Commit Graph

3151 Commits

Author SHA1 Message Date
Tom Zanussi 104f281044 tracing: Add a per-event-trigger 'paused' field
Add a simple per-trigger 'paused' flag, allowing individual triggers
to pause.  We could leave it to individual triggers that need this
functionality to do it themselves, but we also want to allow other
events to control pausing, so add it to the trigger data.

Link: http://lkml.kernel.org/r/fed37e4879684d7dcc57fe00ce0cbf170032b06d.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:33 -05:00
Tom Zanussi dbfeaa7aba tracing: Add get_syscall_name()
Add a utility function to grab the syscall name from the syscall
metadata, given a syscall id.

Link: http://lkml.kernel.org/r/be26a8dfe3f15e16a837799f1c1e2b4d62742843.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:32 -05:00
Tom Zanussi c4a5923055 tracing: Add event record param to trigger_ops.func()
Some triggers may need access to the trace event, so pass it in.  Also
fix up the existing trigger funcs and their callers.

Link: http://lkml.kernel.org/r/543e31e9fc445ef61077421ab219033401c39846.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:31 -05:00
Tom Zanussi ab4bf00892 tracing: Make event trigger functions available
Make various event trigger utility functions available outside of
trace_events_trigger.c so that new triggers can be defined outside of
that file.

Link: http://lkml.kernel.org/r/4a40c1695dd43cac6cd475d72e13ffe30ba84bff.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:30 -05:00
Tom Zanussi 4ef56902fb tracing: Make ftrace_event_field checking functions available
Make is_string_field() and is_function_field() accessible outside of
trace_event_filters.c for other users of ftrace_event_fields.

Link: http://lkml.kernel.org/r/2d3f00d3311702e556e82eed7754bae6f017939f.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:29 -05:00
Chunyu Hu d39cdd2036 tracing: Make tracer_flags use the right set_flag callback
When I was updating the ftrace_stress test of ltp. I encountered
a strange phenomemon, excute following steps:

echo nop > /sys/kernel/debug/tracing/current_tracer
echo 0 > /sys/kernel/debug/tracing/options/funcgraph-cpu
bash: echo: write error: Invalid argument

check dmesg:
[ 1024.903855] nop_test_refuse flag set to 0: we refuse.Now cat trace_options to see the result

The reason is that the trace option test will randomly setup trace
option under tracing/options no matter what the current_tracer is.
but the set_tracer_option is always using the set_flag callback
from the current_tracer. This patch adds a pointer to tracer_flags
and make it point to the tracer it belongs to. When the option is
setup, the set_flag of the right tracer will be used no matter
what the the current_tracer is.

And the old dummy_tracer_flags is used for all the tracers which
doesn't have a tracer_flags, having issue to use it to save the
pointer of a tracer. So remove it and use dynamic dummy tracer_flags
for tracers needing a dummy tracer_flags, as a result, there are no
tracers sharing tracer_flags, so remove the check code.

And save the current tracer to trace_option_dentry seems not good as
it may waste mem space when mount the debug/trace fs more than one time.

Link: http://lkml.kernel.org/r/1457444222-8654-1-git-send-email-chuhu@redhat.com

Signed-off-by: Chunyu Hu <chuhu@redhat.com>
[ Fixed up function tracer options to work with the change ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-08 11:19:08 -05:00
Linus Torvalds 78baab7aa8 A feature was added in 4.3 that allowed users to filter trace points on
a tasks "comm" field. But this prevented filtering on a comm field that
 is within a trace event (like sched_migrate_task).
 
 When trying to filter on when a program migrated, this change prevented
 the filtering of the sched_migrate_task.
 
 To fix this, the event fields are examined first, and then the extra fields
 like "comm" and "cpu" are examined. Also, instead of testing to assign
 the comm filter function based on the field's name, the generic comm field
 is given a new filter type (FILTER_COMM). When this field is used to filter
 the type is checked. The same is done for the cpu filter field.
 
 Two new special filter types are added: "COMM" and "CPU". This allows users
 to still filter the tasks comm for events that have "comm" as one of their
 fields, in cases that users would like to filter sched_migrate_task on the
 comm of the task that called the event, and not the comm of the task that
 is being migrated.
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Merge tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A feature was added in 4.3 that allowed users to filter trace points
  on a tasks "comm" field.  But this prevented filtering on a comm field
  that is within a trace event (like sched_migrate_task).

  When trying to filter on when a program migrated, this change
  prevented the filtering of the sched_migrate_task.

  To fix this, the event fields are examined first, and then the extra
  fields like "comm" and "cpu" are examined.  Also, instead of testing
  to assign the comm filter function based on the field's name, the
  generic comm field is given a new filter type (FILTER_COMM).  When
  this field is used to filter the type is checked.  The same is done
  for the cpu filter field.

  Two new special filter types are added: "COMM" and "CPU".  This allows
  users to still filter the tasks comm for events that have "comm" as
  one of their fields, in cases that users would like to filter
  sched_migrate_task on the comm of the task that called the event, and
  not the comm of the task that is being migrated"

* tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Do not have 'comm' filter override event 'comm' field
2016-03-04 16:57:04 -08:00
Steven Rostedt (Red Hat) e57cbaf0eb tracing: Do not have 'comm' filter override event 'comm' field
Commit 9f61668073 "tracing: Allow triggers to filter for CPU ids and
process names" added a 'comm' filter that will filter events based on the
current tasks struct 'comm'. But this now hides the ability to filter events
that have a 'comm' field too. For example, sched_migrate_task trace event.
That has a 'comm' field of the task to be migrated.

 echo 'comm == "bash"' > events/sched_migrate_task/filter

will now filter all sched_migrate_task events for tasks named "bash" that
migrates other tasks (in interrupt context), instead of seeing when "bash"
itself gets migrated.

This fix requires a couple of changes.

1) Change the look up order for filter predicates to look at the events
   fields before looking at the generic filters.

2) Instead of basing the filter function off of the "comm" name, have the
   generic "comm" filter have its own filter_type (FILTER_COMM). Test
   against the type instead of the name to assign the filter function.

3) Add a new "COMM" filter that works just like "comm" but will filter based
   on the current task, even if the trace event contains a "comm" field.

Do the same for "cpu" field, adding a FILTER_CPU and a filter "CPU".

Cc: stable@vger.kernel.org # v4.3+
Fixes: 9f61668073 "tracing: Allow triggers to filter for CPU ids and process names"
Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 09:57:10 -05:00
Taeung Song 026842d148 tracing/syscalls: Rename "/format" tracepoint field name "nr" to "__syscall_nr:
Some tracepoint have multiple fields with the same name, "nr", the first
one is a unique syscall ID, the other is a syscall argument:

  # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
  name: sys_enter_io_getevents
  ID: 747
  format:
 	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
 	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
 	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
 	field:int common_pid;	offset:4;	size:4;	signed:1;

 	field:int nr;	offset:8;	size:4;	signed:1;
 	field:aio_context_t ctx_id;	offset:16;	size:8;	signed:0;
 	field:long min_nr;	offset:24;	size:8;	signed:0;
 	field:long nr;	offset:32;	size:8;	signed:0;
 	field:struct io_event * events;	offset:40;	size:8;	signed:0;
 	field:struct timespec * timeout;	offset:48;	size:8;	signed:0;

  print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))
  #

Fix it by renaming the "/format" common tracepoint field "nr" to "__syscall_nr".

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
[ Do not rename the struct member, just the '/format' field name ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160226132301.3ae065a4@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-29 11:34:53 -03:00
Ingo Molnar 0a7348925f Linux 4.5-rc6
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Merge tag 'v4.5-rc6' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-29 09:04:01 +01:00
Linus Torvalds 5bb9871eb8 Another small bug reported to me by Chunyu Hu.
When perf added a "reg" function to the function tracing event (not a
 tracepoint), it caused that event to be displayed as a tracepoint and
 could cause errors in tracepoint handling. That was solved by adding a
 flag to ignore ftrace non-tracepoint events. But that flag was missed
 when displaying events in available_events, which should only contain
 tracepoint events.
 
 This broke a documented way to enable all events with:
 
   cat available_events > set_event
 
 As the function non-tracepoint event would cause that to error out.
 The commit here fixes that by having the available_events file not list
 events that have the ignore flag set.
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Merge tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Another small bug reported to me by Chunyu Hu.

  When perf added a "reg" function to the function tracing event (not a
  tracepoint), it caused that event to be displayed as a tracepoint and
  could cause errors in tracepoint handling.  That was solved by adding
  a flag to ignore ftrace non-tracepoint events.  But that flag was
  missed when displaying events in available_events, which should only
  contain tracepoint events.

  This broke a documented way to enable all events with:

      cat available_events > set_event

  As the function non-tracepoint event would cause that to error out.
  The commit here fixes that by having the available_events file not
  list events that have the ignore flag set"

* tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix showing function event in available_events
2016-02-25 20:12:09 -08:00
Steven Rostedt (Red Hat) d045437a16 tracing: Fix showing function event in available_events
The ftrace:function event is only displayed for parsing the function tracer
data. It is not used to enable function tracing, and does not include an
"enable" file in its event directory.

Originally, this event was kept separate from other events because it did
not have a ->reg parameter. But perf added a "reg" parameter for its use
which caused issues, because it made the event available to functions where
it was not compatible for.

Commit 9b63776fa3 "tracing: Do not enable function event with enable"
added a TRACE_EVENT_FL_IGNORE_ENABLE flag that prevented the function event
from being enabled by normal trace events. But this commit missed keeping
the function event from being displayed by the "available_events" directory,
which is used to show what events can be enabled by set_event.

One documented way to enable all events is to:

 cat available_events > set_event

But because the function event is displayed in the available_events, this
now causes an INVALID error:

 cat: write error: Invalid argument

Reported-by: Chunyu Hu <chuhu@redhat.com>
Fixes: 9b63776fa3 "tracing: Do not enable function event with enable"
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-24 09:17:11 -05:00
David S. Miller b633353115 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/phy/bcm7xxx.c
	drivers/net/phy/marvell.c
	drivers/net/vxlan.c

All three conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23 00:09:14 -05:00
Linus Torvalds 4de8ebeff8 Two more small fixes.
One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
 stack made by the stack tracer. As the stack tracer scans the entire
 kernel stack, KASAN triggers seeing it as a "stack out of bounds" error.
 As the scan is looking at the contents of the stack from parent functions.
 The NOCHECK() tells KASAN that this is done on purpose, and is not some
 kind of stack overflow.
 
 The second fix is to the ftrace selftests, to retrieve the PID of executed
 commands from the shell with "$!" and not by parsing "jobs".
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Merge tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two more small fixes.

  One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
  stack made by the stack tracer.  As the stack tracer scans the entire
  kernel stack, KASAN triggers seeing it as a "stack out of bounds"
  error.  As the scan is looking at the contents of the stack from
  parent functions.  The NOCHECK() tells KASAN that this is done on
  purpose, and is not some kind of stack overflow.

  The second fix is to the ftrace selftests, to retrieve the PID of
  executed commands from the shell with '$!' and not by parsing 'jobs'"

* tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
  ftracetest: Fix instance test to use proper shell command for pids
2016-02-22 14:09:18 -08:00
Alexei Starovoitov d5a3b1f691 bpf: introduce BPF_MAP_TYPE_STACK_TRACE
add new map type to store stack traces and corresponding helper
bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id
@ctx: struct pt_regs*
@map: pointer to stack_trace map
@flags: bits 0-7 - numer of stack frames to skip
        bit 8 - collect user stack instead of kernel
        bit 9 - compare stacks by hash only
        bit 10 - if two different stacks hash into the same stackid
                 discard old
        other bits - reserved
Return: >= 0 stackid on success or negative error

stackid is a 32-bit integer handle that can be further combined with
other data (including other stackid) and used as a key into maps.

Userspace will access stackmap using standard lookup/delete syscall commands to
retrieve full stack trace for given stackid.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-20 00:21:44 -05:00
Yang Shi 6e22c83664 tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
When enabling stack trace via "echo 1 > /proc/sys/kernel/stack_tracer_enabled",
the below KASAN warning is triggered:

BUG: KASAN: stack-out-of-bounds in check_stack+0x344/0x848 at addr ffffffc0689ebab8
Read of size 8 by task ksoftirqd/4/29
page:ffffffbdc3a27ac0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.5.0-rc1 #129
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffffffc000091300>] dump_backtrace+0x0/0x3a0
[<ffffffc0000916c4>] show_stack+0x24/0x30
[<ffffffc0009bbd78>] dump_stack+0xd8/0x168
[<ffffffc000420bb0>] kasan_report_error+0x6a0/0x920
[<ffffffc000421688>] kasan_report+0x70/0xb8
[<ffffffc00041f7f0>] __asan_load8+0x60/0x78
[<ffffffc0002e05c4>] check_stack+0x344/0x848
[<ffffffc0002e0c8c>] stack_trace_call+0x1c4/0x370
[<ffffffc0002af558>] ftrace_ops_no_ops+0x2c0/0x590
[<ffffffc00009f25c>] ftrace_graph_call+0x0/0x14
[<ffffffc0000881bc>] fpsimd_thread_switch+0x24/0x1e8
[<ffffffc000089864>] __switch_to+0x34/0x218
[<ffffffc0011e089c>] __schedule+0x3ac/0x15b8
[<ffffffc0011e1f6c>] schedule+0x5c/0x178
[<ffffffc0001632a8>] smpboot_thread_fn+0x350/0x960
[<ffffffc00015b518>] kthread+0x1d8/0x2b0
[<ffffffc0000874d0>] ret_from_fork+0x10/0x40
Memory state around the buggy address:
 ffffffc0689eb980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f4 f4 f4
 ffffffc0689eba00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc0689eba80: 00 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00
                                        ^
 ffffffc0689ebb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc0689ebb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

The stacker tracer traverses the whole kernel stack when saving the max stack
trace. It may touch the stack red zones to cause the warning. So, just disable
the instrumentation to silence the warning.

