Pull workqueue fixes from Tejun Heo:
"Three more workqueue regression fixes.
- Fix unbalanced unlock in trylock failure path of manage_workers().
This shouldn't happen often in the wild but is possible.
- While making schedule_work() and friends inline, they become
unavailable to !GPL modules. Allow !GPL modules to access basic
stuff - system_wq and queue_*work_on() - so that schedule_work()
and friends can be used.
- During boot, the unbound NUMA support code allocates a cpumask for
each possible node using alloc_cpumask_var_node(), which ends up
trying to allocate node-specific memory even for offline nodes
triggering BUG in the memory alloc code. Use NUMA_NO_NODE for
offline nodes."
* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init()
workqueue: Make schedule_work() available again to non GPL modules
workqueue: correct handling of the pool spin_lock
Pull RCU fixes from Paul McKenney:
"A couple of fixes for RCU regressions:
- A boneheaded boolean-logic bug that resulted in excessive delays on
boot, hibernation and suspend that was reported by Borislav Petkov,
Bjørn Mork, and Joerg Roedel. The fix inserts a single "!".
- A fix for a boot-time splat due to allocating from bootmem too late
in boot, fix courtesy of Sasha Levin with additional help from
Yinghai Lu."
* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
rcu: Don't allocate bootmem from rcu_init()
rcu: Fix comparison sense in rcu_needs_cpu()
argv_split(empty_or_all_spaces) happily succeeds, it simply returns
argc == 0 and argv[0] == NULL. Change call_usermodehelper_exec() to
check sub_info->path != NULL to avoid the crash.
This is the minimal fix, todo:
- perhaps we should change argv_split() to return NULL or change the
callers.
- kill or justify ->path[0] check
- narrow the scope of helper_lock()
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-By: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull target fixes from Nicholas Bellinger:
"A handful of fixes + minor changes this time around, along with one
important >= v3.9 regression fix for IBLOCK backends. The highlights
include:
- Use FD_MAX_SECTORS in FILEIO for block_device as
well as files (agrover)
- Fix processing of out-of-order CmdSNs with
iSBD driver (shlomo)
- Close long-standing target_put_sess_cmd() vs.
core_tmr_abort_task() race with the addition of
kref_put_spinlock_irqsave() (joern + greg-kh)
- Fix IBLOCK WCE=1 + DPOFUA=1 backend WRITE
regression in >= v3.9 (nab + bootc)
Note these four patches are CC'ed to stable.
Also, there is still some work left to be done on the active I/O
shutdown path in target_wait_for_sess_cmds() used by tcm_qla2xxx +
ib_isert fabrics that is still being discussed on the list, and will
hopefully be resolved soon."
* 'queue' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
target: close target_put_sess_cmd() vs. core_tmr_abort_task() race
target: removed unused transport_state flag
target/iblock: Fix WCE=1 + DPOFUA=1 backend WRITE regression
MAINTAINERS: Update target git tree URL
iscsi-target: Fix typos in RDMAEXTENSIONS macro usage
target/rd: Add ramdisk bit for NULLIO operation
iscsi-target: Fix processing of OOO commands
iscsi-target: Make buf param of iscsit_do_crypto_hash_buf() const void *
iscsi-target: Fix NULL pointer dereference in iscsit_send_reject
target: Have dev/enable show if TCM device is configured
target: Use FD_MAX_SECTORS/FD_BLOCKSIZE for blockdevs using fileio
target: Remove unused struct members in se_dev_entry
Pull tracing fixes from Steven Rostedt:
"This includes a fix to a memory leak when adding filters to traces.
Also, Masami Hiramatsu fixed up some minor bugs that were discovered
by sparse."
* tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Make print_*probe_event static
tracing/kprobes: Fix a sparse warning for incorrect type in assignment
tracing/kprobes: Use rcu_dereference_raw for tp->files
tracing: Fix leaks of filter preds
Pull x86 fixes from Thomas Gleixner:
- Fix for a CPU hot-add deadlock in microcode update code
- Fix for idle consolidation fallout
- Documentation update for initial kernel direct mapping
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Add missing comments for initial kernel direct mapping
x86/microcode: Add local mutex to fix physical CPU hot-add deadlock
x86: Fix idle consolidation fallout
Pull perf fixes from Thomas Gleixner:
- Fix for a task exit cleanup race caused by a missing a preempt
disable
- Cleanup of the event notification functions with a massive reduction
of duplicated code
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Factor out auxiliary events notification
perf: Fix EXIT event notification
Pull timer fixes from Thomas Gleixner:
- Cure for not using zalloc in the first place, which leads to random
crashes with CPUMASK_OFF_STACK.
- Revert a user space visible change which broke udev
- Add a missing cpu_online early return introduced by the new full
dyntick conversions
- Plug a long standing race in the timer wheel cpu hotplug code.
Sigh...
- Cleanup NOHZ per cpu data on cpu down to prevent stale data on cpu
up.
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons
timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE
tick: Don't invoke tick_nohz_stop_sched_tick() if the cpu is offline
tick: Cleanup NOHZ per cpu data on cpu down
tick: Use zalloc_cpumask_var for allocating offstack cpumasks
Pull core fixes from Thomas Gleixner:
- Two fixlets for the fallout of the generic idle task conversion
- Documentation update
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu/idle: Wrap cpu-idle poll mode within rcu_idle_enter/exit
idle: Fix hlt/nohlt command-line handling in new generic idle
kthread: Document ways of reducing OS jitter due to per-CPU kthreads
Pull ARM fixes from Russell King:
"A small number of fixes for stuff from the last merge window, and in
one case (IRQ time accounting) the previous merge window."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7720/1: ARM v6/v7 cmpxchg64 shouldn't clear upper 32 bits of the old/new value
ARM: 7715/1: MCPM: adapt to GIC changes after upstream merge
ARM: 7714/1: mmc: mmci: Ensure return value of regulator_enable() is checked
ARM: 7712/1: Remove trailing whitespace in arch/arm/Makefile
ARM: 7711/1: dove: fix Dove cpu type from V7 to PJ4
ARM: finally enable IRQ time accounting config
Pull Ceph fixes from Sage Weil:
"Yes, this is a much larger pull than I would like after -rc1. There
are a few things included:
- a few fixes for leaks and incorrect assertions
- a few patches fixing behavior when mapped images are resized
- handling for cloned/layered images that are flattened out from
underneath the client
The last bit was non-trivial, and there is some code movement and
associated cleanup mixed in. This was ready and was meant to go in
last week but I missed the boat on Friday. My only excuse is that I
was waiting for an all clear from the testing and there were many
other shiny things to distract me.
Strictly speaking, handling the flatten case isn't a regression and
could wait, so if you like we can try to pull the series apart, but
Alex and I would much prefer to have it all in as it is a case real
users will hit with 3.10."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (33 commits)
rbd: re-submit flattened write request (part 2)
rbd: re-submit write request for flattened clone
rbd: re-submit read request for flattened clone
rbd: detect when clone image is flattened
rbd: reference count parent requests
rbd: define parent image request routines
rbd: define rbd_dev_unparent()
rbd: don't release write request until necessary
rbd: get parent info on refresh
rbd: ignore zero-overlap parent
rbd: support reading parent page data for writes
rbd: fix parent request size assumption
libceph: init sent and completed when starting
rbd: kill rbd_img_request_get()
rbd: only set up watch for mapped images
rbd: set mapping read-only flag in rbd_add()
rbd: support reading parent page data
rbd: fix an incorrect assertion condition
rbd: define rbd_dev_v2_header_info()
rbd: get rid of trivial v1 header wrappers
...
Special preds are created when folding a series of preds that
can be done in serial. These are allocated in an ops field of
the pred structure. But they were never freed, causing memory
leaks.
