sel_netport_free) to kfree_rcu()
  security,rcu: Convert call_rcu(sel_netnode_free) to kfree_rcu()
  ia64,rcu: Convert call_rcu(sn_irq_info_free) to kfree_rcu()
  block,rcu: Convert call_rcu(disk_free_ptbl_rcu_cb) to kfree_rcu()
  scsi,rcu: Convert call_rcu(fc_rport_free_rcu) to kfree_rcu()
  audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
  security,rcu: Convert call_rcu(whitelist_item_free) to kfree_rcu()
  md,rcu: Convert call_rcu(free_conf) to kfree_rcu()
2011-07-22 16:44:08 -07:00
Linus Torvalds 391d6276db Merge branch 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix trace_[soft,hard]irqs_[on,off]() recursion
  printk: Fix console_sem vs logbuf_lock unlock race
  printk: Release console_sem after logbuf_lock
2011-07-22 16:43:49 -07:00
Linus Torvalds 75b56ec294 Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix lockdep_no_validate against IRQ states
  mutex: Make mutex_destroy() an inline function
  plist: Remove the need to supply locks to plist heads
  lockup detector: Fix reference to the non-existent CONFIG_DETECT_SOFTLOCKUP option
2011-07-22 16:43:21 -07:00
Linus Torvalds 431bf99d26 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (51 commits)
  PM: Improve error code of pm_notifier_call_chain()
  PM: Add "RTC" to PM trace time stamps to avoid confusion
  PM / Suspend: Export suspend_set_ops, suspend_valid_only_mem
  PM / Suspend: Add .suspend_again() callback to suspend_ops
  PM / OPP: Introduce function to free cpufreq table
  ARM / shmobile: Return -EBUSY from A4LC power off if A3RV is active
  PM / Domains: Take .power_off() error code into account
  ARM / shmobile: Use genpd_queue_power_off_work()
  ARM / shmobile: Use pm_genpd_poweroff_unused()
  PM / Domains: Introduce function to power off all unused PM domains
  OMAP: PM: disable idle on suspend for GPIO and UART
  OMAP: PM: omap_device: add API to disable idle on suspend
  OMAP: PM: omap_device: add system PM methods for PM domain handling
  OMAP: PM: omap_device: conditionally use PM domain runtime helpers
  PM / Runtime: Add new helper function: pm_runtime_status_suspended()
  PM / Domains: Queue up power off work only if it is not pending
  PM / Domains: Improve handling of wakeup devices during system suspend
  PM / Domains: Do not restore all devices on power off error
  PM / Domains: Allow callbacks to execute all runtime PM helpers
  PM / Domains: Do not execute device callbacks under locks
  ...
2011-07-22 16:01:57 -07:00
Linus Torvalds 5a791ea4fa Merge branch 'for-3.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-3.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: separate out drain_workqueue() from destroy_workqueue()
  workqueue: remove cancel_rearming_delayed_work[queue]()
2011-07-22 15:07:15 -07:00
Linus Torvalds 8209f53d79 Merge branch 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc
* 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (39 commits)
  ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever
  ptrace: fix ptrace_signal() && STOP_DEQUEUED interaction
  connector: add an event for monitoring process tracers
  ptrace: dont send SIGSTOP on auto-attach if PT_SEIZED
  ptrace: mv send-SIGSTOP from do_fork() to ptrace_init_task()
  ptrace_init_task: initialize child->jobctl explicitly
  has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/
  ptrace: make former thread ID available via PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop
  ptrace: wait_consider_task: s/same_thread_group/ptrace_reparented/
  ptrace: kill real_parent_is_ptracer() in in favor of ptrace_reparented()
  ptrace: ptrace_reparented() should check same_thread_group()
  redefine thread_group_leader() as exit_signal >= 0
  do not change dead_task->exit_signal
  kill task_detached()
  reparent_leader: check EXIT_DEAD instead of task_detached()
  make do_notify_parent() __must_check, update the callers
  __ptrace_detach: avoid task_detached(), check do_notify_parent()
  kill tracehook_notify_death()
  make do_notify_parent() return bool
  ptrace: s/tracehook_tracer_task()/ptrace_parent()/
  ...
2011-07-22 15:06:50 -07:00
Linus Torvalds 951cc93a74 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1287 commits)
  icmp: Fix regression in nexthop resolution during replies.
  net: Fix ppc64 BPF JIT dependencies.
  acenic: include NET_SKB_PAD headroom to incoming skbs
  ixgbe: convert to ndo_fix_features
  ixgbe: only enable WoL for magic packet by default
  ixgbe: remove ifdef check for non-existent define
  ixgbe: Pass staterr instead of re-reading status and error bits from descriptor
  ixgbe: Move interrupt related values out of ring and into q_vector
  ixgbe: add structure for containing RX/TX rings to q_vector
  ixgbe: inline the ixgbe_maybe_stop_tx function
  ixgbe: Update ATR to use recorded TX queues instead of CPU for routing
  igb: Fix for DH89xxCC near end loopback test
  e1000: always call e1000_check_for_link() on e1000_ce4100 MACs.
  netxen: add fw version compatibility check
  be2net: request native mode each time the card is reset
  ipv4: Constrain UFO fragment sizes to multiples of 8 bytes
  virtio_net: Fix panic in virtnet_remove
  ipv6: make fragment identifications less predictable
  ipv6: unshare inetpeers
  can: make function can_get_bittiming static
  ...
2011-07-22 14:43:13 -07:00
Lin Ming 0f3171438f sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair
No need to define a new "cfs_rq" variable in the "for" block.
Just use the one at the top of the function.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1311297271.3938.1352.camel@minggr.sh.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-22 12:47:22 +02:00
David S. Miller 033b1142f4 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/bluetooth/l2cap_core.c
2011-07-21 13:38:42 -07:00
David S. Miller f5caadbb3d Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6 2011-07-21 12:39:35 -07:00
Peter Zijlstra efbe2eee6d lockdep: Fix lockdep_no_validate against IRQ states
Thomas noticed that a lock marked with lockdep_set_novalidate_class()
will still trigger warnings for IRQ inversions. Cure this by skipping
those when marking irq state.

Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-2dp5vmpsxeraqm42kgww6ge2@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 20:43:16 +02:00
Lin Ming 9985c20f9e perf: Remove perf_event_attr::type check
PMU type id can be allocated dynamically, so perf_event_attr::type check
when copying attribute from userspace to kernel is not valid.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Cc: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309421396-17438-4-git-send-email-ming.m.lin@intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 20:41:55 +02:00
Stephan Baerwolf 2bd2d6f2dc sched: Replace use of entity_key()
"entity_key()" is only used in "__enqueue_entity()" and
its only function is to subtract a tasks vruntime by
its groups minvruntime.
Before this patch a rbtree enqueue-decision is done by
comparing two tasks in the style:

	"if (entity_key(cfs_rq, se) < entity_key(cfs_rq, entry))"

which would be

	"if (se->vruntime-cfs_rq->min_vruntime < entry->vruntime-cfs_rq->min_vruntime)"

or (if reducing cfs_rq->min_vruntime out)

	"if (se->vruntime < entry->vruntime)"

which is

	"if (entity_before(se, entry))"

So we do not need "entity_key()".
If "entity_before()" is inline we will also save one subtraction (only one,
because "entity_key(cfs_rq, se)"  was cached in "key")

Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-ns12mnd2h5w8rb9agd8hnsfk@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:55 +02:00
Jan H. Schönherr acb5a9ba3b sched: Separate group-scheduling code more clearly
Clean up cfs/rt runqueue initialization by moving group scheduling
related code into the corresponding functions.

Also, keep group scheduling as an add-on, so that things are only done
additionally, i. e. remove the init_*_rq() calls from init_tg_*_entry().
(This removes a redundant initalization during sched_init()).

In case of group scheduling rt_rq->highest_prio.curr is now initialized
twice, but adding another #ifdef seems not worth it.

Signed-off-by: Jan H. Schönherr <schnhrr@cs.tu-berlin.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1310661163-16606-1-git-send-email-schnhrr@cs.tu-berlin.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:54 +02:00
Richard Kennedy 26a148eb9c sched: Reorder root_domain to remove 64 bit alignment padding
Reorder root_domain to remove 8 bytes of alignment padding on 64 bit
builds, this shrinks the size from 1736 to 1728 bytes, therefore using
one fewer cachelines.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1310726492.1977.5.camel@castor.rsk
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:52 +02:00
Bianca Lutz 99bc52429f sched: Do not attempt to destroy uninitialized rt_bandwidth
If a task group is to be created and alloc_fair_sched_group() fails,
then the rt_bandwidth of the corresponding task group is not yet
initialized. The caller, sched_create_group(), starts a clean up
procedure which calls free_rt_sched_group() which unconditionally
destroys the not yet initialized rt_bandwidth.

This crashes or hangs the system in lock_hrtimer_base(): UP systems
dereference a NULL pointer, while SMP systems loop endlessly on a
condition that cannot become true.

This patch simply avoids the destruction of rt_bandwidth when the
initialization code path was not reached.

(This was discovered by accident with a custom kernel modification.)

Signed-off-by: Bianca Lutz <sowilo@cs.tu-berlin.de>
Signed-off-by: Jan Schoenherr <schnhrr@cs.tu-berlin.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1310580816-10861-7-git-send-email-schnhrr@cs.tu-berlin.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:51 +02:00
Jan Schoenherr 045176d22f sched: Remove unused function cpu_cfs_rq()
The last reference to cpu_cfs_rq() was removed with commit 88ec22d3
("sched: Remove the cfs_rq dependency from set_task_cpu()"). Thus,
remove this function, too.

Signed-off-by: Jan Schoenherr <schnhrr@cs.tu-berlin.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1310580816-10861-3-git-send-email-schnhrr@cs.tu-berlin.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:49 +02:00
Jan Schoenherr 5f817d676b sched: Fix (harmless) typo 'CONFG_FAIR_GROUP_SCHED'
This patch fixes a typo located in a comment.

Signed-off-by: Jan Schoenherr <schnhrr@cs.tu-berlin.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1310580816-10861-2-git-send-email-schnhrr@cs.tu-berlin.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:48 +02:00
Peter Zijlstra 9763b67fb9 sched, cgroup: Optimize load_balance_fair()
Use for_each_leaf_cfs_rq() instead of list_for_each_entry_rcu(), this
achieves that load_balance_fair() only iterates those task_groups that
actually have tasks on busiest, and that we iterate bottom-up, trying to
move light groups before the heavier ones.

No idea if it will actually work out to be beneficial in practice, does
anybody have a cgroup workload that might show a difference one way or
the other?

[ Also move update_h_load to sched_fair.c, loosing #ifdef-ery ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/1310557009.2586.28.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:46 +02:00
Paul Turner 9598c82dca sched: Don't update shares twice on on_rq parent
In dequeue_task_fair() we bail on dequeue when we encounter a parenting entity
with additional weight.  However, we perform a double shares update on this
entity as we continue the shares update traversal from this point, despite
dequeue_entity() having already updated its queuing cfs_rq.
Avoid this by starting from the parent when we resume.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110707053059.797714697@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:44 +02:00
Paul Turner 9bbd737436 sched: update correct entity's runtime in check_preempt_wakeup()
While looking at check_preempt_wakeup() I realized that we are
potentially updating the wrong entity in the fair-group scheduling
case. In this case the current task's cfs_rq may not be the same as
the one used for the comparison between the waking task and the
existing task's vruntime.

This potentially results in us using a stale vruntime in the
pre-emption decision, providing a small false preference for the
previous task. The effects of this are bounded since we always
perform a hierarchal update on the tick.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/CAPM31R+2Ke2urUZKao5W92_LupdR4AYEv-EZWiJ3tG=tEes2cw@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:01:43 +02:00
Ingo Molnar 994bf1c922 Merge branch 'linus' into sched/core
Merge reason: pick up the latest scheduler fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 18:00:01 +02:00
Oleg Nesterov 8a35241803 ptrace: fix ptrace_signal() && STOP_DEQUEUED interaction
Simple test-case,

	int main(void)
	{
		int pid, status;

		pid = fork();
		if (!pid) {
			pause();
			assert(0);
			return 0x23;
		}

		assert(ptrace(PTRACE_ATTACH, pid, 0,0) == 0);
		assert(wait(&status) == pid);
		assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);

		kill(pid, SIGCONT);	// <--- also clears STOP_DEQUEUD

		assert(ptrace(PTRACE_CONT, pid, 0,0) == 0);
		assert(wait(&status) == pid);
		assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGCONT);

		assert(ptrace(PTRACE_CONT, pid, 0, SIGSTOP) == 0);
		assert(wait(&status) == pid);
		assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP);

		kill(pid, SIGKILL);
		return 0;
	}

Without the patch it hangs. After the patch SIGSTOP "injected" by the
tracer is not ignored and stops the tracee.

Note also that if this test-case uses, say, SIGWINCH instead of SIGCONT,
everything works without the patch. This can't be right, and this is
confusing.

