arch/parisc/kernel/stacktrace.c

   1 /*
   2  * Stack trace management functions
   3  *
   4  *  Copyright (C) 2009 Helge Deller <deller@gmx.de>
   5  *  based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
   6  *  and parisc unwind functions by Randolph Chung <tausq@debian.org>
   7  *
   8  *  TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
   9  */
  10 #include <linux/module.h>
  11 #include <linux/stacktrace.h>
  12
  13 #include <asm/unwind.h>
  14
  15 static void dump_trace(struct task_struct *task, struct stack_trace *trace)
  16 {
  17         struct unwind_frame_info info;
  18
  19         /* initialize unwind info */
  20         if (task == current) {
  21                 unsigned long sp;
  22                 struct pt_regs r;
  23 HERE:
  24                 asm volatile ("copy %%r30, %0" : "=r"(sp));
  25                 memset(&r, 0, sizeof(struct pt_regs));
  26                 r.iaoq[0] = (unsigned long)&&HERE;
  27                 r.gr[2] = (unsigned long)__builtin_return_address(0);
  28                 r.gr[30] = sp;
  29                 unwind_frame_init(&info, task, &r);
  30         } else {
  31                 unwind_frame_init_from_blocked_task(&info, task);
  32         }
  33
  34         /* unwind stack and save entries in stack_trace struct */
  35         trace->nr_entries = 0;
  36         while (trace->nr_entries < trace->max_entries) {
  37                 if (unwind_once(&info) < 0 || info.ip == 0)
  38                         break;
  39
  40                 if (__kernel_text_address(info.ip))
  41                         trace->entries[trace->nr_entries++] = info.ip;
  42         }
  43 }
  44
  45
  46 /*
  47  * Save stack-backtrace addresses into a stack_trace buffer.
  48  */
  49 void save_stack_trace(struct stack_trace *trace)
  50 {
  51         dump_trace(current, trace);
  52         if (trace->nr_entries < trace->max_entries)
  53                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  54 }
  55 EXPORT_SYMBOL_GPL(save_stack_trace);
  56
  57 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  58 {
  59         dump_trace(tsk, trace);
  60         if (trace->nr_entries < trace->max_entries)
  61                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  62 }
  63 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);