tracing: Fix kconfig warning due to a typo

Commit f3f096cfe ("tracing: Provide trace events interface for
uprobes") throws a warning about unmet dependencies.

The exact warning message is:
	warning: (UPROBE_EVENT) selects UPROBES which has unmet direct dependencies (UPROBE_EVENTS && PERF_EVENTS)

This is due to a typo in arch/Kconfig file. Fix similar typos in
the uprobetracer documentation.

Also add sample format of a uprobe event in the uprobetracer
documentation as suggested by Masami Hiramatsu.

Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120508111126.21004.38285.sendpatchset@srdronam.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/Documentation/trace/uprobetracer.txt b/Documentation/trace/uprobetracer.txt
index eae40a0..24ce682 100644 (file)
--- a/Documentation/trace/uprobetracer.txt
+++ b/Documentation/trace/uprobetracer.txt
@@ -5,7 +5,7 @@
 Overview
 --------
 Uprobe based trace events are similar to kprobe based trace events.
-To enable this feature, build your kernel with CONFIG_UPROBE_EVENTS=y.
+To enable this feature, build your kernel with CONFIG_UPROBE_EVENT=y.
 
 Similar to the kprobe-event tracer, this doesn't need to be activated via
 current_tracer. Instead of that, add probe points via
@@ -68,7 +68,25 @@ in the object. We can see the events that are registered by looking at the
 uprobe_events file.
 
     # cat uprobe_events
-    p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420
+    p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax
+
+The format of events can be seen by viewing the file events/uprobes/p_zsh_0x46420/format
+
+    # cat events/uprobes/p_zsh_0x46420/format
+    name: p_zsh_0x46420
+    ID: 922
+    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:int common_padding;       offset:8;       size:4; signed:1;
+
+       field:unsigned long __probe_ip; offset:12;      size:4; signed:0;
+       field:u32 arg1; offset:16;      size:4; signed:0;
+       field:u32 arg2; offset:20;      size:4; signed:0;
+
+    print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2
 
 Right after definition, each event is disabled by default. For tracing these
 events, you need to enable it by:

diff --git a/arch/Kconfig b/arch/Kconfig
index 0f8f968..2880abf 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -78,7 +78,7 @@ config OPTPROBES
 
 config UPROBES
        bool "Transparent user-space probes (EXPERIMENTAL)"
-       depends on UPROBE_EVENTS && PERF_EVENTS
+       depends on UPROBE_EVENT && PERF_EVENTS
        default n
        help
          Uprobes is the user-space counterpart to kprobes: they