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The last remaining user was oprofile and its use has been
removed a while ago in commit bc078e4eab65f11bba
("oprofile: convert oprofile from timer_hook to hrtimer").
There doesn't seem to be any upstream user of this hook
for about two years now. And I'm not even aware of any out of
tree user.
Let's remove it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1356191991-2251-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
Pull small function-tracing smatch fixlet from Steve Rostedt.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Dan's smatch found a compare bug with the result of the
trace_test_and_set_recursion() and comparing to less than
zero. If the function fails, it returns -1, but was saved in
an unsigned int, which will never be less than zero and will
ignore the result of the test if a recursion did happen.
Luckily this is the last of the recursion tests, as the
infrastructure of ftrace would catch recursions before it
got here, except for some few exceptions.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
Pull tracing updates from Steve Rostedt.
This commit:
tracing: Remove the extra 4 bytes of padding in events
changes the ABI. All involved parties seem to agree that it's safe to
do now, but the devil is in the details ...
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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ring_buffer.c use to require declarations from trace.h, but
these have moved to the generic header files. There's nothing
in trace.h that ring_buffer.c requires.
There's some headers that trace.h included that ring_buffer.c
needs, but it's best that it includes them directly, and not
include trace.h.
Also, some things may use ring_buffer.c without having tracing
configured. This removes the dependency that may come in the
future.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Using context bit recursion checking, we can help increase the
performance of the ring buffer.
Before this patch:
# echo function > /debug/tracing/current_tracer
# for i in `seq 10`; do ./hackbench 50; done
Time: 10.285
Time: 10.407
Time: 10.243
Time: 10.372
Time: 10.380
Time: 10.198
Time: 10.272
Time: 10.354
Time: 10.248
Time: 10.253
(average: 10.3012)
Now we have:
# echo function > /debug/tracing/current_tracer
# for i in `seq 10`; do ./hackbench 50; done
Time: 9.712
Time: 9.824
Time: 9.861
Time: 9.827
Time: 9.962
Time: 9.905
Time: 9.886
Time: 10.088
Time: 9.861
Time: 9.834
(average: 9.876)
a 4% savings!
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The function tracer had two different versions of function tracing.
The disabling of irqs version and the preempt disable version.
As function tracing in very intrusive and can cause nasty recursion
issues, it has its own recursion protection. But the old method to
do this was a flat layer. If it detected that a recursion was happening
then it would just return without recording.
This made the preempt version (much faster than the irq disabling one)
not very useful, because if an interrupt were to occur after the
recursion flag was set, the interrupt would not be traced at all,
because every function that was traced would think it recursed on
itself (due to the context it preempted setting the recursive flag).
Now that we have a recursion flag for every context level, we
no longer need to worry about that. We can disable preemption,
set the current context recursion check bit, and go on. If an
interrupt were to come along, it would check its own context bit
and happily continue to trace.
As the preempt version is faster than the irq disable version,
there's no more reason to keep the preempt version around.
And the irq disable version still had an issue with missing
out on tracing NMI code.
Remove the irq disable function tracer version and have the
preempt disable version be the default (and only version).
Before this patch we had from running:
# echo function > /debug/tracing/current_tracer
# for i in `seq 10`; do ./hackbench 50; done
Time: 12.028
Time: 11.945
Time: 11.925
Time: 11.964
Time: 12.002
Time: 11.910
Time: 11.944
Time: 11.929
Time: 11.941
Time: 11.924
(average: 11.9512)
Now we have:
# echo function > /debug/tracing/current_tracer
# for i in `seq 10`; do ./hackbench 50; done
Time: 10.285
Time: 10.407
Time: 10.243
Time: 10.372
Time: 10.380
Time: 10.198
Time: 10.272
Time: 10.354
Time: 10.248
Time: 10.253
(average: 10.3012)
a 13.8% savings!
