ARM: kprobes: treat R7 as the frame pointer register in Thumb2 builds

Thumb2 code uses R7 as the frame pointer rather than R11, because the
opcodes to access it are generally shorter.

This means that there are cases where we cannot simply add it to the
clobber list of an asm() block, but need to preserve/restore it
explicitly, or the compiler may complain in some cases (e.g., Clang
builds with ftrace enabled).

Since R11 is not special in that case, clobber it instead, and use it to
preserve/restore the value of R7.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: probes: move all probe code to dedicate directory

In discussion on LKML (https://lkml.org/lkml/2014/11/28/158), Russell
King suggests to move all probe related code to arch/arm/probes. This
patch does the work. Due to dependency on 'arch/arm/kernel/patch.h', this
patch also moves patch.h to 'arch/arm/include/asm/patch.h', and related
'#include' directives are also midified to '#include <asm/patch.h>'.

Following is an overview of this patch:

./arch/arm/kernel/ ./arch/arm/probes/
|-- Makefile |-- Makefile
|-- probes-arm.c ==> |-- decode-arm.c
|-- probes-arm.h ==> |-- decode-arm.h
|-- probes-thumb.c ==> |-- decode-thumb.c
|-- probes-thumb.h ==> |-- decode-thumb.h
|-- probes.c ==> |-- decode.c
|-- probes.h ==> |-- decode.h
| |-- kprobes
| | |-- Makefile
|-- kprobes-arm.c ==> | |-- actions-arm.c
|-- kprobes-common.c ==> | |-- actions-common.c
|-- kprobes-thumb.c ==> | |-- actions-thumb.c
|-- kprobes.c ==> | |-- core.c
|-- kprobes.h ==> | |-- core.h
|-- kprobes-test-arm.c ==> | |-- test-arm.c
|-- kprobes-test.c ==> | |-- test-core.c
|-- kprobes-test.h ==> | |-- test-core.h
|-- kprobes-test-thumb.c ==> | `-- test-thumb.c
| `-- uprobes
| |-- Makefile
|-- uprobes-arm.c ==> |-- actions-arm.c
|-- uprobes.c ==> |-- core.c
|-- uprobes.h ==> `-- core.h
|
`-- patch.h ==> arch/arm/include/asm/patch.h

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>