Link: http://lkml.kernel.org/r/1455309960-18930-1-git-send-email-yang.shi@linaro.org

Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-02-19 12:36:44 -05:00
Linus Torvalds 705d43dbe1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching fixes from Jiri Kosina:

 - regression (from 4.4) fix for ordering issue, introduced by an
   earlier ftrace change, that broke live patching of modules.

   The fix replaces the ftrace module notifier by direct call in order
   to make the ordering guaranteed and well-defined.  The patch, from
   Jessica Yu, has been acked both by Steven and Rusty

 - error message fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  ftrace/module: remove ftrace module notifier
  livepatch: change the error message in asm/livepatch.h header files
2016-02-18 16:34:15 -08:00
Jessica Yu 7dcd182bec ftrace/module: remove ftrace module notifier
Remove the ftrace module notifier in favor of directly calling
ftrace_module_enable() and ftrace_release_mod() in the module loader.
Hard-coding the function calls directly in the module loader removes
dependence on the module notifier call chain and provides better
visibility and control over what gets called when, which is important
to kernel utilities such as livepatch.

This fixes a notifier ordering issue in which the ftrace module notifier
(and hence ftrace_module_enable()) for coming modules was being called
after klp_module_notify(), which caused livepatch modules to initialize
incorrectly. This patch removes dependence on the module notifier call
chain in favor of hard coding the corresponding function calls in the
module loader. This ensures that ftrace and livepatch code get called in
the correct order on patch module load and unload.

Fixes: 5156dca34a ("ftrace: Fix the race between ftrace and insmod")
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-02-17 22:14:06 +01:00
Rafael J. Wysocki b2a3b193b7 Merge branch 'pm-opp' into pm-cpufreq 2016-02-11 00:24:00 +01:00
Martin KaFai Lau a7636d9ecf kprobes: Optimize hot path by using percpu counter to collect 'nhit' statistics
When doing ebpf+kprobe on some hot TCP functions (e.g.
tcp_rcv_established), the kprobe_dispatcher() function
shows up in 'perf report'.

In kprobe_dispatcher(), there is a lot of cache bouncing
on 'tk->nhit++'.  'tk->nhit' and 'tk->tp.flags' also share
the same cacheline.

perf report (cycles:pp):

	8.30%  ipv4_dst_check
	4.74%  copy_user_enhanced_fast_string
	3.93%  dst_release
	2.80%  tcp_v4_rcv
	2.31%  queued_spin_lock_slowpath
	2.30%  _raw_spin_lock
	1.88%  mlx4_en_process_rx_cq
	1.84%  eth_get_headlen
	1.81%  ip_rcv_finish
	~~~~
	1.71%  kprobe_dispatcher
	~~~~
	1.55%  mlx4_en_xmit
	1.09%  __probe_kernel_read

perf report after patch:

	9.15%  ipv4_dst_check
	5.00%  copy_user_enhanced_fast_string
	4.12%  dst_release
	2.96%  tcp_v4_rcv
	2.50%  _raw_spin_lock
	2.39%  queued_spin_lock_slowpath
	2.11%  eth_get_headlen
	2.03%  mlx4_en_process_rx_cq
	1.69%  mlx4_en_xmit
	1.19%  ip_rcv_finish
	1.12%  __probe_kernel_read
	1.02%  ehci_hcd_cleanup

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Kernel Team <kernel-team@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454531308-2441898-1-git-send-email-kafai@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-09 11:08:58 +01:00
Shilpasri G Bhat 0306e481d4 cpufreq: powernv/tracing: Add powernv_throttle tracepoint
This patch adds the powernv_throttle tracepoint to trace the CPU
frequency throttling event, which is used by the powernv-cpufreq
driver in POWER8.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-05 02:38:02 +01:00
Linus Torvalds ef582d095d A cleanup to the stack tracer broke stack tracing on s390.
Here's a simple fix to correct that issue.
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Merge tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A cleanup to the stack tracer broke stack tracing on s390.  Here's a
  simple fix to correct that issue"

* tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/stacktrace: Show entire trace if passed in function not found
2016-02-03 09:31:34 -08:00
Linus Torvalds 29d14f0835 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "This is much bigger than typical fixes, but Peter found a category of
  races that spurred more fixes and more debugging enhancements.  Work
  started before the merge window, but got finished only now.

  Aside of that this contains the usual small fixes to perf and tools.
  Nothing particular exciting"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  perf: Remove/simplify lockdep annotation
  perf: Synchronously clean up child events
  perf: Untangle 'owner' confusion
  perf: Add flags argument to perf_remove_from_context()
  perf: Clean up sync_child_event()
  perf: Robustify event->owner usage and SMP ordering
  perf: Fix STATE_EXIT usage
  perf: Update locking order
  perf: Remove __free_event()
  perf/bpf: Convert perf_event_array to use struct file
  perf: Fix NULL deref
  perf/x86: De-obfuscate code
  perf/x86: Fix uninitialized value usage
  perf: Fix race in perf_event_exit_task_context()
  perf: Fix orphan hole
  perf stat: Do not clean event's private stats
  perf hists: Fix HISTC_MEM_DCACHELINE width setting
  perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
  perf tests: Remove wrong semicolon in while loop in CQM test
  perf: Synchronously free aux pages in case of allocation failure
  ...
2016-01-31 15:38:27 -08:00
Steven Rostedt 6ccd83714a tracing/stacktrace: Show entire trace if passed in function not found
When a max stack trace is discovered, the stack dump is saved. In order to
not record the overhead of the stack tracer, the ip of the traced function
is looked for within the dump. The trace is started from the location of
that function. But if for some reason the ip is not found, the entire stack
trace is then truncated. That's not very useful. Instead, print everything
if the ip of the traced function is not found within the trace.

This issue showed up on s390.

Link: http://lkml.kernel.org/r/20160129102241.1b3c9c04@gandalf.local.home

Fixes: 72ac426a5b ("tracing: Clean up stack tracing and fix fentry updates")
Cc: stable@vger.kernel.org # v4.3+
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>
2016-01-29 12:19:10 -05:00
Alexei Starovoitov e03e7ee34f perf/bpf: Convert perf_event_array to use struct file
Robustify refcounting.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160126045947.GA40151@ast-mbp.thefacebook.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 08:35:25 +01:00
Linus Torvalds 26cd83670f This includes three minor fixes, mostly due to cut-and-paste issues.
The first is a cut and paste issue that changed the amount of stack
 to skip when tracing a stack dump from 0 to 6, which basically made
 the stack disappear for small stack traces.
 
 The second fix is just removing an unused field in a struct that is no
 longer used, and currently just wastes space.
 
 The third is another cut-and-paste fix that had a tracepoint recording
 the wrong field (it was recording the previous field a second time).
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Merge tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull minor tracing fixes from Steven Rostedt:
 "This includes three minor fixes, mostly due to cut-and-paste issues.

  The first is a cut and paste issue that changed the amount of stack to
  skip when tracing a stack dump from 0 to 6, which basically made the
  stack disappear for small stack traces.

  The second fix is just removing an unused field in a struct that is no
  longer used, and currently just wastes space.

  The third is another cut-and-paste fix that had a tracepoint recording
  the wrong field (it was recording the previous field a second time)"

* tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/dma-buf/fence: Fix timeline str value on fence_annotate_wait_on
  ftrace: Remove unused nr_trampolines var
  tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
2016-01-28 17:00:50 -08:00
Steven Rostedt (Red Hat) 7717c6be69 tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
While cleaning the stacktrace code I unintentially changed the skip depth of
trace_buffer_unlock_commit_regs() from 0 to 6. kprobes uses this function,
and with skipping 6 call backs, it can easily produce no stack.

Here's how I tested it:

 # echo 'p:ext4_sync_fs ext4_sync_fs ' > /sys/kernel/debug/tracing/kprobe_events
 # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable
 # cat /sys/kernel/debug/trace
            sync-2394  [005]   502.457060: ext4_sync_fs: (ffffffff81317650)
            sync-2394  [005]   502.457063: kernel_stack:         <stack trace>
            sync-2394  [005]   502.457086: ext4_sync_fs: (ffffffff81317650)
            sync-2394  [005]   502.457087: kernel_stack:         <stack trace>
            sync-2394  [005]   502.457091: ext4_sync_fs: (ffffffff81317650)

After putting back the skip stack to zero, we have:

            sync-2270  [000]   748.052693: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.052695: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)
            sync-2270  [000]   748.053017: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.053019: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)
            sync-2270  [000]   748.053381: ext4_sync_fs: (ffffffff81317650)
            sync-2270  [000]   748.053383: kernel_stack:         <stack trace>
 => iterate_supers (ffffffff8126412e)
 => sys_sync (ffffffff8129c4b6)
 => entry_SYSCALL_64_fastpath (ffffffff8181f0b2)

Cc: stable@vger.kernel.org # v4.4+
Fixes: 73dddbb57b "tracing: Only create stacktrace option when STACKTRACE is configured"
Reported-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-14 09:28:19 -05:00
Linus Torvalds c17488d066 Not much new with tracing for this release. Mostly just clean ups and
minor fixes.
 
 Here's what else is new:
 
  o  A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.
 
  o  New selftest to test the instance create and delete
 
  o  Better debug output when ftrace fails
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Merge tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Not much new with tracing for this release.  Mostly just clean ups and
  minor fixes.

  Here's what else is new:

   - A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
     those that want both.

   - New selftest to test the instance create and delete

   - Better debug output when ftrace fails"

* tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  ftrace: Fix the race between ftrace and insmod
  ftrace: Add infrastructure for delayed enabling of module functions
  x86: ftrace: Fix the comments for ftrace_modify_code_direct()
  tracing: Fix comment to use tracing_on over tracing_enable
  metag: ftrace: Fix the comments for ftrace_modify_code
  sh: ftrace: Fix the comments for ftrace_modify_code()
  ia64: ftrace: Fix the comments for ftrace_modify_code()
  ftrace: Clean up ftrace_module_init() code
  ftrace: Join functions ftrace_module_init() and ftrace_init_module()
  tracing: Introduce TRACE_EVENT_FN_COND macro
  tracing: Use seq_buf_used() in seq_buf_to_user() instead of len
  bpf: Constify bpf_verifier_ops structure
  ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
  ftrace: Remove use of control list and ops
  ftrace: Fix output of enabled_functions for showing tramp
  ftrace: Fix a typo in comment
  ftrace: Show all tramps registered to a record on ftrace_bug()
  ftrace: Add variable ftrace_expected for archs to show expected code
  ftrace: Add new type to distinguish what kind of ftrace_bug()
  tracing: Update cond flag when enabling or disabling a trigger
  ...
2016-01-12 20:04:15 -08:00
Linus Torvalds 33caf82acf Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...
2016-01-12 17:11:47 -08:00
Qiu Peiyang 5156dca34a ftrace: Fix the race between ftrace and insmod
We hit ftrace_bug report when booting Android on a 64bit ATOM SOC chip.
Basically, there is a race between insmod and ftrace_run_update_code.

After load_module=>ftrace_module_init, another thread jumps in to call
ftrace_run_update_code=>ftrace_arch_code_modify_prepare
                        =>set_all_modules_text_rw, to change all modules
as RW. Since the new module is at MODULE_STATE_UNFORMED, the text attribute
is not changed. Then, the 2nd thread goes ahead to change codes.
However, load_module continues to call complete_formation=>set_section_ro_nx,
then 2nd thread would fail when probing the module's TEXT.

The patch fixes it by using notifier to delay the enabling of ftrace
records to the time when module is at state MODULE_STATE_COMING.

Link: http://lkml.kernel.org/r/567CE628.3000609@intel.com

Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-07 15:56:21 -05:00
Steven Rostedt (Red Hat) b7ffffbb46 ftrace: Add infrastructure for delayed enabling of module functions
Qiu Peiyang pointed out that there's a race when enabling function tracing
and loading a module. In order to make the modifications of converting nops
in the prologue of functions into callbacks, the text needs to be converted
from read-only to read-write. When enabling function tracing, the text
permission is updated, the functions are modified, and then they are put
back.

When loading a module, the updates to convert function calls to mcount is
done before the module text is set to read-only. But after it is done, the
module text is visible by the function tracer. Thus we have the following
race:

	CPU 0			CPU 1
	-----			-----
   start function tracing
   set text to read-write
			     load_module
			     add functions to ftrace
			     set module text read-only

   update all functions to callbacks
   modify module functions too
   < Can't it's read-only >

When this happens, ftrace detects the issue and disables itself till the
next reboot.

To fix this, a new DISABLED flag is added for ftrace records, which all
module functions get when they are added. Then later, after the module code
is all set, the records will have the DISABLED flag cleared, and they will
be enabled if any callback wants all functions to be traced.

Note, this doesn't add the delay to later. It simply changes the
ftrace_module_init() to do both the setting of DISABLED records, and then
immediately calls the enable code. This helps with testing this new code as
it has the same behavior as previously. Another change will come after this
to have the ftrace_module_enable() called after the text is set to
read-only.