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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When function tracing occurs, the following steps are made:
If arch does not support a ftrace feature:
call internal function (uses INTERNAL bits) which calls...
If callback is registered to the "global" list, the list
function is called and recursion checks the GLOBAL bits.
then this function calls...
The function callback, which can use the FTRACE bits to
check for recursion.
Now if the arch does not suppport a feature, and it calls
the global list function which calls the ftrace callback
all three of these steps will do a recursion protection.
There's no reason to do one if the previous caller already
did. The recursion that we are protecting against will
go through the same steps again.
To prevent the multiple recursion checks, if a recursion
bit is set that is higher than the MAX bit of the current
check, then we know that the check was made by the previous
caller, and we can skip the current check.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Convert the bits into enums which makes the code a little easier
to maintain.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Currently for recursion checking in the function tracer, ftrace
tests a task_struct bit to determine if the function tracer had
recursed or not. If it has, then it will will return without going
further.
But this leads to races. If an interrupt came in after the bit
was set, the functions being traced would see that bit set and
think that the function tracer recursed on itself, and would return.
Instead add a bit for each context (normal, softirq, irq and nmi).
A check of which context the task is in is made before testing the
associated bit. Now if an interrupt preempts the function tracer
after the previous context has been set, the interrupt functions
can still be traced.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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There is lots of places that perform:
op = rcu_dereference_raw(ftrace_control_list);
while (op != &ftrace_list_end) {
Add a helper macro to do this, and also optimize for a single
entity. That is, gcc will optimize a loop for either no iterations
or more than one iteration. But usually only a single callback
is registered to the function tracer, thus the optimized case
should be a single pass. to do this we now do:
op = rcu_dereference_raw(list);
do {
[...]
} while (likely(op = rcu_dereference_raw((op)->next)) &&
unlikely((op) != &ftrace_list_end));
An op is always registered (ftrace_list_end when no callbacks is
registered), thus when a single callback is registered, the link
list looks like:
top => callback => ftrace_list_end => NULL.
The likely(op = op->next) still must be performed due to the race
of removing the callback, where the first op assignment could
equal ftrace_list_end. In that case, the op->next would be NULL.
But this is unlikely (only happens in a race condition when
removing the callback).
But it is very likely that the next op would be ftrace_list_end,
unless more than one callback has been registered. This tells
gcc what the most common case is and makes the fast path with
the least amount of branches.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The function tracing recursion self test should not crash
the machine if the resursion test fails. If it detects that
the function tracing is recursing when it should not be, then
bail, don't go into an infinite recursive loop.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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If one of the function tracers set by the global ops is not recursion
safe, it can still be called directly without the added recursion
supplied by the ftrace infrastructure.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The test that checks function recursion does things differently
if the arch does not support all ftrace features. But that really
doesn't make a difference with how the test runs, and either way
the count variable should be 2 at the end.
Currently the test wrongly fails for archs that don't support all
the ftrace features.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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There's a race condition between the setting of a new tracer and
the update of the max trace buffers (the swap). When a new tracer
is added, it sets current_trace to nop_trace before disabling
the old tracer. At this moment, if the old tracer uses update_max_tr(),
the update may trigger the warning against !current_trace->use_max-tr,
as nop_trace doesn't have that set.
As update_max_tr() requires that interrupts be disabled, we can
add a check to see if current_trace == nop_trace and bail if it
does. Then when disabling the current_trace, set it to nop_trace
and run synchronize_sched(). This will make sure all calls to
update_max_tr() have completed (it was called with interrupts disabled).
As a clean up, this commit also removes shrinking and recreating
the max_tr buffer if the old and new tracers both have use_max_tr set.
The old way use to always shrink the buffer, and then expand it
for the next tracer. This is a waste of time.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Commit 083b804c4d3e ("async: use workqueue for worker pool") made it
possible that async jobs are moved from pending to running out-of-order.