The problem is that SIGSTOP (or any other sig_kernel_stop() signal) has
no effect without JOBCTL_STOP_DEQUEUED. This means it is simply ignored
after PTRACE_CONT unless JOBCTL_STOP_DEQUEUED was set "by accident", say
it wasn't cleared after initial SIGSTOP sent by PTRACE_ATTACH.

At first glance we could change ptrace_signal() to add STOP_DEQUEUED
after return from ptrace_stop(), but this is not right in case when the
tracer does not change the reported SIGSTOP and SIGCONT comes in between.
This is even more wrong with PT_SEIZED, SIGCONT adds JOBCTL_TRAP_NOTIFY
which will be "lost" during the TRAP_STOP | TRAP_NOTIFY report.

So lets add STOP_DEQUEUED _before_ we report the signal. It has no effect
unless sig_kernel_stop() == T after the tracer resumes us, and in the
latter case the pending STOP_DEQUEUED means no SIGCONT in between, we
should stop.

Note also that if SIGCONT was sent, PT_SEIZED tracee will correctly
report PTRACE_EVENT_STOP/SIGTRAP and thus the tracer can notice the fact
SIGSTOP was cancelled.

Also, move the current->ptrace check from ptrace_signal() to its caller,
get_signal_to_deliver(), this looks more natural.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
2011-07-21 17:06:53 +02:00
Ingo Molnar 40bcea7bbe Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core 2011-07-21 09:32:40 +02:00
Ingo Molnar 492f73a303 Merge branch 'perf/urgent' into perf/core
Merge reason: pick up the latest fixes - they won't make v3.0.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-21 09:29:21 +02:00
Christoph Hellwig 11b80f459a rw_semaphore: remove up/down_read_non_owner
Now that the last users is gone these can be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:47 -04:00
Linus Torvalds cf6ace16a3 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  signal: align __lock_task_sighand() irq disabling and RCU
  softirq,rcu: Inform RCU of irq_exit() activity
  sched: Add irq_{enter,exit}() to scheduler_ipi()
  rcu: protect __rcu_read_unlock() against scheduler-using irq handlers
  rcu: Streamline code produced by __rcu_read_unlock()
  rcu: Fix RCU_BOOST race handling current->rcu_read_unlock_special
  rcu: decrease rcu_report_exp_rnp coupling with scheduler
2011-07-20 15:56:25 -07:00
John Stultz cbaa51524b time: Fix stupid KERN_WARN compile issue
Terribly embarassing. Don't know how I committed this, but its
KERN_WARNING not KERN_WARN.

This fixes the following compile error:
kernel/time/timekeeping.c: In function ‘__timekeeping_inject_sleeptime’:
kernel/time/timekeeping.c:608: error: ‘KERN_WARN’ undeclared (first use in this function)
kernel/time/timekeeping.c:608: error: (Each undeclared identifier is reported only once
kernel/time/timekeeping.c:608: error: for each function it appears in.)
kernel/time/timekeeping.c:608: error: expected ‘)’ before string constant
make[2]: *** [kernel/time/timekeeping.o] Error 1

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-07-20 15:42:55 -07:00
Paul E. McKenney a95cded32d sysctl,rcu: Convert call_rcu(free_head) to kfree
The RCU callback free_head just calls kfree(), so we can use kfree_rcu()
instead of call_rcu().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-07-20 14:10:18 -07:00
Lai Jiangshan 3b097c4696 audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
The rcu callback __put_tree() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(__put_tree).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-07-20 14:10:11 -07:00
Ingo Molnar d1e9ae47a0 Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/urgent 2011-07-20 20:59:26 +02:00
Paul E. McKenney a841796f11 signal: align __lock_task_sighand() irq disabling and RCU
The __lock_task_sighand() function calls rcu_read_lock() with interrupts
and preemption enabled, but later calls rcu_read_unlock() with interrupts
disabled.  It is therefore possible that this RCU read-side critical
section will be preempted and later RCU priority boosted, which means that
rcu_read_unlock() will call rt_mutex_unlock() in order to deboost itself, but
with interrupts disabled. This results in lockdep splats, so this commit
nests the RCU read-side critical section within the interrupt-disabled
region of code.  This prevents the RCU read-side critical section from
being preempted, and thus prevents the attempt to deboost with interrupts
disabled.

It is quite possible that a better long-term fix is to make rt_mutex_unlock()
disable irqs when acquiring the rt_mutex structure's ->wait_lock.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-20 11:04:54 -07:00
Peter Zijlstra ec433f0c51 softirq,rcu: Inform RCU of irq_exit() activity
The rcu_read_unlock_special() function relies on in_irq() to exclude
scheduler activity from interrupt level.  This fails because exit_irq()
can invoke the scheduler after clearing the preempt_count() bits that
in_irq() uses to determine that it is at interrupt level.  This situation
can result in failures as follows:

 $task			IRQ		SoftIRQ

 rcu_read_lock()

 /* do stuff */

 <preempt> |= UNLOCK_BLOCKED

 rcu_read_unlock()
   --t->rcu_read_lock_nesting

			irq_enter();
			/* do stuff, don't use RCU */
			irq_exit();
			  sub_preempt_count(IRQ_EXIT_OFFSET);
			  invoke_softirq()

					ttwu();
					  spin_lock_irq(&pi->lock)
					  rcu_read_lock();
					  /* do stuff */
					  rcu_read_unlock();
					    rcu_read_unlock_special()
					      rcu_report_exp_rnp()
					        ttwu()
					          spin_lock_irq(&pi->lock) /* deadlock */

   rcu_read_unlock_special(t);

Ed can simply trigger this 'easy' because invoke_softirq() immediately
does a ttwu() of ksoftirqd/# instead of doing the in-place softirq stuff
first, but even without that the above happens.

Cure this by also excluding softirqs from the
rcu_read_unlock_special() handler and ensuring the force_irqthreads
ksoftirqd/# wakeup is done from full softirq context.

[ Alternatively, delaying the ->rcu_read_lock_nesting decrement
  until after the special handling would make the thing more robust
  in the face of interrupts as well.  And there is a separate patch
  for that. ]

Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-and-tested-by: Ed Tomlinson <edt@aei.ca>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-20 10:50:12 -07:00
Peter Zijlstra c5d753a55a sched: Add irq_{enter,exit}() to scheduler_ipi()
Ensure scheduler_ipi() calls irq_{enter,exit} when it does some actual
work. Traditionally we never did any actual work from the resched IPI
and all magic happened in the return from interrupt path.

Now that we do do some work, we need to ensure irq_{enter,exit} are
called so that we don't confuse things.

This affects things like timekeeping, NO_HZ and RCU, basically
everything with a hook in irq_enter/exit.

Explicit examples of things going wrong are:

  sched_clock_cpu() -- has a callback when leaving NO_HZ state to take
                    a new reading from GTOD and TSC. Without this
                    callback, time is stuck in the past.