Cc: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-07 15:40:01 -05:00
Qiu Peiyang f36d1be293 tracing: Fix setting of start_index in find_next()
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel
panic at t_show.

general protection fault: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 2957 Comm: sh Tainted: G W  O 3.14.55-x86_64-01062-gd4acdc7 #2
RIP: 0010:[<ffffffff811375b2>]
 [<ffffffff811375b2>] t_show+0x22/0xe0
RSP: 0000:ffff88002b4ebe80  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1
RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec
R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0
R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570
FS:  0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0
Call Trace:
 [<ffffffff811dc076>] seq_read+0x2f6/0x3e0
 [<ffffffff811b749b>] vfs_read+0x9b/0x160
 [<ffffffff811b7f69>] SyS_read+0x49/0xb0
 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13
 ---[ end trace 5bd9eb630614861e ]---
Kernel panic - not syncing: Fatal exception

When the first time find_next calls find_next_mod_format, it should
iterate the trace_bprintk_fmt_list to find the first print format of
the module. However in current code, start_index is smaller than *pos
at first, and code will not iterate the list. Latter container_of will
get the wrong address with former v, which will cause mod_fmt be a
meaningless object and so is the returned mod_fmt->fmt.

This patch will fix it by correcting the start_index. After fixed,
when the first time calls find_next_mod_format, start_index will be
equal to *pos, and code will iterate the trace_bprintk_fmt_list to
get the right module printk format, so is the returned mod_fmt->fmt.

Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com

Cc: stable@vger.kernel.org # 3.12+
Fixes: 102c9323c3 "tracing: Add __tracepoint_string() to export string pointers"
Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-04 15:22:47 -05:00
Al Viro 70f6cbb6f9 kernel/*: switch to memdup_user_nul()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-04 10:27:55 -05:00
Al Viro 16e5c1fc36 convert a bunch of open-coded instances of memdup_user_nul()
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-04 10:26:58 -05:00
Chuyu Hu 05a724bd44 tracing: Fix comment to use tracing_on over tracing_enable
The file tracing_enable is obsolete and does not exist anymore. Replace
the comment that references it with the proper tracing_on file.

Link: http://lkml.kernel.org/r/1450787141-45544-1-git-send-email-chuhu@redhat.com

Signed-off-by: Chuyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:25 -05:00
Steven Rostedt (Red Hat) 97e9b4fca5 ftrace: Clean up ftrace_module_init() code
The start and end variables were only used when ftrace_module_init() was
split up into multiple functions. No need to keep them around after the
merger.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:23 -05:00
Abel Vesa b6b71f66a1 ftrace: Join functions ftrace_module_init() and ftrace_init_module()
Simple cleanup. No need for two functions here.
The whole work can simply be done inside 'ftrace_module_init'.

Link: http://lkml.kernel.org/r/1449067197-5718-1-git-send-email-abelvesa@linux.com

Signed-off-by: Abel Vesa <abelvesa@linux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:22 -05:00
Julia Lawall 27dff4e041 bpf: Constify bpf_verifier_ops structure
This bpf_verifier_ops structure is never modified, like the other
bpf_verifier_ops structures, so declare it as const.

Done with the help of Coccinelle.

Link: http://lkml.kernel.org/r/1449855359-13724-1-git-send-email-Julia.Lawall@lip6.fr

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:19 -05:00
Steven Rostedt (Red Hat) c68c0fa293 ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
Jiri Olsa noted that the change to replace the control_ops did not update
the trampoline for when running perf on a single CPU and with CONFIG_PREEMPT
disabled (where dynamic ops, like perf, can use trampolines directly). The
result was that perf function could be called when RCU is not watching as
well as not handle the ftrace_local_disable().

Modify the ftrace_ops_get_func() to also check the RCU and PER_CPU ops flags
and use the recursive function if they are set. The recursive function is
modified to check those flags and execute the appropriate checks if they are
set.

Link: http://lkml.kernel.org/r/20151201134213.GA14155@krava.brq.redhat.com

Reported-by: Jiri Olsa <jolsa@redhat.com>
Patch-fixed-up-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:19 -05:00
Steven Rostedt (Red Hat) ba27f2bc73 ftrace: Remove use of control list and ops
Currently perf has its own list function within the ftrace infrastructure
that seems to be used only to allow for it to have per-cpu disabling as well
as a check to make sure that it's not called while RCU is not watching. It
uses something called the "control_ops" which is used to iterate over ops
under it with the control_list_func().

The problem is that this control_ops and control_list_func unnecessarily
complicates the code. By replacing FTRACE_OPS_FL_CONTROL with two new flags
(FTRACE_OPS_FL_RCU and FTRACE_OPS_FL_PER_CPU) we can remove all the code
that is special with the control ops and add the needed checks within the
generic ftrace_list_func().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:18 -05:00
Steven Rostedt (Red Hat) 030f4e1cb8 ftrace: Fix output of enabled_functions for showing tramp
When showing all tramps registered to a ftrace record in the file
enabled_functions, it exits the loop with ops == NULL. But then it is
suppose to show the function on the ops->trampoline and
add_trampoline_func() is called with the given ops. But because ops is now
NULL (to exit the loop), it always shows the static trampoline instead of
the one that is really registered to the record.

The call to add_trampoline_func() that shows the trampoline for the given
ops needs to be called at every iteration.

Fixes: 39daa7b9e8 "ftrace: Show all tramps registered to a record on ftrace_bug()"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:27:17 -05:00
Li Bin b8ec330a63 ftrace: Fix a typo in comment
s/ARCH_SUPPORT_FTARCE_OPS/ARCH_SUPPORTS_FTRACE_OPS/

Link: http://lkml.kernel.org/r/1448879016-8659-1-git-send-email-huawei.libin@huawei.com

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-23 14:26:51 -05:00
Linus Torvalds 51825c8a86 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "This tree includes four core perf fixes for misc bugs, three fixes to
  x86 PMU drivers, and two updates to old email addresses"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Do not send exit event twice
  perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro
  perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell
  perf: Fix PERF_EVENT_IOC_PERIOD deadlock
  treewide: Remove old email address
  perf/x86: Fix LBR call stack save/restore
  perf: Update email address in MAINTAINERS
  perf/core: Robustify the perf_cgroup_from_task() RCU checks
  perf/core: Fix RCU problem with cgroup context switching code
2015-12-08 13:01:23 -08:00
Steven Rostedt (Red Hat) 0f72e37e42 tracing: Add sched_wakeup_new and sched_waking tracepoints for pid filter
The set_event_pid filter relies on attaching to the sched_switch and
sched_wakeup tracepoints to see if it should filter the tracing on schedule
tracepoints. By adding the callbacks to sched_wakeup, pids in the
set_event_pid file will trace the wakeups of those tasks with those pids.

But sched_wakeup_new and sched_waking were missed. These two should also be
traced. Luckily, these tracepoints share the same class as sched_wakeup
which means they can use the same pre and post callbacks as sched_wakeup
does.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-01 16:08:05 -05:00
Steven Rostedt (Red Hat) 39daa7b9e8 ftrace: Show all tramps registered to a record on ftrace_bug()
When an anomaly is detected in the function call modification code,
ftrace_bug() is called to disable function tracing as well as give any
information that may help debug the problem. Currently, only the first found
trampoline that is attached to the failed record is reported. Instead, show
all trampolines that are hooked to it.

Also, not only show the ops pointer but also report the function it calls.

While at it, add this info to the enabled_functions debug file too.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 16:04:59 -05:00
Steven Rostedt (Red Hat) b05086c77a ftrace: Add variable ftrace_expected for archs to show expected code
When an anomaly is found while modifying function code, ftrace_bug() is
called which disables the function tracing infrastructure and reports
information about what failed. If the code that is to be replaced does not
match what is expected, then actual code is shown. Currently there is no
arch generic way to show what was expected.

Add a new variable pointer calld ftrace_expected that the arch code can set
to point to what it expected so that ftrace_bug() can report the actual text
as well as the text that was expected to be there.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:16 -05:00
Steven Rostedt (Red Hat) 02a392a043 ftrace: Add new type to distinguish what kind of ftrace_bug()
The ftrace function hook utility has several internal checks to make sure
that whatever it modifies is exactly what it expects to be modifying. This
is essential as modifying running code can be extremely dangerous to the
system.

When an anomaly is detected, ftrace_bug() is called which sends a splat to
the console and disables function tracing. There's some extra information
that is printed to help diagnose the issue.

One thing that is missing though is output of what ftrace was doing at the
time of the crash. Was it updating a call site or perhaps converting a call
site to a nop? A new global enum variable is created to state what ftrace
was doing at the time of the anomaly, and this is reported in ftrace_bug().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:15 -05:00
Tom Zanussi 4e4a4d7570 tracing: Update cond flag when enabling or disabling a trigger
When a trigger is enabled, the cond flag should be set beforehand,
otherwise a trigger that's expecting to process a trace record
(e.g. one with post_trigger set) could be invoked without one.

Likewise a trigger's cond flag should be reset after it's disabled,
not before.

Link: http://lkml.kernel.org/r/a420b52a67b1c2d3cab017914362d153255acb99.1448303214.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:14 -05:00
Steven Rostedt (Red Hat) 4239c38fe0 ring-buffer: Process commits whenever moving to a new page.
When crossing over to a new page, commit the current work. This will allow
readers to get data with less latency, and also simplifies the work to get
timestamps working for interrupted events.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-25 15:24:05 -05:00
Steven Rostedt (Red Hat) 70004986ff ring-buffer: Remove redundant update of page timestamp
The first commit of a buffer page updates the timestamp of that page. No
need to have the update to the next page add the timestamp too. It will only
be replaced by the first commit on that page anyway.

Only update to a page if it contains an event.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-24 09:29:16 -05:00
Steven Rostedt (Red Hat) 8573636ea7 ring-buffer: Use READ_ONCE() for most tail_page access
As cpu_buffer->tail_page may be modified by interrupts at almost any time,
the flow of logic is very important. Do not let gcc get smart with
re-reading cpu_buffer->tail_page by adding READ_ONCE() around most of its
accesses.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-24 09:29:15 -05:00
Steven Rostedt (Red Hat) bd1b7cd360 ring-buffer: Put back the length if crossed page with add_timestamp
Commit fcc742eaad "ring-buffer: Add event descriptor to simplify passing
data" added a descriptor that holds various data instead of passing around
several variables through parameters. The problem was that one of the
parameters was modified in a function and the code was designed not to have
an effect on that modified  parameter. Now that the parameter is a
descriptor and any modifications to it are non-volatile, the size of the
data could be unnecessarily expanded.

Remove the extra space added if a timestamp was added and the event went
across the page.

Cc: stable@vger.kernel.org # 4.3+
Fixes: fcc742eaad "ring-buffer: Add event descriptor to simplify passing data"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-24 09:27:25 -05:00
Steven Rostedt (Red Hat) b81f472a20 ring-buffer: Update read stamp with first real commit on page
Do not update the read stamp after swapping out the reader page from the
write buffer. If the reader page is swapped out of the buffer before an
event is written to it, then the read_stamp may get an out of date
timestamp, as the page timestamp is updated on the first commit to that
page.

rb_get_reader_page() only returns a page if it has an event on it, otherwise
it will return NULL. At that point, check if the page being returned has
events and has not been read yet. Then at that point update the read_stamp
to match the time stamp of the reader page.

Cc: stable@vger.kernel.org # 2.6.30+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-24 09:23:17 -05:00
Peter Zijlstra 90eec103b9 treewide: Remove old email address
There were still a number of references to my old Red Hat email
address in the kernel source. Remove these while keeping the
Red Hat copyright notices intact.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23 09:44:58 +01:00
Linus Torvalds 0e97606425 This contains three more clean up patches.
One patch is needed to make tracing work without debugfs now that tracing
 uses its own tracefs.
 
 The second is removing an unused variable.
 
 The third is fixing a warning about unused variables when MAX_TRACER is
 not configured. Note, this warning shows up in gcc 6.0, but does not show
 up in gcc 4.9, as it seems that gcc does not complain about constants
 not being used.
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Merge tag 'trace-v4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull trace cleanups from Steven Rostedt:
 "This contains three more clean up patches.

  One patch is needed to make tracing work without debugfs now that
  tracing uses its own tracefs.

  The second is removing an unused variable.

  The third is fixing a warning about unused variables when MAX_TRACER
  is not configured.  Note, this warning shows up in gcc 6.0, but does
  not show up in gcc 4.9, as it seems that gcc does not complain about
  constants not being used"

* tag 'trace-v4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: #ifdef out uses of max trace when CONFIG_TRACER_MAX_TRACE is not set
  tracing: Remove unused ftrace_cpu_disabled per cpu variable
  tracing: Make tracing work when debugfs is not configured in
2015-11-12 16:22:54 -08:00
Linus Torvalds 2df4ee78d0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix null deref in xt_TEE netfilter module, from Eric Dumazet.

 2) Several spots need to get to the original listner for SYN-ACK
    packets, most spots got this ok but some were not.  Whilst covering
    the remaining cases, create a helper to do this.  From Eric Dumazet.

 3) Missiing check of return value from alloc_netdev() in CAIF SPI code,
    from Rasmus Villemoes.

 4) Don't sleep while != TASK_RUNNING in macvtap, from Vlad Yasevich.

 5) Use after free in mvneta driver, from Justin Maggard.

 6) Fix race on dst->flags access in dst_release(), from Eric Dumazet.

 7) Add missing ZLIB_INFLATE dependency for new qed driver.  From Arnd
    Bergmann.

 8) Fix multicast getsockopt deadlock, from WANG Cong.

 9) Fix deadlock in btusb, from Kuba Pawlak.

10) Some ipv6_add_dev() failure paths were not cleaning up the SNMP6
    counter state.  From Sabrina Dubroca.

11) Fix packet_bind() race, which can cause lost notifications, from
    Francesco Ruggeri.

