Line data    Source code

       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           1 : void dump_trace(struct task_struct *tsk,
      17             :                 const struct stacktrace_ops *ops,
      18             :                 void *data)
      19             : {
      20           1 :         int reliable = 0;
      21             :         unsigned long *sp, bp, addr;
      22           1 :         struct pt_regs *segv_regs = tsk->thread.segv_regs;
      23             :         struct stack_frame *frame;
      24             : 
      25           1 :         bp = get_frame_pointer(tsk, segv_regs);
      26           1 :         sp = get_stack_pointer(tsk, segv_regs);
      27             : 
      28           1 :         frame = (struct stack_frame *)bp;
      29         120 :         while (((long) sp & (THREAD_SIZE-1)) != 0) {
      30         118 :                 addr = READ_ONCE_NOCHECK(*sp);
      31         118 :                 if (__kernel_text_address(addr)) {
      32          27 :                         reliable = 0;
      33          27 :                         if ((unsigned long) sp == bp + sizeof(long)) {
      34          10 :                                 frame = frame ? frame->next_frame : NULL;
      35          10 :                                 bp = (unsigned long)frame;
      36          10 :                                 reliable = 1;
      37             :                         }
      38          27 :                         ops->address(data, addr, reliable);
      39             :                 }
      40         118 :                 sp++;
      41             :         }
      42           1 : }
      43             : 
      44           0 : static void save_addr(void *data, unsigned long address, int reliable)
      45             : {
      46           0 :         struct stack_trace *trace = data;
      47             : 
      48           0 :         if (!reliable)
      49             :                 return;
      50           0 :         if (trace->nr_entries >= trace->max_entries)
      51             :                 return;
      52             : 
      53           0 :         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           0 :         dump_trace(tsk, &dump_ops, trace);
      63             : }
      64             : 
      65           0 : void save_stack_trace(struct stack_trace *trace)
      66             : {
      67           0 :         __save_stack_trace(current, trace);
      68           0 : }
      69             : EXPORT_SYMBOL_GPL(save_stack_trace);
      70             : 
      71           0 : void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
      72             : {
      73           0 :         __save_stack_trace(tsk, trace);
      74           0 : }
      75             : EXPORT_SYMBOL_GPL(save_stack_trace_tsk);