  RCU -- needs in_irq() to work in order to avoid some nasty deadlocks

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-20 10:50:11 -07:00
Paul E. McKenney 10f39bb1b2 rcu: protect __rcu_read_unlock() against scheduler-using irq handlers
The addition of RCU read-side critical sections within runqueue and
priority-inheritance lock critical sections introduced some deadlock
cycles, for example, involving interrupts from __rcu_read_unlock()
where the interrupt handlers call wake_up().  This situation can cause
the instance of __rcu_read_unlock() invoked from interrupt to do some
of the processing that would otherwise have been carried out by the
task-level instance of __rcu_read_unlock().  When the interrupt-level
instance of __rcu_read_unlock() is called with a scheduler lock held
from interrupt-entry/exit situations where in_irq() returns false,
deadlock can result.

This commit resolves these deadlocks by using negative values of
the per-task ->rcu_read_lock_nesting counter to indicate that an
instance of __rcu_read_unlock() is in flight, which in turn prevents
instances from interrupt handlers from doing any special processing.
This patch is inspired by Steven Rostedt's earlier patch that similarly
made __rcu_read_unlock() guard against interrupt-mediated recursion
(see https://lkml.org/lkml/2011/7/15/326), but this commit refines
Steven's approach to avoid the need for preemption disabling on the
__rcu_read_unlock() fastpath and to also avoid the need for manipulating
a separate per-CPU variable.

This patch avoids need for preempt_disable() by instead using negative
values of the per-task ->rcu_read_lock_nesting counter.  Note that nested
rcu_read_lock()/rcu_read_unlock() pairs are still permitted, but they will
never see ->rcu_read_lock_nesting go to zero, and will therefore never
invoke rcu_read_unlock_special(), thus preventing them from seeing the
RCU_READ_UNLOCK_BLOCKED bit should it be set in ->rcu_read_unlock_special.
This patch also adds a check for ->rcu_read_unlock_special being negative
in rcu_check_callbacks(), thus preventing the RCU_READ_UNLOCK_NEED_QS
bit from being set should a scheduling-clock interrupt occur while
__rcu_read_unlock() is exiting from an outermost RCU read-side critical
section.

Of course, __rcu_read_unlock() can be preempted during the time that
->rcu_read_lock_nesting is negative.  This could result in the setting
of the RCU_READ_UNLOCK_BLOCKED bit after __rcu_read_unlock() checks it,
and would also result it this task being queued on the corresponding
rcu_node structure's blkd_tasks list.  Therefore, some later RCU read-side
critical section would enter rcu_read_unlock_special() to clean up --
which could result in deadlock if that critical section happened to be in
the scheduler where the runqueue or priority-inheritance locks were held.

This situation is dealt with by making rcu_preempt_note_context_switch()
check for negative ->rcu_read_lock_nesting, thus refraining from
queuing the task (and from setting RCU_READ_UNLOCK_BLOCKED) if we are
already exiting from the outermost RCU read-side critical section (in
other words, we really are no longer actually in that RCU read-side
critical section).  In addition, rcu_preempt_note_context_switch()
invokes rcu_read_unlock_special() to carry out the cleanup in this case,
which clears out the ->rcu_read_unlock_special bits and dequeues the task
(if necessary), in turn avoiding needless delay of the current RCU grace
period and needless RCU priority boosting.

It is still illegal to call rcu_read_unlock() while holding a scheduler
lock if the prior RCU read-side critical section has ever had either
preemption or irqs enabled.  However, the common use case is legal,
namely where then entire RCU read-side critical section executes with
irqs disabled, for example, when the scheduler lock is held across the
entire lifetime of the RCU read-side critical section.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-20 10:50:11 -07:00
Peter Zijlstra d110235d2c sched: Avoid creating superfluous NUMA domains on non-NUMA systems
When creating sched_domains, stop when we've covered the entire
target span instead of continuing to create domains, only to
later find they're redundant and throw them away again.

This avoids single node systems from touching funny NUMA
sched_domain creation code and reduces the risks of the new
SD_OVERLAP code.

Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Anton Blanchard <anton@samba.org>
Cc: mahesh@linux.vnet.ibm.com
Cc: benh@kernel.crashing.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1311180177.29152.57.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-20 18:54:33 +02:00
Peter Zijlstra e3589f6c81 sched: Allow for overlapping sched_domain spans
Allow for sched_domain spans that overlap by giving such domains their
own sched_group list instead of sharing the sched_groups amongst
each-other.

This is needed for machines with more than 16 nodes, because
sched_domain_node_span() will generate a node mask from the
16 nearest nodes without regard if these masks have any overlap.

Currently sched_domains have a sched_group that maps to their child
sched_domain span, and since there is no overlap we share the
sched_group between the sched_domains of the various CPUs. If however
there is overlap, we would need to link the sched_group list in
different ways for each cpu, and hence sharing isn't possible.

In order to solve this, allocate private sched_groups for each CPU's
sched_domain but have the sched_groups share a sched_group_power
structure such that we can uniquely track the power.

Reported-and-tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-20 18:32:41 +02:00
Peter Zijlstra 9c3f75cbd1 sched: Break out cpu_power from the sched_group structure
In order to prepare for non-unique sched_groups per domain, we need to
carry the cpu_power elsewhere, so put a level of indirection in.

Reported-and-tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-qkho2byuhe4482fuknss40ad@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-20 18:32:40 +02:00
Al Viro 6657719390 make sure that nsproxy_cache is initialized early enough
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:07 -04:00
Al Viro 3bfa784a65 kill file_permission() completely
convert the last remaining caller to inode_permission()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:11 -04:00
Paul E. McKenney be0e1e21ef rcu: Streamline code produced by __rcu_read_unlock()
Given some common flag combinations, particularly -Os, gcc will inline
rcu_read_unlock_special() despite its being in an unlikely() clause.
Use noinline to prohibit this misoptimization.

In addition, move the second barrier() in __rcu_read_unlock() so that
it is not on the common-case code path.  This will allow the compiler to
generate better code for the common-case path through __rcu_read_unlock().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2011-07-19 21:38:53 -07:00
Paul E. McKenney 7765be2fec rcu: Fix RCU_BOOST race handling current->rcu_read_unlock_special
The RCU_BOOST commits for TREE_PREEMPT_RCU introduced an other-task
write to a new RCU_READ_UNLOCK_BOOSTED bit in the task_struct structure's
->rcu_read_unlock_special field, but, as noted by Steven Rostedt, without
correctly synchronizing all accesses to ->rcu_read_unlock_special.
This could result in bits in ->rcu_read_unlock_special being spuriously
set and cleared due to conflicting accesses, which in turn could result
in deadlocks between the rcu_node structure's ->lock and the scheduler's
rq and pi locks.  These deadlocks would result from RCU incorrectly
believing that the just-ended RCU read-side critical section had been
preempted and/or boosted.  If that RCU read-side critical section was
executed with either rq or pi locks held, RCU's ensuing (incorrect)
calls to the scheduler would cause the scheduler to attempt to once
again acquire the rq and pi locks, resulting in deadlock.  More complex
deadlock cycles are also possible, involving multiple rq and pi locks
as well as locks from multiple rcu_node structures.