While pending async jobs will be queued and dispatched for execution in
the same order, nothing guarantees they'll enter "1) move self to the
running queue" of async_run_entry_fn() in the same order.
Before the conversion, async implemented its own worker pool. An async
worker, upon being woken up, fetches the first item from the pending
list, which kept the executing lists sorted. The conversion to
workqueue was done by adding work_struct to each async_entry and async
just schedules the work item. The queueing and dispatching of such work
items are still in order but now each worker thread is associated with a
specific async_entry and moves that specific async_entry to the
executing list. So, depending on which worker reaches that point
earlier, which is non-deterministic, we may end up moving an async_entry
with larger cookie before one with smaller one.
This broke __lowest_in_progress(). running->domain may not be properly
sorted and is not guaranteed to contain lower cookies than pending list
when not empty. Fix it by ensuring sort-inserting to the running list
and always looking at both pending and running when trying to determine
the lowest cookie.
Over time, the async synchronization implementation became quite messy.
We better restructure it such that each async_entry is linked to two
lists - one global and one per domain - and not move it when execution
starts. There's no reason to distinguish pending and running. They
behave the same for synchronization purposes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fix from Steven Rostedt:
"Kprobes now uses the function tracer if it can. That is, if a probe
is placed on a function mcount/nop location, and the arch supports it,
instead of adding a breakpoint, kprobes will register a function
callback as that is much more efficient.
The function tracer requires to update modules before they run, and
uses the module notifier to do so. But if something else in the
module notifiers registers a kprobe at one of these locations, before
ftrace can get to it, then the system could fail.
The function tracer must be initialized early, otherwise module
notifiers that probe will only work by chance."
* tag 'trace-3.8-rc4-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Be first to run code modification on modules
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wake_up_process() should never wakeup a TASK_STOPPED/TRACED task.
Change it to use TASK_NORMAL and add the WARN_ON().
TASK_ALL has no other users, probably can be killed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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putreg() assumes that the tracee is not running and pt_regs_access() can
safely play with its stack. However a killed tracee can return from
ptrace_stop() to the low-level asm code and do RESTORE_REST, this means
that debugger can actually read/modify the kernel stack until the tracee
does SAVE_REST again.
set_task_blockstep() can race with SIGKILL too and in some sense this
race is even worse, the very fact the tracee can be woken up breaks the
logic.
As Linus suggested we can clear TASK_WAKEKILL around the arch_ptrace()
call, this ensures that nobody can ever wakeup the tracee while the
debugger looks at it. Not only this fixes the mentioned problems, we
can do some cleanups/simplifications in arch_ptrace() paths.
Probably ptrace_unfreeze_traced() needs more callers, for example it
makes sense to make the tracee killable for oom-killer before
access_process_vm().
While at it, add the comment into may_ptrace_stop() to explain why
ptrace_stop() still can't rely on SIGKILL and signal_pending_state().
Reported-by: Salman Qazi <sqazi@google.com>
Reported-by: Suleiman Souhlal <suleiman@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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As trace_clock is used by other things besides tracing, and it
does not require anything from trace.h, it is best not to include
the header file in trace_clock.c.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Cleanup and preparation for the next change.
signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
necessary mask.
Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
which adds __TASK_TRACED.
This way ptrace_signal_wake_up() can work "inside" ptrace_request()
even if the tracee doesn't have the TASK_WAKEKILL bit set.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Due to a userspace issue with PowerTop v2beta, which hardcoded
the offset of event fields that it was using, it broke when
we removed the Big Kernel Lock counter from the event header.
(commit e6e1e2593 "tracing: Remove lock_depth from event entry")
Because this broke userspace, it was determined that we must
keep those 4 bytes around.
(commit a3a4a5acd "Regression: partial revert "tracing: Remove lock_depth from event entry"")
This unfortunately wastes space in the ring buffer. 4 bytes per
event, where a lot of events are just 24 bytes. That's 16% of the
buffer wasted. A million events will add 4 megs of white space
into the buffer.
