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Commit Graph

3904 Commits

Author SHA1 Message Date
Masami Hiramatsu
1ce25e9f6f tracing: Add generic event-name based remove event method
Add a generic method to remove event from dynamic event
list. This is same as other system under ftrace. You
just need to pass the event name with '!', e.g.

  # echo p:new_grp/new_event _do_fork > dynamic_events

This creates an event, and

  # echo '!p:new_grp/new_event _do_fork' > dynamic_events

Or,

  # echo '!p:new_grp/new_event' > dynamic_events

will remove new_grp/new_event event.

Note that this doesn't check the event prefix (e.g. "p:")
strictly, because the "group/event" name must be unique.

Link: http://lkml.kernel.org/r/154140869774.17322.8887303560398645347.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-10 12:22:44 -05:00
Steven Rostedt (VMware)
7e1413edd6 tracing: Consolidate trace_add/remove_event_call back to the nolock functions
The trace_add/remove_event_call_nolock() functions were added to allow
the tace_add/remove_event_call() code be called when the event_mutex
lock was already taken. Now that all callers are done within the
event_mutex, there's no reason to have two different interfaces.

Remove the current wrapper trace_add/remove_event_call()s and rename the
_nolock versions back to the original names.

Link: http://lkml.kernel.org/r/154140866955.17322.2081425494660638846.stgit@devbox

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-10 12:22:10 -05:00
Masami Hiramatsu
0e2b81f7b5 tracing: Remove unneeded synth_event_mutex
Rmove unneeded synth_event_mutex. This mutex protects the reference
count in synth_event, however, those operational points are already
protected by event_mutex.

1. In __create_synth_event() and create_or_delete_synth_event(),
 those synth_event_mutex clearly obtained right after event_mutex.

2. event_hist_trigger_func() is trigger_hist_cmd.func() which is
 called by trigger_process_regex(), which is a part of
 event_trigger_regex_write() and this function takes event_mutex.

3. hist_unreg_all() is trigger_hist_cmd.unreg_all() which is called
 by event_trigger_regex_open() and it takes event_mutex.

4. onmatch_destroy() and onmatch_create() have long call tree,
 but both are finally invoked from event_trigger_regex_write()
 and event_trace_del_tracer(), former takes event_mutex, and latter
 ensures called under event_mutex locked.

Finally, I ensured there is no resource conflict. For safety,
I added lockdep_assert_held(&event_mutex) for each function.

Link: http://lkml.kernel.org/r/154140864134.17322.4796059721306031894.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:10 -05:00
Masami Hiramatsu
7bbab38d07 tracing: Use dyn_event framework for synthetic events
Use dyn_event framework for synthetic events. This shows
synthetic events on "tracing/dynamic_events" file in addition
to tracing/synthetic_events interface.

User can also define new events via tracing/dynamic_events
with "s:" prefix. So, the new syntax is below;

  s:[synthetic/]EVENT_NAME TYPE ARG; [TYPE ARG;]...

To remove events via tracing/dynamic_events, you can use
"-:" prefix as same as other events.

Link: http://lkml.kernel.org/r/154140861301.17322.15454611233735614508.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:10 -05:00
Masami Hiramatsu
0597c49c69 tracing/uprobes: Use dyn_event framework for uprobe events
Use dyn_event framework for uprobe events. This shows
uprobe events on "dynamic_events" file.
User can also define new uprobe events via dynamic_events.

Link: http://lkml.kernel.org/r/154140858481.17322.9091293846515154065.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:10 -05:00
Masami Hiramatsu
6212dd2968 tracing/kprobes: Use dyn_event framework for kprobe events
Use dyn_event framework for kprobe events. This shows
kprobe events on "tracing/dynamic_events" file.

User can also define new events via tracing/dynamic_events.

Link: http://lkml.kernel.org/r/154140855646.17322.6619219995865980392.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:09 -05:00
Masami Hiramatsu
5448d44c38 tracing: Add unified dynamic event framework
Add unified dynamic event framework for ftrace kprobes, uprobes
and synthetic events. Those dynamic events can be co-exist on
same file because those syntax doesn't overlap.

This introduces a framework part which provides a unified tracefs
interface and operations.

Link: http://lkml.kernel.org/r/154140852824.17322.12250362185969352095.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:09 -05:00
Masami Hiramatsu
d00bbea945 tracing: Integrate similar probe argument parsers
Integrate similar argument parsers for kprobes and uprobes events
into traceprobe_parse_probe_arg().

Link: http://lkml.kernel.org/r/154140850016.17322.9836787731210512176.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:09 -05:00
Masami Hiramatsu
faacb361f2 tracing: Simplify creation and deletion of synthetic events
Since the event_mutex and synth_event_mutex ordering issue
is gone, we can skip existing event check when adding or
deleting events, and some redundant code in error path.

This changes release_all_synth_events() to abort the process
when it hits any error and returns the error code. It succeeds
only if it has no error.

