[ARM] 5613/1: implement CALLER_ADDRESSx
commit4bf1fa5a34aa2dd0d2cc58f0fc213a2e22d007a4
authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tue, 21 Jul 2009 08:56:27 +0000 (21 09:56 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Tue, 21 Jul 2009 16:21:28 +0000 (21 17:21 +0100)
tree5618012a57263bf81e3e2678b622be948e4171b0
parent6a00cded91532f3d58e07729ba56269339281d8e
[ARM] 5613/1: implement CALLER_ADDRESSx

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

As __builtin_return_address(n) doesn't work for ARM with n > 0, the
kernel needs its own implementation.

This fixes many warnings saying:

warning: unsupported argument to '__builtin_return_address'

The new methods and walk_stackframe must not be instrumented because
CALLER_ADDRESSx is used in the various tracers and tracing the tracer is
a bad idea.

What's currently missing is an implementation using unwind tables.  This
is not fatal though, it's just that the tracers don't get enough
information to be really useful.

Note that if both ARM_UNWIND and FRAME_POINTER are enabled,
walk_stackframe uses unwind information.  So in this case the same
implementation is used as when FRAME_POINTER is disabled.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/include/asm/ftrace.h
arch/arm/kernel/Makefile
arch/arm/kernel/return_address.c [new file with mode: 0644]
arch/arm/kernel/stacktrace.c