1 /* 2 * arch/sh/kernel/stacktrace.c 3 * 4 * Stack trace management functions 5 * 6 * Copyright (C) 2006 - 2008 Paul Mundt 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12 #include <linux/sched.h> 13 #include <linux/stacktrace.h> 14 #include <linux/thread_info.h> 15 #include <linux/module.h> 16 #include <asm/unwinder.h> 17 #include <asm/ptrace.h> 18 #include <asm/stacktrace.h> 19 20 static int save_stack_stack(void *data, char *name) 21 { 22 return 0; 23 } 24 25 /* 26 * Save stack-backtrace addresses into a stack_trace buffer. 27 */ 28 static void save_stack_address(void *data, unsigned long addr, int reliable) 29 { 30 struct stack_trace *trace = data; 31 32 if (!reliable) 33 return; 34 35 if (trace->skip > 0) { 36 trace->skip--; 37 return; 38 } 39 40 if (trace->nr_entries < trace->max_entries) 41 trace->entries[trace->nr_entries++] = addr; 42 } 43 44 static const struct stacktrace_ops save_stack_ops = { 45 .stack = save_stack_stack, 46 .address = save_stack_address, 47 }; 48 49 void save_stack_trace(struct stack_trace *trace) 50 { 51 unsigned long *sp = (unsigned long *)current_stack_pointer; 52 53 unwind_stack(current, NULL, sp, &save_stack_ops, trace); 54 if (trace->nr_entries < trace->max_entries) 55 trace->entries[trace->nr_entries++] = ULONG_MAX; 56 } 57 EXPORT_SYMBOL_GPL(save_stack_trace); 58 59 static void 60 save_stack_address_nosched(void *data, unsigned long addr, int reliable) 61 { 62 struct stack_trace *trace = (struct stack_trace *)data; 63 64 if (!reliable) 65 return; 66 67 if (in_sched_functions(addr)) 68 return; 69 70 if (trace->skip > 0) { 71 trace->skip--; 72 return; 73 } 74 75 if (trace->nr_entries < trace->max_entries) 76 trace->entries[trace->nr_entries++] = addr; 77 } 78 79 static const struct stacktrace_ops save_stack_ops_nosched = { 80 .stack = save_stack_stack, 81 .address = save_stack_address_nosched, 82 }; 83 84 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 85 { 86 unsigned long *sp = (unsigned long *)tsk->thread.sp; 87 88 unwind_stack(current, NULL, sp, &save_stack_ops_nosched, trace); 89 if (trace->nr_entries < trace->max_entries) 90 trace->entries[trace->nr_entries++] = ULONG_MAX; 91 } 92 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 93