Link: http://lkml.kernel.org/r/154140847194.17322.17960275728005067803.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:09 -05:00
Masami Hiramatsu
fc800a10be tracing: Lock event_mutex before synth_event_mutex
synthetic event is using synth_event_mutex for protecting
synth_event_list, and event_trigger_write() path acquires
locks as below order.

event_trigger_write(event_mutex)
  ->trigger_process_regex(trigger_cmd_mutex)
    ->event_hist_trigger_func(synth_event_mutex)

On the other hand, synthetic event creation and deletion paths
call trace_add_event_call() and trace_remove_event_call()
which acquires event_mutex. In that case, if we keep the
synth_event_mutex locked while registering/unregistering synthetic
events, its dependency will be inversed.

To avoid this issue, current synthetic event is using a 2 phase
process to create/delete events. For example, it searches existing
events under synth_event_mutex to check for event-name conflicts, and
unlocks synth_event_mutex, then registers a new event under event_mutex
locked. Finally, it locks synth_event_mutex and tries to add the
new event to the list. But it can introduce complexity and a chance
for name conflicts.

To solve this simpler, this introduces trace_add_event_call_nolock()
and trace_remove_event_call_nolock() which don't acquire
event_mutex inside. synthetic event can lock event_mutex before
synth_event_mutex to solve the lock dependency issue simpler.

Link: http://lkml.kernel.org/r/154140844377.17322.13781091165954002713.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:09 -05:00
Masami Hiramatsu
547cd9eacd tracing/uprobes: Add busy check when cleanup all uprobes
Add a busy check loop in cleanup_all_probes() before
trying to remove all events in uprobe_events, the same way
that kprobe_events does.

Without this change, writing null to uprobe_events will
try to remove events but if one of them is enabled, it will
stop there leaving some events cleared and others not clceared.

With this change, writing null to uprobe_events makes
sure all events are not enabled before removing events.
So, it clears all events, or returns an error (-EBUSY)
with keeping all events.

Link: http://lkml.kernel.org/r/154140841557.17322.12653952888762532401.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:08 -05:00
Steven Rostedt (VMware)
a7b1d74e87 tracing: Change default buffer_percent to 50
After running several tests, it appears that having the reader wait till
half the buffer is full before starting to read (and causing its own events
to fill up the ring buffer constantly), works well. It keeps trace-cmd (the
main user of this interface) from dominating the traces it records.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:08 -05:00
Steven Rostedt (VMware)
03329f9939 tracing: Add tracefs file buffer_percentage
Add a "buffer_percentage" file, that allows users to specify how much of the
buffer (percentage of pages) need to be filled before waking up a task
blocked on a per cpu trace_pipe_raw file.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:08 -05:00
Steven Rostedt (VMware)
2c2b0a78b3 ring-buffer: Add percentage of ring buffer full to wake up reader
Instead of just waiting for a page to be full before waking up a pending
reader, allow the reader to pass in a "percentage" of pages that have
content before waking up a reader. This should help keep the process of
reading the events not cause wake ups that constantly cause reading of the
buffer.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:08 -05:00
Dan Carpenter
ca16b0fbb0 tracing: Have trace_stack nr_entries compare not be so subtle
Dan Carpenter reviewed the trace_stack.c code and figured he found an off by
one bug.

 "From reviewing the code, it seems possible for
  stack_trace_max.nr_entries to be set to .max_entries and in that case we
  would be reading one element beyond the end of the stack_dump_trace[]
  array.  If it's not set to .max_entries then the bug doesn't affect
  runtime."

Although it looks to be the case, it is not. Because we have:

 static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
	 { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };

 struct stack_trace stack_trace_max = {
	.max_entries		= STACK_TRACE_ENTRIES - 1,
	.entries		= &stack_dump_trace[0],
 };

And:

	stack_trace_max.nr_entries = x;
	for (; x < i; x++)
		stack_dump_trace[x] = ULONG_MAX;

Even if nr_entries equals max_entries, indexing with it into the
stack_dump_trace[] array will not overflow the array. But if it is the case,
the second part of the conditional that tests stack_dump_trace[nr_entries]
to ULONG_MAX will always be true.

By applying Dan's patch, it removes the subtle aspect of it and makes the if
conditional slightly more efficient.

Link: http://lkml.kernel.org/r/20180620110758.crunhd5bfep7zuiz@kili.mountain

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware)
b0e21a61d3 function_graph: Have profiler use new helper ftrace_graph_get_ret_stack()
The ret_stack processing is going to change, and that is going
to break anything that is accessing the ret_stack directly. One user is the
function graph profiler. By using the ftrace_graph_get_ret_stack() helper
function, the profiler can access the ret_stack entry without relying on the
implementation details of the stack itself.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware)
76b42b63ed function_graph: Move ftrace_graph_ret_addr() to fgraph.c
Move the function function_graph_ret_addr() to fgraph.c, as the management
of the curr_ret_stack is going to change, and all the accesses to ret_stack
needs to be done in fgraph.c.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware)
688f7089d8 fgraph: Add new fgraph_ops structure to enable function graph hooks
Currently the registering of function graph is to pass in a entry and return
function. We need to have a way to associate those functions together where
the entry can determine to run the return hook. Having a structure that
contains both functions will facilitate the process of converting the code
to be able to do such.

This is similar to the way function hooks are enabled (it passes in
ftrace_ops). Instead of passing in the functions to use, a single structure
is passed in to the registering function.

