1 /* 2 * Stack trace management functions 3 * 4 * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> 5 */ 6 #include <linux/sched.h> 7 #include <linux/stacktrace.h> 8 #include <linux/module.h> 9 #include <asm/stacktrace.h> 10 11 static void save_stack_warning(void *data, char *msg) 12 { 13 } 14 15 static void 16 save_stack_warning_symbol(void *data, char *msg, unsigned long symbol) 17 { 18 } 19 20 static int save_stack_stack(void *data, char *name) 21 { 22 return -1; 23 } 24 25 static void save_stack_address(void *data, unsigned long addr, int reliable) 26 { 27 struct stack_trace *trace = data; 28 if (!reliable) 29 return; 30 if (trace->skip > 0) { 31 trace->skip--; 32 return; 33 } 34 if (trace->nr_entries < trace->max_entries) 35 trace->entries[trace->nr_entries++] = addr; 36 } 37 38 static void 39 save_stack_address_nosched(void *data, unsigned long addr, int reliable) 40 { 41 struct stack_trace *trace = (struct stack_trace *)data; 42 if (!reliable) 43 return; 44 if (in_sched_functions(addr)) 45 return; 46 if (trace->skip > 0) { 47 trace->skip--; 48 return; 49 } 50 if (trace->nr_entries < trace->max_entries) 51 trace->entries[trace->nr_entries++] = addr; 52 } 53 54 static const struct stacktrace_ops save_stack_ops = { 55 .warning = save_stack_warning, 56 .warning_symbol = save_stack_warning_symbol, 57 .stack = save_stack_stack, 58 .address = save_stack_address, 59 }; 60 61 static const struct stacktrace_ops save_stack_ops_nosched = { 62 .warning = save_stack_warning, 63 .warning_symbol = save_stack_warning_symbol, 64 .stack = save_stack_stack, 65 .address = save_stack_address_nosched, 66 }; 67 68 /* 69 * Save stack-backtrace addresses into a stack_trace buffer. 70 */ 71 void save_stack_trace(struct stack_trace *trace) 72 { 73 dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace); 74 if (trace->nr_entries < trace->max_entries) 75 trace->entries[trace->nr_entries++] = ULONG_MAX; 76 } 77 78 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 79 { 80 dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace); 81 if (trace->nr_entries < trace->max_entries) 82 trace->entries[trace->nr_entries++] = ULONG_MAX; 83 } 84