1 /* 2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Copyright (C) 2013 Richard Weinberger <richard@nod.at> 4 * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/kallsyms.h> 12 #include <linux/kernel.h> 13 #include <linux/sched.h> 14 #include <linux/stacktrace.h> 15 #include <linux/module.h> 16 #include <linux/uaccess.h> 17 #include <asm/stacktrace.h> 18 19 void dump_trace(struct task_struct *tsk, 20 const struct stacktrace_ops *ops, 21 void *data) 22 { 23 int reliable = 0; 24 unsigned long *sp, bp, addr; 25 struct pt_regs *segv_regs = tsk->thread.segv_regs; 26 struct stack_frame *frame; 27 28 bp = get_frame_pointer(tsk, segv_regs); 29 sp = get_stack_pointer(tsk, segv_regs); 30 31 frame = (struct stack_frame *)bp; 32 while (((long) sp & (THREAD_SIZE-1)) != 0) { 33 addr = *sp; 34 if (__kernel_text_address(addr)) { 35 reliable = 0; 36 if ((unsigned long) sp == bp + sizeof(long)) { 37 frame = frame ? frame->next_frame : NULL; 38 bp = (unsigned long)frame; 39 reliable = 1; 40 } 41 ops->address(data, addr, reliable); 42 } 43 sp++; 44 } 45 } 46 47 static void save_addr(void *data, unsigned long address, int reliable) 48 { 49 struct stack_trace *trace = data; 50 51 if (!reliable) 52 return; 53 if (trace->nr_entries >= trace->max_entries) 54 return; 55 56 trace->entries[trace->nr_entries++] = address; 57 } 58 59 static const struct stacktrace_ops dump_ops = { 60 .address = save_addr 61 }; 62 63 static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace) 64 { 65 dump_trace(tsk, &dump_ops, trace); 66 if (trace->nr_entries < trace->max_entries) 67 trace->entries[trace->nr_entries++] = ULONG_MAX; 68 } 69 70 void save_stack_trace(struct stack_trace *trace) 71 { 72 __save_stack_trace(current, trace); 73 } 74 EXPORT_SYMBOL_GPL(save_stack_trace); 75 76 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 77 { 78 __save_stack_trace(tsk, trace); 79 } 80 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 81