This commit fixes synchronization by creating ->rcu_boosted field in
task_struct that is accessed and modified only when holding the ->lock
in the rcu_node structure on which the task is queued (on that rcu_node
structure's ->blkd_tasks list).  This results in tasks accessing only
their own current->rcu_read_unlock_special fields, making unsynchronized
access once again legal, and keeping the rcu_read_unlock() fastpath free
of atomic instructions and memory barriers.

The reason that the rcu_read_unlock() fastpath does not need to access
the new current->rcu_boosted field is that this new field cannot
be non-zero unless the RCU_READ_UNLOCK_BLOCKED bit is set in the
current->rcu_read_unlock_special field.  Therefore, rcu_read_unlock()
need only test current->rcu_read_unlock_special: if that is zero, then
current->rcu_boosted must also be zero.

This bug does not affect TINY_PREEMPT_RCU because this implementation
of RCU accesses current->rcu_read_unlock_special with irqs disabled,
thus preventing races on the !SMP systems that TINY_PREEMPT_RCU runs on.

Maybe-reported-by: Dave Jones <davej@redhat.com>
Maybe-reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-19 21:38:52 -07:00
Paul E. McKenney 131906b006 rcu: decrease rcu_report_exp_rnp coupling with scheduler
PREEMPT_RCU read-side critical sections blocking an expedited grace
period invoke rcu_report_exp_rnp().  When the last such critical section
has completed, rcu_report_exp_rnp() invokes the scheduler to wake up the
task that invoked synchronize_rcu_expedited() -- needlessly holding the
root rcu_node structure's lock while doing so, thus needlessly providing
a way for RCU and the scheduler to deadlock.

This commit therefore releases the root rcu_node structure's lock before
calling wake_up().

Reported-by: Ed Tomlinson <edt@aei.ca>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-07-19 21:38:51 -07:00
Peter Foley e78e8f2d83 kernel: prevent unnecessary rebuilding due to config_data.gz
When IKCONFIG is built-in make oldconfig will cause the kernel to be
relinked even if .config didn't change. This happens because of a
config_data.gz dependency on .config. This patch changes the if_changed
to a filechk so that config_data.h is only rebuilt when the contents
have actually changed.

Signed-off-by: Peter Foley <pefoley2@verizon.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2011-07-20 01:32:32 +02:00
Vladimir Zapolskiy f701e5b73a connector: add an event for monitoring process tracers
This change adds a procfs connector event, which is emitted on every
successful process tracer attach or detach.

If some process connects to other one, kernelspace connector reports
process id and thread group id of both these involved processes. On
disconnection null process id is returned.

Such an event allows to create a simple automated userspace mechanism
to be aware about processes connecting to others, therefore predefined
process policies can be applied to them if needed.

Note, a detach signal is emitted only in case, if a tracer process
explicitly executes PTRACE_DETACH request. In other cases like tracee
or tracer exit detach event from proc connector is not reported.

Signed-off-by: Vladimir Zapolskiy <vzapolskiy@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2011-07-18 21:38:33 +02:00
Oleg Nesterov dcace06cc2 ptrace: mv send-SIGSTOP from do_fork() to ptrace_init_task()
If the new child is traced, do_fork() adds the pending SIGSTOP.
It assumes that either it is traced because of auto-attach or the
tracer attached later, in both cases sigaddset/set_thread_flag is
correct even if SIGSTOP is already pending.

Now that we have PTRACE_SEIZE this is no longer right in the latter
case. If the tracer does PTRACE_SEIZE after copy_process() makes the
child visible the queued SIGSTOP is wrong.

We could check PT_SEIZED bit and change ptrace_attach() to set both
PT_PTRACED and PT_SEIZED bits simultaneously but see the next patch,
we need to know whether this child was auto-attached or not anyway.

So this patch simply moves this code to ptrace_init_task(), this
way we can never race with ptrace_attach().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
2011-07-17 20:23:51 +02:00
Oleg Nesterov 961c4675c7 has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/
has_stopped_jobs() naively checks task_is_stopped(group_leader). This
was always wrong even without ptrace, group_leader can be dead. And
given that ptrace can change the state to TRACED this is wrong even
in the single-threaded case.

Change the code to check SIGNAL_STOP_STOPPED and simplify the code,
retval + break/continue doesn't make this trivial code more readable.

We could probably add the usual "|| signal->group_stop_count" check
but I don't think this makes sense, the task can start the group-stop
right after the check anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
2011-07-17 20:23:50 +02:00
Rafael J. Wysocki ba1389d74f Merge branch 'pm-domains' into for-linus
* pm-domains: (33 commits)
  ARM / shmobile: Return -EBUSY from A4LC power off if A3RV is active
  PM / Domains: Take .power_off() error code into account
  ARM / shmobile: Use genpd_queue_power_off_work()
  ARM / shmobile: Use pm_genpd_poweroff_unused()
  PM / Domains: Introduce function to power off all unused PM domains
  PM / Domains: Queue up power off work only if it is not pending
  PM / Domains: Improve handling of wakeup devices during system suspend
  PM / Domains: Do not restore all devices on power off error
  PM / Domains: Allow callbacks to execute all runtime PM helpers
  PM / Domains: Do not execute device callbacks under locks
  PM / Domains: Make failing pm_genpd_prepare() clean up properly
  PM / Domains: Set device state to "active" during system resume
  ARM: mach-shmobile: sh7372 A3RV requires A4LC
  PM / Domains: Export pm_genpd_poweron() in header
  ARM: mach-shmobile: sh7372 late pm domain off
  ARM: mach-shmobile: Runtime PM late init callback
  ARM: mach-shmobile: sh7372 D4 support
  ARM: mach-shmobile: sh7372 A4MP support
  ARM: mach-shmobile: sh7372: make sure that fsi is peripheral of spu2
  ARM: mach-shmobile: sh7372 A3SG support
  ...
2011-07-15 23:59:09 +02:00
Akinobu Mita f0c077a8b7 PM: Improve error code of pm_notifier_call_chain()
This enables pm_notifier_call_chain() to get the actual error code
in the callback rather than always assume -EINVAL by converting all
PM notifier calls to return encapsulate error code with
notifier_from_errno().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-15 23:58:20 +02:00
Kevin Hilman a5e4fd8783 PM / Suspend: Export suspend_set_ops, suspend_valid_only_mem
Some platforms wish to implement their PM core suspend code as
modules.  To do so, these functions need to be exported to modules.