This was discovered using the kmemleak checker:
unreferenced object 0xffff8800797fd5e0 (size 32):
comm "swapper/0", pid 1, jiffies 4294690605 (age 104.608s)
hex dump (first 32 bytes):
00 00 01 00 03 00 05 00 07 00 09 00 0b 00 0d 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814b52af>] kmemleak_alloc+0x73/0x98
[<ffffffff8111ff84>] kmemleak_alloc_recursive.constprop.42+0x16/0x18
[<ffffffff81120e68>] __kmalloc+0xd7/0x125
[<ffffffff810d47eb>] kcalloc.constprop.24+0x2d/0x2f
[<ffffffff810d4896>] fold_pred_tree_cb+0xa9/0xf4
[<ffffffff810d3781>] walk_pred_tree+0x47/0xcc
[<ffffffff810d5030>] replace_preds.isra.20+0x6f8/0x72f
[<ffffffff810d50b5>] create_filter+0x4e/0x8b
[<ffffffff81b1c30d>] ftrace_test_event_filter+0x5a/0x155
[<ffffffff8100028d>] do_one_initcall+0xa0/0x137
[<ffffffff81afbedf>] kernel_init_freeable+0x14d/0x1dc
[<ffffffff814b24b7>] kernel_init+0xe/0xdb
[<ffffffff814d539c>] ret_from_fork+0x7c/0xb0
[<ffffffffffffffff>] 0xffffffffffffffff
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When rcu_init() is called we already have slab working, allocating
bootmem at that point results in warnings and an allocation from
slab. This commit therefore changes alloc_bootmem_cpumask_var() to
alloc_cpumask_var() in rcu_bootup_announce_oddness(), which is called
from rcu_init().
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Robin Holt <holt@sgi.com>
[paulmck: convert to zalloc_cpumask_var(), as suggested by Yinghai Lu.]
It is possible for one thread to to take se_sess->sess_cmd_lock in
core_tmr_abort_task() before taking a reference count on
se_cmd->cmd_kref, while another thread in target_put_sess_cmd() drops
se_cmd->cmd_kref before taking se_sess->sess_cmd_lock.
This introduces kref_put_spinlock_irqsave() and uses it in
target_put_sess_cmd() to close the race window.
Signed-off-by: Joern Engel <joern@logfs.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch fixes a regression bug introduced in v3.9-rc1 where if the
underlying struct block_device for a IBLOCK backend is configured with
WCE=1 + DPOFUA=1 settings, the rw = WRITE assignment no longer occurs
in iblock_execute_rw(), and rw = 0 is passed to iblock_submit_bios()
in effect causing a READ bio operation to occur.
The offending commit is:
commit d0c8b259f8
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Tue Jan 29 22:10:06 2013 -0800
target/iblock: Use backend REQ_FLUSH hint for WriteCacheEnabled status
Note the WCE=1 + DPOFUA=0, WCE=0 + DPOFUA=1, and WCE=0 + DPOFUA=0 cases
are not affected by this regression bug.
Reported-by: Chris Boot <bootc@bootc.net>
Tested-by: Chris Boot <bootc@bootc.net>
Reported-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Kay Sievers noted that the ALWAYS_USE_PERSISTENT_CLOCK config,
which enables some minor compile time optimization to avoid
uncessary code in mostly the suspend/resume path could cause
problems for userland.
In particular, the dependency for RTC_HCTOSYS on
!ALWAYS_USE_PERSISTENT_CLOCK, which avoids setting the time
twice and simplifies suspend/resume, has the side effect
of causing the /sys/class/rtc/rtcN/hctosys flag to always be
zero, and this flag is commonly used by udev to setup the
/dev/rtc symlink to /dev/rtcN, which can cause pain for
older applications.
While the udev rules could use some work to be less fragile,
breaking userland should strongly be avoided. Additionally
the compile time optimizations are fairly minor, and the code
being optimized is likely to be reworked in the future, so
lets revert this change.
Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: stable <stable@vger.kernel.org> #3.9
Cc: Feng Tang <feng.tang@intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Link: http://lkml.kernel.org/r/1366828376-18124-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit 8425e3d5bd ("workqueue: inline trivial wrappers") changed
schedule_work() and schedule_delayed_work() to inline wrappers,
but these rely on some symbols that are EXPORT_SYMBOL_GPL, while
the original functions were EXPORT_SYMBOL. This has the effect of
changing the licensing requirement for these functions and making
them unavailable to non GPL modules.
Make them available again by removing the restriction on the
required symbols.
Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When we fail to mutex_trylock(), we release the pool spin_lock and do
mutex_lock(). After that, we should regrab the pool spin_lock, but,
regrabbing is missed in current code. So correct it.
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Commit c0f4dfd4f (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks) introduced a bug that can result in excessively long grace
periods. This bug reverse the senes of the "if" statement checking
for lazy callbacks, so that RCU takes a lazy approach when there are
in fact non-lazy callbacks. This can result in excessive boot, suspend,
and resume times.
This commit therefore fixes the sense of this "if" statement.
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Bjørn Mork <bjorn@mork.no>
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Joerg Roedel <joro@8bytes.org>
Pull ext4 update from Ted Ts'o:
"Fixed regressions (two stability regressions and a performance
regression) introduced during the 3.10-rc1 merge window.
Also included is a bug fix relating to allocating blocks after
resizing an ext3 file system when using the ext4 file system driver"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
jbd,jbd2: fix oops in jbd2_journal_put_journal_head()
ext4: revert "ext4: use io_end for multiple bios"
ext4: limit group search loop for non-extent files
ext4: fix fio regression
Pull workqueue fix from Tejun Heo:
"A fix for a workqueue_congested() regression that broke fscache"
* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: workqueue_congested() shouldn't translate WORK_CPU_UNBOUND into node number
An inactive timer's base can refer to a offline cpu's base.
In the current code, cpu_base's lock is blindly reinitialized each
time a CPU is brought up. If a CPU is brought online during the period
that another thread is trying to modify an inactive timer on that CPU
with holding its timer base lock, then the lock will be reinitialized
under its feet. This leads to following SPIN_BUG().
<0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466
<0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466, .owner_cpu: 1
<4> [<c0013dc4>] (unwind_backtrace+0x0/0x11c) from [<c026e794>] (do_raw_spin_unlock+0x40/0xcc)
<4> [<c026e794>] (do_raw_spin_unlock+0x40/0xcc) from [<c076c160>] (_raw_spin_unlock+0x8/0x30)
<4> [<c076c160>] (_raw_spin_unlock+0x8/0x30) from [<c009b858>] (mod_timer+0x294/0x310)
<4> [<c009b858>] (mod_timer+0x294/0x310) from [<c00a5e04>] (queue_delayed_work_on+0x104/0x120)
<4> [<c00a5e04>] (queue_delayed_work_on+0x104/0x120) from [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c)
<4> [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c) from [<c04d8780>] (sdhci_disable+0x40/0x48)
<4> [<c04d8780>] (sdhci_disable+0x40/0x48) from [<c04bf300>] (mmc_release_host+0x4c/0xb0)
<4> [<c04bf300>] (mmc_release_host+0x4c/0xb0) from [<c04c7aac>] (mmc_sd_detect+0x90/0xfc)
<4> [<c04c7aac>] (mmc_sd_detect+0x90/0xfc) from [<c04c2504>] (mmc_rescan+0x7c/0x2c4)
<4> [<c04c2504>] (mmc_rescan+0x7c/0x2c4) from [<c00a6a7c>] (process_one_work+0x27c/0x484)
<4> [<c00a6a7c>] (process_one_work+0x27c/0x484) from [<c00a6e94>] (worker_thread+0x210/0x3b0)
<4> [<c00a6e94>] (worker_thread+0x210/0x3b0) from [<c00aad9c>] (kthread+0x80/0x8c)
<4> [<c00aad9c>] (kthread+0x80/0x8c) from [<c000ea80>] (kernel_thread_exit+0x0/0x8)
As an example, this particular crash occurred when CPU #3 is executing
mod_timer() on an inactive timer whose base is refered to offlined CPU
#2. The code locked the timer_base corresponding to CPU #2. Before it
could proceed, CPU #2 came online and reinitialized the spinlock
corresponding to its base. Thus now CPU #3 held a lock which was
reinitialized. When CPU #3 finally ended up unlocking the old cpu_base
corresponding to CPU #2, we hit the above SPIN_BUG().