It was later noticed that PowerTop v2beta could not work on systems
where the kernel was 64 bit but the userspace was 32 bits.
The reason was because the offsets are different between the
two and the hard coded offset of one would not work with the other.
With PowerTop v2 final, it implemented the same interface that both
perf and trace-cmd use. That is, it reads the format file of
the event to find the offsets of the fields it needs. This fixes
the problem with running powertop on a 32 bit userspace running
on a 64 bit kernel. It also no longer requires the 4 byte padding.
As PowerTop v2 has been out for a while, and is included in all
major distributions, it is time that we can safely remove the
4 bytes of padding. Users of PowerTop v2beta should upgrade to
PowerTop v2 final.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Split ftrace-based kprobes code from kprobes, and introduce
CONFIG_(HAVE_)KPROBES_ON_FTRACE Kconfig flags.
For the cleanup reason, this also moves kprobe_ftrace check
into skip_singlestep.
Link: http://lkml.kernel.org/r/20120928081520.3560.25624.stgit@ltc138.sdl.hitachi.co.jp
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Move SAVE_REGS support flag into Kconfig and rename
it to CONFIG_DYNAMIC_FTRACE_WITH_REGS. This also introduces
CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which indicates
the architecture depending part of ftrace has a code
that saves full registers.
On the other hand, CONFIG_DYNAMIC_FTRACE_WITH_REGS indicates
the code is enabled.
Link: http://lkml.kernel.org/r/20120928081516.3560.72534.stgit@ltc138.sdl.hitachi.co.jp
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Add the file max_graph_depth to the debug tracing directory that lets
the user define the depth of the function graph.
A very useful operation is to set the depth to 1. Then it traces only
the first function that is called when entering the kernel. This can
be used to determine what system operations interrupt a process.
For example, to work on NOHZ processes (single tasks running without
a timer tick), if any interrupt goes off and preempts that task, this
code will show it happening.
# cd /sys/kernel/debug/tracing
# echo 1 > max_graph_depth
# echo function_graph > current_tracer
# cat per_cpu/cpu/<cpu-of-process>/trace
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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There's now a check in tracing_reset_online_cpus() if the buffer is
allocated or NULL. No need to do a check before calling it with max_tr.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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max_tr->buffer could be NULL in the tracing_reset{_online_cpus}. In this
case, a NULL pointer dereference happens, so we should return immediately
from these functions.
Note, the current code does not call tracing_reset*() with max_tr when
its buffer is NULL, but future code will. This patch is needed to prevent
the future code from crashing.
Link: http://lkml.kernel.org/r/20121219070234.31200.93863.stgit@liselsia
Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Some functions in the syscall tracing is used only locally to
the file, but they are labeled global. Convert them to static functions.
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Without this patch, we can register a uprobe event for a directory.
Enabling such a uprobe event would anyway fail.
Example:
$ echo 'p /bin:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events
However dirctories cannot be valid targets for uprobe.
Hence verify if the target is a regular file during the probe
registration.
Link: http://lkml.kernel.org/r/20130103004212.690763002@goodmis.org
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[ cleaned up whitespace and removed redundant IS_DIR() check ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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typeof(&buffer) is a pointer to array of 1024 char, or char (*)[1024].
But, typeof(&buffer[0]) is a pointer to char which match the return type of get_trace_buf().
As well-known, the value of &buffer is equal to &buffer[0].
so return this_cpu_ptr(&percpu_buffer->buffer[0]) can avoid type cast.
Link: http://lkml.kernel.org/r/50A1A800.3020102@gmail.com
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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The original ring-buffer code had special checks at the start
of rb_advance_iter() and instead of repeating them again at the
end of the function if a certain condition existed, I just did
a recursive call to rb_advance_iter() because the special condition
would cause rb_advance_iter() to return early (after the checks).