12) Fix MAC restoration in qlcnic driver during bonding mode changes,
    from Jarod Wilson.

13) Revert bridging forward delay change which broke libvirt and other
    userspace things, from Vlad Yasevich.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  Revert "bridge: Allow forward delay to be cfgd when STP enabled"
  bpf_trace: Make dependent on PERF_EVENTS
  qed: select ZLIB_INFLATE
  net: fix a race in dst_release()
  net: mvneta: Fix memory use after free.
  net: Documentation: Fix default value tcp_limit_output_bytes
  macvtap: Resolve possible __might_sleep warning in macvtap_do_read()
  mvneta: add FIXED_PHY dependency
  net: caif: check return value of alloc_netdev
  net: hisilicon: NET_VENDOR_HISILICON should depend on HAS_DMA
  drivers: net: xgene: fix RGMII 10/100Mb mode
  netfilter: nft_meta: use skb_to_full_sk() helper
  net_sched: em_meta: use skb_to_full_sk() helper
  sched: cls_flow: use skb_to_full_sk() helper
  netfilter: xt_owner: use skb_to_full_sk() helper
  smack: use skb_to_full_sk() helper
  net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid()
  bpf: doc: correct arch list for supported eBPF JIT
  dwc_eth_qos: Delete an unnecessary check before the function call "of_node_put"
  bonding: fix panic on non-ARPHRD_ETHER enslave failure
  ...
2015-11-10 18:11:41 -08:00
Steven Rostedt a31d82d85a bpf_trace: Make dependent on PERF_EVENTS
Arnd Bergmann reported:

  In my ARM randconfig tests, I'm getting a build error for
  newly added code in bpf_perf_event_read and bpf_perf_event_output
  whenever CONFIG_PERF_EVENTS is disabled:

  kernel/trace/bpf_trace.c: In function 'bpf_perf_event_read':
  kernel/trace/bpf_trace.c:203:11: error: 'struct perf_event' has no member named 'oncpu'
  if (event->oncpu != smp_processor_id() ||
           ^
  kernel/trace/bpf_trace.c:204:11: error: 'struct perf_event' has no member named 'pmu'
        event->pmu->count)

  This can happen when UPROBE_EVENT is enabled but KPROBE_EVENT
  is disabled. I'm not sure if that is a configuration we care
  about, otherwise we could prevent this case from occuring by
  adding Kconfig dependencies.

Looking at this further, it's really that UPROBE_EVENT enables PERF_EVENTS.
By just having BPF_EVENTS depend on PERF_EVENTS, then all is fine.

Link: http://lkml.kernel.org/r/4525348.Aq9YoXkChv@wuerfel
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-10 15:40:14 -05:00
Chen Gang e428abbbf6 tracing: #ifdef out uses of max trace when CONFIG_TRACER_MAX_TRACE is not set
tracing_max_lat_fops is used only when TRACER_MAX_TRACE enabled, so also
swith the related code. The related warning with defconfig under x86_64:

    CC      kernel/trace/trace.o
  kernel/trace/trace.c:5466:37: warning: ‘tracing_max_lat_fops’ defined but not used [-Wunused-const-variable]
   static const struct file_operations tracing_max_lat_fops = {

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-10 10:16:05 -05:00
Dmitry Safonov 03e88ae6b3 tracing: Remove unused ftrace_cpu_disabled per cpu variable
Since the ring buffer is lockless, there is no need to disable ftrace on
CPU. And no one doing so: after commit 68179686ac ("tracing: Remove
ftrace_disable/enable_cpu()") ftrace_cpu_disabled stays the same after
initialization, nothing changes it.
ftrace_cpu_disabled shouldn't be used by any external module since it
disables only function and graph_function tracers but not any other
tracer.

Link: http://lkml.kernel.org/r/1446836846-22239-1-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-07 13:25:14 -05:00
Linus Torvalds 22402cd0af Most of the changes are clean ups and small fixes. Some of them have
stable tags to them. I searched through my INBOX just as the merge window
 opened and found lots of patches to pull. I ran them through all my tests
 and they were in linux-next for a few days.
 
 Features added this release:
 ----------------------------
 
  o Module globbing. You can now filter function tracing to several
    modules. # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov)
 
  o Tracer specific options are now visible even when the tracer is not
    active. It was rather annoying that you can only see and modify tracer
    options after enabling the tracer. Now they are in the options/ directory
    even when the tracer is not active. Although they are still only visible
    when the tracer is active in the trace_options file.
 
  o Trace options are now per instance (although some of the tracer specific
    options are global)
 
  o New tracefs file: set_event_pid. If any pid is added to this file, then
    all events in the instance will filter out events that are not part of
    this pid. sched_switch and sched_wakeup events handle next and the wakee
    pids.
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Merge tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracking updates from Steven Rostedt:
 "Most of the changes are clean ups and small fixes.  Some of them have
  stable tags to them.  I searched through my INBOX just as the merge
  window opened and found lots of patches to pull.  I ran them through
  all my tests and they were in linux-next for a few days.

  Features added this release:
  ----------------------------

   - Module globbing.  You can now filter function tracing to several
     modules.  # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov)

   - Tracer specific options are now visible even when the tracer is not
     active.  It was rather annoying that you can only see and modify
     tracer options after enabling the tracer.  Now they are in the
     options/ directory even when the tracer is not active.  Although
     they are still only visible when the tracer is active in the
     trace_options file.

   - Trace options are now per instance (although some of the tracer
     specific options are global)

   - New tracefs file: set_event_pid.  If any pid is added to this file,
     then all events in the instance will filter out events that are not
     part of this pid.  sched_switch and sched_wakeup events handle next
     and the wakee pids"

* tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits)
  tracefs: Fix refcount imbalance in start_creating()
  tracing: Put back comma for empty fields in boot string parsing
  tracing: Apply tracer specific options from kernel command line.
  tracing: Add some documentation about set_event_pid
  ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark
  tracing: Allow dumping traces without tracking trace started cpus
  ring_buffer: Fix more races when terminating the producer in the benchmark
  ring_buffer: Do no not complete benchmark reader too early
  tracing: Remove redundant TP_ARGS redefining
  tracing: Rename max_stack_lock to stack_trace_max_lock
  tracing: Allow arch-specific stack tracer
  recordmcount: arm64: Replace the ignored mcount call into nop
  recordmcount: Fix endianness handling bug for nop_mcount
  tracepoints: Fix documentation of RCU lockdep checks
  tracing: ftrace_event_is_function() can return boolean
  tracing: is_legal_op() can return boolean
  ring-buffer: rb_event_is_commit() can return boolean
  ring-buffer: rb_per_cpu_empty() can return boolean
  ring_buffer: ring_buffer_empty{cpu}() can return boolean
  ring-buffer: rb_is_reader_page() can return boolean
  ...
2015-11-06 13:30:20 -08:00
Jiaxing Wang 8b1291994d tracing: Make tracing work when debugfs is not configured in
Currently tracing_init_dentry() returns -ENODEV when debugfs is not
configured in, which causes tracefs not populated with tracing files and
directories, so we will get an empty directory even after we manually
mount tracefs.

We can make tracing_init_dentry() return NULL if debugfs is not
configured in and can manually mount tracefs. But return -ENODEV
if debugfs is configured in but not initialized or failed to create
automount point as that would break backward compatibility with older
tools.

Link: http://lkml.kernel.org/r/1446797056-11683-1-git-send-email-hello.wjx@gmail.com

Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-06 10:02:33 -05:00
Linus Torvalds d9734e0d1c Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "This is the core block pull request for 4.4.  I've got a few more
  topic branches this time around, some of them will layer on top of the
  core+drivers changes and will come in a separate round.  So not a huge
  chunk of changes in this round.

  This pull request contains:

   - Enable blk-mq page allocation tracking with kmemleak, from Catalin.

   - Unused prototype removal in blk-mq from Christoph.

   - Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
     xchg()'s, from Davidlohr.

   - A plug flush fix from Jeff.

   - Also from Jeff, a fix that means we don't have to update shared tag
     sets at init time unless we do a state change.  This cuts down boot
     times on thousands of devices a lot with scsi/blk-mq.

   - blk-mq waitqueue barrier fix from Kosuke.

   - Various fixes from Ming:

        - Fixes for segment merging and splitting, and checks, for
          the old core and blk-mq.

        - Potential blk-mq speedup by marking ctx pending at the end
          of a plug insertion batch in blk-mq.

        - direct-io no page dirty on kernel direct reads.

   - A WRITE_SYNC fix for mpage from Roman"

* 'for-4.4/core' of git://git.kernel.dk/linux-block:
  blk-mq: avoid excessive boot delays with large lun counts
  blktrace: re-write setting q->blk_trace
  blk-mq: mark ctx as pending at batch in flush plug path
  blk-mq: fix for trace_block_plug()
  block: check bio_mergeable() early before merging
  blk-mq: check bio_mergeable() early before merging
  block: avoid to merge splitted bio
  block: setup bi_phys_segments after splitting
  block: fix plug list flushing for nomerge queues
  blk-mq: remove unused blk_mq_clone_flush_request prototype
  blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
  fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
  fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
  block: kmemleak: Track the page allocations for struct request
2015-11-04 20:28:10 -08:00
Linus Torvalds b0f85fa11a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

Changes of note:

 1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.

 2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
    David Ahern.

 3) Allow the user to ask for the statistics to be filtered out of
    ipv4/ipv6 address netlink dumps.  From Sowmini Varadhan.

 4) More work to pass the network namespace context around deep into
    various packet path APIs, starting with the netfilter hooks.  From
    Eric W Biederman.

 5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
    Richter.

 6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.

 7) Support Very High Throughput in wireless MESH code, from Bob
    Copeland.

 8) Allow setting the ageing_time in switchdev/rocker.  From Scott
    Feldman.

 9) Properly autoload L2TP type modules, from Stephen Hemminger.

10) Fix and enable offload features by default in 8139cp driver, from
    David Woodhouse.

11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
    Jiri Benc.

12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
    Opstad.

13) Fix IPSEC flowcache overflows on large systems, from Steffen
    Klassert.

14) Convert bridging to track VLANs using rhashtable entries rather than
    a bitmap.  From Nikolay Aleksandrov.

15) Make TCP listener handling completely lockless, this is a major
    accomplishment.  Incoming request sockets now live in the
    established hash table just like any other socket too.

    From Eric Dumazet.

15) Provide more bridging attributes to netlink, from Nikolay
    Aleksandrov.

16) Use hash based algorithm for ipv4 multipath routing, this was very
    long overdue.  From Peter Nørlund.

17) Several y2038 cures, mostly avoiding timespec.  From Arnd Bergmann.

18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.

19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet.  This
    influences the port binding selection logic used by SO_REUSEPORT.

20) Add ipv6 support to VRF, from David Ahern.

21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.

22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.

23) Implement RACK loss recovery in TCP, from Yuchung Cheng.

24) Support multipath routes in MPLS, from Roopa Prabhu.

25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
    Dumazet.

26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
    Sudarsana Kalluru.

27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
    Sowa.

28) Support ipv6 geneve tunnels, from John W Linville.

29) Add flood control support to switchdev layer, from Ido Schimmel.

30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
    Hannes Frederic Sowa.

31) Support persistent maps and progs in bpf, from Daniel Borkmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
  sh_eth: use DMA barriers
  switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
  net: sched: kill dead code in sch_choke.c
  irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
  net: dsa: mv88e6xxx: include DSA ports in VLANs
  net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
  net/core: fix for_each_netdev_feature
  vlan: Invoke driver vlan hooks only if device is present
  arcnet/com20020: add LEDS_CLASS dependency
  bpf, verifier: annotate verbose printer with __printf
  dp83640: Only wait for timestamps for packets with timestamping enabled.
  ptp: Change ptp_class to a proper bitmask
  dp83640: Prune rx timestamp list before reading from it
  dp83640: Delay scheduled work.
  dp83640: Include hash in timestamp/packet matching
  ipv6: fix tunnel error handling
  net/mlx5e: Fix LSO vlan insertion
  net/mlx5e: Re-eanble client vlan TX acceleration
  net/mlx5e: Return error in case mlx5e_set_features() fails
  net/mlx5e: Don't allow more than max supported channels
  ...
2015-11-04 09:41:05 -08:00
Steven Rostedt (Red Hat) 43ed384339 tracing: Put back comma for empty fields in boot string parsing
Both early_enable_events() and apply_trace_boot_options() parse a boot
string that may get parsed later on. They both use strsep() which converts a
comma into a nul character. To still allow the boot string to be parsed
again the same way, the nul character gets converted back to a comma after
the token is processed.

The problem is that these two functions check for an empty parameter (two
commas in a row ",,"), and continue the loop if the parameter is empty, but
fails to place the comma back. In this case, the second parsing will end at
this blank field, and not process fields afterward.

In most cases, users should not have an empty field, but if its going to be
checked, the code might as well be correct.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 22:15:14 -05:00
Jiaxing Wang a4d1e68823 tracing: Apply tracer specific options from kernel command line.
Currently, the trace_options parameter is only applied in
tracer_alloc_buffers() when global_trace.current_trace is nop_trace,
so a tracer specific option will not be applied even when the specific
tracer is also enabled from kernel command line. For example, the
'func_stack_trace' option can't be enabled with the following kernel
parameter:

  ftrace=function ftrace_filter=kfree trace_options=func_stack_trace

We can enable tracer specific options by simply apply the options again
if the specific tracer is also supplied from command line and started
in register_tracer().

To make trace_boot_options_buf can be parsed again, a comma and a space
is put back if they were replaced by strsep and strstrip respectively.