The unregister function is now passed in the fgraph_ops handle. When we
allow more than one callback to the function graph hooks, this will let the
system know which one to remove.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware)
317e04ca90 tracing: Rearrange functions in trace_sched_wakeup.c
Rearrange the functions in trace_sched_wakeup.c so that there are fewer
 #ifdef CONFIG_FUNCTION_TRACER and #ifdef CONFIG_FUNCTION_GRAPH_TRACER,
instead of having the #ifdefs spread all over.

No functional change is made.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware)
e73e679f65 fgraph: Move function graph specific code into fgraph.c
To make the function graph infrastructure more managable, the code needs to
be in its own file (fgraph.c). Move the code that is specific for managing
the function graph infrastructure out of ftrace.c and into fgraph.c

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:06 -05:00
Steven Rostedt (VMware)
c8dd0f4587 function_graph: Do not expose the graph_time option when profiler is not configured
When the function profiler is not configured, the "graph_time" option is
meaningless, as the function profiler is the only thing that makes use of
it. Do not expose it if the profiler is not configured.

Link: http://lkml.kernel.org/r/20181123061133.GA195223@google.com

Reported-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:06 -05:00
Steven Rostedt (VMware)
3306fc4aff ftrace: Create new ftrace_internal.h header
In order to move function graph infrastructure into its own file (fgraph.h)
it needs to access various functions and variables in ftrace.c that are
currently static. Create a new file called ftrace-internal.h that holds the
function prototypes and the extern declarations of the variables needed by
fgraph.c as well, and make them global in ftrace.c such that they can be
used outside that file.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:06 -05:00
Steven Rostedt (VMware)
761efe8a94 function_graph: Remove the use of FTRACE_NOTRACE_DEPTH
The curr_ret_stack is no longer set to a negative value when a function is
not to be traced by the function graph tracer. Remove the usage of
FTRACE_NOTRACE_DEPTH, as it is no longer needed.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:06 -05:00
Steven Rostedt (VMware)
9cd2992f2d fgraph: Have set_graph_notrace only affect function_graph tracer
In order to make the function graph infrastructure more generic, there can
not be code specific for the function_graph tracer in the generic code. This
includes the set_graph_notrace logic, that stops all graph calls when a
function in the set_graph_notrace is hit.

By using the trace_recursion mask, we can use a bit in the current
task_struct to implement the notrace code, and move the logic out of
fgraph.c and into trace_functions_graph.c and keeps it affecting only the
tracer and not all call graph callbacks.

Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-29 23:38:34 -05:00
Steven Rostedt (VMware)
d864a3ca88 fgraph: Create a fgraph.c file to store function graph infrastructure
As the function graph infrastructure can be used by thing other than
tracing, moving the code to its own file out of the trace_functions_graph.c
code makes more sense.

The fgraph.c file will only contain the infrastructure required to hook into
functions and their return code.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-29 23:38:34 -05:00
Steven Rostedt (VMware)
c43ac4a530 tracing: Do not line wrap short line in function_graph_enter()
Commit 588ca1786f2dd ("function_graph: Use new curr_ret_depth to manage
depth instead of curr_ret_stack") removed a parameter from the call
ftrace_push_return_trace() that made it so that the entire call was under 80
characters, but it did not remove the line break. There's no reason to break
that line up, so make it a single line.

Link: http://lkml.kernel.org/r/20181122100322.GN2131@hirez.programming.kicks-ass.net

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-29 23:38:34 -05:00
Steven Rostedt (VMware)
5cf99a0f31 tracing/fgraph: Fix set_graph_function from showing interrupts
The tracefs file set_graph_function is used to only function graph functions
that are listed in that file (or all functions if the file is empty). The
way this is implemented is that the function graph tracer looks at every
function, and if the current depth is zero and the function matches
something in the file then it will trace that function. When other functions
are called, the depth will be greater than zero (because the original
function will be at depth zero), and all functions will be traced where the
depth is greater than zero.

The issue is that when a function is first entered, and the handler that
checks this logic is called, the depth is set to zero. If an interrupt comes
in and a function in the interrupt handler is traced, its depth will be
greater than zero and it will automatically be traced, even if the original
function was not. But because the logic only looks at depth it may trace
interrupts when it should not be.

The recent design change of the function graph tracer to fix other bugs
caused the depth to be zero while the function graph callback handler is
being called for a longer time, widening the race of this happening. This
bug was actually there for a longer time, but because the race window was so
small it seldom happened. The Fixes tag below is for the commit that widen
the race window, because that commit belongs to a series that will also help
fix the original bug.

Cc: stable@kernel.org
Fixes: 39eb456dac ("function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack")
Reported-by: Joe Lawrence <joe.lawrence@redhat.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-29 22:09:00 -05:00
Steven Rostedt (VMware)
b1b35f2e21 function_graph: Have profiler use curr_ret_stack and not depth
The profiler uses trace->depth to find its entry on the ret_stack, but the
depth may not match the actual location of where its entry is (if an
interrupt were to preempt the processing of the profiler for another
function, the depth and the curr_ret_stack will be different).

