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tracing/kprobes: Rename Kprobe-tracer to kprobe-event 

Rename Kprobes-based event tracer to kprobes-based tracing event
(kprobe-event), since it is not a tracer but an extensible
tracing event interface.

This also changes CONFIG_KPROBE_TRACER to CONFIG_KPROBE_EVENT
and sets it y by default.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
LKML-Reference: <20091104001247.3454.14131.stgit@harusame>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Masami Hiramatsu 2009-11-03 19:12:47 -05:00 committed by Ingo Molnar
parent 91365bbe4f
commit 77b44d1b7c
4 changed files with 31 additions and 30 deletions
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34
Documentation/trace/kprobetrace.txt
View File

@ -1,26 +1,23 @@
Kprobe-based Event Tracer
=========================
Kprobe-based Event Tracing
==========================
Documentation is written by Masami Hiramatsu
Overview
--------
This tracer is similar to the events tracer which is based on Tracepoint
infrastructure. Instead of Tracepoint, this tracer is based on kprobes(kprobe
and kretprobe). It probes anywhere where kprobes can probe(this means, all
functions body except for __kprobes functions).
These events are similar to tracepoint based events. Instead of Tracepoint,
this is based on kprobes (kprobe and kretprobe). So it can probe wherever
kprobes can probe (this means, all functions body except for __kprobes
functions). Unlike the Tracepoint based event, this can be added and removed
dynamically, on the fly.
Unlike the function tracer, this tracer can probe instructions inside of
kernel functions. It allows you to check which instruction has been executed.
To enable this feature, build your kernel with CONFIG_KPROBE_TRACING=y.
Unlike the Tracepoint based events tracer, this tracer can add and remove
probe points on the fly.
Similar to the events tracer, this tracer doesn't need to be activated via
current_tracer, instead of that, just set probe points via
/sys/kernel/debug/tracing/kprobe_events. And you can set filters on each
probe events via /sys/kernel/debug/tracing/events/kprobes/<EVENT>/filter.
Similar to the events tracer, this doesn't need to be activated via
current_tracer. Instead of that, add probe points via
/sys/kernel/debug/tracing/kprobe_events, and enable it via
/sys/kernel/debug/tracing/events/kprobes/<EVENT>/enabled.
Synopsis of kprobe_events
@ -55,9 +52,9 @@ Per-Probe Event Filtering
-------------------------
Per-probe event filtering feature allows you to set different filter on each
probe and gives you what arguments will be shown in trace buffer. If an event
name is specified right after 'p:' or 'r:' in kprobe_events, the tracer adds
an event under tracing/events/kprobes/<EVENT>, at the directory you can see
'id', 'enabled', 'format' and 'filter'.
name is specified right after 'p:' or 'r:' in kprobe_events, it adds an event
under tracing/events/kprobes/<EVENT>, at the directory you can see 'id',
'enabled', 'format' and 'filter'.
enabled:
You can enable/disable the probe by writing 1 or 0 on it.
@ -71,6 +68,7 @@ filter:
id:
This shows the id of this probe event.
Event Profiling
---------------
You can check the total number of probe hits and probe miss-hits via

19
kernel/trace/Kconfig
View File

@ -428,17 +428,22 @@ config BLK_DEV_IO_TRACE
If unsure, say N.
config KPROBE_TRACER
config KPROBE_EVENT
depends on KPROBES
depends on X86
bool "Trace kprobes"
bool "Enable kprobes-based dynamic events"
select TRACING
select GENERIC_TRACER
default y
help
This tracer probes everywhere where kprobes can probe it, and
records various registers and memories specified by user.
This also allows you to trace kprobe probe points as a dynamic
defined events. It provides per-probe event filtering interface.
This allows the user to add tracing events (similar to tracepoints) on the fly
via the ftrace interface. See Documentation/trace/kprobetrace.txt
for more details.
Those events can be inserted wherever kprobes can probe, and record
various register and memory values.
This option is also required by perf-probe subcommand of perf tools. If
you want to use perf tools, this option is strongly recommended.
config DYNAMIC_FTRACE
bool "enable/disable ftrace tracepoints dynamically"

2
kernel/trace/Makefile
View File

@ -53,7 +53,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o
obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o
obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o
obj-$(CONFIG_KPROBE_TRACER) += trace_kprobe.o
obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o
obj-$(CONFIG_EVENT_TRACING) += power-traces.o
libftrace-y := ftrace.o

6
kernel/trace/trace_kprobe.c
View File

@ -1,5 +1,5 @@
/*
* kprobe based kernel tracer
* Kprobes-based tracing events
*
* Created by Masami Hiramatsu <mhiramat@redhat.com>
*
@ -57,8 +57,6 @@ const char *reserved_field_names[] = {
FIELD_STRING_FUNC,
};
/* currently, trace_kprobe only supports X86. */
struct fetch_func {
unsigned long (*func)(struct pt_regs *, void *);
void *data;
@ -191,7 +189,7 @@ static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data)
}
/**
* Kprobe tracer core functions
* Kprobe event core functions
*/
struct probe_arg {