Also make register_tracer() be __init to access the __init data, and
in fact register_tracer is only called from __init code.

Link: http://lkml.kernel.org/r/1446599669-9294-1-git-send-email-hello.wjx@gmail.com

Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 21:51:43 -05:00
Linus Torvalds 53528695ff Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "The main changes in this cycle were:

   - sched/fair load tracking fixes and cleanups (Byungchul Park)

   - Make load tracking frequency scale invariant (Dietmar Eggemann)

   - sched/deadline updates (Juri Lelli)

   - stop machine fixes, cleanups and enhancements for bugs triggered by
     CPU hotplug stress testing (Oleg Nesterov)

   - scheduler preemption code rework: remove PREEMPT_ACTIVE and related
     cleanups (Peter Zijlstra)

   - Rework the sched_info::run_delay code to fix races (Peter Zijlstra)

   - Optimize per entity utilization tracking (Peter Zijlstra)

   - ... misc other fixes, cleanups and smaller updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
  sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
  sched: Start stopper early
  stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
  stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
  stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
  stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
  stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
  sched/x86: Fix typo in __switch_to() comments
  sched/core: Remove a parameter in the migrate_task_rq() function
  sched/core: Drop unlikely behind BUG_ON()
  sched/core: Fix task and run queue sched_info::run_delay inconsistencies
  sched/numa: Fix task_tick_fair() from disabling numa_balancing
  sched/core: Add preempt_count invariant check
  sched/core: More notrace annotations
  sched/core: Kill PREEMPT_ACTIVE
  sched/core, sched/x86: Kill thread_info::saved_preempt_count
  sched/core: Simplify preempt_count tests
  sched/core: Robustify preemption leak checks
  sched/core: Stop setting PREEMPT_ACTIVE
  ...
2015-11-03 18:03:50 -08:00
Steven Rostedt (Red Hat) 54ed144405 ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark
wake_up_process() has a memory barrier before doing anything, thus adding a
memory barrier before calling it is redundant.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 16:19:02 -05:00
Sasha Levin 919cd97999 tracing: Allow dumping traces without tracking trace started cpus
We don't init iter->started when dumping the ftrace buffer, and there's no
real need to do so - so allow skipping that check if the iter doesn't have
an initialized ->started cpumask.

Link: http://lkml.kernel.org/r/1441385156-27279-1-git-send-email-sasha.levin@oracle.com

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 16:10:08 -05:00
Petr Mladek f47cb66df2 ring_buffer: Fix more races when terminating the producer in the benchmark
The commit b44754d826 ("ring_buffer: Allow to exit the ring
buffer benchmark immediately") added a hack into ring_buffer_producer()
that set @kill_test when kthread_should_stop() returned true. It improved
the situation a lot. It stopped the kthread in most cases because
the producer spent most of the time in the patched while cycle.

But there are still few possible races when kthread_should_stop()
is set outside of the cycle. Then we do not set @kill_test and
some other checks pass.

This patch adds a better fix. It renames @test_kill/TEST_KILL() into
a better descriptive @test_error/TEST_ERROR(). Also it introduces
break_test() function that checks for both @test_error and
kthread_should_stop().

The new function is used in the producer when the check for @test_error
is not enough. It is not used in the consumer because its state
is manipulated by the producer via the "reader_finish" variable.

Also we add a missing check into ring_buffer_producer_thread()
between setting TASK_INTERRUPTIBLE and calling schedule_timeout().
Otherwise, we might miss a wakeup from kthread_stop().

Link: http://lkml.kernel.org/r/1441629518-32712-3-git-send-email-pmladek@suse.com

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 16:03:45 -05:00
Petr Mladek 8b46ff6938 ring_buffer: Do no not complete benchmark reader too early
It seems that complete(&read_done) might be called too early
in some situations.

1st scenario:
-------------

CPU0					CPU1

ring_buffer_producer_thread()
  wake_up_process(consumer);
  wait_for_completion(&read_start);

					ring_buffer_consumer_thread()
					  complete(&read_start);

  ring_buffer_producer()
    # producing data in
    # the do-while cycle

					  ring_buffer_consumer();
					    # reading data
					    # got error
					    # set kill_test = 1;
					    set_current_state(
						TASK_INTERRUPTIBLE);
					    if (reader_finish)  # false
					    schedule();

    # producer still in the middle of
    # do-while cycle
    if (consumer && !(cnt % wakeup_interval))
      wake_up_process(consumer);

					    # spurious wakeup
					    while (!reader_finish &&
						   !kill_test)
					    # leaving because
					    # kill_test == 1
					    reader_finish = 0;
					    complete(&read_done);

1st BANG: We might access uninitialized "read_done" if this is the
	  the first round.

    # producer finally leaving
    # the do-while cycle because kill_test == 1;

    if (consumer) {
      reader_finish = 1;
      wake_up_process(consumer);
      wait_for_completion(&read_done);

2nd BANG: This will never complete because consumer already did
	  the completion.

2nd scenario:
-------------

CPU0					CPU1

ring_buffer_producer_thread()
  wake_up_process(consumer);
  wait_for_completion(&read_start);

					ring_buffer_consumer_thread()
					  complete(&read_start);

  ring_buffer_producer()
    # CPU3 removes the module	  <--- difference from
    # and stops producer          <--- the 1st scenario
    if (kthread_should_stop())
      kill_test = 1;

					  ring_buffer_consumer();
					    while (!reader_finish &&
						   !kill_test)
					    # kill_test == 1 => we never go
					    # into the top level while()
					    reader_finish = 0;
					    complete(&read_done);

    # producer still in the middle of
    # do-while cycle
    if (consumer && !(cnt % wakeup_interval))
      wake_up_process(consumer);

					    # spurious wakeup
					    while (!reader_finish &&
						   !kill_test)
					    # leaving because kill_test == 1
					    reader_finish = 0;
					    complete(&read_done);

BANG: We are in the same "bang" situations as in the 1st scenario.

Root of the problem:
--------------------

ring_buffer_consumer() must complete "read_done" only when "reader_finish"
variable is set. It must not be skipped due to other conditions.

Note that we still must keep the check for "reader_finish" in a loop
because there might be spurious wakeups as described in the
above scenarios.

Solution:
----------

The top level cycle in ring_buffer_consumer() will finish only when
"reader_finish" is set. The data will be read in "while-do" cycle
so that they are not read after an error (kill_test == 1)
or a spurious wake up.

In addition, "reader_finish" is manipulated by the producer thread.
Therefore we add READ_ONCE() to make sure that the fresh value is
read in each cycle. Also we add the corresponding barrier
to synchronize the sleep check.

Next we set the state back to TASK_RUNNING for the situation where we
did not sleep.

Just from paranoid reasons, we initialize both completions statically.
This is safer, in case there are other races that we are unaware of.

As a side effect we could remove the memory barrier from
ring_buffer_producer_thread(). IMHO, this was the reason for
the barrier. ring_buffer_reset() uses spin locks that should
provide the needed memory barrier for using the buffer.

Link: http://lkml.kernel.org/r/1441629518-32712-2-git-send-email-pmladek@suse.com

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 16:03:24 -05:00
Dmitry Safonov fb8c2293e1 tracing: Remove redundant TP_ARGS redefining
TP_ARGS is not used anywhere in trace.h nor trace_entries.h
Firstly, I left just #undef TP_ARGS and had no errors - remove it.

Link: http://lkml.kernel.org/r/1446576560-14085-1-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 15:07:07 -05:00
Steven Rostedt (Red Hat) d332736df0 tracing: Rename max_stack_lock to stack_trace_max_lock
Now that max_stack_lock is a global variable, it requires a naming
convention that is unlikely to collide. Rename it to the same naming
convention that the other stack_trace variables have.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 14:50:15 -05:00
AKASHI Takahiro bb99d8ccec tracing: Allow arch-specific stack tracer
A stack frame may be used in a different way depending on cpu architecture.
Thus it is not always appropriate to slurp the stack contents, as current
check_stack() does, in order to calcurate a stack index (height) at a given
function call. At least not on arm64.
In addition, there is a possibility that we will mistakenly detect a stale
stack frame which has not been overwritten.

This patch makes check_stack() a weak function so as to later implement
arch-specific version.

Link: http://lkml.kernel.org/r/1446182741-31019-5-git-send-email-takahiro.akashi@linaro.org

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03 14:31:06 -05:00
Yaowei Bai c6650b2e57 tracing: ftrace_event_is_function() can return boolean
Make ftrace_event_is_function() return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-9-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:28:05 -05:00
Yaowei Bai 907bff917a tracing: is_legal_op() can return boolean
Make is_legal_op() return bool to improve readability due to this particular
function only using either one or zero as its return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-8-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:26:51 -05:00
Yaowei Bai cdb2a0a915 ring-buffer: rb_event_is_commit() can return boolean
Make rb_event_is_commit() return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-7-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:25:29 -05:00
Yaowei Bai da58834cf2 ring-buffer: rb_per_cpu_empty() can return boolean
Makes rb_per_cpu_empty() return bool to improve readability.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-6-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:24:27 -05:00
Yaowei Bai 3d4e204d81 ring_buffer: ring_buffer_empty{cpu}() can return boolean
Make ring_buffer_empty() and ring_buffer_empty_cpu() return bool.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-5-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:23:38 -05:00
Yaowei Bai 06ca320952 ring-buffer: rb_is_reader_page() can return boolean
Make rb_is_reader_page() return bool to improve readability due to this
particular function only using either true or false as its return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-4-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:23:20 -05:00
Yaowei Bai 79851821b2 tracing: report_latency() in trace_irqsoff.c can return boolean
This patch makes report_latency return bool due to this
particular function only using either one or zero as its
return value.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-3-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:20:19 -05:00
Yaowei Bai 26ab2ef451 tracing: report_latency() in trace_sched_wakeup.c can return boolean
This patch makes report_latency return bool to improve readability,
indicating whether this new latency should be reported/recorded.

No functional change.

Link: http://lkml.kernel.org/r/1443537816-5788-2-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 14:20:06 -05:00
Jiaxing Wang 681a4a2f45 tracing: Update instance_rmdir() to use tracefs_remove_recursive
Update instancd_rmdir to use tracefs_remove_recursive instead of
debugfs_remove_recursive.This was left in the transition from debugfs
to tracefs.

Link: http://lkml.kernel.org/r/1445169490-18315-2-git-send-email-hello.wjx@gmail.com

Cc: stable@vger.kernel.org # 4.1+
Fixes: 8434dc9340 ("tracing: Convert the tracing facility over to use tracefs")
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 13:59:06 -05:00
Chunyan Zhang bdb5d0f904 tracing: Only benchmark the time tracepoints take if tracing is on
There's no need to record the time tracepoints take when tracing is off.
This is because:
1) We cannot see these records since ring_buffer record is off at that
moment.
2) If tracing is off and benchmark tracepoint is enabled, the time
tracepoint takes is fewer than the same situation when tracing is on,
since the tracepoints need to be wrote into ring_buffer, it would
take more time. If turn on tracing at this moment, the average and
standard deviation cannot exactly present the time that tracepoints
take to write data into ring_buffer.

Link: http://lkml.kernel.org/r/1445947933-27955-1-git-send-email-zhang.chunyan@linaro.org

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 13:34:58 -05:00
Steven Rostedt (Red Hat) 799fd44cf5 tracing: Call on_each_cpu() when adding or removing single pids from set_event_pid
For the case where pids are already in set_event_pid, and one is added or
removed then each CPU should be checked to make sure that the new or old pid
is on or not on a CPU.

 For example:

 # echo 123 >> set_event_pid

or

 # echo '!123' >> set_event_pid

Link: http://lkml.kernel.org/r/20151030061643.GA19480@cac

Suggested-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02 13:08:26 -05:00
David S. Miller b75ec3af27 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-11-01 00:15:30 -04:00
Davidlohr Bueso cdea01b2bf blktrace: re-write setting q->blk_trace
This is really about simplifying the double xchg patterns into
a single cmpxchg, with the same logic. Other than the immediate
cleanup, there are some subtleties this change deals with:

(i) While the load of the old bt is fully ordered wrt everything,
ie:

        old_bt = xchg(&q->blk_trace, bt);             [barrier]
        if (old_bt)
	     (void) xchg(&q->blk_trace, old_bt);    [barrier]

blk_trace could still be changed between the xchg and the old_bt
load. Note that this description is merely theoretical and afaict
very small, but doing everything in a single context with cmpxchg
closes this potential race.

(ii) Ordering guarantees are obviously kept with cmpxchg.

(iii) Gets rid of the hacky-by-nature (void)xchg pattern.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
eviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-30 05:25:59 +09:00
Alexei Starovoitov 1075ef5950 bpf: make tracing helpers gpl only
exported perf symbols are GPL only, mark eBPF helper functions
used in tracing as GPL only as well.

Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-26 21:53:34 -07:00
Alexei Starovoitov 62544ce8e0 bpf: fix bpf_perf_event_read() helper
Fix safety checks for bpf_perf_event_read():
- only non-inherited events can be added to perf_event_array map
  (do this check statically at map insertion time)
- dynamically check that event is local and !pmu->count
Otherwise buggy bpf program can cause kernel splat.

Also fix error path after perf_event_attrs()
and remove redundant 'extern'.

Fixes: 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-26 21:49:26 -07:00
Steven Rostedt (Red Hat) fb66228828 tracing: Fix sparse RCU warning
p_start() and p_stop() are seq_file functions that match. Teach sparse to
know that rcu_read_lock_sched() that is taken by p_start() is released by
p_stop.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-26 03:51:32 -04:00
Steven Rostedt (Red Hat) 8ca532ad2b tracing: Check all tasks on each CPU when filtering pids
My tests found that if a task is running but not filtered when set_event_pid
is modified, then it can still be traced.