But as things have changed, the special checks no longer exist
and the only thing done for the special_condition is to call
rb_inc_iter() and return. Instead of doing a confusing recursive call,
just call rb_inc_iter instead.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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If some other kernel subsystem has a module notifier, and adds a kprobe
to a ftrace mcount point (now that kprobes work on ftrace points),
when the ftrace notifier runs it will fail and disable ftrace, as well
as kprobes that are attached to ftrace points.
Here's the error:
WARNING: at kernel/trace/ftrace.c:1618 ftrace_bug+0x239/0x280()
Hardware name: Bochs
Modules linked in: fat(+) stap_56d28a51b3fe546293ca0700b10bcb29__8059(F) nfsv4 auth_rpcgss nfs dns_resolver fscache xt_nat iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack lockd sunrpc ppdev parport_pc parport microcode virtio_net i2c_piix4 drm_kms_helper ttm drm i2c_core [last unloaded: bid_shared]
Pid: 8068, comm: modprobe Tainted: GF 3.7.0-0.rc8.git0.1.fc19.x86_64 #1
Call Trace:
[<ffffffff8105e70f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff81134106>] ? __probe_kernel_read+0x46/0x70
[<ffffffffa0180000>] ? 0xffffffffa017ffff
[<ffffffffa0180000>] ? 0xffffffffa017ffff
[<ffffffff8105e76a>] warn_slowpath_null+0x1a/0x20
[<ffffffff810fd189>] ftrace_bug+0x239/0x280
[<ffffffff810fd626>] ftrace_process_locs+0x376/0x520
[<ffffffff810fefb7>] ftrace_module_notify+0x47/0x50
[<ffffffff8163912d>] notifier_call_chain+0x4d/0x70
[<ffffffff810882f8>] __blocking_notifier_call_chain+0x58/0x80
[<ffffffff81088336>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff810c2a23>] sys_init_module+0x73/0x220
[<ffffffff8163d719>] system_call_fastpath+0x16/0x1b
---[ end trace 9ef46351e53bbf80 ]---
ftrace failed to modify [<ffffffffa0180000>] init_once+0x0/0x20 [fat]
actual: cc:bb:d2:4b:e1
A kprobe was added to the init_once() function in the fat module on load.
But this happened before ftrace could have touched the code. As ftrace
didn't run yet, the kprobe system had no idea it was a ftrace point and
simply added a breakpoint to the code (0xcc in the cc:bb:d2:4b:e1).
Then when ftrace went to modify the location from a call to mcount/fentry
into a nop, it didn't see a call op, but instead it saw the breakpoint op
and not knowing what to do with it, ftrace shut itself down.
The solution is to simply give the ftrace module notifier the max priority.
This should have been done regardless, as the core code ftrace modification
also happens very early on in boot up. This makes the module modification
closer to core modification.
Link: http://lkml.kernel.org/r/20130107140333.593683061@goodmis.org
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Frank Ch. Eigler <fche@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Commit 1fb9341ac348 ("module: put modules in list much earlier") moved
some of the module initialization code around, and in the process
changed the exit paths too. But for the duplicate export symbol error
case the change made the ddebug_cleanup path jump to after the module
mutex unlock, even though it happens with the mutex held.
Rusty has some patches to split this function up into some helper
functions, hopefully the mess of complex goto targets will go away
eventually.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module fixes and a virtio block fix from Rusty Russell:
"Various minor fixes, but a slightly more complex one to fix the
per-cpu overload problem introduced recently by kvm id changes."
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
module: put modules in list much earlier.
module: add new state MODULE_STATE_UNFORMED.
module: prevent warning when finit_module a 0 sized file
virtio-blk: Don't free ida when disk is in use
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull misc syscall fixes from Al Viro:
- compat syscall fixes (discussed back in December)
- a couple of "make life easier for sigaltstack stuff by reducing
inter-tree dependencies"
- fix up compiler/asmlinkage calling convention disagreement of
sys_clone()
- misc
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
sys_clone() needs asmlinkage_protect
make sure that /linuxrc has std{in,out,err}
x32: fix sigtimedwait
x32: fix waitid()
switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE
switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE
CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h
Ensure that kernel_init_freeable() is not inlined into non __init code
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The ia64 function "thread_matches()" has no users since commit
e868a55c2a8c ("[IA64] remove find_thread_for_addr()"). Remove it.