CPU #0 CPU #3 CPU #2
------ ------- -------
..... ...... <Offline>
mod_timer()
lock_timer_base
spin_lock_irqsave(&base->lock)
cpu_up(2) ..... ......
init_timers_cpu()
.... ..... spin_lock_init(&base->lock)
..... spin_unlock_irqrestore(&base->lock) ......
<spin_bug>
Allocation of per_cpu timer vector bases is done only once under
"tvec_base_done[]" check. In the current code, spinlock_initialization
of base->lock isn't under this check. When a CPU is up each time the
base lock is reinitialized. Move base spinlock initialization under
the check.
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1368520142-4136-1-git-send-email-tirupath@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Bjørn Mork reported the following warning when running powertop.
[ 49.289034] ------------[ cut here ]------------
[ 49.289055] WARNING: at kernel/rcutree.c:502 rcu_eqs_exit_common.isra.48+0x3d/0x125()
[ 49.289244] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-bisect-rcu-warn+ #107
[ 49.289251] ffffffff8157d8c8 ffffffff81801e28 ffffffff8137e4e3 ffffffff81801e68
[ 49.289260] ffffffff8103094f ffffffff81801e68 0000000000000000 ffff88023afcd9b0
[ 49.289268] 0000000000000000 0140000000000000 ffff88023bee7700 ffffffff81801e78
[ 49.289276] Call Trace:
[ 49.289285] [<ffffffff8137e4e3>] dump_stack+0x19/0x1b
[ 49.289293] [<ffffffff8103094f>] warn_slowpath_common+0x62/0x7b
[ 49.289300] [<ffffffff8103097d>] warn_slowpath_null+0x15/0x17
[ 49.289306] [<ffffffff810a9006>] rcu_eqs_exit_common.isra.48+0x3d/0x125
[ 49.289314] [<ffffffff81079b49>] ? trace_hardirqs_off_caller+0x37/0xa6
[ 49.289320] [<ffffffff810a9692>] rcu_idle_exit+0x85/0xa8
[ 49.289327] [<ffffffff8107076e>] trace_cpu_idle_rcuidle+0xae/0xff
[ 49.289334] [<ffffffff810708b1>] cpu_startup_entry+0x72/0x115
[ 49.289341] [<ffffffff813689e5>] rest_init+0x149/0x150
[ 49.289347] [<ffffffff8136889c>] ? csum_partial_copy_generic+0x16c/0x16c
[ 49.289355] [<ffffffff81a82d34>] start_kernel+0x3f0/0x3fd
[ 49.289362] [<ffffffff81a8274c>] ? repair_env_string+0x5a/0x5a
[ 49.289368] [<ffffffff81a82481>] x86_64_start_reservations+0x2a/0x2c
[ 49.289375] [<ffffffff81a82550>] x86_64_start_kernel+0xcd/0xd1
[ 49.289379] ---[ end trace 07a1cc95e29e9036 ]---
The warning is that 'rdtp->dynticks' has an unexpected value, which roughly
translates to - the calls to rcu_idle_enter() and rcu_idle_exit() were not
made in the correct order, or otherwise messed up.