[rjw: Replaced EXPORT_SYMBOL with EXPORT_SYMBOL_GPL]

Reported-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-15 23:58:19 +02:00
MyungJoo Ham 3b5fe85252 PM / Suspend: Add .suspend_again() callback to suspend_ops
A system or a device may need to control suspend/wakeup events. It may
want to wakeup the system after a predefined amount of time or at a
predefined event decided while entering suspend for polling or delayed
work. Then, it may want to enter suspend again if its predefined wakeup
condition is the only wakeup reason and there is no outstanding events;
thus, it does not wakeup the userspace unnecessary or unnecessary
devices and keeps suspended as long as possible (saving the power).

Enabling a system to wakeup after a specified time can be easily
achieved by using RTC. However, to enter suspend again immediately
without invoking userland and unrelated devices, we need additional
features in the suspend framework.

Such need comes from:

 1. Monitoring a critical device status without interrupts that can
wakeup the system. (in-suspend polling)
 An example is ambient temperature monitoring that needs to shut down
the system or a specific device function if it is too hot or cold. The
temperature of a specific device may be needed to be monitored as well;
e.g., a charger monitors battery temperature in order to stop charging
if overheated.

 2. Execute critical "delayed work" at suspend.
 A driver or a system/board may have a delayed work (or any similar
things) that it wants to execute at the requested time.
 For example, some chargers want to check the battery voltage some
time (e.g., 30 seconds) after the battery is fully charged and the
charger has stopped. Then, the charger restarts charging if the voltage
has dropped more than a threshold, which is smaller than "restart-charger"
voltage, which is a threshold to restart charging regardless of the
time passed.

This patch allows to add "suspend_again" callback at struct
platform_suspend_ops and let the "suspend_again" callback return true if
the system is required to enter suspend again after the current instance
of wakeup. Device-wise suspend_again implemented at dev_pm_ops or
syscore is not done because: a) suspend_again feature is usually under
platform-wise decision and controls the behavior of the whole platform
and b) There are very limited devices related to the usage cases of
suspend_again; chargers and temperature sensors are mentioned so far.

With suspend_again callback registered at struct platform_suspend_ops
suspend_ops in kernel/power/suspend.c with suspend_set_ops by the
platform, the suspend framework tries to enter suspend again by
looping suspend_enter() if suspend_again has returned true and there has
been no errors in the suspending sequence or pending wakeups (by
pm_wakeup_pending).

Tested at Exynos4-NURI.

[rjw: Fixed up kerneldoc comment for suspend_enter().]

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-15 23:58:19 +02:00
Masami Hiramatsu 7f6878a3d7 tracing/kprobe: Update symbol reference when loading module
Since the address of a module-local variable can only be
solved after the target module is loaded, the symbol
fetch-argument should be updated when loading target
module.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/20110627072703.6528.75042.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 15:45:32 -04:00
Masami Hiramatsu 6142431810 tracing/kprobes: Support module init function probing
To support probing module init functions, kprobe-tracer allows
user to define a probe on non-existed function when it is given
with a module name. This also enables user to set a probe on
a function on a specific module, even if a same name (but different)
function is locally defined in another module.

The module name must be in the front of function name and separated
by a ':'. e.g. btrfs:btrfs_init_sysfs

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/20110627072656.6528.89970.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 15:17:14 -04:00
Masami Hiramatsu bc81d48d13 kprobes: Return -ENOENT if probe point doesn't exist
Return -ENOENT if probe point doesn't exist, but still returns
-EINVAL if both of kprobe->addr and kprobe->symbol_name are
specified or both are not specified.

Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20110627072650.6528.67329.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 15:11:47 -04:00
Masami Hiramatsu 1538f888f1 tracing/kprobes: Merge trace probe enable/disable functions
Merge redundant enable/disable functions into enable_trace_probe()
and disable_trace_probe().

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: http://lkml.kernel.org/r/20110627072644.6528.26910.stgit@fedora15

[ converted kprobe selftest to use  enable_trace_probe ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 15:10:58 -04:00
Linus Torvalds df8d6fe9ef Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu
* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu:
  rcu: Prevent RCU callbacks from executing before scheduler initialized
2011-07-15 09:54:34 -07:00
Peter Zijlstra c64be78ffb sched: Fix 32bit race
Commit 3fe1698b7f ("sched: Deal with non-atomic min_vruntime reads
on 32bit") forgot to initialize min_vruntime_copy which could lead to
an infinite while loop in task_waking_fair() under some circumstances
(early boot, lucky timing).

[ This bug was also reported by others that blamed it on the RCU
  initialization problems ]

Reported-and-tested-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-15 09:54:02 -07:00
Steven Rostedt f7bc8b61f6 ftrace: Fix regression where ftrace breaks when modules are loaded
Enabling function tracer to trace all functions, then load a module and
then disable function tracing will cause ftrace to fail.

This can also happen by enabling function tracing on the command line:

  ftrace=function

and during boot up, modules are loaded, then you disable function tracing
with 'echo nop > current_tracer' you will trigger a bug in ftrace that
will shut itself down.

The reason is, the new ftrace code keeps ref counts of all ftrace_ops that
are registered for tracing. When one or more ftrace_ops are registered,
all the records that represent the functions that the ftrace_ops will
trace have a ref count incremented. If this ref count is not zero,
when the code modification runs, that function will be enabled for tracing.
If the ref count is zero, that function will be disabled from tracing.

To make sure the accounting was working, FTRACE_WARN_ON()s were added
to updating of the ref counts.

If the ref count hits its max (> 2^30 ftrace_ops added), or if
the ref count goes below zero, a FTRACE_WARN_ON() is triggered which
disables all modification of code.

Since it is common for ftrace_ops to trace all functions in the kernel,
instead of creating > 20,000 hash items for the ftrace_ops, the hash
count is just set to zero, and it represents that the ftrace_ops is
to trace all functions. This is where the issues arrise.

If you enable function tracing to trace all functions, and then add
a module, the modules function records do not get the ref count updated.
When the function tracer is disabled, all function records ref counts
are subtracted. Since the modules never had their ref counts incremented,
they go below zero and the FTRACE_WARN_ON() is triggered.

