diff options
Diffstat (limited to 'arch/arm/kernel/return_address.c')
-rw-r--r-- | arch/arm/kernel/return_address.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/arm/kernel/return_address.c b/arch/arm/kernel/return_address.c new file mode 100644 index 0000000000..ac15db66df --- /dev/null +++ b/arch/arm/kernel/return_address.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * arch/arm/kernel/return_address.c + * + * Copyright (C) 2009 Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> + * for Pengutronix + */ +#include <linux/export.h> +#include <linux/ftrace.h> +#include <linux/sched.h> + +#include <asm/stacktrace.h> + +struct return_address_data { + unsigned int level; + void *addr; +}; + +static bool save_return_addr(void *d, unsigned long pc) +{ + struct return_address_data *data = d; + + if (!data->level) { + data->addr = (void *)pc; + + return false; + } else { + --data->level; + return true; + } +} + +void *return_address(unsigned int level) +{ + struct return_address_data data; + struct stackframe frame; + + data.level = level + 2; + data.addr = NULL; + + frame.fp = (unsigned long)__builtin_frame_address(0); + frame.sp = current_stack_pointer; + frame.lr = (unsigned long)__builtin_return_address(0); +here: + frame.pc = (unsigned long)&&here; +#ifdef CONFIG_KRETPROBES + frame.kr_cur = NULL; + frame.tsk = current; +#endif + frame.ex_frame = false; + + walk_stackframe(&frame, save_return_addr, &data); + + if (!data.level) + return data.addr; + else + return NULL; +} + +EXPORT_SYMBOL_GPL(return_address); |