6b13f685e
 김민수
BSP 최초 추가
|
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
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/**
* @file backtrace.c
*
* @remark Copyright 2004 Silicon Graphics Inc. All Rights Reserved.
* @remark Read the file COPYING
*
* @author Greg Banks <gnb@melbourne.sgi.com>
* @author Keith Owens <kaos@melbourne.sgi.com>
* Based on work done for the ia64 port of the SGI kernprof patch, which is
* Copyright (c) 2003-2004 Silicon Graphics Inc. All Rights Reserved.
*/
#include <linux/oprofile.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm/ptrace.h>
/*
* For IA64 we need to perform a complex little dance to get both
* the struct pt_regs and a synthetic struct switch_stack in place
* to allow the unwind code to work. This dance requires our unwind
* using code to be called from a function called from unw_init_running().
* There we only get a single void* data pointer, so use this struct
* to hold all the data we need during the unwind.
*/
typedef struct
{
unsigned int depth;
struct pt_regs *regs;
struct unw_frame_info frame;
unsigned long *prev_pfs_loc; /* state for WAR for old spinlock ool code */
} ia64_backtrace_t;
/* Returns non-zero if the PC is in the Interrupt Vector Table */
static __inline__ int in_ivt_code(unsigned long pc)
{
extern char ia64_ivt[];
return (pc >= (u_long)ia64_ivt && pc < (u_long)ia64_ivt+32768);
}
/*
* Unwind to next stack frame.
*/
static __inline__ int next_frame(ia64_backtrace_t *bt)
{
/*
* Avoid unsightly console message from unw_unwind() when attempting
* to unwind through the Interrupt Vector Table which has no unwind
* information.
*/
if (in_ivt_code(bt->frame.ip))
return 0;
/*
* WAR for spinlock contention from leaf functions. ia64_spinlock_contention_pre3_4
* has ar.pfs == r0. Leaf functions do not modify ar.pfs so ar.pfs remains
* as 0, stopping the backtrace. Record the previous ar.pfs when the current
* IP is in ia64_spinlock_contention_pre3_4 then unwind, if pfs_loc has not changed
* after unwind then use pt_regs.ar_pfs which is where the real ar.pfs is for
* leaf functions.
*/
if (bt->prev_pfs_loc && bt->regs && bt->frame.pfs_loc == bt->prev_pfs_loc)
bt->frame.pfs_loc = &bt->regs->ar_pfs;
bt->prev_pfs_loc = NULL;
return unw_unwind(&bt->frame) == 0;
}
static void do_ia64_backtrace(struct unw_frame_info *info, void *vdata)
{
ia64_backtrace_t *bt = vdata;
struct switch_stack *sw;
int count = 0;
u_long pc, sp;
sw = (struct switch_stack *)(info+1);
/* padding from unw_init_running */
sw = (struct switch_stack *)(((unsigned long)sw + 15) & ~15);
unw_init_frame_info(&bt->frame, current, sw);
/* skip over interrupt frame and oprofile calls */
do {
unw_get_sp(&bt->frame, &sp);
if (sp >= (u_long)bt->regs)
break;
if (!next_frame(bt))
return;
} while (count++ < 200);
/* finally, grab the actual sample */
while (bt->depth-- && next_frame(bt)) {
unw_get_ip(&bt->frame, &pc);
oprofile_add_trace(pc);
if (unw_is_intr_frame(&bt->frame)) {
/*
* Interrupt received on kernel stack; this can
* happen when timer interrupt fires while processing
* a softirq from the tail end of a hardware interrupt
* which interrupted a system call. Don't laugh, it
* happens! Splice the backtrace into two parts to
* avoid spurious cycles in the gprof output.
*/
/* TODO: split rather than drop the 2nd half */
break;
}
}
}
void
ia64_backtrace(struct pt_regs * const regs, unsigned int depth)
{
ia64_backtrace_t bt;
unsigned long flags;
/*
* On IA64 there is little hope of getting backtraces from
* user space programs -- the problems of getting the unwind
* information from arbitrary user programs are extreme.
*/
if (user_mode(regs))
return;
bt.depth = depth;
bt.regs = regs;
bt.prev_pfs_loc = NULL;
local_irq_save(flags);
unw_init_running(do_ia64_backtrace, &bt);
local_irq_restore(flags);
}
|