1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 * Copyright (C) 2013 Richard Weinberger <richard@nod.at> 5 * Copyright (C) 2014 Google Inc., Author: Daniel Walter <dwalter@google.com> 6 */ 7 8 #include <linux/kallsyms.h> 9 #include <linux/kernel.h> 10 #include <linux/sched.h> 11 #include <linux/stacktrace.h> 12 #include <linux/module.h> 13 #include <linux/uaccess.h> 14 #include <asm/stacktrace.h> 15 16 void dump_trace(struct task_struct *tsk, 17 const struct stacktrace_ops *ops, 18 void *data) 19 { 20 int reliable = 0; 21 unsigned long *sp, bp, addr; 22 struct pt_regs *segv_regs = tsk->thread.segv_regs; 23 struct stack_frame *frame; 24 25 bp = get_frame_pointer(tsk, segv_regs); 26 sp = get_stack_pointer(tsk, segv_regs); 27 28 frame = (struct stack_frame *)bp; 29 while (((long) sp & (THREAD_SIZE-1)) != 0) { 30 addr = *sp; 31 if (__kernel_text_address(addr)) { 32 reliable = 0; 33 if ((unsigned long) sp == bp + sizeof(long)) { 34 frame = frame ? frame->next_frame : NULL; 35 bp = (unsigned long)frame; 36 reliable = 1; 37 } 38 ops->address(data, addr, reliable); 39 } 40 sp++; 41 } 42 } 43 44 static void save_addr(void *data, unsigned long address, int reliable) 45 { 46 struct stack_trace *trace = data; 47 48 if (!reliable) 49 return; 50 if (trace->nr_entries >= trace->max_entries) 51 return; 52 53 trace->entries[trace->nr_entries++] = address; 54 } 55 56 static const struct stacktrace_ops dump_ops = { 57 .address = save_addr 58 }; 59 60 static void __save_stack_trace(struct task_struct *tsk, struct stack_trace *trace) 61 { 62 dump_trace(tsk, &dump_ops, trace); 63 } 64 65 void save_stack_trace(struct stack_trace *trace) 66 { 67 __save_stack_trace(current, trace); 68 } 69 EXPORT_SYMBOL_GPL(save_stack_trace); 70 71 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 72 { 73 __save_stack_trace(tsk, trace); 74 } 75 EXPORT_SYMBOL_GPL(save_stack_trace_tsk); 76