Have it use the curr_ret_stack as the index to find its ret_stack entry
instead of using the depth variable, as that is no longer guaranteed to be
the same.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:55 -05:00
Steven Rostedt (VMware)
7c6ea35ef5 function_graph: Reverse the order of pushing the ret_stack and the callback
The function graph profiler uses the ret_stack to store the "subtime" and
reuse it by nested functions and also on the return. But the current logic
has the profiler callback called before the ret_stack is updated, and it is
just modifying the ret_stack that will later be allocated (it's just lucky
that the "subtime" is not touched when it is allocated).

This could also cause a crash if we are at the end of the ret_stack when
this happens.

By reversing the order of the allocating the ret_stack and then calling the
callbacks attached to a function being traced, the ret_stack entry is no
longer used before it is allocated.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:54 -05:00
Steven Rostedt (VMware)
552701dd0f function_graph: Move return callback before update of curr_ret_stack
In the past, curr_ret_stack had two functions. One was to denote the depth
of the call graph, the other is to keep track of where on the ret_stack the
data is used. Although they may be slightly related, there are two cases
where they need to be used differently.

The one case is that it keeps the ret_stack data from being corrupted by an
interrupt coming in and overwriting the data still in use. The other is just
to know where the depth of the stack currently is.

The function profiler uses the ret_stack to save a "subtime" variable that
is part of the data on the ret_stack. If curr_ret_stack is modified too
early, then this variable can be corrupted.

The "max_depth" option, when set to 1, will record the first functions going
into the kernel. To see all top functions (when dealing with timings), the
depth variable needs to be lowered before calling the return hook. But by
lowering the curr_ret_stack, it makes the data on the ret_stack still being
used by the return hook susceptible to being overwritten.

Now that there's two variables to handle both cases (curr_ret_depth), we can
move them to the locations where they can handle both cases.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:54 -05:00
Steven Rostedt (VMware)
39eb456dac function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack
Currently, the depth of the ret_stack is determined by curr_ret_stack index.
The issue is that there's a race between setting of the curr_ret_stack and
calling of the callback attached to the return of the function.

Commit 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling
trace return callback") moved the calling of the callback to after the
setting of the curr_ret_stack, even stating that it was safe to do so, when
in fact, it was the reason there was a barrier() there (yes, I should have
commented that barrier()).

Not only does the curr_ret_stack keep track of the current call graph depth,
it also keeps the ret_stack content from being overwritten by new data.

The function profiler, uses the "subtime" variable of ret_stack structure
and by moving the curr_ret_stack, it allows for interrupts to use the same
structure it was using, corrupting the data, and breaking the profiler.

To fix this, there needs to be two variables to handle the call stack depth
and the pointer to where the ret_stack is being used, as they need to change
at two different locations.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:54 -05:00
Steven Rostedt (VMware)
d125f3f866 function_graph: Make ftrace_push_return_trace() static
As all architectures now call function_graph_enter() to do the entry work,
no architecture should ever call ftrace_push_return_trace(). Make it static.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:54 -05:00
Steven Rostedt (VMware)
8114865ff8 function_graph: Create function_graph_enter() to consolidate architecture code
Currently all the architectures do basically the same thing in preparing the
function graph tracer on entry to a function. This code can be pulled into a
generic location and then this will allow the function graph tracer to be
fixed, as well as extended.

Create a new function graph helper function_graph_enter() that will call the
hook function (ftrace_graph_entry) and the shadow stack operation
(ftrace_push_return_trace), and remove the need of the architecture code to
manage the shadow stack.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-26 16:18:04 -05:00
Masami Hiramatsu
ee474b81fe tracing/kprobes: Fix strpbrk() argument order
Fix strpbrk()'s argument order, it must pass acceptable string
in 2nd argument. Note that this can cause a kernel panic where
it recovers backup character to code->data.

Link: http://lkml.kernel.org/r/154108256792.2604.1816052586385217811.stgit@devbox

Fixes: a6682814f3 ("tracing/kprobes: Allow kprobe-events to record module symbol")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-05 09:47:14 -05:00
Linus Torvalds
5f21585384 for-linus-20181102
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Merge tag 'for-linus-20181102' of git://git.kernel.dk/linux-block

Pull block layer fixes from Jens Axboe:
 "The biggest part of this pull request is the revert of the blkcg
  cleanup series. It had one fix earlier for a stacked device issue, but
  another one was reported. Rather than play whack-a-mole with this,
  revert the entire series and try again for the next kernel release.

  Apart from that, only small fixes/changes.

  Summary:

   - Indentation fixup for mtip32xx (Colin Ian King)

   - The blkcg cleanup series revert (Dennis Zhou)

   - Two NVMe fixes. One fixing a regression in the nvme request
     initialization in this merge window, causing nvme-fc to not work.
     The other is a suspend/resume p2p resource issue (James, Keith)

   - Fix sg discard merge, allowing us to merge in cases where we didn't
     before (Jianchao Wang)

   - Call rq_qos_exit() after the queue is frozen, preventing a hang
     (Ming)

   - Fix brd queue setup, fixing an oops if we fail setting up all
     devices (Ming)"

* tag 'for-linus-20181102' of git://git.kernel.dk/linux-block:
  nvme-pci: fix conflicting p2p resource adds
  nvme-fc: fix request private initialization
  blkcg: revert blkcg cleanups series
  block: brd: associate with queue until adding disk
  block: call rq_qos_exit() after queue is frozen
  mtip32xx: clean an indentation issue, remove extraneous tabs
  block: fix the DISCARD request merge
2018-11-02 11:25:48 -07:00
Dennis Zhou
b5f2954d30 blkcg: revert blkcg cleanups series
This reverts a series committed earlier due to null pointer exception
bug report in [1]. It seems there are edge case interactions that I did
not consider and will need some time to understand what causes the
adverse interactions.