Call on_each_cpu() to check if the current running task should be filtered
and update the per cpu flags of tr->data appropriately.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-25 21:33:56 -04:00
Steven Rostedt (Red Hat) 3fdaf80f4a tracing: Implement event pid filtering
Add the necessary hooks to use the pids loaded in set_event_pid to filter
all the events enabled in the tracing instance that match the pids listed.

Two probes are added to both sched_switch and sched_wakeup tracepoints to be
called before other probes are called and after the other probes are called.
The first is used to set the necessary flags to let the probes know to test
if they should be traced or not.

The sched_switch pre probe will set the "ignore_pid" flag if neither the
previous or next task has a matching pid.

The sched_switch probe will set the "ignore_pid" flag if the next task
does not match the matching pid.

The pre probe allows for probes tracing sched_switch to be traced if
necessary.

The sched_wakeup pre probe will set the "ignore_pid" flag if neither the
current task nor the wakee task has a matching pid.

The sched_wakeup post probe will set the "ignore_pid" flag if the current
task does not have a matching pid.

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-25 21:33:56 -04:00
Steven Rostedt (Red Hat) 4909010788 tracing: Add set_event_pid directory for future use
Create a tracing directory called set_event_pid, which currently has no
function, but will be used to filter all events for the tracing instance or
the pids that are added to the file.

The reason no functionality is added with this commit is that this commit
focuses on the creation and removal of the pids in a safe manner. And tests
can be made against this change to make sure things are correct before
hooking features to the list of pids.

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-25 21:33:55 -04:00
Alexei Starovoitov a43eec3042 bpf: introduce bpf_perf_event_output() helper
This helper is used to send raw data from eBPF program into
special PERF_TYPE_SOFTWARE/PERF_COUNT_SW_BPF_OUTPUT perf_event.
User space needs to perf_event_open() it (either for one or all cpus) and
store FD into perf_event_array (similar to bpf_perf_event_read() helper)
before eBPF program can send data into it.

Today the programs triggered by kprobe collect the data and either store
it into the maps or print it via bpf_trace_printk() where latter is the debug
facility and not suitable to stream the data. This new helper replaces
such bpf_trace_printk() usage and allows programs to have dedicated
channel into user space for post-processing of the raw data collected.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-22 06:42:15 -07:00
Dmitry Safonov 3061692921 tracing: Remove {start,stop}_branch_trace
Both start_branch_trace() and stop_branch_trace() are used in only one
location, and are both static. As they are small functions there is no
need to keep them separated out.

Link: http://lkml.kernel.org/r/1445000689-32596-1-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-21 10:10:09 -04:00
Tal Shorer ddd70280bf tracing: gpio: Add Kconfig option for enabling/disabling trace events
Add a new options to trace Kconfig, CONFIG_TRACING_EVENTS_GPIO, that is
used for enabling/disabling compilation of gpio function trace events.

Link: http://lkml.kernel.org/r/1438432079-11704-4-git-send-email-tal.shorer@gmail.com

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 21:56:10 -04:00
Steven Rostedt (Red Hat) 1904be1b6b tracing: Do not allow stack_tracer to record stack in NMI
The code in stack tracer should not be executed within an NMI as it grabs
spinlocks and stack tracing an NMI gives the possibility of causing a
deadlock. Although this is safe on x86_64, because it does not perform stack
traces when the task struct stack is not in use (interrupts and NMIs), it
may be an issue for NMIs on i386 and other archs that use the same stack as
the NMI.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 21:52:23 -04:00
Dmitry Safonov 0b507e1ed1 ftrace: add module globbing
Extend module command for function filter selection with globbing.
It uses the same globbing as function filter.

  sh# echo '*alloc*:mod:*' > set_ftrace_filter

Will trace any function with the letters 'alloc' in the name in any
module but not in kernel.

  sh# echo '!*alloc*:mod:ipv6' >> set_ftrace_filter

Will prevent from tracing functions with 'alloc' in the name from module
ipv6 (do not forget to append to set_ftrace_filter file).

  sh# echo '*alloc*:mod:!ipv6' > set_ftrace_filter

Will trace functions with 'alloc' in the name from kernel and any
module except ipv6.

  sh# echo '*alloc*:mod:!*' > set_ftrace_filter

Will trace any function with the letters 'alloc' in the name only from
kernel, but not from any module.

  sh# echo '*:mod:!*' > set_ftrace_filter
or
  sh# echo ':mod:!' > set_ftrace_filter

Will trace every function in the kernel, but will not trace functions
from any module.

  sh# echo '*:mod:*' > set_ftrace_filter
or
  sh# echo ':mod:' > set_ftrace_filter

As the opposite will trace all functions from all modules, but not from
kernel.

  sh# echo '*:mod:*snd*' > set_ftrace_filter

Will trace your sound drivers only (if any).

Link: http://lkml.kernel.org/r/1443545176-3215-4-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made format changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 20:02:03 -04:00
Dmitry Safonov 3ba0092971 ftrace: Introduce ftrace_glob structure
ftrace_match parameters are very related and I reduce the number of local
variables & parameters with it.
This is also preparation for module globbing as it would introduce more
realated variables & parameters.

Link: http://lkml.kernel.org/r/1443545176-3215-3-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made some formatting changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 18:23:07 -04:00
Steven Rostedt (Red Hat) a2d7629048 tracing: Have stack tracer force RCU to be watching
The stack tracer was triggering the WARN_ON() in module.c:

 static void module_assert_mutex_or_preempt(void)
 {
 #ifdef CONFIG_LOCKDEP
	if (unlikely(!debug_locks))
		return;

	WARN_ON(!rcu_read_lock_sched_held() &&
		!lockdep_is_held(&module_mutex));
 #endif
 }

The reason is that the stack tracer traces all function calls, and some of
those calls happen while exiting or entering user space and idle. Some of
these functions are called after RCU had already stopped watching, as RCU
does not watch userspace or idle CPUs.

If a max stack is hit, then the save_stack_trace() is called, which will
check module addresses and call module_assert_mutex_or_preempt(), and then
trigger the warning. Sad part is, the warning itself will also do a stack
trace and tigger the same warning. That probably should be fixed.

The warning was added by 0be964be0d "module: Sanitize RCU usage and
locking" but this bug has probably been around longer. But it's unlikely to
cause much harm, but the new warning causes the system to lock up.

Cc: stable@vger.kernel.org # 4.2+
Cc: Peter Zijlstra <peterz@infradead.org>
Cc:"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 11:38:08 -04:00
Dmitry Safonov f0a3b154bd ftrace: Clarify code for mod command
"Not" is too abstract variable name - changed to clear_filter.
Removed ftrace_match_module_records function: comparison with !* or *
not does the general code in filter_parse_regex() as it works without
mod command for
  sh# echo '!*' > /sys/kernel/debug/tracing/set_ftrace_filter

Link: http://lkml.kernel.org/r/1443545176-3215-2-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-16 10:29:53 -04:00
Dmitry Safonov 5e3949f0ac ftrace: Remove redundant strsep in mod_callback
By now there isn't any subcommand for mod.

Before:
	sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
	sh$ echo '*:mod:ipv6' > set_ftrace_filter
had the same results, but now first will result in:
	sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
	-bash: echo: write error: Invalid argument

Also, I clarified ftrace_mod_callback code a little.

Link: http://lkml.kernel.org/r/1443545176-3215-1-git-send-email-0x7f454c46@gmail.com

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ converted 'if (ret == 0)' to 'if (!ret)' ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-13 20:59:24 -04:00
Peter Zijlstra c73464b1c8 sched/core: Fix trace_sched_switch()
__trace_sched_switch_state() is the last remaining PREEMPT_ACTIVE
user, move trace_sched_switch() from prepare_task_switch() to
__schedule() and propagate the @preempt argument.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:08:15 +02:00
Rasmus Villemoes 6db0290322 ftrace: Remove redundant swap function
To cover the common case of sorting an array of pointers, Daniel
Wagner recently modified the library sort() to use a specific swap
function for size==8, in addition to the size==4 case which was
already handled. Since sizeof(long) is either 4 or 8,
ftrace_swap_ips() is redundant and we can just let sort() pick an
appropriate and fast swap callback.

Link: http://lkml.kernel.org/r/1441834023-13130-1-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-01 09:32:20 -04:00
Rasmus Villemoes 79ac6ef521 tracing: Use kstrdup_const instead of private implementation
The kernel now has kstrdup_const/kfree_const for reusing .rodata
(typically string literals) when possible; there's no reason to
duplicate that logic in the tracing system. Moreover, as the comment
above core_kernel_data states, it may not always return true for
.rodata - that is for example the case on x86_64, where we thus end up
kstrdup'ing all the passed-in strings.

Arguably, testing for .rodata explicitly (as kstrdup_const does) is
also more correct: I don't think one is supposed to be able to change
the name after creating the event_subsystem by passing the address of
a static char (but non-const) array.

Link: http://lkml.kernel.org/r/1441833841-12955-1-git-send-email-linux@rasmusvillemoes.dk

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-01 09:05:17 -04:00
Steven Rostedt (Red Hat) 37aea98b84 tracing: Add trace options for tracer options to instances
Add the tracer options to instances options directory as well. Only add the
options for tracers that are allowed to be enabled by an instance. But note,
that tracer options are global. That is, tracer options enabled in an
instance, also take affect at the top level and in other instances.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 15:22:58 -04:00
Steven Rostedt (Red Hat) 16270145ce tracing: Add trace options for core options to instances
Allow instances to have their own options, at least for the core options
(non tracer specific ones). There are a few global options that should not
be added to instances, like enabling of trace_printk, and the sched comm
recording, which do not have a specific trace instance associated to them.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 15:22:57 -04:00
Steven Rostedt (Red Hat) 2d34f48955 tracing: Make ftrace_trace_stack() depend on general trace_array flag
In preparation for the multi buffer instances to have their own trace_flags,
the check in ftrace_trace_stack() needs to test the trace_array descriptor
flag that is for the current event, not the global_trace descriptor.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 15:22:57 -04:00
Steven Rostedt (Red Hat) 9a38a8856f tracing: Add a method to pass in trace_array descriptor to option files
In preparation of having the multi buffer instances having their own trace
option flags, the trace option files needs a way to not only pass in the
flag they represent, but also the trace_array descriptor.

A new field is added to the trace_array descriptor called trace_flags_index,
which is a 32 byte character array representing a bit. This array is simply
filled with the index of the array, where

  index_array[n] = n;

Then the address of this array is passed to the file callbacks instead of
the index of the flag index. Then to retrieve both the flag index and the
trace_array descriptor:

  data is the passed in argument.

  index = *(unsigned char *)data;

  data -= index;

  /* Now data points to the address of the array in the trace_array */

  tr = container_of(data, struct trace_array, trace_flags_index);

Suggested-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 15:22:56 -04:00
Steven Rostedt (Red Hat) 983f938ae6 tracing: Move trace_flags from global to a trace_array field
In preparation to make trace options per instance, the global trace_flags
needs to be moved from being a global variable to a field within the trace
instance trace_array structure.

There's still more work to do, as there's some functions that use
trace_flags without passing in a way to get to the current_trace array. For
those, the global_trace is used directly (from trace.c). This includes
setting and clearing the trace_flags. This means that when a new instance is
created, it just gets the trace_flags of the global_trace and will not be
able to modify them. Depending on the functions that have access to the
trace_array, the flags of an instance may not affect parts of its trace,
where the global_trace is used. These will be fixed in future changes.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 15:22:55 -04:00
Steven Rostedt (Red Hat) 5557720415 tracing: Move sleep-time and graph-time options out of the core trace_flags
The sleep-time and graph-time options are only for the function graph tracer
and are not used by anything else. As tracer options are now visible when
the tracer is not activated, its better to move the function graph specific
tracer options into the function graph tracer.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 15:22:42 -04:00
Steven Rostedt (Red Hat) b9f9108cad tracing: Remove access to trace_flags in trace_printk.c
In the effort to move the global trace_flags to the tracing instances, the
direct access to trace_flags must be removed from trace_printk.c

Instead, add a new trace_printk_enabled boolean that is set by a new access
function trace_printk_control(), that will enable or disable trace_printk.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 04:35:18 -04:00
Steven Rostedt (Red Hat) b5e87c0581 tracing: Add build bug if we have more trace_flags than bits
Add a enum that denotes the last bit of the trace_flags and have a
BUILD_BUG_ON(last_bit > 32).

If we add more bits than we have in trace_flags, the kernel wont build.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 04:35:18 -04:00
Steven Rostedt (Red Hat) 41d9c0becc tracing: Always show all tracer options in the options directory
There are options that are unique to a specific tracer (like function and
function graph). Currently, these options are only visible in the options
directory when the tracer is enabled.

This has been a pain, especially for something like the func_stack_trace
option that if used inappropriately, could bring the system to a crawl. But
the only way to see it, is to enable the function tracer.

For example, if one had done:

 # cd /sys/kernel/tracing
 # echo __schedule > set_ftrace_filter
 # echo 1 > options/func_stack_trace
 # echo function > current_tracer

The __schedule call will be traced and a stack trace will also be recorded
there. Now when you were done, you may do...

 # echo nop > current_tracer
 # echo > set_ftrace_filter

But you forgot to disable the func_stack_trace. The only way to disable it
is to re-enable function tracing first. If you do not add a filter to
set_ftrace_filter and just do:

 # echo function > current_tracer

Now you would be performing a stack trace on *every* function! On some
systems, that causes a live lock. Others may take a few minutes to fix your
mistake.