This allows us to make ptrace_check_attach() static to kernel/ptrace.c,
which is good since we'll need to change the semantics of it and fix up
all the callers.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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If the default iosched is built as module, the kernel may deadlock
while trying to load the iosched module on device probe if the probing
was running off async. This is because async_synchronize_full() at
the end of module init ends up waiting for the async job which
initiated the module loading.
async A modprobe
1. finds a device
2. registers the block device
3. request_module(default iosched)
4. modprobe in userland
5. load and init module
6. async_synchronize_full()
Async A waits for modprobe to finish in request_module() and modprobe
waits for async A to finish in async_synchronize_full().
Because there's no easy to track dependency once control goes out to
userland, implementing properly nested flushing is difficult. For
now, make module init perform async_synchronize_full() iff module init
has queued async jobs as suggested by Linus.
This avoids the described deadlock because iosched module doesn't use
async and thus wouldn't invoke async_synchronize_full(). This is
hacky and incomplete. It will deadlock if async module loading nests;
however, this works around the known problem case and seems to be the
best of bad options.
For more details, please refer to the following thread.
http://thread.gmane.org/gmane.linux.kernel/1420814
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Alex Riesen <raa.lkml@gmail.com>
Tested-by: Ming Lei <ming.lei@canonical.com>
Tested-by: Alex Riesen <raa.lkml@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing regression fixes from Steven Rostedt:
"The clean up patch commit 0fb9656d957d "tracing: Make tracing_enabled
be equal to tracing_on" caused two regressions.
1) The irqs off latency tracer no longer starts if tracing_on is off
when the tracer is set, and then tracing_on is enabled. The
tracing_on file needs the hook that tracing_enabled had to enable
tracers if they request it (call the tracer's start() method).
2) That commit had a separate change that really should have been a
separate patch, but it must have been added accidently with the -a
option of git commit. But as the change is still related to the
commit it wasn't noticed in review. That change, changed the way
blocking is done by the trace_pipe file with respect to the
tracing_on settings. I've been told that this change breaks
current userspace, and this specific change is being reverted."
* tag 'trace-3.8-rc3-regression-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix regression of trace_pipe
tracing: Fix regression with irqsoff tracer and tracing_on file
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Commit 0fb9656d "tracing: Make tracing_enabled be equal to tracing_on"
changes the behaviour of trace_pipe, ie. it makes trace_pipe return if
we've read something and tracing is enabled, and this means that we have
to 'cat trace_pipe' again and again while running tests.
IMO the right way is if tracing is enabled, we always block and wait for
ring buffer, or we may lose what we want since ring buffer's size is limited.
Link: http://lkml.kernel.org/r/1358132051-5410-1-git-send-email-bo.li.liu@oracle.com
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Prarit's excellent bug report:
> In recent Fedora releases (F17 & F18) some users have reported seeing
> messages similar to
>
> [ 15.478160] kvm: Could not allocate 304 bytes percpu data
> [ 15.478174] PERCPU: allocation failed, size=304 align=32, alloc from
> reserved chunk failed
>
> during system boot. In some cases, users have also reported seeing this
> message along with a failed load of other modules.
>
> What is happening is systemd is loading an instance of the kvm module for
> each cpu found (see commit e9bda3b). When the module load occurs the kernel
> currently allocates the modules percpu data area prior to checking to see
> if the module is already loaded or is in the process of being loaded. If
> the module is already loaded, or finishes load, the module loading code
> releases the current instance's module's percpu data.
