1 /* 2 * Stack trace management functions 3 * 4 * Copyright IBM Corp. 2006 5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com> 6 */ 7 8 #include <linux/sched.h> 9 #include <linux/sched/debug.h> 10 #include <linux/stacktrace.h> 11 #include <linux/kallsyms.h> 12 #include <linux/export.h> 13 14 static int __save_address(void *data, unsigned long address, int nosched) 15 { 16 struct stack_trace *trace = data; 17 18 if (nosched && in_sched_functions(address)) 19 return 0; 20 if (trace->skip > 0) { 21 trace->skip--; 22 return 0; 23 } 24 if (trace->nr_entries < trace->max_entries) { 25 trace->entries[trace->nr_entries++] = address; 26 return 0; 27 } 28 return 1; 29 } 30 31 static int save_address(void *data, unsigned long address, int reliable) 32 { 33 return __save_address(data, address, 0); 34 } 35 36 static int save_address_nosched(void *data, unsigned long address, int reliable) 37 { 38 return __save_address(data, address, 1); 39 } 40 41 void save_stack_trace(struct stack_trace *trace) 42 { 43 unsigned long sp; 44 45 sp = current_stack_pointer(); 46 dump_trace(save_address, trace, NULL, sp); 47 if (trace->nr_entries < trace->max_entries) 48 trace->entries[trace->nr_entries++] = ULONG_MAX; 49 } 50 EXPORT_SYMBOL_GPL(save_stack_trace); 51 52 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 53 { 54 unsigned long sp; 55 56 sp = tsk->thread.ksp; 57 if (tsk == current) 58 sp = current_stack_pointer(); 59 dump_trace(save_address_nosched, trace, tsk, sp); 60 if (trace->nr_entries < trace->max_entries) 61 trace->entries[trace->nr_entries++] = ULONG_MAX; 62 } 63 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 64 65 void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) 66 { 67 unsigned long sp; 68 69 sp = kernel_stack_pointer(regs); 70 dump_trace(save_address, trace, NULL, sp); 71 if (trace->nr_entries < trace->max_entries) 72 trace->entries[trace->nr_entries++] = ULONG_MAX; 73 } 74 EXPORT_SYMBOL_GPL(save_stack_trace_regs); 75