And Bjørn's painstaking debugging indicated that this happens when the idle
loop enters the poll mode. Looking at the poll function cpu_idle_poll(), and
the implementation of trace_cpu_idle_rcuidle(), the problem becomes very clear:
cpu_idle_poll() lacks calls to rcu_idle_enter/exit(), and trace_cpu_idle_rcuidle()
calls them in the reverse order - first rcu_idle_exit(), and then rcu_idle_enter().
Hence the even/odd alternative sequencing of rdtp->dynticks goes for a toss.
And powertop readily triggers this because powertop uses the idle-tracing
infrastructure extensively.
So, to fix this, wrap the code in cpu_idle_poll() within rcu_idle_enter/exit(),
so that it blends properly with the calls inside trace_cpu_idle_rcuidle() and
thus get the function ordering right.
Reported-and-tested-by: Bjørn Mork <bjorn@mork.no>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/519169BF.4080208@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull powerpc fixes from Benjamin Herrenschmidt:
"This is mostly bug fixes (some of them regressions, some of them I
deemed worth merging now) along with some patches from Li Zhong
hooking up the new context tracking stuff (for the new full NO_HZ)"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits)
powerpc: Set show_unhandled_signals to 1 by default
powerpc/perf: Fix setting of "to" addresses for BHRB
powerpc/pmu: Fix order of interpreting BHRB target entries
powerpc/perf: Move BHRB code into CONFIG_PPC64 region
powerpc: select HAVE_CONTEXT_TRACKING for pSeries
powerpc: Use the new schedule_user API on userspace preemption
powerpc: Exit user context on notify resume
powerpc: Exception hooks for context tracking subsystem
powerpc: Syscall hooks for context tracking subsystem
powerpc/booke64: Fix kernel hangs at kernel_dbg_exc
powerpc: Fix irq_set_affinity() return values
powerpc: Provide __bswapdi2
powerpc/powernv: Fix starting of secondary CPUs on OPALv2 and v3
powerpc/powernv: Detect OPAL v3 API version
powerpc: Fix MAX_STACK_TRACE_ENTRIES too low warning again
powerpc: Make CONFIG_RTAS_PROC depend on CONFIG_PROC_FS
powerpc: Bring all threads online prior to migration/hibernation
powerpc/rtas_flash: Fix validate_flash buffer overflow issue
powerpc/kexec: Fix kexec when using VMX optimised memcpy
powerpc: Fix build errors STRICT_MM_TYPECHECKS
...
Currently we only set the "to" address in the branch stack when the CPU
explicitly gives us a value. Unfortunately it only does this for XL form
branches (eg blr, bctr, bctar) and not I and B form branches (eg b, bc).
Fortunately if we read the instruction from memory we can extract the offset of
a branch and calculate the target address.
This adds a function power_pmu_bhrb_to() to calculate the target/to address of
the corresponding I and B form branches. It handles branches in both user and
kernel spaces. It also plumbs this into the perf brhb reading code.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The current Branch History Rolling Buffer (BHRB) code misinterprets the order
of entries in the hardware buffer. It assumes that a branch target address
will be read _after_ its corresponding branch. In reality the branch target
comes before (lower mfbhrb entry) it's corresponding branch.
This is a rewrite of the code to take this into account.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The new Branch History Rolling buffer (BHRB) code is only useful on 64bit
processors, so move it into the #ifdef CONFIG_PPC64 region.
This avoids code bloat on 32bit systems.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch allows RCU usage in do_notify_resume, e.g. signal handling.
It corresponds to
[PATCH] x86: Exit RCU extended QS on notify resume
commit edf55fda35
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is the exception hooks for context tracking subsystem, including
data access, program check, single step, instruction breakpoint, machine check,
alignment, fp unavailable, altivec assist, unknown exception, whose handlers
might use RCU.
