tracing/kprobes: Add short documentation for HAVE_REGS_AND_STACK_ACCESS_API

So that arch developers know how to implement it without the
need to dig into changelogs.

Reported-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20100218132521.GB2406@osiris.boeblingen.de.ibm.com>
[added reference to ptrace.h in the config help]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 04e3aa77da25..50877ef25844 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -123,6 +123,11 @@ config USE_GENERIC_SMP_HELPERS
 
 config HAVE_REGS_AND_STACK_ACCESS_API
         bool
+        help
+          This symbol should be selected by an architecure if it supports
+          the API needed to access registers and stack entries from pt_regs,
+          declared in asm/ptrace.h
+          For example the kprobes-based event tracer needs this API.
 
 config HAVE_CLK
         bool