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/sched/debug.h> 14 #include <linux/stacktrace.h> 15 #include <linux/thread_info.h> 16 #include <linux/module.h> 17 #include <asm/unwinder.h> 18 #include <asm/ptrace.h> 19 #include <asm/stacktrace.h> 20 21 static int save_stack_stack(void *data, char *name) 22 { 23 return 0; 24 } 25 26 /* 27 * Save stack-backtrace addresses into a stack_trace buffer. 28 */ 29 static void save_stack_address(void *data, unsigned long addr, int reliable) 30 { 31 struct stack_trace *trace = data; 32 33 if (!reliable) 34 return; 35 36 if (trace->skip > 0) { 37 trace->skip--; 38 return; 39 } 40 41 if (trace->nr_entries < trace->max_entries) 42 trace->entries[trace->nr_entries++] = addr; 43 } 44 45 static const struct stacktrace_ops save_stack_ops = { 46 .stack = save_stack_stack, 47 .address = save_stack_address, 48 }; 49 50 void save_stack_trace(struct stack_trace *trace) 51 { 52 unsigned long *sp = (unsigned long *)current_stack_pointer; 53 54 unwind_stack(current, NULL, sp, &save_stack_ops, trace); 55 if (trace->nr_entries < trace->max_entries) 56 trace->entries[trace->nr_entries++] = ULONG_MAX; 57 } 58 EXPORT_SYMBOL_GPL(save_stack_trace); 59 60 static void 61 save_stack_address_nosched(void *data, unsigned long addr, int reliable) 62 { 63 struct stack_trace *trace = (struct stack_trace *)data; 64 65 if (!reliable) 66 return; 67 68 if (in_sched_functions(addr)) 69 return; 70 71 if (trace->skip > 0) { 72 trace->skip--; 73 return; 74 } 75 76 if (trace->nr_entries < trace->max_entries) 77 trace->entries[trace->nr_entries++] = addr; 78 } 79 80 static const struct stacktrace_ops save_stack_ops_nosched = { 81 .stack = save_stack_stack, 82 .address = save_stack_address_nosched, 83 }; 84 85 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 86 { 87 unsigned long *sp = (unsigned long *)tsk->thread.sp; 88 89 unwind_stack(current, NULL, sp, &save_stack_ops_nosched, trace); 90 if (trace->nr_entries < trace->max_entries) 91 trace->entries[trace->nr_entries++] = ULONG_MAX; 92 } 93 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 94