Now we have a new state MODULE_STATE_UNFORMED, we can insert the
module into the list (and thus guarantee its uniqueness) before we
allocate the per-cpu region.
Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Prarit Bhargava <prarit@redhat.com>
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You should never look at such a module, so it's excised from all paths
which traverse the modules list.
We add the state at the end, to avoid gratuitous ABI break (ksplice).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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audit_log_start() performs the same jiffies comparison in two places.
If sufficient time has elapsed between the two comparisons, the second
one produces a negative sleep duration:
schedule_timeout: wrong timeout value fffffffffffffff0
Pid: 6606, comm: trinity-child1 Not tainted 3.8.0-rc1+ #43
Call Trace:
schedule_timeout+0x305/0x340
audit_log_start+0x311/0x470
audit_log_exit+0x4b/0xfb0
__audit_syscall_exit+0x25f/0x2c0
sysret_audit+0x17/0x21
Fix it by performing the comparison a single time.
Reported-by: Dave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It's possible for audit_log_start() to return NULL. Handle it in the
various callers.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Julien Tinnes <jln@google.com>
Cc: Will Drewry <wad@google.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The seccomp path was using AUDIT_ANOM_ABEND from when seccomp mode 1
could only kill a process. While we still want to make sure an audit
record is forced on a kill, this should use a separate record type since
seccomp mode 2 introduces other behaviors.
In the case of "handled" behaviors (process wasn't killed), only emit a
record if the process is under inspection. This change also fixes
userspace examination of seccomp audit events, since it was considered
malformed due to missing fields of the AUDIT_ANOM_ABEND event type.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Julien Tinnes <jln@google.com>
Acked-by: Will Drewry <wad@chromium.org>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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down_write_nest_lock() provides a means to annotate locking scenario
where an outer lock is guaranteed to serialize the order nested locks
are being acquired.
This is analogoue to already existing mutex_lock_nest_lock() and
spin_lock_nest_lock().
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mel Gorman <mel@csn.ul.ie>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit 02404baf1b47 "tracing: Remove deprecated tracing_enabled file"
removed the tracing_enabled file as it never worked properly and
the tracing_on file should be used instead. But the tracing_on file
didn't call into the tracers start/stop routines like the
tracing_enabled file did. This caused trace-cmd to break when it
enabled the irqsoff tracer.
If you just did "echo irqsoff > current_tracer" then it would work
properly. But the tool trace-cmd disables tracing first by writing
"0" into the tracing_on file. Then it writes "irqsoff" into
current_tracer and then writes "1" into tracing_on. Unfortunately,
the above commit changed the irqsoff tracer to check the tracing_on
status instead of the tracing_enabled status. If it's disabled then
it does not start the tracer internals.
The problem is that writing "1" into tracing_on does not call the
tracers "start" routine like writing "1" into tracing_enabled did.
This makes the irqsoff tracer not start when using the trace-cmd
tool, and is a regression for userspace.
Simple fix is to have the tracing_on file call the tracers start()
method when being enabled (and the stop() method when disabled).
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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Fix new kernel-doc warning in auditfilter.c:
Warning(kernel/auditfilter.c:1157): Excess function parameter 'uid' description in 'audit_receive_filter'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com (subscribers-only)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing regression fix from Steven Rostedt:
"A change that came in this merge window broke the writing to the
trace_options file. It causes garbage to be read during the compare
of option names, and breaks setting options via the trace_options
file, although options can still be set via the options/<option>
files."
* tag 'trace-3.8-rc2-regression-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix regression of trace_options file setting
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The latest change to allow trace options to be set on the command
line also broke the trace_options file.
The zeroing of the last byte of the option name that is echoed into
the trace_option file was removed with the consolidation of some
of the code. The compare between the option and what was written to
the trace_options file fails because the string holding the data
written doesn't terminate with a null character.
A zero needs to be added to the end of the string copied from
user space.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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