The original series can be found in [2] with a follow up series in [3].

[1] https://www.spinics.net/lists/cgroups/msg20719.html
[2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/
[3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/

This reverts the following commits:
d459d853c2, b2c3fa5467, 101246ec02, b3b9f24f5f, e2b0989954,
f0fcb3ec89, c839e7a03f, bdc2491708, 74b7c02a9b, 5bf9a1f3b4,
a7b39b4e96, 07b05bcc32, 49f4c2dc2b, 27e6fa996c

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-01 19:59:53 -06:00
Linus Torvalds
eb7046e9bf platform-drivers-x86 for v4.20-1
Move the Dell dcdbas and dell_rbu drivers into platform/drivers/x86 as
 they are closely coupled with other drivers in this location.
 
 Improve _init* usage for acerhdf and fix some usage issues with messages
 and module parameters.
 
 Simplify asus-wmi by calling ACPI/WMI methods directly, eliminating
 workqueue overhead, eliminate double reporting of keyboard backlight.
 
 Fix wake from USB failure on Bay Trail devices (intel_int0002_vgpio).
 
 Notify intel_telemetry users when IPC1 device is not enabled.
 
 Update various drivers with new laptop model IDs.
 
 Update several intel drivers to use SPDX identifers and order headers
 alphabetically.
 
 The following is an automated git shortlog grouped by driver:
 
 Add Intel AtomISP2 dummy / power-management driver:
  - Add Intel AtomISP2 dummy / power-management driver
 
 lg-laptop:
  - Add LG Gram laptop special features driver
 
 HID:
  -  asus: only support backlight when it's not driven by WMI
 
 MAINTAINERS:
  -  intel_telemetry: Update maintainers info
  -  intel_pmc_core: Update MAINTAINERS
  -  Update maintainer for dcdbas and dell_rbu
  -  Use my infradead account exclusively for PDx86 work
 
 acerhdf:
  -  restructure to allow large BIOS table be __initconst
  -  mark appropriate content with __init prefix
  -  Add BIOS entry for Gateway LT31 v1.3307
  -  Remove cut-and-paste trap from instructions
  -  Enable ability to list supported systems
  -  clarify modinfo messages for BIOS override
 
 asus-wmi:
  -  export function for evaluating WMI methods
  -  Only notify kbd LED hw_change by fn-key pressed
  -  Simplify the keyboard brightness updating process
 
 firmware:
  -  dcdbas: include linux/io.h
  -  dcdbas: Move dcdbas to drivers/platform/x86
  -  dell_rbu: Move dell_rbu to drivers/platform/x86
  -  dcdbas: Add support for WSMT ACPI table
  -  dell_rbu: Make payload memory uncachable
 
 ideapad-laptop:
  -  Add Y530-15ICH to no_hw_rfkill
  -  Use __func__ instead of read_ec_cmd in pr_err
 
 intel-hid:
  -  Convert to use SPDX identifier
 
 intel-ips:
  -  Convert to use SPDX identifier
 
 intel-rst:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel-smartconnect:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel-wmi-thunderbolt:
  -  Add dynamic debugging
  -  Convert to use SPDX identifier
 
 intel_bxtwc_tmu:
  -  Convert to use SPDX identifier
 
 intel_cht_int33fe:
  -  Convert to use SPDX identifier
 
 intel_chtdc_ti_pwrbtn:
  -  Add SPDX identifier
 
 intel_int0002_vgpio:
  -  Convert to use SPDX identifier
  -  Implement irq_set_wake
  -  Enable the driver on Bay Trail platforms
 
 intel_menlow:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel_mid_powerbtn:
  -  Convert to use SPDX identifier
  -  Remove unnecessary init.h inclusion
  -  Get rid of custom ICPU() macro
 
 intel_mid_thermal:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel_oaktrail:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel_pmc:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel_punit_ipc:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel_scu_ipc:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 intel_telemetry:
  -  Get rid of custom macro
  -  report debugfs failure
  -  Convert to use SPDX identifier
 
 intel_turbo_max_3:
  -  Convert to use SPDX identifier
  -  Sort headers alphabetically
 
 mlx-platform:
  -  Properly use mlxplat_mlxcpld_msn201x_items
 
 touchscreen_dmi:
  -  Add min-x and min-y settings for various models
  -  Add info for the Onda V80 Plus v3 tablet
  -  Add info for the Trekstor Primetab T13B tablet
  -  Add info for the Trekstor Primebook C11 convertible
 
 tracing:
  -  Trivia spelling fix containerof() -> container_of()
 
 wmi:
  -  declare device_type structure as constant
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Merge tag 'platform-drivers-x86-v4.20-1' of git://git.infradead.org/linux-platform-drivers-x86

Pull x86 platform driver updates from Darren Hart:

 - Move the Dell dcdbas and dell_rbu drivers into platform/drivers/x86
   as they are closely coupled with other drivers in this location.

