1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * arch/sh/kernel/stacktrace.c 4 * 5 * Stack trace management functions 6 * 7 * Copyright (C) 2006 - 2008 Paul Mundt 8 */ 9 #include <linux/sched.h> 10 #include <linux/sched/debug.h> 11 #include <linux/stacktrace.h> 12 #include <linux/thread_info.h> 13 #include <linux/module.h> 14 #include <asm/unwinder.h> 15 #include <asm/ptrace.h> 16 #include <asm/stacktrace.h> 17 18 static int save_stack_stack(void *data, char *name) 19 { 20 return 0; 21 } 22 23 /* 24 * Save stack-backtrace addresses into a stack_trace buffer. 25 */ 26 static void save_stack_address(void *data, unsigned long addr, int reliable) 27 { 28 struct stack_trace *trace = data; 29 30 if (!reliable) 31 return; 32 33 if (trace->skip > 0) { 34 trace->skip--; 35 return; 36 } 37 38 if (trace->nr_entries < trace->max_entries) 39 trace->entries[trace->nr_entries++] = addr; 40 } 41 42 static const struct stacktrace_ops save_stack_ops = { 43 .stack = save_stack_stack, 44 .address = save_stack_address, 45 }; 46 47 void save_stack_trace(struct stack_trace *trace) 48 { 49 unsigned long *sp = (unsigned long *)current_stack_pointer; 50 51 unwind_stack(current, NULL, sp, &save_stack_ops, trace); 52 } 53 EXPORT_SYMBOL_GPL(save_stack_trace); 54 55 static void 56 save_stack_address_nosched(void *data, unsigned long addr, int reliable) 57 { 58 struct stack_trace *trace = (struct stack_trace *)data; 59 60 if (!reliable) 61 return; 62 63 if (in_sched_functions(addr)) 64 return; 65 66 if (trace->skip > 0) { 67 trace->skip--; 68 return; 69 } 70 71 if (trace->nr_entries < trace->max_entries) 72 trace->entries[trace->nr_entries++] = addr; 73 } 74 75 static const struct stacktrace_ops save_stack_ops_nosched = { 76 .stack = save_stack_stack, 77 .address = save_stack_address_nosched, 78 }; 79 80 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 81 { 82 unsigned long *sp = (unsigned long *)tsk->thread.sp; 83 84 unwind_stack(current, NULL, sp, &save_stack_ops_nosched, trace); 85 } 86 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 87