1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/sched.h> 3 #include <linux/sched/debug.h> 4 #include <linux/stacktrace.h> 5 #include <linux/thread_info.h> 6 #include <linux/ftrace.h> 7 #include <linux/export.h> 8 #include <asm/ptrace.h> 9 #include <asm/stacktrace.h> 10 11 #include "kstack.h" 12 13 static void __save_stack_trace(struct thread_info *tp, 14 struct stack_trace *trace, 15 bool skip_sched) 16 { 17 unsigned long ksp, fp; 18 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 19 struct task_struct *t; 20 int graph = 0; 21 #endif 22 23 if (tp == current_thread_info()) { 24 stack_trace_flush(); 25 __asm__ __volatile__("mov %%fp, %0" : "=r" (ksp)); 26 } else { 27 ksp = tp->ksp; 28 } 29 30 fp = ksp + STACK_BIAS; 31 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 32 t = tp->task; 33 #endif 34 do { 35 struct sparc_stackf *sf; 36 struct pt_regs *regs; 37 unsigned long pc; 38 39 if (!kstack_valid(tp, fp)) 40 break; 41 42 sf = (struct sparc_stackf *) fp; 43 regs = (struct pt_regs *) (sf + 1); 44 45 if (kstack_is_trap_frame(tp, regs)) { 46 if (!(regs->tstate & TSTATE_PRIV)) 47 break; 48 pc = regs->tpc; 49 fp = regs->u_regs[UREG_I6] + STACK_BIAS; 50 } else { 51 pc = sf->callers_pc; 52 fp = (unsigned long)sf->fp + STACK_BIAS; 53 } 54 55 if (trace->skip > 0) 56 trace->skip--; 57 else if (!skip_sched || !in_sched_functions(pc)) { 58 trace->entries[trace->nr_entries++] = pc; 59 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 60 if ((pc + 8UL) == (unsigned long) &return_to_handler) { 61 struct ftrace_ret_stack *ret_stack; 62 ret_stack = ftrace_graph_get_ret_stack(t, 63 graph); 64 if (ret_stack) { 65 pc = ret_stack->ret; 66 if (trace->nr_entries < 67 trace->max_entries) 68 trace->entries[trace->nr_entries++] = pc; 69 graph++; 70 } 71 } 72 #endif 73 } 74 } while (trace->nr_entries < trace->max_entries); 75 } 76 77 void save_stack_trace(struct stack_trace *trace) 78 { 79 __save_stack_trace(current_thread_info(), trace, false); 80 } 81 EXPORT_SYMBOL_GPL(save_stack_trace); 82 83 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 84 { 85 struct thread_info *tp = task_thread_info(tsk); 86 87 __save_stack_trace(tp, trace, true); 88 } 89 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 90