linux/kernel/trace/trace_events.c, branch v3.16

tracing: instance_rmdir() leaks ftrace_event_file->filter

2014-07-14T18:41:13Z

instance_rmdir() path destroys the event files but forgets to free file->filter. Change remove_event_file_dir() to free_event_filter(). Link: http://lkml.kernel.org/p/20140711190638.GA19517@redhat.com Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Srikar Dronamraju Cc: Tom Zanussi Cc: "zhangwei(Jovi)" Cc: stable@vger.kernel.org # 3.11+ Fixes: f6a84bdc75b5 "tracing: Introduce remove_event_file_dir()" Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt

tracing: Return error if ftrace_trace_arrays list is empty

2014-06-06T08:47:46Z

ftrace_trace_arrays links global_trace.list. However, global_trace is not added to ftrace_trace_arrays if trace_alloc_buffers() failed. As the result, ftrace_trace_arrays becomes an empty list. If ftrace_trace_arrays is an empty list, current top_trace_array() returns an invalid pointer. As the result, the kernel can induce memory corruption or panic. Current implementation does not check whether ftrace_trace_arrays is empty list or not. So, in this patch, if ftrace_trace_arrays is empty list, top_trace_array() returns NULL. Moreover, this patch makes all functions calling top_trace_array() handle it appropriately. Link: http://lkml.kernel.org/p/20140605223517.32311.99233.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE Signed-off-by: Steven Rostedt

tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints

2014-04-09T00:43:28Z

Register/unregister tracepoint probes with struct tracepoint pointer rather than tracepoint name. This change, which vastly simplifies tracepoint.c, has been proposed by Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux size. From this point on, the tracers need to pass a struct tracepoint pointer to probe register/unregister. A probe can now only be connected to a tracepoint that exists. Moreover, tracers are responsible for unregistering the probe before the module containing its associated tracepoint is unloaded. text data bss dec hex filename 10443444 4282528 10391552 25117524 17f4354 vmlinux.orig 10434930 4282848 10391552 25109330 17f2352 vmlinux Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com CC: Ingo Molnar CC: Frederic Weisbecker CC: Andrew Morton CC: Frank Ch. Eigler CC: Johannes Berg Signed-off-by: Mathieu Desnoyers [ SDR - fixed return val in void func in tracepoint_module_going() ] Signed-off-by: Steven Rostedt

Merge tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2014-04-03T17:26:31Z

Pull tracing updates from Steven Rostedt: "Most of the changes were largely clean ups, and some documentation. But there were a few features that were added: Uprobes now work with event triggers and multi buffers and have support under ftrace and perf. The big feature is that the function tracer can now be used within the multi buffer instances. That is, you can now trace some functions in one buffer, others in another buffer, all functions in a third buffer and so on. They are basically agnostic from each other. This only works for the function tracer and not for the function graph trace, although you can have the function graph tracer running in the top level buffer (or any tracer for that matter) and have different function tracing going on in the sub buffers" * tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits) tracing: Add BUG_ON when stack end location is over written tracepoint: Remove unused API functions Revert "tracing: Move event storage for array from macro to standalone function" ftrace: Constify ftrace_text_reserved tracepoints: API doc update to tracepoint_probe_register() return value tracepoints: API doc update to data argument ftrace: Fix compilation warning about control_ops_free ftrace/x86: BUG when ftrace recovery fails ftrace: Warn on error when modifying ftrace function ftrace: Remove freelist from struct dyn_ftrace ftrace: Do not pass data to ftrace_dyn_arch_init ftrace: Pass retval through return in ftrace_dyn_arch_init() ftrace: Inline the code from ftrace_dyn_table_alloc() ftrace: Cleanup of global variables ftrace_new_pgs and ftrace_update_cnt tracing: Evaluate len expression only once in __dynamic_array macro tracing: Correctly expand len expressions from __dynamic_array macro tracing/module: Replace include of tracepoint.h with jump_label.h in module.h tracing: Fix event header migrate.h to include tracepoint.h tracing: Fix event header writeback.h to include tracepoint.h tracing: Warn if a tracepoint is not set via debugfs ...