Having the func_stack_trace option visible allows you to check it and
disable it before enabling the funtion tracer.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-30 04:34:54 -04:00
Steven Rostedt (Red Hat) 73dddbb57b tracing: Only create stacktrace option when STACKTRACE is configured
Only create the stacktrace trace option when CONFIG_STACKTRACE is
configured.

Cleaned up the ftrace_trace_stack() function call a little to allow better
encapsulation of the stacktrace trace flag.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 15:38:55 -04:00
Steven Rostedt (Red Hat) 8179e8a15b tracing: Do not create function tracer options when not compiled in
When the function tracer is not compiled in, do not create the option files
for it.

Fix up both the sched_wakeup and irqsoff tracers to handle the change.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 15:01:34 -04:00
Steven Rostedt (Red Hat) 4ee4301c4b tracing: Only create branch tracer options when compiled in
When the branch tracer is not compiled in, do not create the option files
associated to it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 13:23:59 -04:00
Steven Rostedt (Red Hat) 729358da95 tracing: Only create function graph options when it is compiled in
Do not create fuction graph tracer options when function graph tracer is not
even compiled in.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 13:23:58 -04:00
Steven Rostedt (Red Hat) a3418a364e tracing: Use TRACE_FLAGS macro to keep enums and strings matched
Use a cute little macro trick to keep the names of the trace flags file
guaranteed to match the corresponding masks.

The macro TRACE_FLAGS is defined as a serious of enum names followed by
the string name of the file that matches it. For example:

 #define TRACE_FLAGS						\
		C(PRINT_PARENT,		"print-parent"),	\
		C(SYM_OFFSET,		"sym-offset"),		\
		C(SYM_ADDR,		"sym-addr"),		\
		C(VERBOSE,		"verbose"),

Now we can define the following:

 #undef C
 #define C(a, b) TRACE_ITER_##a##_BIT
 enum trace_iterator_bits { TRACE_FLAGS };

The above creates:

 enum trace_iterator_bits {
	TRACE_ITER_PRINT_PARENT_BIT,
	TRACE_ITER_SYM_OFFSET_BIT,
	TRACE_ITER_SYM_ADDR_BIT,
	TRACE_ITER_VERBOSE_BIT,
 };

Then we can redefine C as:

 #undef C
 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
 enum trace_iterator_flags { TRACE_FLAGS };

Which creates:

 enum trace_iterator_flags {
	TRACE_ITER_PRINT_PARENT	= (1 << TRACE_ITER_PRINT_PARENT_BIT),
	TRACE_ITER_SYM_OFFSET	= (1 << TRACE_ITER_SYM_OFFSET_BIT),
	TRACE_ITER_SYM_ADDR	= (1 << TRACE_ITER_SYM_ADDR_BIT),
	TRACE_ITER_VERBOSE	= (1 << TRACE_ITER_VERBOSE_BIT),
 };

Then finally we can create the list of file names:

 #undef C
 #define C(a, b) b
 static const char *trace_options[] = {
	TRACE_FLAGS
	NULL
 };

Which creates:
 static const char *trace_options[] = {
	"print-parent",
	"sym-offset",
	"sym-addr",
	"verbose",
	NULL
 };

The importance of this is that the strings match the bit index.

	trace_options[TRACE_ITER_SYM_ADDR_BIT] == "sym-addr"

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 13:23:57 -04:00
Steven Rostedt (Red Hat) ce3fed628e tracing: Use enums instead of hard coded bitmasks for TRACE_ITER flags
Using enums with FLAG_BIT and then defining a FLAG = (1 << FLAG_BIT), is a
bit more robust as we require that there are no bits out of order or skipped
to match the file names that represent the bits.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 13:23:56 -04:00
Steven Rostedt (Red Hat) 938db5f569 tracing: Remove unused tracing option "ftrace_preempt"
There was a time where the function tracing would disable interrupts unless
specifically told not to, where it would only disable preemption. With the
new lockless code, the function tracing never disalbes interrupts and just
uses disabling of preemption. Remove the option "ftrace_preempt" as it does
nothing anyway.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 13:23:54 -04:00
Steven Rostedt (Red Hat) 03905582fd tracing: Move "display-graph" option to main options
In order to facilitate making all tracer options visible even when the
tracer is not active, we need to get rid of duplicate options. Any option
that is shared between multiple tracers really should be a main option.

As the wakeup and irqsoff tracers both use the "display-graph" option, and
use it exactly the same way, move that option from the tracer options to the
main options and consolidate them.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-29 12:56:40 -04:00
Steven Rostedt (Red Hat) ef92480a58 tracing: Turn seq_print_user_ip() into a static function
seq_print_user_ip() is used in only one location in one file. Turn it into a
static function. We could inject its code into the caller, but that would
make the code a bit too complex. Keep the code separate.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-28 10:16:12 -04:00
Steven Rostedt (Red Hat) 6b1032d53c tracing: Inject seq_print_userip_objs() into its only user
seq_print_userip_objs() is used only in one location, in one file. Instead
of having it as an external function, go one further than making it static,
but inject is code into its only user. It doesn't make the calling function
much more complex.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-28 10:11:44 -04:00
Steven Rostedt (Red Hat) ca475e831f tracing: Make ftrace_trace_stack() static
ftrace_trace_stack() is not called outside of trace.c. Make it a static
function.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-28 09:41:11 -04:00
Steven Rostedt (Red Hat) b7f0c959ed tracing: Pass trace_array into trace_buffer_unlock_commit()
In preparation for having trace options be per instance, the trace_array
needs to be passed to the trace_buffer_unlock_commit(). The
trace_event_buffer_lock_reserve() already passes in the trace_event_file
where the trace_array can be derived from.

Also added a "__init" to the boot up test event plus function tracing
function function_test_events_call().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-25 17:38:44 -04:00
Steven Rostedt (Red Hat) 41907416bc tracing: Remove unused function trace_current_buffer_lock_reserve()
trace_current_buffer_lock_reserve() is not used by anything. Might as well
get rid of it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-25 15:37:31 -04:00
Steven Rostedt (Red Hat) d78a461427 tracing: Remove ftrace_trace_stack_regs()
ftrace_trace_stack_regs() is used in only one place, and because that is
such a simple function, just move its code into the location that it was
used in (trace_buffer_unlock_commit_regs()).

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-25 15:37:23 -04:00
Yaowei Bai f0132c4e0d kernel/trace_probe: is_good_name can be boolean
This patch makes is_good_name return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Link: http://lkml.kernel.org/r/1442929393-4753-2-git-send-email-bywxiaobai@163.com

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-22 13:11:30 -04:00
Linus Torvalds 59a47fff02 Mostly this is just clean ups and micro optimizations.
The changes with more meat are:
 
  o Allowing the trace event filters to filter on CPU number and process ids
 
  o Two new markers for trace output latency were added
     (10 and 100 msec latencies)
 
  o Have tracing_thresh filter function profiling time
 
 I also worked on modifying the ring buffer code for some future
 work, and moved the adding of the timestamp around. One of my changes
 caused a regression, and since other changes were built on top of it
 and already tested, I had to operate a revert of that change. Instead
 of rebasing, this change set has the code that caused a regression
 as well as the code to revert that change without touching the other
 changes that were made on top of it.
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Merge tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing update from Steven Rostedt:
 "Mostly this is just clean ups and micro optimizations.

  The changes with more meat are:

   - Allowing the trace event filters to filter on CPU number and
     process ids

   - Two new markers for trace output latency were added (10 and 100
     msec latencies)

   - Have tracing_thresh filter function profiling time

  I also worked on modifying the ring buffer code for some future work,
  and moved the adding of the timestamp around.  One of my changes
  caused a regression, and since other changes were built on top of it
  and already tested, I had to operate a revert of that change.  Instead
  of rebasing, this change set has the code that caused a regression as
  well as the code to revert that change without touching the other
  changes that were made on top of it"

* tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated"
  tracing: Don't make assumptions about length of string on task rename
  tracing: Allow triggers to filter for CPU ids and process names
  ftrace: Format MCOUNT_ADDR address as type unsigned long
  tracing: Introduce two additional marks for delay
  ftrace: Fix function_graph duration spacing with 7-digits
  ftrace: add tracing_thresh to function profile
  tracing: Clean up stack tracing and fix fentry updates
  ring-buffer: Reorganize function locations
  ring-buffer: Make sure event has enough room for extend and padding
  ring-buffer: Get timestamp after event is allocated
  ring-buffer: Move the adding of the extended timestamp out of line
  ring-buffer: Add event descriptor to simplify passing data
  ftrace: correct the counter increment for trace_buffer data
  tracing: Fix for non-continuous cpu ids
  tracing: Prefer kcalloc over kzalloc with multiply
2015-09-08 14:04:14 -07:00
Linus Torvalds dd5cdb48ed Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Another merge window, another set of networking changes.  I've heard
  rumblings that the lightweight tunnels infrastructure has been voted
  networking change of the year.  But what do I know?

   1) Add conntrack support to openvswitch, from Joe Stringer.

   2) Initial support for VRF (Virtual Routing and Forwarding), which
      allows the segmentation of routing paths without using multiple
      devices.  There are some semantic kinks to work out still, but
      this is a reasonably strong foundation.  From David Ahern.

   3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov.

   4) Ignore route nexthops with a link down state in ipv6, just like
      ipv4.  From Andy Gospodarek.

   5) Remove spinlock from fast path of act_gact and act_mirred, from
      Eric Dumazet.

   6) Document the DSA layer, from Florian Fainelli.

   7) Add netconsole support to bcmgenet, systemport, and DSA.  Also
      from Florian Fainelli.

   8) Add Mellanox Switch Driver and core infrastructure, from Jiri
      Pirko.

   9) Add support for "light weight tunnels", which allow for
      encapsulation and decapsulation without bearing the overhead of a
      full blown netdevice.  From Thomas Graf, Jiri Benc, and a cast of
      others.

  10) Add Identifier Locator Addressing support for ipv6, from Tom
      Herbert.

  11) Support fragmented SKBs in iwlwifi, from Johannes Berg.

  12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia.

  13) Add BQL support to 3c59x driver, from Loganaden Velvindron.

  14) Stop using a zero TX queue length to mean that a device shouldn't
      have a qdisc attached, use an explicit flag instead.  From Phil
      Sutter.

  15) Use generic geneve netdevice infrastructure in openvswitch, from
      Pravin B Shelar.

  16) Add infrastructure to avoid re-forwarding a packet in software
      that was already forwarded by a hardware switch.  From Scott
      Feldman.

  17) Allow AF_PACKET fanout function to be implemented in a bpf
      program, from Willem de Bruijn"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits)
  netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
  netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled
  net: fec: clear receive interrupts before processing a packet
  ipv6: fix exthdrs offload registration in out_rt path
  xen-netback: add support for multicast control
  bgmac: Update fixed_phy_register()
  sock, diag: fix panic in sock_diag_put_filterinfo
  flow_dissector: Use 'const' where possible.
  flow_dissector: Fix function argument ordering dependency
  ixgbe: Resolve "initialized field overwritten" warnings
  ixgbe: Remove bimodal SR-IOV disabling
  ixgbe: Add support for reporting 2.5G link speed
  ixgbe: fix bounds checking in ixgbe_setup_tc for 82598
  ixgbe: support for ethtool set_rxfh
  ixgbe: Avoid needless PHY access on copper phys
  ixgbe: cleanup to use cached mask value
  ixgbe: Remove second instance of lan_id variable
  ixgbe: use kzalloc for allocating one thing
  flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c
  ixgbe: Remove unused PCI bus types
  ...
2015-09-03 08:08:17 -07:00
Steven Rostedt (Red Hat) b7dc42fd79 ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated"
The commit a4543a2fa9 "ring-buffer: Get timestamp after event is
allocated" is needed for some future work. But after adding it, there is a
race somewhere that causes the saved timestamp to have a slight shift, and
get ahead of the actual timestamp and make it look like time goes backwards.

I'm still looking into why this happens, but in the mean time, this is
holding up other work to get in. I'm reverting the change for now (which
makes the problem go away), and will add it back after I know what is wrong
and fix it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-09-03 08:57:12 -04:00
Linus Torvalds 1081230b74 Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "This first core part of the block IO changes contains:

   - Cleanup of the bio IO error signaling from Christoph.  We used to
     rely on the uptodate bit and passing around of an error, now we
     store the error in the bio itself.

   - Improvement of the above from myself, by shrinking the bio size
     down again to fit in two cachelines on x86-64.

   - Revert of the max_hw_sectors cap removal from a revision again,
     from Jeff Moyer.  This caused performance regressions in various
     tests.  Reinstate the limit, bump it to a more reasonable size
     instead.

   - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
     Most devices have huge trim limits, which can cause nasty latencies
     when deleting files.  Enable the admin to configure the size down.
     We will look into having a more sane default instead of UINT_MAX
     sectors.

   - Improvement of the SGP gaps logic from Keith Busch.

   - Enable the block core to handle arbitrarily sized bios, which
     enables a nice simplification of bio_add_page() (which is an IO hot
     path).  From Kent.

   - Improvements to the partition io stats accounting, making it
     faster.  From Ming Lei.

   - Also from Ming Lei, a basic fixup for overflow of the sysfs pending
     file in blk-mq, as well as a fix for a blk-mq timeout race
     condition.

   - Ming Lin has been carrying Kents above mentioned patches forward
     for a while, and testing them.  Ming also did a few fixes around
     that.

   - Sasha Levin found and fixed a use-after-free problem introduced by
     the bio->bi_error changes from Christoph.

