arch/s390/kernel/stacktrace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Stack trace management functions
   4  *
   5  *  Copyright IBM Corp. 2006
   6  *  Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   7  */
   8
   9 #include <linux/sched.h>
  10 #include <linux/sched/debug.h>
  11 #include <linux/stacktrace.h>
  12 #include <linux/kallsyms.h>
  13 #include <linux/export.h>
  14
  15 static int __save_address(void *data, unsigned long address, int nosched)
  16 {
  17         struct stack_trace *trace = data;
  18
  19         if (nosched && in_sched_functions(address))
  20                 return 0;
  21         if (trace->skip > 0) {
  22                 trace->skip--;
  23                 return 0;
  24         }
  25         if (trace->nr_entries < trace->max_entries) {
  26                 trace->entries[trace->nr_entries++] = address;
  27                 return 0;
  28         }
  29         return 1;
  30 }
  31
  32 static int save_address(void *data, unsigned long address, int reliable)
  33 {
  34         return __save_address(data, address, 0);
  35 }
  36
  37 static int save_address_nosched(void *data, unsigned long address, int reliable)
  38 {
  39         return __save_address(data, address, 1);
  40 }
  41
  42 void save_stack_trace(struct stack_trace *trace)
  43 {
  44         unsigned long sp;
  45
  46         sp = current_stack_pointer();
  47         dump_trace(save_address, trace, NULL, sp);
  48         if (trace->nr_entries < trace->max_entries)
  49                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  50 }
  51 EXPORT_SYMBOL_GPL(save_stack_trace);
  52
  53 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  54 {
  55         unsigned long sp;
  56
  57         sp = tsk->thread.ksp;
  58         if (tsk == current)
  59                 sp = current_stack_pointer();
  60         dump_trace(save_address_nosched, trace, tsk, sp);
  61         if (trace->nr_entries < trace->max_entries)
  62                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  63 }
  64 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
  65
  66 void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
  67 {
  68         unsigned long sp;
  69
  70         sp = kernel_stack_pointer(regs);
  71         dump_trace(save_address, trace, NULL, sp);
  72         if (trace->nr_entries < trace->max_entries)
  73                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  74 }
  75 EXPORT_SYMBOL_GPL(save_stack_trace_regs);