 - Improve _init* usage for acerhdf and fix some usage issues with
   messages and module parameters.

 - Simplify asus-wmi by calling ACPI/WMI methods directly, eliminating
   workqueue overhead, eliminate double reporting of keyboard backlight.

 - Fix wake from USB failure on Bay Trail devices (intel_int0002_vgpio).

 - Notify intel_telemetry users when IPC1 device is not enabled.

 - Update various drivers with new laptop model IDs.

 - Update several intel drivers to use SPDX identifers and order headers
   alphabetically.

* tag 'platform-drivers-x86-v4.20-1' of git://git.infradead.org/linux-platform-drivers-x86: (64 commits)
  HID: asus: only support backlight when it's not driven by WMI
  platform/x86: asus-wmi: export function for evaluating WMI methods
  platform/x86: asus-wmi: Only notify kbd LED hw_change by fn-key pressed
  platform/x86: wmi: declare device_type structure as constant
  platform/x86: ideapad: Add Y530-15ICH to no_hw_rfkill
  platform/x86: Add Intel AtomISP2 dummy / power-management driver
  platform/x86: touchscreen_dmi: Add min-x and min-y settings for various models
  platform/x86: touchscreen_dmi: Add info for the Onda V80 Plus v3 tablet
  platform/x86: touchscreen_dmi: Add info for the Trekstor Primetab T13B tablet
  platform/x86: intel_telemetry: Get rid of custom macro
  platform/x86: intel_telemetry: report debugfs failure
  MAINTAINERS: intel_telemetry: Update maintainers info
  platform/x86: Add LG Gram laptop special features driver
  platform/x86: asus-wmi: Simplify the keyboard brightness updating process
  platform/x86: touchscreen_dmi: Add info for the Trekstor Primebook C11 convertible
  platform/x86: mlx-platform: Properly use mlxplat_mlxcpld_msn201x_items
  MAINTAINERS: intel_pmc_core: Update MAINTAINERS
  firmware: dcdbas: include linux/io.h
  platform/x86: intel-wmi-thunderbolt: Add dynamic debugging
  platform/x86: intel-wmi-thunderbolt: Convert to use SPDX identifier
  ...
2018-11-01 08:42:21 -07:00
Linus Torvalds
343a9f3540 The biggest change here is the updates to kprobes
Back in January I posted patches to create function based events. These were
 the events that you suggested I make to allow developers to easily create
 events in code where no trace event exists. After posting those changes for
 review, it was suggested that we implement this instead with kprobes.
 
 The problem with kprobes is that the interface is too complex and needs to
 be simplified. Masami Hiramatsu posted patches in March and I've been
 playing with them a bit. There's been a bit of clean up in the kprobe code
 that was inspired by the function based event patches, and a couple of
 enhancements to the kprobe event interface.
 
  - If the arch supports it (we added support for x86), you can place a
    kprobe event at the start of a function and use $arg1, $arg2, etc
    to reference the arguments of a function. (Before you needed to know
    what register or where on the stack the argument was).
 
  - The second is a way to see array of events. For example, if you reference
    a mac address, you can add:
 
    echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events
 
    And this will produce:
 
    mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}
 
 Other changes include
 
  - Exporting trace_dump_stack to modules
 
  - Have the stack tracer trace the entire stack (stop trying to remove
    tracing itself, as we keep removing too much).
 
  - Added support for SDT in uprobes
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Merge tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The biggest change here is the updates to kprobes

  Back in January I posted patches to create function based events.
  These were the events that you suggested I make to allow developers to
  easily create events in code where no trace event exists. After
  posting those changes for review, it was suggested that we implement
  this instead with kprobes.

  The problem with kprobes is that the interface is too complex and
  needs to be simplified. Masami Hiramatsu posted patches in March and
  I've been playing with them a bit. There's been a bit of clean up in
  the kprobe code that was inspired by the function based event patches,
  and a couple of enhancements to the kprobe event interface.

   - If the arch supports it (we added support for x86), you can place a
     kprobe event at the start of a function and use $arg1, $arg2, etc
     to reference the arguments of a function. (Before you needed to
     know what register or where on the stack the argument was).

   - The second is a way to see array of events. For example, if you
     reference a mac address, you can add:

	echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events

     And this will produce:

	mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}

  Other changes include

   - Exporting trace_dump_stack to modules

   - Have the stack tracer trace the entire stack (stop trying to remove
     tracing itself, as we keep removing too much).

