alistair23-linux/arch/sh/kernel/return_address.c
Kuninori Morimoto 5933f6d220 sh: kernel: convert to SPDX identifiers
Update license to use SPDX-License-Identifier instead of verbose license
text.

Link: http://lkml.kernel.org/r/8736rccswn.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:45 -08:00

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C

// SPDX-License-Identifier: GPL-2.0
/*
* arch/sh/kernel/return_address.c
*
* Copyright (C) 2009 Matt Fleming
* Copyright (C) 2009 Paul Mundt
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/dwarf.h>
#ifdef CONFIG_DWARF_UNWINDER
void *return_address(unsigned int depth)
{
struct dwarf_frame *frame;
unsigned long ra;
int i;
for (i = 0, frame = NULL, ra = 0; i <= depth; i++) {
struct dwarf_frame *tmp;
tmp = dwarf_unwind_stack(ra, frame);
if (!tmp)
return NULL;
if (frame)
dwarf_free_frame(frame);
frame = tmp;
if (!frame || !frame->return_addr)
break;
ra = frame->return_addr;
}
/* Failed to unwind the stack to the specified depth. */
WARN_ON(i != depth + 1);
if (frame)
dwarf_free_frame(frame);
return (void *)ra;
}
#else
void *return_address(unsigned int depth)
{
return NULL;
}
#endif
EXPORT_SYMBOL_GPL(return_address);