projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 3e4196a5 MF |
1 | /* |
| 2 | * arch/xtensa/kernel/stacktrace.c | |
| 3 | * | |
| 4 | * This file is subject to the terms and conditions of the GNU General Public | |
| 5 | * License. See the file "COPYING" in the main directory of this archive | |
| 6 | * for more details. | |
| 7 | * | |
| 8 | * Copyright (C) 2001 - 2013 Tensilica Inc. | |
| 9 | */ | |
| 10 | #include <linux/export.h> | |
| 11 | #include <linux/sched.h> | |
| 12 | #include <linux/stacktrace.h> | |
| 13 | ||
| 14 | #include <asm/stacktrace.h> | |
| 15 | #include <asm/traps.h> | |
| 16 | ||
| 17 | void walk_stackframe(unsigned long *sp, | |
| 18 | int (*fn)(struct stackframe *frame, void *data), | |
| 19 | void *data) | |
| 20 | { | |
| 21 | unsigned long a0, a1; | |
| 22 | unsigned long sp_end; | |
| 23 | ||
| 24 | a1 = (unsigned long)sp; | |
| 25 | sp_end = ALIGN(a1, THREAD_SIZE); | |
| 26 | ||
| 27 | spill_registers(); | |
| 28 | ||
| 29 | while (a1 < sp_end) { | |
| 30 | struct stackframe frame; | |
| 31 | ||
| 32 | sp = (unsigned long *)a1; | |
| 33 | ||
| 34 | a0 = *(sp - 4); | |
| 35 | a1 = *(sp - 3); | |
| 36 | ||
| 37 | if (a1 <= (unsigned long)sp) | |
| 38 | break; | |
| 39 | ||
| 40 | frame.pc = MAKE_PC_FROM_RA(a0, a1); | |
| 41 | frame.sp = a1; | |
| 42 | ||
| 43 | if (fn(&frame, data)) | |
| 44 | return; | |
| 45 | } | |
| 46 | } | |
| 47 | ||
| 48 | #ifdef CONFIG_STACKTRACE | |
| 49 | ||
| 50 | struct stack_trace_data { | |
| 51 | struct stack_trace *trace; | |
| 52 | unsigned skip; | |
| 53 | }; | |
| 54 | ||
| 55 | static int stack_trace_cb(struct stackframe *frame, void *data) | |
| 56 | { | |
| 57 | struct stack_trace_data *trace_data = data; | |
| 58 | struct stack_trace *trace = trace_data->trace; | |
| 59 | ||
| 60 | if (trace_data->skip) { | |
| 61 | --trace_data->skip; | |
| 62 | return 0; | |
| 63 | } | |
| 64 | if (!kernel_text_address(frame->pc)) | |
| 65 | return 0; | |
| 66 | ||
| 67 | trace->entries[trace->nr_entries++] = frame->pc; | |
| 68 | return trace->nr_entries >= trace->max_entries; | |
| 69 | } | |
| 70 | ||
| 71 | void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace) | |
| 72 | { | |
| 73 | struct stack_trace_data trace_data = { | |
| 74 | .trace = trace, | |
| 75 | .skip = trace->skip, | |
| 76 | }; | |
| 77 | walk_stackframe(stack_pointer(task), stack_trace_cb, &trace_data); | |
| 78 | } | |
| 79 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk); | |
| 80 | ||
| 81 | void save_stack_trace(struct stack_trace *trace) | |
| 82 | { | |
| 83 | save_stack_trace_tsk(current, trace); | |
| 84 | } | |
| 85 | EXPORT_SYMBOL_GPL(save_stack_trace); | |
| 86 | ||
| 87 | #endif | |
| 3ae908c9 MF |
88 | |
| 89 | #ifdef CONFIG_FRAME_POINTER | |
| 90 | ||
| 91 | struct return_addr_data { | |
| 92 | unsigned long addr; | |
| 93 | unsigned skip; | |
| 94 | }; | |
| 95 | ||
| 96 | static int return_address_cb(struct stackframe *frame, void *data) | |
| 97 | { | |
| 98 | struct return_addr_data *r = data; | |
| 99 | ||
| 100 | if (r->skip) { | |
| 101 | --r->skip; | |
| 102 | return 0; | |
| 103 | } | |
| 104 | if (!kernel_text_address(frame->pc)) | |
| 105 | return 0; | |
| 106 | r->addr = frame->pc; | |
| 107 | return 1; | |
| 108 | } | |
| 109 | ||
| 110 | unsigned long return_address(unsigned level) | |
| 111 | { | |
| 112 | struct return_addr_data r = { | |
| 113 | .skip = level + 1, | |
| 114 | }; | |
| 115 | walk_stackframe(stack_pointer(NULL), return_address_cb, &r); | |
| 116 | return r.addr; | |
| 117 | } | |
| 118 | EXPORT_SYMBOL(return_address); | |
| 119 | ||
| 120 | #endif |