diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2013-03-14 15:03:53 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-03-27 02:41:15 +0000 |
| commit | fb0d99792a8d27365da1ebd0b4fd1533a3052629 (patch) | |
| tree | b34420cf28dce013b6bcf1880ef02e4b13dc90ef /kernel/trace/trace.h | |
| parent | ae02f16fd87c84716699065ba9b0e1cafcb17f6e (diff) | |
tracing: Prevent buffer overwrite disabled for latency tracers
commit 613f04a0f51e6e68ac6fe571ab79da3c0a5eb4da upstream.
The latency tracers require the buffers to be in overwrite mode,
otherwise they get screwed up. Force the buffers to stay in overwrite
mode when latency tracers are enabled.
Added a flag_changed() method to the tracer structure to allow
the tracers to see what flags are being changed, and also be able
to prevent the change from happing.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[bwh: Backported to 3.2:
- Adjust context
- Drop some changes that are not needed because trace_set_options() is not
separate from tracing_trace_options_write()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'kernel/trace/trace.h')
| -rw-r--r-- | kernel/trace/trace.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 092e1f8d18dc..c3c3f6b398d3 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -271,10 +271,14 @@ struct tracer { enum print_line_t (*print_line)(struct trace_iterator *iter); /* If you handled the flag setting, return 0 */ int (*set_flag)(u32 old_flags, u32 bit, int set); + /* Return 0 if OK with change, else return non-zero */ + int (*flag_changed)(struct tracer *tracer, + u32 mask, int set); struct tracer *next; struct tracer_flags *flags; int print_max; int use_max_tr; + bool enabled; }; @@ -815,6 +819,9 @@ extern struct list_head ftrace_events; extern const char *__start___trace_bprintk_fmt[]; extern const char *__stop___trace_bprintk_fmt[]; +int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set); +int set_tracer_flag(unsigned int mask, int enabled); + #undef FTRACE_ENTRY #define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \ extern struct ftrace_event_call \ |