The solution to this is rather simple. When modules are loaded, and
their functions are added to the the ftrace pool, look to see if any
ftrace_ops are registered that trace all functions. And for those,
update the ref count for the module function records.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-14 23:02:27 -04:00
Masami Hiramatsu 7143f168e2 tracing/kprobes: Rename probe_* to trace_probe_*
Rename probe_* to trace_probe_* for avoiding namespace
confliction. This also fixes improper names of find_probe_event()
and cleanup_all_probes() to find_trace_probe() and
release_all_trace_probes() respectively.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110627072636.6528.60374.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-14 17:44:43 -04:00
Cyrill Gorcunov f912987097 perf, x86: P4 PMU - Introduce event alias feature
Instead of hw_nmi_watchdog_set_attr() weak function
and appropriate x86_pmu::hw_watchdog_set_attr() call
we introduce even alias mechanism which allow us
to drop this routines completely and isolate quirks
of Netburst architecture inside P4 PMU code only.

The main idea remains the same though -- to allow
nmi-watchdog and perf top run simultaneously.

Note the aliasing mechanism applies to generic
PERF_COUNT_HW_CPU_CYCLES event only because arbitrary
event (say passed as RAW initially) might have some
additional bits set inside ESCR register changing
the behaviour of event and we can't guarantee anymore
that alias event will give the same result.

P.S. Thanks a huge to Don and Steven for for testing
     and early review.

Acked-by: Don Zickus <dzickus@redhat.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Stephane Eranian <eranian@google.com>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110708201712.GS23657@sun
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-14 17:25:04 -04:00
Steven Rostedt 4a9bd3f134 tracing: Have dynamic size event stack traces
Currently the stack trace per event in ftace is only 8 frames.
This can be quite limiting and sometimes useless. Especially when
the "ignore frames" is wrong and we also use up stack frames for
the event processing itself.

Change this to be dynamic by adding a percpu buffer that we can
write a large stack frame into and then copy into the ring buffer.

For interrupts and NMIs that come in while another event is being
process, will only get to use the 8 frame stack. That should be enough
as the task that it interrupted will have the full stack frame anyway.

Requested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-14 16:36:53 -04:00
Glauber Costa 095c0aa83e sched: adjust scheduler cpu power for stolen time
This patch makes update_rq_clock() aware of steal time.
The mechanism of operation is not different from irq_time,
and follows the same principles. This lives in a CONFIG
option itself, and can be compiled out independently of
the rest of steal time reporting. The effect of disabling it
is that the scheduler will still report steal time (that cannot be
disabled), but won't use this information for cpu power adjustments.

Everytime update_rq_clock_task() is invoked, we query information
about how much time was stolen since last call, and feed it into
sched_rt_avg_update().

Although steal time reporting in account_process_tick() keeps
track of the last time we read the steal clock, in prev_steal_time,
this patch do it independently using another field,
prev_steal_time_rq. This is because otherwise, information about time
accounted in update_process_tick() would never reach us in update_rq_clock().

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-14 12:59:47 +03:00
Glauber Costa e6e6685acc KVM guest: Steal time accounting
This patch accounts steal time time in account_process_tick.
If one or more tick is considered stolen in the current
accounting cycle, user/system accounting is skipped. Idle is fine,
since the hypervisor does not report steal time if the guest
is halted.

Accounting steal time from the core scheduler give us the
advantage of direct acess to the runqueue data. In a later
opportunity, it can be used to tweak cpu power and make
the scheduler aware of the time it lost.

[avi: <asm/paravirt.h> doesn't exist on many archs]

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-14 12:59:46 +03:00
Glauber Costa c9aaa8957f KVM: Steal time implementation
To implement steal time, we need the hypervisor to pass the guest
information about how much time was spent running other processes
outside the VM, while the vcpu had meaningful work to do - halt
time does not count.

This information is acquired through the run_delay field of
delayacct/schedstats infrastructure, that counts time spent in a
runqueue but not running.

Steal time is a per-cpu information, so the traditional MSR-based
infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the
memory area address containing information about steal time

This patch contains the hypervisor part of the steal time infrasructure,
and can be backported independently of the guest portion.

[avi, yongjie: export delayacct_on, to avoid build failures in some configs]

Signed-off-by: Glauber Costa <glommer@redhat.com>
Tested-by: Eric B Munson <emunson@mgebm.net>
CC: Rik van Riel <riel@redhat.com>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Yongjie Ren <yongjie.ren@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-14 12:59:14 +03:00
Steven Rostedt 6331c28c96 ftrace: Fix dynamic selftest failure on some archs
Archs that do not implement CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST, will
fail the dynamic ftrace selftest.

The function tracer has a quick 'off' variable that will prevent
the call back functions from being called. This variable is called
function_trace_stop. In x86, this is implemented directly in the mcount
assembly, but for other archs, an intermediate function is used called
ftrace_test_stop_func().

In dynamic ftrace, the function pointer variable ftrace_trace_function is
used to update the caller code in the mcount caller. But for archs that
do not have CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST set, it only calls
ftrace_test_stop_func() instead, which in turn calls __ftrace_trace_function.

When more than one ftrace_ops is registered, the function it calls is
ftrace_ops_list_func(), which will iterate over all registered ftrace_ops
and call the callbacks that have their hash matching.

The issue happens when two ftrace_ops are registered for different functions
and one is then unregistered. The __ftrace_trace_function is then pointed
to the remaining ftrace_ops callback function directly. This mean it will
be called for all functions that were registered to trace by both ftrace_ops
that were registered.

This is not an issue for archs with CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST,
because the update of ftrace_trace_function doesn't happen until after all
functions have been updated, and then the mcount caller is updated. But
for those archs that do use the ftrace_test_stop_func(), the update is
immediate.

The dynamic selftest fails because it hits this situation, and the
ftrace_ops that it registers fails to only trace what it was suppose to
and instead traces all other functions.

The solution is to delay the setting of __ftrace_trace_function until
after all the functions have been updated according to the registered
ftrace_ops. Also, function_trace_stop is set during the update to prevent
function tracing from calling code that is caused by the function tracer
itself.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-13 22:25:09 -04:00
Steven Rostedt 072126f452 ftrace: Update filter when tracing enabled in set_ftrace_filter()
Currently, if set_ftrace_filter() is called when the ftrace_ops is
active, the function filters will not be updated. They will only be updated
when tracing is disabled and re-enabled.

Update the functions immediately during set_ftrace_filter().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-13 22:10:05 -04:00
Steven Rostedt 41fb61c2d0 ftrace: Balance records when updating the hash
Whenever the hash of the ftrace_ops is updated, the record counts
must be balance. This requires disabling the records that are set
in the original hash, and then enabling the records that are set
in the updated hash.

