1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
/* -*- linux-c -*-
* arm stack tracing functions
* Copyright (C) 2007 Quentin Barnes
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
/*
* For STR and STM instructions, an ARM core may choose to use either
* a +8 or a +12 displacement from the current instruction's address.
* Whichever value is chosen for a given core, it must be the same for
* both instructions and may not change. This function measures it.
*/
static int __init find_str_pc_offset(void)
{
int addr;
int scratch;
int ret;
__asm__("sub %[ret], pc, #4 \n\t"
"str pc, %[addr] \n\t"
"ldr %[scr], %[addr] \n\t"
"sub %[ret], %[scr], %[ret] \n\t"
: [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr) );
return ret;
}
static void __stp_stack_print (struct pt_regs *regs, int verbose, int levels)
{
#ifdef CONFIG_FRAME_POINTER
int pc_offset = find_str_pc_offset();
unsigned long *fp = (unsigned long *)regs->ARM_fp;
unsigned long *next_fp, *pc;
if (levels == 0)
--levels;
while (fp && levels--) {
next_fp = (unsigned long *)*(fp - 3);
pc = (unsigned long *)(*fp - pc_offset);
/* 0xe92dd8xx == stmfd sp!, { ..., fp, ip, lr, pc } */
if ((*pc & 0xffffd800) == 0xe92dd800) {
pc -= 1;
/* Varargs functions have two stmfd instructions. */
if ((*pc & 0xffff0000) == 0xe92d0000)
pc -= 1;
}
_stp_print_addr((unsigned long)pc, verbose, NULL);
/* Sanity check the next_fp. */
if (next_fp && next_fp <= fp)
break;
fp = next_fp;
}
#endif /* CONFIG_FRAME_POINTER */
}
|
