linux/kernel/trace/trace_events.c, branch v2.6.30

tracing/filters: return proper error code when writing filter file

2009-04-12T09:59:29Z

- propagate return value of filter_add_pred() to the user - return -ENOSPC but not -ENOMEM or -EINVAL when the filter array is full Signed-off-by: Li Zefan Acked-by: Tom Zanussi Acked-by: Frederic Weisbecker Cc: Steven Rostedt LKML-Reference: <49E04CF0.3010105@cn.fujitsu.com> Signed-off-by: Ingo Molnar

tracing/filters: NIL-terminate user input filter

2009-04-12T09:59:27Z

Make sure messages from user space are NIL-terminated strings, otherwise we could dump random memory while reading filter file. Try this: # echo 'parent_comm ==' > events/sched/sched_process_fork/filter # cat events/sched/sched_process_fork/filter parent_comm == � Signed-off-by: Li Zefan Acked-by: Tom Zanussi Acked-by: Frederic Weisbecker Cc: Steven Rostedt LKML-Reference: <49E04C32.6060508@cn.fujitsu.com> Signed-off-by: Ingo Molnar

tracing: filter fix for TRACE_EVENT_FORMAT events

2009-03-26T08:13:14Z

Impact: fix crash (hang) when using TRACE_EVENT_FORMAT filter files filters are only hooked up to the tracepoint events defined using TRACE_EVENT but not the tracers that use TRACE_EVENT_FORMAT, such as ftrace. Do not display the filter files at all for TRACE_EVENT_FORMAT events for the time being. Cc: Steven Rostedt Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker LKML-Reference: <1237878882.8339.61.camel@charm-linux> Signed-off-by: Ingo Molnar

tracing/filters: use trace_seq_printf() to print filters

2009-03-24T07:26:52Z

Impact: cleanup Instead of just using the trace_seq buffer to print the filters, use trace_seq_printf() as it was intended to be used. Reported-by: Steven Rostedt Signed-off-by: Tom Zanussi Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker LKML-Reference: <1237878871.8339.59.camel@charm-linux> Signed-off-by: Ingo Molnar

tracing/filters: free pred when clearing filters

2009-03-24T07:26:51Z

Impact: fix (small) per trace filter modification memory leak Free the current pred when clearing the filters via the filter files. Signed-off-by: Tom Zanussi Cc: Steven Rostedt Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker LKML-Reference: <1237878851.8339.58.camel@charm-linux> Signed-off-by: Ingo Molnar

tracing/filters: clean up filter_add_subsystem_pred()

2009-03-23T08:30:37Z

Impact: cleanup, memory leak fix This patch cleans up filter_add_subsystem_pred(): - searches for the field before creating a copy of the pred - fixes memory leak in the case a predicate isn't applied - if -ENOMEM, makes sure there's no longer a reference to the pred so the caller can free the half-finished filter - changes the confusing i == MAX_FILTER_PRED - 1 comparison previously remarked upon This affects only per-subsystem event filtering. Signed-off-by: Tom Zanussi Cc: Steven Rostedt Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker LKML-Reference: <1237796808.7527.40.camel@charm-linux> Signed-off-by: Ingo Molnar

tracing/events: make the filter files writable

2009-03-23T08:22:14Z

We need the filter files to be writable, the current filter file permissions are only set readable. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Tom Zanussi LKML-Reference: <1237759847-21025-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar

tracing: add run-time field descriptions for event filtering, kfree fix

2009-03-22T17:43:25Z

Impact: fix potential kfree of random data in (rare) failure path Zero-initialize the field structure. Reported-by: Frederic Weisbecker Cc: Tom Zanussi LKML-Reference: <1237710639.7703.46.camel@charm-linux> Signed-off-by: Ingo Molnar

tracing: add per-subsystem filtering

2009-03-22T17:38:47Z

This patch adds per-subsystem filtering to the event tracing subsystem. It adds a 'filter' debugfs file to each subsystem directory. This file can be written to to set filters; reading from it will display the current set of filters set for that subsystem. Basically what it does is propagate the filter down to each event contained in the subsystem. If a particular event doesn't have a field with the name specified in the filter, it simply doesn't get set for that event. You can verify whether or not the filter was set for a particular event by looking at the filter file for that event. As with per-event filters, compound expressions are supported, echoing '0' to the subsystem's filter file clears all filters in the subsystem, etc. Signed-off-by: Tom Zanussi Acked-by: Frederic Weisbecker LKML-Reference: <1237710677.7703.49.camel@charm-linux> Signed-off-by: Ingo Molnar

tracing: add per-event filtering

2009-03-22T17:38:46Z

This patch adds per-event filtering to the event tracing subsystem. It adds a 'filter' debugfs file to each event directory. This file can be written to to set filters; reading from it will display the current set of filters set for that event. Basically, any field listed in the 'format' file for an event can be filtered on (including strings, but not yet other array types) using either matching ('==') or non-matching ('!=') 'predicates'. A 'predicate' can be either a single expression: # echo pid != 0 > filter # cat filter pid != 0 or a compound expression of up to 8 sub-expressions combined using '&&' or '||': # echo comm == Xorg > filter # echo "&& sig != 29" > filter # cat filter comm == Xorg && sig != 29 Only events having field values matching an expression will be available in the trace output; non-matching events are discarded. Note that a compound expression is built up by echoing each sub-expression separately - it's not the most efficient way to do things, but it keeps the parser simple and assumes that compound expressions will be relatively uncommon. In any case, a subsequent patch introducing a way to set filters for entire subsystems should mitigate any need to do this for lots of events. Setting a filter without an '&&' or '||' clears the previous filter completely and sets the filter to the new expression: # cat filter comm == Xorg && sig != 29 # echo comm != Xorg # cat filter comm != Xorg To clear a filter, echo 0 to the filter file: # echo 0 > filter # cat filter none The limit of 8 predicates for a compound expression is arbitrary - for efficiency, it's implemented as an array of pointers to predicates, and 8 seemed more than enough for any filter... Signed-off-by: Tom Zanussi Acked-by: Frederic Weisbecker LKML-Reference: <1237710665.7703.48.camel@charm-linux> Signed-off-by: Ingo Molnar