Revert "tracing: Move event storage for array from macro to standalone function"

2014-03-21T17:11:41Z

I originally wrote commit 35bb4399bd0e to shrink the size of the overhead of tracepoints by several kilobytes. Later, I received a patch from Vaibhav Nagarnaik that fixed a bug in the same code that this commit touches. Not only did it fix a bug, it also removed code and shrunk the size of the overhead of trace events even more than this commit did. Since this commit is scheduled for 3.15 and Vaibhav's patch is already in mainline, I need to revert this patch in order to keep it from conflicting with Vaibhav's patch. Not to mention, Vaibhav's patch makes this patch obsolete. Link: http://lkml.kernel.org/r/20140320225637.0226041b@gandalf.local.home Cc: Vaibhav Nagarnaik Signed-off-by: Steven Rostedt

tracing: Fix array size mismatch in format string

2014-03-20T17:21:05Z

In event format strings, the array size is reported in two locations. One in array subscript and then via the "size:" attribute. The values reported there have a mismatch. For e.g., in sched:sched_switch the prev_comm and next_comm character arrays have subscript values as [32] where as the actual field size is 16. name: sched_switch ID: 301 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:char prev_comm[32]; offset:8; size:16; signed:1; field:pid_t prev_pid; offset:24; size:4; signed:1; field:int prev_prio; offset:28; size:4; signed:1; field:long prev_state; offset:32; size:8; signed:1; field:char next_comm[32]; offset:40; size:16; signed:1; field:pid_t next_pid; offset:56; size:4; signed:1; field:int next_prio; offset:60; size:4; signed:1; After bisection, the following commit was blamed: 92edca0 tracing: Use direct field, type and system names This commit removes the duplication of strings for field->name and field->type assuming that all the strings passed in __trace_define_field() are immutable. This is not true for arrays, where the type string is created in event_storage variable and field->type for all array fields points to event_storage. Use __stringify() to create a string constant for the type string. Also, get rid of event_storage and event_storage_mutex that are not needed anymore. also, an added benefit is that this reduces the overhead of events a bit more: text data bss dec hex filename 8424787 2036472 1302528 11763787 b3804b vmlinux 8420814 2036408 1302528 11759750 b37086 vmlinux.patched Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com Cc: Laurent Chavey Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Vaibhav Nagarnaik Signed-off-by: Steven Rostedt

tracing: Use helper functions in event assignment to shrink macro size

2014-03-07T15:06:07Z

The functions that assign the contents for the ftrace events are defined by the TRACE_EVENT() macros. Each event has its own unique way to assign data to its buffer. When you have over 500 events, that means there's 500 functions assigning data uniquely for each event (not really that many, as DECLARE_EVENT_CLASS() and multiple DEFINE_EVENT()s will only need a single function). By making helper functions in the core kernel to do some of the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux 12959102 1913504 9785344 24657950 178401e /tmp/vmlinux.patched That's a total of 28288 bytes, which comes down to 56 bytes per event. Link: http://lkml.kernel.org/r/20120810034708.370808175@goodmis.org Signed-off-by: Steven Rostedt

tracing: Move event storage for array from macro to standalone function

2014-03-07T15:06:06Z

The code that shows array fields for events is defined for all events. This can add up quite a bit when you have over 500 events. By making helper functions in the core kernel to do the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux.patched That's a total of 3556 bytes, which comes down to 7 bytes per event. Although it's not much, this code is just called at initialization of the events. Link: http://lkml.kernel.org/r/20120810034708.084036335@goodmis.org Signed-off-by: Steven Rostedt

tracing: Do not add event files for modules that fail tracepoints

2014-03-04T02:11:05Z

If a module fails to add its tracepoints due to module tainting, do not create the module event infrastructure in the debugfs directory. As the events will not work and worse yet, they will silently fail, making the user wonder why the events they enable do not display anything. Having a warning on module load and the events not visible to the users will make the cause of the problem much clearer. Link: http://lkml.kernel.org/r/20140227154923.265882695@goodmis.org Fixes: 6d723736e472 "tracing/events: add support for modules to TRACE_EVENT" Acked-by: Mathieu Desnoyers Cc: stable@vger.kernel.org # 2.6.31+ Cc: Rusty Russell Signed-off-by: Steven Rostedt

tracing: Move ftrace_event_file() out of DYNAMIC_FTRACE ifdef

2013-12-22T03:02:17Z

Now that event triggers use ftrace_event_file(), it needs to be outside the #ifdef CONFIG_DYNAMIC_FTRACE, as it can now be used when that is not defined. Signed-off-by: Steven Rostedt