   - Added support for SDT in uprobes"

[ SDT - "Statically Defined Tracing" are userspace markers for tracing.
  Let's not use random TLA's in explanations unless they are fairly
  well-established as generic (at least for kernel people) - Linus ]

* tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  tracing: Have stack tracer trace full stack
  tracing: Export trace_dump_stack to modules
  tracing: probeevent: Fix uninitialized used of offset in parse args
  tracing/kprobes: Allow kprobe-events to record module symbol
  tracing/kprobes: Check the probe on unloaded module correctly
  tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
  tracing: probeevent: Add $argN for accessing function args
  x86: ptrace: Add function argument access API
  tracing: probeevent: Add array type support
  tracing: probeevent: Add symbol type
  tracing: probeevent: Unify fetch_insn processing common part
  tracing: probeevent: Append traceprobe_ for exported function
  tracing: probeevent: Return consumed bytes of dynamic area
  tracing: probeevent: Unify fetch type tables
  tracing: probeevent: Introduce new argument fetching code
  tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions
  tracing: probeevent: Cleanup argument field definition
  tracing: probeevent: Cleanup print argument functions
  trace_uprobe: support reference counter in fd-based uprobe
  perf probe: Support SDT markers having reference counter (semaphore)
  ...
2018-10-30 09:49:56 -07:00
Linus Torvalds
f4267b3604 Masami had a couple more fixes to the synthetic events. One was a proper
error return value, and the other is for the self tests.
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Merge tag 'trace-v4.19-rc8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Masami had a couple more fixes to the synthetic events. One was a
  proper error return value, and the other is for the self tests"

* tag 'trace-v4.19-rc8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests/ftrace: Fix synthetic event test to delete event correctly
  tracing: Return -ENOENT if there is no target synthetic event
2018-10-30 09:47:28 -07:00
Masami Hiramatsu
18858511fd tracing: Return -ENOENT if there is no target synthetic event
Return -ENOENT error if there is no target synthetic event.
This notices an operation failure to user as below;

  # echo 'wakeup_latency u64 lat; pid_t pid;' > synthetic_events
  # echo '!wakeup' >> synthetic_events
  sh: write error: No such file or directory

Link: http://lkml.kernel.org/r/154013449986.25576.9487131386597290172.stgit@devbox

Acked-by: Tom Zanussi <zanussi@linux.intel.com>
Tested-by: Tom Zanussi <zanussi@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Rajvi Jingar <rajvi.jingar@intel.com>
Cc: stable@vger.kernel.org
Fixes: 4b147936fa ('tracing: Add support for 'synthetic' events')
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-28 04:58:15 -04:00
Steven Rostedt (VMware)
a2acce5369 tracing: Have stack tracer trace full stack
The stack tracer traces every function call checking the current stack (in
non interrupt context), looking for the deepest stack, and saving it when it
finds a new max depth. The problem is that it calls save_stack_trace(), and
with the new ORC unwinder, it can skip too much. As it looks at the ip of
the function call in the backtrace to find where it should start, it doesn't
need to skip anything.

The stack trace selftest would fail when the kernel was complied with the
ORC UNDWINDER enabled. Without skipping functions when doing the stack
trace, it now passes again.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-27 11:15:04 -04:00
Nikolay Borisov
da387e5c93 tracing: Export trace_dump_stack to modules
There is no reason for this function to be unexprted and it's a useful
debugging aid.

Link: http://lkml.kernel.org/r/1539759103-5923-1-git-send-email-nborisov@suse.com

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-27 11:15:03 -04:00
Linus Torvalds
6ab9e09238 for-4.20/block-20181021
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Merge tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "This is the main pull request for block changes for 4.20. This
  contains:

   - Series enabling runtime PM for blk-mq (Bart).

   - Two pull requests from Christoph for NVMe, with items such as;
      - Better AEN tracking
      - Multipath improvements
      - RDMA fixes
      - Rework of FC for target removal
      - Fixes for issues identified by static checkers
      - Fabric cleanups, as prep for TCP transport
      - Various cleanups and bug fixes

   - Block merging cleanups (Christoph)

   - Conversion of drivers to generic DMA mapping API (Christoph)

   - Series fixing ref count issues with blkcg (Dennis)

   - Series improving BFQ heuristics (Paolo, et al)

   - Series improving heuristics for the Kyber IO scheduler (Omar)

   - Removal of dangerous bio_rewind_iter() API (Ming)

   - Apply single queue IPI redirection logic to blk-mq (Ming)

   - Set of fixes and improvements for bcache (Coly et al)

   - Series closing a hotplug race with sysfs group attributes (Hannes)

   - Set of patches for lightnvm:
      - pblk trace support (Hans)
      - SPDX license header update (Javier)
      - Tons of refactoring patches to cleanly abstract the 1.2 and 2.0
        specs behind a common core interface. (Javier, Matias)
      - Enable pblk to use a common interface to retrieve chunk metadata
        (Matias)
      - Bug fixes (Various)

   - Set of fixes and updates to the blk IO latency target (Josef)

   - blk-mq queue number updates fixes (Jianchao)

   - Convert a bunch of drivers from the old legacy IO interface to
     blk-mq. This will conclude with the removal of the legacy IO
     interface itself in 4.21, with the rest of the drivers (me, Omar)

   - Removal of the DAC960 driver. The SCSI tree will introduce two
     replacement drivers for this (Hannes)"

* tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block: (204 commits)
  block: setup bounce bio_sets properly
  blkcg: reassociate bios when make_request() is called recursively
  blkcg: fix edge case for blk_get_rl() under memory pressure
  nvme-fabrics: move controller options matching to fabrics
  nvme-rdma: always have a valid trsvcid
  mtip32xx: fully switch to the generic DMA API
  rsxx: switch to the generic DMA API
  umem: switch to the generic DMA API
  sx8: switch to the generic DMA API
  sx8: remove dead IF_64BIT_DMA_IS_POSSIBLE code
  skd: switch to the generic DMA API
  ubd: remove use of blk_rq_map_sg
  nvme-pci: remove duplicate check
  drivers/block: Remove DAC960 driver
  nvme-pci: fix hot removal during error handling
  nvmet-fcloop: suppress a compiler warning
  nvme-core: make implicit seed truncation explicit
  nvmet-fc: fix kernel-doc headers
  nvme-fc: rework the request initialization code
  nvme-fc: introduce struct nvme_fcp_op_w_sgl
  ...
2018-10-22 17:46:08 +01:00
Masami Hiramatsu
a360d9e401 tracing: Fix synthetic event to allow semicolon at end
Fix synthetic event to allow independent semicolon at end.

