I think that "ftrace_event_file *trace_probe[]" complicates the
code for no reason, turn it into list_head to simplify the code.
enable_trace_probe() no longer needs synchronize_sched().
This needs the extra sizeof(list_head) memory for every attached
ftrace_event_file, hopefully not a problem in this case.
Link: http://lkml.kernel.org/r/20130620173814.GA13165@redhat.com
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The comment on the soft disable 'disable' case of
__ftrace_event_enable_disable() states that the soft disable bit
should be cleared in that case, but currently only the soft mode bit
is actually cleared.
This essentially leaves the standard non-soft-enable enable/disable
paths as the only way to clear the soft disable flag, but the soft
disable bit should also be cleared when removing a trigger with '!'.
Also, the SOFT_DISABLED bit should never be set if SOFT_MODE is
cleared.
This fixes the above discrepancies.
Link: http://lkml.kernel.org/r/b9c68dd50bc07019e6c67d3f9b29be4ef1b2badb.1372479499.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
enable_trace_probe() and disable_trace_probe() should not worry about
serialization, the caller (perf_trace_init or __ftrace_set_clr_event)
holds event_mutex.
They are also called by kprobe_trace_self_tests_init(), but this __init
function can't race with itself or trace_events.c
And note that this code depended on event_mutex even before 41a7dd420c
which introduced probe_enable_lock. In fact it assumes that the caller
kprobe_register() can never race with itself. Otherwise, say, tp->flags
manipulations are racy.
Link: http://lkml.kernel.org/r/20130620173809.GA13158@redhat.com
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
perf_trace_buf_prepare() + perf_trace_buf_submit() make no sense
if this task/CPU has no active counters. Change kprobe_perf_func()
and kretprobe_perf_func() to check call->perf_events beforehand
and return if this list is empty.
For example, "perf record -e some_probe -p1". Only /sbin/init will
report, all other threads which hit the same probe will do
perf_trace_buf_prepare/perf_trace_buf_submit just to realize that
nobody wants perf_swevent_event().
Link: http://lkml.kernel.org/r/20130620173806.GA13151@redhat.com
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Running the following:
# cd /sys/kernel/debug/tracing
# echo p:i do_sys_open > kprobe_events
# echo p:j schedule >> kprobe_events
# cat kprobe_events
p:kprobes/i do_sys_open
p:kprobes/j schedule
# echo p:i do_sys_open >> kprobe_events
# cat kprobe_events
p:kprobes/j schedule
p:kprobes/i do_sys_open
# ls /sys/kernel/debug/tracing/events/kprobes/
enable filter j
Notice that the 'i' is missing from the kprobes directory.
The console produces:
"Failed to create system directory kprobes"
This is because kprobes passes in a allocated name for the system
and the ftrace event subsystem saves off that name instead of creating
a duplicate for it. But the kprobes may free the system name making
the pointer to it invalid.
This bug was introduced by 92edca073c "tracing: Use direct field, type
and system names" which switched from using kstrdup() on the system name
in favor of just keeping apointer to it, as the internal ftrace event
system names are static and exist for the life of the computer being booted.
Instead of reverting back to duplicating system names again, we can use
core_kernel_data() to determine if the passed in name was allocated or
static. Then use the MSB of the ref_count to be a flag to keep track if
the name was allocated or not. Then we can still save from having to duplicate
strings that will always exist, but still copy the ones that may be freed.
Cc: stable@vger.kernel.org # 3.10
Reported-by: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com>
Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Merge in a recent upstream commit:
c2853c8df5 include/linux/math64.h: add div64_ul()
because:
72a4cf20cb sched: Change cfs_rq load avg to unsigned long
relies on it.
[ We don't rebase sched/core for this, because the handful of
followup commits after the broken commit are not behavioral
changes so are unlikely to be needed during bisection. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
0ce6cba357 ("cgroup: CGRP_ROOT_SUBSYS_BOUND should be ignored when
comparing mount options") only updated the remount path but
CGRP_ROOT_SUBSYS_BOUND should also be ignored when comparing options
while mounting an existing hierarchy. As option mismatch triggers a
warning but doesn't fail the mount without sane_behavior, this only
triggers a spurious warning message.
Fix it by only comparing CGRP_ROOT_OPTION_MASK bits when comparing new
and existing root options.
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull timer fix from Thomas Gleixner:
"Correct an ordering issue in the tick broadcast code. I really wish
we'd get compensation for pain and suffering for each line of code we
write to work around dysfunctional timer hardware."
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick: Fix tick_broadcast_pending_mask not cleared
hrtimers_resume() only reprograms the timers for the current CPU as it
assumes that all other CPUs are offline at this point in the resume
process. If other CPUs are online then their timers will not be
corrected and they may fire at the wrong time.
When running as a Xen guest, this assumption is not true. Non-boot
CPUs are only stopped with IRQs disabled instead of offlining them.
This is a performance optimization as disabling the CPUs would add an
unacceptable amount of additional downtime during a live migration (>
200 ms for a 4 VCPU guest).
hrtimers_resume() cannot call on_each_cpu(retrigger_next_event,...)
as the other CPUs will be stopped with IRQs disabled. Instead, defer
the call to the next softirq.
[ tglx: Separated the xen change out ]
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/1372329348-20841-2-git-send-email-david.vrabel@citrix.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* freezer:
af_unix: use freezable blocking calls in read
sigtimedwait: use freezable blocking call
nanosleep: use freezable blocking call
futex: use freezable blocking call
select: use freezable blocking call
epoll: use freezable blocking call
binder: use freezable blocking calls
freezer: add new freezable helpers using freezer_do_not_count()
freezer: convert freezable helpers to static inline where possible
freezer: convert freezable helpers to freezer_do_not_count()
freezer: skip waking up tasks with PF_FREEZER_SKIP set
freezer: shorten freezer sleep time using exponential backoff
lockdep: check that no locks held at freeze time
lockdep: remove task argument from debug_check_no_locks_held
freezer: add unsafe versions of freezable helpers for CIFS
freezer: add unsafe versions of freezable helpers for NFS
When building imx_v6_v7_defconfig with imx-drm drivers selected as
modules, we get the following build errors:
ERROR: "irq_gc_mask_clr_bit" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
ERROR: "irq_gc_mask_set_bit" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
ERROR: "irq_gc_ack_set_bit" [drivers/staging/imx-drm/ipu-v3/imx-ipu-v3.ko] undefined!
Export the required functions to avoid this problem.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Cc: shawn.guo@linaro.org
Cc: kernel@pengutronix.de
Link: http://lkml.kernel.org/r/1372389789-7048-1-git-send-email-festevam@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1672d04070 ("cgroup: fix cgroupfs_root early destruction path")
introduced CGRP_ROOT_SUBSYS_BOUND which is used to mark completion of
subsys binding on a new root; however, this broke remounts.
cgroup_remount() doesn't allow changing root options via remount and
CGRP_ROOT_SUBSYS_BOUND, which is set on all fully initialized roots,
makes the function reject all remounts.
Fix it by putting the options part in the lower 16 bits of root->flags
and masking the comparions. While at it, make cgroup_remount() emit
an error message explaining why it's rejecting a remount request, so
that it's less of a mystery.
Signed-off-by: Tejun Heo <tj@kernel.org>