Moving the update into ftrace_hash_move() removes the bug where the
hash was updated but the records were not, which results in ftrace
triggering a warning and disabling itself because the ftrace_ops filter
is updated while the ftrace_ops was registered, and then the failure
happens when the ftrace_ops is unregistered.

The current code will not trigger this bug, but new code will.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-13 22:00:50 -04:00
Paul E. McKenney b0d304172f rcu: Prevent RCU callbacks from executing before scheduler initialized
Under some rare but real combinations of configuration parameters, RCU
callbacks are posted during early boot that use kernel facilities that
are not yet initialized.  Therefore, when these callbacks are invoked,
hard hangs and crashes ensue.  This commit therefore prevents RCU
callbacks from being invoked until after the scheduler is fully up and
running, as in after multiple tasks have been spawned.

It might well turn out that a better approach is to identify the specific
RCU callbacks that are causing this problem, but that discussion will
wait until such time as someone really needs an RCU callback to be invoked
(as opposed to merely registered) during early boot.

Reported-by: julie Sullivan <kernelmail.jms@gmail.com>
Reported-by: RKK <kulkarni.ravi4@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: julie Sullivan <kernelmail.jms@gmail.com>
Tested-by: RKK <kulkarni.ravi4@gmail.com>
2011-07-13 08:17:56 -07:00
Linus Torvalds d93a881dd7 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc:
  pcmcia: pxa2xx/vpac270: free gpios on exist rather than requesting
  ARM: pxa/raumfeld: fix device name for codec ak4104
  ARM: pxa/raumfeld: display initialisation fixes
  ARM: pxa/raumfeld: adapt to upcoming hardware change
  ARM: pxa: fix gpio_to_chip() clash with gpiolib namespace
  genirq: replace irq_gc_ack() with {set,clr}_bit variants (fwd)
  arm: mach-vt8500: add forgotten irq_data conversion
  ARM: pxa168: correct nand pmu setting
  ARM: pxa910: correct nand pmu setting
  ARM: pxa: fix PGSR register address calculation
2011-07-12 14:19:51 -07:00
Alexander Graf 1dda606c5f KVM: Add compat ioctl for KVM_SET_SIGNAL_MASK
KVM has an ioctl to define which signal mask should be used while running
inside VCPU_RUN. At least for big endian systems, this mask is different
on 32-bit and 64-bit systems (though the size is identical).

Add a compat wrapper that converts the mask to whatever the kernel accepts,
allowing 32-bit kvm user space to set signal masks.

This patch fixes qemu with --enable-io-thread on ppc64 hosts when running
32-bit user land.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-12 13:16:17 +03:00
Justin TerAvest 4aede84b33 fixlet: Remove fs_excl from struct task.
fs_excl is a poor man's priority inheritance for filesystems to hint to
the block layer that an operation is important. It was never clearly
specified, not widely adopted, and will not prevent starvation in many
cases (like across cgroups).

fs_excl was introduced with the time sliced CFQ IO scheduler, to
indicate when a process held FS exclusive resources and thus needed
a boost.

It doesn't cover all file systems, and it was never fully complete.
Lets kill it.

Signed-off-by: Justin TerAvest <teravest@google.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-12 08:35:10 +02:00
Michael Witten 2dc98fd320 doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-11 14:20:07 +02:00
Jiri Kosina b7e9c223be Merge branch 'master' into for-next
Sync with Linus' tree to be able to apply pending patches that
are based on newer code already present upstream.
2011-07-11 14:15:55 +02:00
Michal Hocko d8bf4ca9ca rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
Since ca5ecddf (rcu: define __rcu address space modifier for sparse)
rcu_dereference_check use rcu_read_lock_held as a part of condition
automatically so callers do not have to do that as well.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-08 22:21:58 +02:00
Dima Zavin 732375c6a5 plist: Remove the need to supply locks to plist heads
This was legacy code brought over from the RT tree and
is no longer necessary.

Signed-off-by: Dima Zavin <dima@android.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Walker <dwalker@codeaurora.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/1310084879-10351-2-git-send-email-dima@android.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-08 14:02:53 +02:00
Steven Rostedt 4376cac667 ftrace: Do not disable interrupts for modules in mcount update
When I mounted an NFS directory, it caused several modules to be loaded. At the
time I was running the preemptirqsoff tracer, and it showed the following
output:

# tracer: preemptirqsoff
#
# preemptirqsoff latency trace v1.1.5 on 2.6.33.9-rt30-mrg-test
# --------------------------------------------------------------------
# latency: 1177 us, #4/4, CPU#3 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4)
#    -----------------
#    | task: modprobe-19370 (uid:0 nice:0 policy:0 rt_prio:0)
#    -----------------
#  => started at: ftrace_module_notify
#  => ended at:   ftrace_module_notify
#
#
#                  _------=> CPU#
#                 / _-----=> irqs-off
#                | / _----=> need-resched
#                || / _---=> hardirq/softirq
#                ||| / _--=> preempt-depth
#                |||| /_--=> lock-depth
#                |||||/     delay
#  cmd     pid   |||||| time  |   caller
#     \   /      ||||||   \   |   /
modprobe-19370   3d....    0us!: ftrace_process_locs <-ftrace_module_notify
modprobe-19370   3d.... 1176us : ftrace_process_locs <-ftrace_module_notify
modprobe-19370   3d.... 1178us : trace_hardirqs_on <-ftrace_module_notify
modprobe-19370   3d.... 1178us : <stack trace>
 => ftrace_process_locs
 => ftrace_module_notify
 => notifier_call_chain
 => __blocking_notifier_call_chain
 => blocking_notifier_call_chain
 => sys_init_module
 => system_call_fastpath

That's over 1ms that interrupts are disabled on a Real-Time kernel!

Looking at the cause (being the ftrace author helped), I found that the
interrupts are disabled before the code modification of mcounts into nops. The
interrupts only need to be disabled on start up around this code, not when
modules are being loaded.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-07 22:39:38 -04:00
Steven Rostedt e4a3f541f0 tracing: Still trace filtered irq functions when irq trace is disabled
If a function is set to be traced by the set_graph_function, but the
option funcgraph-irqs is zero, and the traced function happens to be
called from a interrupt, it will not be traced.

The point of funcgraph-irqs is to not trace interrupts when we are
preempted by an irq, not to not trace functions we want to trace that
happen to be *in* a irq.

Luckily the current->trace_recursion element is perfect to add a flag
to help us be able to trace functions within an interrupt even when
we are not tracing interrupts that preempt the trace.

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-07 22:26:27 -04:00
Linus Torvalds 31cb852809 Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / Hibernate: Fix free_unnecessary_pages()
2011-07-07 13:22:41 -07:00