This patch corresponds to
[PATCH] x86: Exception hooks for userspace RCU extended QS
commit 6ba3c97a38
But after the exception handling moved to generic code, and some changes in
following two commits:
56dd9470d7
context_tracking: Move exception handling to generic code
6c1e0256fa
context_tracking: Restore correct previous context state on exception exit
it is able for exception hooks to use the generic code above instead of a
redundant arch implementation.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is the syscall slow path hooks for context tracking subsystem,
corresponding to
[PATCH] x86: Syscall hooks for userspace RCU extended QS
commit bf5a3c13b9
TIF_MEMDIE is moved to the second 16-bits (with value 17), as it seems there
is no asm code using it. TIF_NOHZ is added to _TIF_SYCALL_T_OR_A, so it is
better for it to be in the same 16 bits with others in the group, so in the
asm code, andi. with this group could work.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
MSR_DE is not cleared on entry to the kernel, and we don't clear it
explicitly outside of debug code. If we have MSR_DE set in
prime_debug_regs(), and the new thread has events enabled in DBCR0
(e.g. ICMP is set in thread->dbsr0, even though it was cleared in the
real DBCR0 when the thread got scheduled out), we'll end up taking a
debug exception in the kernel when DBCR0 is loaded. DSRR0 will not
point to an exception vector, and the kernel ends up hanging at
kernel_dbg_exc. Fix this by always clearing MSR_DE when we load new
debug state.
Another observed source of kernel_dbg_exc hangs is with the branch
taken event. If this event is active, but we take a non-debug trap
(e.g. a TLB miss or an asynchronous interrupt) before the next branch.
We end up taking a branch-taken debug exception on the initial branch
instruction of the exception vector, but because the debug exception is
DBSR_BT rather than DBSR_IC we branch to kernel_dbg_exc before even
checking the DSRR0 address. Fix this by checking for DBSR_BT as well
as DBSR_IC, which is what 32-bit does and what the comments suggest was
intended in the 64-bit code as well.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some versions of GCC apparently expect this to be provided by libgcc.
Updates from Mikey to fix 32 bit version and adding "r" to registers.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The current code fails to handle kexec on OPALv2. This fixes it
and adds code to improve the situation on OPALv3 where we can
query the CPU status from the firmware and decide what to do
based on that.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Saw this warning again, and this time from the ret_from_fork path.
It seems we could clear the back chain earlier in copy_thread(), which
could cover both path, and also fix potential lockdep usage in
schedule_tail(), or exception occurred before we clear the back chain.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We are getting build errors with CONFIG_PROC_FS=n:
arch/powerpc/kernel/rtas_flash.c
In function 'rtas_flash_init':
745:33: error: unused variable 'f' [-Werror=unused-variable]
But rtas_flash.c should not be built when CONFIG_PROC_FS=n, beacause all
it does is provide a /proc interface to the RTAS flash routines.
CONFIG_RTAS_FLASH already depends on CONFIG_RTAS_PROC, to indicate that
it depends on the RTAS proc support, but CONFIG_RTAS_PROC does not
depend on CONFIG_PROC_FS. So fix that.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch brings online all threads which are present but not online
prior to migration/hibernation. After migration/hibernation those
threads are taken back offline.
During migration/hibernation all online CPUs must call H_JOIN, this is
required by the hypervisor. Without this patch, threads that are offline
(H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be
deadlocked (all threads either JOIN'd or CEDE'd).
Cc: <stable@kernel.org>
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
commit b3f271e86e (powerpc: POWER7 optimised memcpy using VMX and
enhanced prefetch) uses VMX when it is safe to do so (ie not in
interrupt). It also looks at the task struct to decide if we have to
save the current tasks' VMX state.
kexec calls memcpy() at a point where the task struct may have been
overwritten by the new kexec segments. If it has been overwritten
then when memcpy -> enable_altivec looks up current->thread.regs->msr
we get a cryptic oops or lockup.
I also notice we aren't initialising thread_info->cpu, which means
smp_processor_id is broken. Fix that too.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@vger.kernel.org> # 3.6+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Linus Torvalds