linux/kernel/trace
Steven Rostedt e68746a271 ftrace: enable filtering only when a function is filtered on
Impact: fix to prevent empty set_ftrace_filter and no ftrace output

The function filter is used to only trace a given set of functions.
The filter is enabled when a function name is echoed into the
set_ftrace_filter file. But if the name has a typo and the function
is not found, the filter is enabled, but no function is listed.

This makes a confusing situation where set_ftrace_filter is empty
but no functions ever get enabled for tracing.

For example:

 # cat /debug/tracing/set_ftrace_filter

  #### all functions enabled ####

 # echo bad_name > set_ftrace_filter
 # cat /debug/tracing/set_ftrace_filter

 # echo function > current_tracer
 # cat trace

  # tracer: nop
  #
  #           TASK-PID    CPU#    TIMESTAMP  FUNCTION
  #              | |       |          |         |

This patch changes that to only enable filtering if a function
is set to be filtered on. Now, the filter is not enabled if
a bad name is echoed into set_ftrace_filter.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-16 17:03:49 -05:00
..
blktrace.c tracing/blktrace: move the tracing file to kernel/trace 2009-02-09 10:51:02 +01:00
ftrace.c ftrace: enable filtering only when a function is filtered on 2009-02-16 17:03:49 -05:00
Kconfig tracing/sysprof: add missing tracing_{start,stop}_record_cmdline() 2009-02-11 12:55:19 +01:00
kmemtrace.c tracing: Introduce trace_buffer_{lock_reserve,unlock_commit} 2009-02-06 01:01:41 +01:00
Makefile tracing/blktrace: move the tracing file to kernel/trace 2009-02-09 10:51:02 +01:00
ring_buffer.c Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace 2009-02-13 10:26:45 +01:00
trace_boot.c tracing: Introduce trace_buffer_{lock_reserve,unlock_commit} 2009-02-06 01:01:41 +01:00
trace_branch.c tracing: remove unneeded variable 2009-02-10 12:32:18 -05:00
trace_functions_graph.c tracing: provide correct return value after outputting the event 2009-02-10 12:32:33 -05:00
trace_functions.c trace: Call tracing_reset_online_cpus before tracer->init() 2009-02-06 01:01:41 +01:00
trace_hw_branches.c tracing: fix typos in comments 2009-02-10 12:32:35 -05:00
trace_irqsoff.c trace: Remove unused trace_array_cpu parameter 2009-02-05 14:35:47 +01:00
trace_mmiotrace.c tracing: Introduce trace_buffer_{lock_reserve,unlock_commit} 2009-02-06 01:01:41 +01:00
trace_nop.c trace: Call tracing_reset_online_cpus before tracer->init() 2009-02-06 01:01:41 +01:00
trace_output.c Merge branch 'tip/tracing/core/devel' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace 2009-02-09 10:35:12 +01:00
trace_output.h trace: make the trace_event callbacks return enum print_line_t 2009-02-04 20:48:39 +01:00
trace_power.c tracing/power: move the power trace headers to a dedicated file 2009-02-09 10:51:38 +01:00
trace_sched_switch.c trace: Call tracing_reset_online_cpus before tracer->init() 2009-02-06 01:01:41 +01:00
trace_sched_wakeup.c trace: Remove unused trace_array_cpu parameter 2009-02-05 14:35:47 +01:00
trace_selftest_dynamic.c ftrace: fix dynamic ftrace selftest 2008-05-23 21:13:23 +02:00
trace_selftest.c tracing/function-graph-tracer: provide a selftest for the function graph tracer 2009-02-09 10:51:37 +01:00
trace_stack.c trace: better use of stack_trace_enabled for boot up code 2008-12-18 12:56:56 +01:00
trace_stat.c tracing: trace_stat.c cleanup 2009-01-15 11:31:21 +01:00
trace_stat.h tracing/ftrace: separate events tracing and stats tracing engine 2009-01-14 12:11:37 +01:00
trace_sysprof.c Merge branches 'tracing/ftrace', 'tracing/ring-buffer', 'tracing/sysprof', 'tracing/urgent' and 'linus' into tracing/core 2009-02-13 10:25:18 +01:00
trace_workqueue.c trace_workqueue: use percpu data for workqueue stat 2009-01-20 13:06:59 +01:00
trace.c tracing: fix sparse warning: attribute function with __acquires/__releases 2009-02-11 10:15:42 +01:00
trace.h tracing: splice support for tracing_pipe 2009-02-09 12:24:34 -05:00