The synthetic_events interface accepts a semicolon after the
last word if there is no space.

 # echo "myevent u64 var;" >> synthetic_events

But if there is a space, it returns an error.

 # echo "myevent u64 var ;" > synthetic_events
 sh: write error: Invalid argument

This behavior is difficult for users to understand. Let's
allow the last independent semicolon too.

Link: http://lkml.kernel.org/r/153986835420.18251.2191216690677025744.stgit@devbox

Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: stable@vger.kernel.org
Fixes: commit 4b147936fa ("tracing: Add support for 'synthetic' events")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-19 17:25:11 -04:00
Masami Hiramatsu
282447ba6b tracing: Fix synthetic event to accept unsigned modifier
Fix synthetic event to accept unsigned modifier for its field type
correctly.

Currently, synthetic_events interface returns error for "unsigned"
modifiers as below;

 # echo "myevent unsigned long var" >> synthetic_events
 sh: write error: Invalid argument

This is because argv_split() breaks "unsigned long" into "unsigned"
and "long", but parse_synth_field() doesn't expected it.

With this fix, synthetic_events can handle the "unsigned long"
correctly like as below;

 # echo "myevent unsigned long var" >> synthetic_events
 # cat synthetic_events
 myevent	unsigned long var

Link: http://lkml.kernel.org/r/153986832571.18251.8448135724590496531.stgit@devbox

Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: stable@vger.kernel.org
Fixes: commit 4b147936fa ("tracing: Add support for 'synthetic' events")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-19 17:25:11 -04:00
Steven Rostedt (VMware)
12ad0cb212 tracing: Use trace_clock_local() for looping in preemptirq_delay_test.c
The preemptirq_delay_test module is used for the ftrace selftest code that
tests the latency tracers. The problem is that it uses ktime for the delay
loop, and then checks the tracer to see if the delay loop is caught, but the
tracer uses trace_clock_local() which uses various different other clocks to
measure the latency. As ktime uses the clock cycles, and the code then
converts that to nanoseconds, it causes rounding errors, and the preemptirq
latency tests are failing due to being off by 1 (it expects to see a delay
of 500000 us, but the delay is only 499999 us). This is happening due to a
rounding error in the ktime (which is totally legit). The purpose of the
test is to see if it can catch the delay, not to test the accuracy between
trace_clock_local() and ktime_get(). Best to use apples to apples, and have
the delay loop use the same clock as the latency tracer does.

Cc: stable@vger.kernel.org
Fixes: f96e8577da ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-17 15:35:33 -04:00
Steven Rostedt (VMware)
bf173ca92d tracing: probeevent: Fix uninitialized used of offset in parse args
Dan's smatch utility found an uninitialized use of offset in a path in
parse_probe_args(). Unless an offset is specifically specified for commands
that allow them, it should default to zero.

Link: http://lkml.kernel.org/r/20181012134246.5doqaobxunlqqs53@mwanda
Fixes: 533059281e ("tracing: probeevent: Introduce new argument fetching code")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> (smatch)
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-12 12:50:22 -04:00
Masami Hiramatsu
a6682814f3 tracing/kprobes: Allow kprobe-events to record module symbol
Allow kprobe-events to record module symbols.

Since data symbols in a non-loaded module doesn't exist, it fails to
define such symbol as an argument of kprobe-event. But if the kprobe
event is defined on that module, we can defer to resolve the symbol
address.

Note that if given symbol is not found, the event is kept unavailable.
User can enable it but the event is not recorded.

Link: http://lkml.kernel.org/r/153547312336.26502.11432902826345374463.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10 22:19:12 -04:00
Masami Hiramatsu
59158ec4ae tracing/kprobes: Check the probe on unloaded module correctly
Current kprobe event doesn't checks correctly whether the
given event is on unloaded module or not. It just checks
the event has ":" in the name.

That is not enough because if we define a probe on non-exist
symbol on loaded module, it allows to define that (with
warning message)

To ensure it correctly, this searches the module name on
loaded module list and only if there is not, it allows to
define it. (this event will be available when the target
module is loaded)

Link: http://lkml.kernel.org/r/153547309528.26502.8300278470528281328.stgit@devbox

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10 22:19:12 -04:00
Masami Hiramatsu
f3f58935ed tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
Fix probe_mem_read() to return -EFAULT if copy_from_user()
failed. The copy_from_user() returns remaining bytes
when it failed, but probe_mem_read() caller expects it
returns error code like as probe_kernel_read().

Link: http://lkml.kernel.org/r/153547306719.26502.8353484532699160223.stgit@devbox

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10 22:19:11 -04:00