projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 4bf1fa5a UKK |
1 | /* |
| 2 | * arch/arm/kernel/return_address.c | |
| 3 | * | |
| 4 | * Copyright (C) 2009 Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> | |
| 5 | * for Pengutronix | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify it | |
| 8 | * under the terms of the GNU General Public License version 2 as published by | |
| 9 | * the Free Software Foundation. | |
| 10 | */ | |
| ecea4ab6 | 11 | #include <linux/export.h> |
| 2bbd7e9b | 12 | #include <linux/ftrace.h> |
| 4bf1fa5a UKK |
13 | |
| 14 | #if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) | |
| 15 | #include <linux/sched.h> | |
| 16 | ||
| 17 | #include <asm/stacktrace.h> | |
| 18 | ||
| 19 | struct return_address_data { | |
| 20 | unsigned int level; | |
| 21 | void *addr; | |
| 22 | }; | |
| 23 | ||
| 24 | static int save_return_addr(struct stackframe *frame, void *d) | |
| 25 | { | |
| 26 | struct return_address_data *data = d; | |
| 27 | ||
| 28 | if (!data->level) { | |
| 01223f36 | 29 | data->addr = (void *)frame->pc; |
| 4bf1fa5a UKK |
30 | |
| 31 | return 1; | |
| 32 | } else { | |
| 33 | --data->level; | |
| 34 | return 0; | |
| 35 | } | |
| 36 | } | |
| 37 | ||
| 38 | void *return_address(unsigned int level) | |
| 39 | { | |
| 40 | struct return_address_data data; | |
| 41 | struct stackframe frame; | |
| 42 | register unsigned long current_sp asm ("sp"); | |
| 43 | ||
| 01223f36 KP |
44 | data.level = level + 2; |
| 45 | data.addr = NULL; | |
| 4bf1fa5a UKK |
46 | |
| 47 | frame.fp = (unsigned long)__builtin_frame_address(0); | |
| 48 | frame.sp = current_sp; | |
| 49 | frame.lr = (unsigned long)__builtin_return_address(0); | |
| 50 | frame.pc = (unsigned long)return_address; | |
| 51 | ||
| 52 | walk_stackframe(&frame, save_return_addr, &data); | |
| 53 | ||
| 54 | if (!data.level) | |
| 55 | return data.addr; | |
| 56 | else | |
| 57 | return NULL; | |
| 58 | } | |
| 59 | ||
| 60 | #else /* if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) */ | |
| 61 | ||
| 62 | #if defined(CONFIG_ARM_UNWIND) | |
| 63 | #warning "TODO: return_address should use unwind tables" | |
| 64 | #endif | |
| 65 | ||
| 66 | void *return_address(unsigned int level) | |
| 67 | { | |
| 68 | return NULL; | |
| 69 | } | |
| 70 | ||
| 71 | #endif /* if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) / else */ | |
| 72 | ||
| 73 | EXPORT_SYMBOL_GPL(return_address); |