1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2005-2017 Andes Technology Corporation 3 4 #include <linux/sched/debug.h> 5 #include <linux/sched/task_stack.h> 6 #include <linux/stacktrace.h> 7 #include <linux/ftrace.h> 8 save_stack_trace(struct stack_trace * trace)9 void save_stack_trace(struct stack_trace *trace) 10 { 11 save_stack_trace_tsk(current, trace); 12 } 13 EXPORT_SYMBOL_GPL(save_stack_trace); 14 save_stack_trace_tsk(struct task_struct * tsk,struct stack_trace * trace)15 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 16 { 17 unsigned long *fpn; 18 int skip = trace->skip; 19 int savesched; 20 int graph_idx = 0; 21 22 if (tsk == current) { 23 __asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(fpn)); 24 savesched = 1; 25 } else { 26 fpn = (unsigned long *)thread_saved_fp(tsk); 27 savesched = 0; 28 } 29 30 while (!kstack_end(fpn) && !((unsigned long)fpn & 0x3) 31 && (fpn >= (unsigned long *)TASK_SIZE)) { 32 unsigned long lpp, fpp; 33 34 lpp = fpn[LP_OFFSET]; 35 fpp = fpn[FP_OFFSET]; 36 if (!__kernel_text_address(lpp)) 37 break; 38 else 39 lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL); 40 41 if (savesched || !in_sched_functions(lpp)) { 42 if (skip) { 43 skip--; 44 } else { 45 trace->entries[trace->nr_entries++] = lpp; 46 if (trace->nr_entries >= trace->max_entries) 47 break; 48 } 49 } 50 fpn = (unsigned long *)fpp; 51 } 52 } 53 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 54