When a dynamic array is defined, we add __data_loc_foo in
trace_entry to record the offset of the array, but the
size of the array is not recorded, which causes 2 problems:
- the event filter just compares the first 2 chars of the strings.
- parsers can't parse dynamic arrays.
So we encode the size of each dynamic array in the higher 16 bits
of __data_loc_foo, while the offset is in lower 16 bits.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A5E964A.9000403@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Rewrite the __ftrace_replace_code() function, simplify it, but don't
change the code's logic.
First, we get the state we want to set, if the record has the same
state, then do nothing, otherwise enable/disable it.
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
ftrace_trace_onoff_callback() will return an error even if we do the
right operation, for example:
# echo _spin_*:traceon:10 > set_ftrace_filter
-bash: echo: write error: Invalid argument
# cat set_ftrace_filter
#### all functions enabled ####
_spin_trylock_bh:traceon:count=10
_spin_unlock_irq:traceon:count=10
_spin_unlock_bh:traceon:count=10
_spin_lock_irq:traceon:count=10
_spin_unlock:traceon:count=10
_spin_trylock:traceon:count=10
_spin_unlock_irqrestore:traceon:count=10
_spin_lock_irqsave:traceon:count=10
_spin_lock_bh:traceon:count=10
_spin_lock:traceon:count=10
We want to set _spin_*:traceon:10 to set_ftrace_filter, it complains
with "Invalid argument", but the operation is successful.
This is because ftrace_process_regex() returns the number of functions that
matched the pattern. If the number is not 0, this value is returned
by ftrace_regex_write() whereas we want to return the number of bytes
virtually written.
Also the file offset pointer is not updated in this case.
If the number of matched functions is lower than the number of bytes written
by the user, this results to a reprocessing of the string given by the user with
a lower size, leading to a malformed ftrace regex and then a -EINVAL returned.
So, this patch fixes it by returning 0 if no error occured.
The fix also applies on 2.6.30
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
kernel/trace/ring_buffer.c: In function 'rb_tail_page_update':
kernel/trace/ring_buffer.c:849: warning: value computed is not used
kernel/trace/ring_buffer.c:850: warning: value computed is not used
Add "(void)"s to fix this warning, because we don't need here to handle
the fail case of cmpxchg, it's fine if an interrupt already did the
job.
Changed from V1:
Add a comment(which is written by Steven) for it.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-sched:
sched: Fix bug in SCHED_IDLE interaction with group scheduling
sched: Fix rt_rq->pushable_tasks initialization in init_rt_rq()
sched: Reset sched stats on fork()
sched_rt: Fix overload bug on rt group scheduling
sched: Documentation/sched-rt-group: Fix style issues & bump version
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
hrtimer: Fix migration expiry check
hrtimer: migration: do not check expiry time on current CPU
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futexes: Fix infinite loop in get_futex_key() on huge page
The per cpu variable stat is freeded if we fail to allocate a name
on start up. This was due to stat at first being allocated in the
initial design. But since then, it has become a static per cpu variable
but the free on error was not removed.
Also added __init annotation to the function that this is in.
[ Impact: prevent possible memory corruption on low mem at boot up ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: Remove alloc_bootmem annotations introduced in the past
kmemleak: Add callbacks to the bootmem allocator
kmemleak: Allow partial freeing of memory blocks
kmemleak: Trace the kmalloc_large* functions in slub
kmemleak: Scan objects allocated during a scanning episode
kmemleak: Do not acquire scan_mutex in kmemleak_open()
kmemleak: Remove the reported leaks number limitation
kmemleak: Add more cond_resched() calls in the scanning thread
kmemleak: Renice the scanning thread to +10
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One of the isolation modifications for SCHED_IDLE is the
unitization of sleeper credit. However the check for this
assumes that the sched_entity we're placing always belongs to a
task.
This is potentially not true with group scheduling and leaves
us rummaging randomly when we try to pull the policy.
Signed-off-by: Paul Turner <pjt@google.com>
Cc: peterz@infradead.org
LKML-Reference: <alpine.DEB.1.00.0907101649570.29914@kitami.corp.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
dma-debug: Fix the overlap() function to be correct and readable
oprofile: reset bt_lost_no_mapping with other stats
x86/oprofile: rename kernel parameter for architectural perfmon to arch_perfmon
signals: declare sys_rt_tgsigqueueinfo in syscalls.h
rcu: Mark Hierarchical RCU no longer experimental
dma-debug: Put all hash-chain locks into the same lock class
dma-debug: fix off-by-one error in overlap function
Optimize cond_resched() by removing one conditional.
Currently cond_resched() checks system_state ==
SYSTEM_RUNNING in order to avoid scheduling before the
scheduler is running.
We can however, as per suggestion of Matt, use
PREEMPT_ACTIVE to accomplish that very same.
Suggested-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Fix trace_print_seq()
kprobes: No need to unlock kprobe_insn_mutex
tracing/fastboot: Document the need of initcall_debug
trace_export: Repair missed fields
tracing: Fix stack tracer sysctl handling
The timer migration expiry check should prevent the migration of a
timer to another CPU when the timer expires before the next event is
scheduled on the other CPU. Migrating the timer might delay it because
we can not reprogram the clock event device on the other CPU. But the
code implementing that check has two flaws:
- for !HIGHRES the check compares the expiry value with the clock
events device expiry value which is wrong for CLOCK_REALTIME based
timers.
- the check is racy. It holds the hrtimer base lock of the target CPU,
but the clock event device expiry value can be modified
nevertheless, e.g. by an timer interrupt firing.
The !HIGHRES case is easy to fix as we can enqueue the timer on the
cpu which was selected by the load balancer. It runs the idle
balancing code once per jiffy anyway. So the maximum delay for the
timer is the same as when we keep the tick on the current cpu going.
In the HIGHRES case we can get the next expiry value from the hrtimer
cpu_base of the target CPU and serialize the update with the cpu_base
lock. This moves the lock section in hrtimer_interrupt() so we can set
next_event to KTIME_MAX while we are handling the expired timers and
set it to the next expiry value after we handled the timers under the
base lock. While the expired timers are processed timer migration is
blocked because the expiry time of the timer is always <= KTIME_MAX.
Also remove the now useless clockevents_get_next_event() function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The timer migration code needs to check whether the expiry time of the
timer is before the programmed clock event expiry time when the timer
is enqueued on another CPU because we can not reprogram the timer
device on the other CPU. The current logic checks the expiry time even
if we enqueue on the current CPU when nohz_get_load_balancer() returns
current CPU. This might lead to an endless loop in the expiry check
code when the expiry time of the timer is before the current
programmed next event.
Check whether nohz_get_load_balancer() returns current CPU and skip
the expiry check if this is the case.
The bug was triggered from the networking code. The patch fixes the
regression http://bugzilla.kernel.org/show_bug.cgi?id=13738
(Soft-Lockup/Race in networking in 2.6.31-rc1+195)
Cc: Arun Bharadwaj <arun@linux.vnet.ibm.com
Tested-by: Joao Correia <joaomiguelcorreia@gmail.com>
Tested-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The stat entries can be freed when the stat file is being read.
The worse is, the ptr can be freed immediately after it's returned
from workqueue_stat_start/next().
Add a refcnt to struct cpu_workqueue_stats to avoid use-after-free.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A51B16F.6010608@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