   - Small blk cgroup cleanup from Viresh Kumar"

* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
  blk: Fix bio_io_vec index when checking bvec gaps
  block: Replace SG_GAPS with new queue limits mask
  block: bump BLK_DEF_MAX_SECTORS to 2560
  Revert "block: remove artifical max_hw_sectors cap"
  blk-mq: fix race between timeout and freeing request
  blk-mq: fix buffer overflow when reading sysfs file of 'pending'
  Documentation: update notes in biovecs about arbitrarily sized bios
  block: remove bio_get_nr_vecs()
  fs: use helper bio_add_page() instead of open coding on bi_io_vec
  block: kill merge_bvec_fn() completely
  md/raid5: get rid of bio_fits_rdev()
  md/raid5: split bio for chunk_aligned_read
  block: remove split code in blkdev_issue_{discard,write_same}
  btrfs: remove bio splitting and merge_bvec_fn() calls
  bcache: remove driver private bio splitting code
  block: simplify bio_add_page()
  block: make generic_make_request handle arbitrarily sized bios
  blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
  block: don't access bio->bi_error after bio_put()
  block: shrink struct bio down to 2 cache lines again
  ...
2015-09-02 13:10:25 -07:00
Linus Torvalds a1d8561172 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The biggest change in this cycle is the rewrite of the main SMP load
  balancing metric: the CPU load/utilization.  The main goal was to make
  the metric more precise and more representative - see the changelog of
  this commit for the gory details:

    9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")

  It is done in a way that significantly reduces complexity of the code:

    5 files changed, 249 insertions(+), 494 deletions(-)

  and the performance testing results are encouraging.  Nevertheless we
  need to keep an eye on potential regressions, since this potentially
  affects every SMP workload in existence.

  This work comes from Yuyang Du.

  Other changes:

   - SCHED_DL updates.  (Andrea Parri)

   - Simplify architecture callbacks by removing finish_arch_switch().
     (Peter Zijlstra et al)

   - cputime accounting: guarantee stime + utime == rtime.  (Peter
     Zijlstra)

   - optimize idle CPU wakeups some more - inspired by Facebook server
     loads.  (Mike Galbraith)

   - stop_machine fixes and updates.  (Oleg Nesterov)

   - Introduce the 'trace_sched_waking' tracepoint.  (Peter Zijlstra)

   - sched/numa tweaks.  (Srikar Dronamraju)

   - misc fixes and small cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  sched/deadline: Fix comment in enqueue_task_dl()
  sched/deadline: Fix comment in push_dl_tasks()
  sched: Change the sched_class::set_cpus_allowed() calling context
  sched: Make sched_class::set_cpus_allowed() unconditional
  sched: Fix a race between __kthread_bind() and sched_setaffinity()
  sched: Ensure a task has a non-normalized vruntime when returning back to CFS
  sched/numa: Fix NUMA_DIRECT topology identification
  tile: Reorganize _switch_to()
  sched, sparc32: Update scheduler comments in copy_thread()
  sched: Remove finish_arch_switch()
  sched, tile: Remove finish_arch_switch
  sched, sh: Fold finish_arch_switch() into switch_to()
  sched, score: Remove finish_arch_switch()
  sched, avr32: Remove finish_arch_switch()
  sched, MIPS: Get rid of finish_arch_switch()
  sched, arm: Remove finish_arch_switch()
  sched/fair: Clean up load average references
  sched/fair: Provide runnable_load_avg back to cfs_rq
  sched/fair: Remove task and group entity load when they are dead
  sched/fair: Init cfs_rq's sched_entity load average
  ...
2015-08-31 20:26:22 -07:00
Alexei Starovoitov 8d3b7dce86 bpf: add support for %s specifier to bpf_trace_printk()
%s specifier makes bpf program and kernel debugging easier.
To make sure that trace_printk won't crash the unsafe string
is copied into stack and unsafe pointer is substituted.

The following C program:
 #include <linux/fs.h>
int foo(struct pt_regs *ctx, struct filename *filename)
{
  void *name = 0;

  bpf_probe_read(&name, sizeof(name), &filename->name);
  bpf_trace_printk("executed %s\n", name);
  return 0;
}

when attached to kprobe do_execve()
will produce output in /sys/kernel/debug/tracing/trace_pipe :
    make-13492 [002] d..1  3250.997277: : executed /bin/sh
      sh-13493 [004] d..1  3250.998716: : executed /usr/bin/gcc
     gcc-13494 [002] d..1  3250.999822: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1
     gcc-13495 [002] d..1  3251.006731: : executed /usr/bin/as
     gcc-13496 [002] d..1  3251.011831: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/collect2
collect2-13497 [000] d..1  3251.012941: : executed /usr/bin/ld

Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-28 16:27:27 -07:00
Alexei Starovoitov 1a6877b9c0 lib: introduce strncpy_from_unsafe()
generalize FETCH_FUNC_NAME(memory, string) into
strncpy_from_unsafe() and fix sparse warnings that were
present in original implementation.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-28 16:27:27 -07:00
Wang Nan a2fb3382ed tracing/uprobes: Do not print '0x (null)' when offset is 0
When manually added uprobe point with zero address, 'uprobe_events'
output '(null)' instead of 0x00000000:

  # echo p:probe_libc/abs_0 /path/to/lib.bin:0x0 arg1=%ax > \
            /sys/kernel/debug/tracing/uprobe_events

  # cat /sys/kernel/debug/tracing/uprobe_events
    p:probe_libc/abs_0 /path/to/lib.bin:0x          (null) arg1=%ax

 This patch fixes this behavior:

  # cat /sys/kernel/debug/tracing/uprobe_events
  p:probe_libc/abs_0 /path/to/lib.bin:0x0000000000000000

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1440586666-235233-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-26 10:43:01 -03:00
Daniel Wagner 9f61668073 tracing: Allow triggers to filter for CPU ids and process names
By extending the filter rules by more generic fields
we can write triggers filters like

  echo 'stacktrace if cpu == 1' > \
	/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger

or

  echo 'stacktrace if comm == sshd'  > \
	/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger

CPU and COMM are not part of struct trace_entry. We could add the two
new fields to ftrace_common_field list and fix up all depending
sides. But that looks pretty ugly. Another thing I would like to
avoid that the 'format' file contents changes.

All this can be avoided by introducing another list which contains
non field members of struct trace_entry.

Link: http://lkml.kernel.org/r/1439210146-24707-1-git-send-email-daniel.wagner@bmw-carit.de

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-08-11 18:01:06 -04:00
Kaixu Xia 35578d7984 bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter
According to the perf_event_map_fd and index, the function
bpf_perf_event_read() can convert the corresponding map
value to the pointer to struct perf_event and return the
Hardware PMU counter value.

Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-09 22:50:06 -07:00
Wang Nan 04a22fae4c tracing, perf: Implement BPF programs attached to uprobes
By copying BPF related operation to uprobe processing path, this patch
allow users attach BPF programs to uprobes like what they are already
doing on kprobes.

After this patch, users are allowed to use PERF_EVENT_IOC_SET_BPF on a
uprobe perf event. Which make it possible to profile user space programs
and kernel events together using BPF.

Because of this patch, CONFIG_BPF_EVENTS should be selected by
CONFIG_UPROBE_EVENT to ensure trace_call_bpf() is compiled even if
KPROBE_EVENT is not set.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-06 15:29:14 -03:00
Peter Zijlstra fbd705a0c6 sched: Introduce the 'trace_sched_waking' tracepoint
Mathieu reported that since 317f394160 ("sched: Move the second half
of ttwu() to the remote cpu") trace_sched_wakeup() can happen out of
context of the waker.

This is a problem when you want to analyse wakeup paths because it is
now very hard to correlate the wakeup event to whoever issued the
wakeup.

OTOH trace_sched_wakeup() is issued at the point where we set
p->state = TASK_RUNNING, which is right were we hand the task off to
the scheduler, so this is an important point when looking at
scheduling behaviour, up to here its been the wakeup path everything
hereafter is due to scheduler policy.

To bridge this gap, introduce a second tracepoint: trace_sched_waking.
It is guaranteed to be called in the waker context.

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Francis Giraldeau <francis.giraldeau@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150609091336.GQ3644@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-03 12:21:22 +02:00
Christoph Hellwig 4246a0b63b block: add a bi_error field to struct bio
Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29 08:55:15 -06:00
Steven Rostedt (Red Hat) e3eea1404f ftrace: Fix breakage of set_ftrace_pid
Commit 4104d326b6 ("ftrace: Remove global function list and call function
directly") simplified the ftrace code by removing the global_ops list with a
new design. But this cleanup also broke the filtering of PIDs that are added
to the set_ftrace_pid file.

Add back the proper hooks to have pid filtering working once again.

Cc: stable@vger.kernel.org # 3.16+
Reported-by: Matt Fleming <matt@console-pimps.org>
Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Tested-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-24 13:58:14 -04:00
Jungseok Lee b838e1d96c tracing: Introduce two additional marks for delay
A fine granulity support for delay would be very useful when profiling
VM logics, such as page allocation including page reclaim and memory
compaction with function graph.

Thus, this patch adds two additional marks with two changes.

 - An equal sign in mark selection function is removed to align code
   behavior with comments and documentation.

 - The function graph example related to delay in ftrace.txt is updated
   to cover all supported marks.

Link: http://lkml.kernel.org/r/1436626300-1679-3-git-send-email-jungseoklee85@gmail.com

Cc: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:52 -04:00
Steven Rostedt (Red Hat) 82c355e81a ftrace: Fix function_graph duration spacing with 7-digits
Jungseok Lee noticed the following:

Currently, row's width of 7-digit duration numbers not aligned with
other cases like the following example.

 3) $ 3999884 us |      }
 3)               |      finish_task_switch() {
 3)   0.365 us    |        _raw_spin_unlock_irq();
 3)   3.333 us    |      }
 3) $ 3999976 us |    }
 3) $ 3999979 us |  } /* schedule */

As adding a single white space in case of 7-digit numbers, the format
could be unified easily as follows.

 3) $ 2237472 us  |      }
 3)               |      finish_task_switch() {
 3)   0.364 us    |        _raw_spin_unlock_irq();
 3)   3.125 us    |      }
 3) $ 2237556 us  |    }
 3) $ 2237559 us  |  } /* schedule */

Instead of making a special case for 7-digit numbers, the logic
of the len and the space loop is slightly modified to make the
two cases have the same format.

Link: http://lkml.kernel.org/r/1436626300-1679-2-git-send-email-jungseoklee85@gmail.com

Reported-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:52 -04:00
Umesh Tiwari 8e436ca042 ftrace: add tracing_thresh to function profile
This patch extends tracing_thresh functionality to function profile tracer.
If tracing_thresh is set, print those entries only,
whose average is > tracing thresh.

Link: http://lkml.kernel.org/r/1434972488-8571-1-git-send-email-umesh.t@samsung.com

Signed-off-by: Umesh Tiwari <umesh.t@samsung.com>
[ Removed unnecessary 'moved' comment ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:51 -04:00
Steven Rostedt (Red Hat) 72ac426a5b tracing: Clean up stack tracing and fix fentry updates
Akashi Takahiro was porting the stack tracer to arm64 and found some
issues with it. One was that it repeats the top function, due to the
stack frame added by the mcount caller and added by itself. This
was added when fentry came in, and before fentry created its own stack
frame. But x86's fentry now creates its own stack frame, and there's
no need to insert the function again.

This also cleans up the code a bit, where it doesn't need to do something
special for fentry, and doesn't include insertion of a duplicate
entry for the called function being traced.

Link: http://lkml.kernel.org/r/55A646EE.6030402@linaro.org

Some-suggestions-by: Jungseok Lee <jungseoklee85@gmail.com>
Some-suggestions-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:50 -04:00
Steven Rostedt (Red Hat) d90fd77402 ring-buffer: Reorganize function locations
Functions in ring-buffer.c have gotten interleaved between different
use cases. Move the functions around to get like functions closer
together. This may or may not help gcc keep cache locality, but it
makes it a little easier to work with the code.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:49 -04:00
Steven Rostedt (Red Hat) 7d75e6833b ring-buffer: Make sure event has enough room for extend and padding
Now that events only add time extends after it is committed, in case
an event comes in before it can discard the allocated event, the time
extend needs to be stored within the event. If the event is bigger
than then size needed for the time extend, padding must be added.
The minimum padding size is 8 bytes. Thus if the event is 12 bytes
(size of time extend + 4), there will not be enough room to add both
the time extend and padding. Make sure all events are either 8 bytes
or 16 or more bytes.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:49 -04:00
Steven Rostedt (Red Hat) a4543a2fa9 ring-buffer: Get timestamp after event is allocated
Move the capturing of the timestamp to after an event is allocated.
If the event is not a commit (where it is an event that preempted
another event), then no timestamp is needed, because the delta of
nested events is always zero.

If the event starts on a new page, no delta needs to be calculated
as the full timestamp will be added to the page header, and the
event will have a delta of zero.

Now if the event requires a time extend (the delta does not fit
in the 27 bit delta slot in the header), then the event is discarded,
the length is extended to hold the TIME_EXTEND event that allows for
a 59 bit delta, and the commit is tried again.

If the event can't be discarded (another event came in after it),
then the TIME_EXTEND is added directly to the allocated event and
the rest of the event is given padding.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:48 -04:00
Steven Rostedt (Red Hat) 9826b2733a ring-buffer: Move the adding of the extended timestamp out of line
Requiring a extended time stamp is an uncommon occurrence, and it is
best to do it out of line when needed.

Add a noinline function that handles the extended timestamp and
have it called with an unlikely to completely move it out of the
fast path.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-07-20 22:30:47 -04:00