Merge git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / arch / s390 / oprofile / backtrace.c
1 /**
2  * arch/s390/oprofile/backtrace.c
3  *
4  * S390 Version
5  *   Copyright (C) 2005 IBM Corporation, IBM Deutschland Entwicklung GmbH.
6  *   Author(s): Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
7  */
8
9 #include <linux/oprofile.h>
10
11 #include <asm/processor.h> /* for struct stack_frame */
12
13 static unsigned long
14 __show_trace(unsigned int *depth, unsigned long sp,
15              unsigned long low, unsigned long high)
16 {
17         struct stack_frame *sf;
18         struct pt_regs *regs;
19
20         while (*depth) {
21                 sp = sp & PSW_ADDR_INSN;
22                 if (sp < low || sp > high - sizeof(*sf))
23                         return sp;
24                 sf = (struct stack_frame *) sp;
25                 (*depth)--;
26                 oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
27
28                 /* Follow the backchain.  */
29                 while (*depth) {
30                         low = sp;
31                         sp = sf->back_chain & PSW_ADDR_INSN;
32                         if (!sp)
33                                 break;
34                         if (sp <= low || sp > high - sizeof(*sf))
35                                 return sp;
36                         sf = (struct stack_frame *) sp;
37                         (*depth)--;
38                         oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
39
40                 }
41
42                 if (*depth == 0)
43                         break;
44
45                 /* Zero backchain detected, check for interrupt frame.  */
46                 sp = (unsigned long) (sf + 1);
47                 if (sp <= low || sp > high - sizeof(*regs))
48                         return sp;
49                 regs = (struct pt_regs *) sp;
50                 (*depth)--;
51                 oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
52                 low = sp;
53                 sp = regs->gprs[15];
54         }
55         return sp;
56 }
57
58 void s390_backtrace(struct pt_regs * const regs, unsigned int depth)
59 {
60         unsigned long head;
61         struct stack_frame* head_sf;
62
63         if (user_mode (regs))
64                 return;
65
66         head = regs->gprs[15];
67         head_sf = (struct stack_frame*)head;
68
69         if (!head_sf->back_chain)
70                 return;
71
72         head = head_sf->back_chain;
73
74         head = __show_trace(&depth, head, S390_lowcore.async_stack - ASYNC_SIZE,
75                             S390_lowcore.async_stack);
76
77         __show_trace(&depth, head, S390_lowcore.thread_info,
78                      S390_lowcore.thread_info + THREAD_SIZE);
79 }