| Christoph Hellwig | fd3e0bb | 2008-04-17 14:35:00 +1000 | [diff] [blame^] | 1 | /* |
| 2 | * Stack trace utility |
| 3 | * |
| 4 | * Copyright 2008 Christoph Hellwig, IBM Corp. |
| 5 | * |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the License, or (at your option) any later version. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/stacktrace.h> |
| 15 | #include <asm/ptrace.h> |
| 16 | #include <asm/asm-offsets.h> |
| 17 | |
| 18 | /* |
| 19 | * Save stack-backtrace addresses into a stack_trace buffer. |
| 20 | */ |
| 21 | void save_stack_trace(struct stack_trace *trace) |
| 22 | { |
| 23 | unsigned long sp; |
| 24 | |
| 25 | asm("mr %0,1" : "=r" (sp)); |
| 26 | |
| 27 | for (;;) { |
| 28 | unsigned long *stack = (unsigned long *) sp; |
| 29 | unsigned long newsp, ip; |
| 30 | |
| 31 | if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD)) |
| 32 | return; |
| 33 | |
| 34 | newsp = stack[0]; |
| 35 | ip = stack[STACK_FRAME_LR_SAVE]; |
| 36 | |
| 37 | if (!trace->skip) |
| 38 | trace->entries[trace->nr_entries++] = ip; |
| 39 | else |
| 40 | trace->skip--; |
| 41 | |
| 42 | if (trace->nr_entries >= trace->max_entries) |
| 43 | return; |
| 44 | |
| 45 | sp = newsp; |
| 46 | } |
| 47 | } |