blob: b13f9ec6f2946506c2b42ef4748b447652db81c1 (
plain)
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
|
/*
* Code for tracing calls in Linux kernel.
* Copyright (C) 2009-2016 Helge Deller <deller@gmx.de>
*
* based on code for x86 which is:
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
*
* future possible enhancements:
* - add CONFIG_DYNAMIC_FTRACE
* - add CONFIG_STACK_TRACER
*/
#include <linux/init.h>
#include <linux/ftrace.h>
#include <asm/assembly.h>
#include <asm/sections.h>
#include <asm/ftrace.h>
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/*
* Hook the return address and push it in the stack of return addrs
* in current thread info.
*/
static void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
{
unsigned long old;
struct ftrace_graph_ent trace;
extern int parisc_return_to_handler;
if (unlikely(ftrace_graph_is_dead()))
return;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
return;
old = *parent;
trace.func = self_addr;
trace.depth = current->curr_ret_stack + 1;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace))
return;
if (ftrace_push_return_trace(old, self_addr, &trace.depth,
0 ) == -EBUSY)
return;
/* activate parisc_return_to_handler() as return point */
*parent = (unsigned long) &parisc_return_to_handler;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
void notrace ftrace_function_trampoline(unsigned long parent,
unsigned long self_addr,
unsigned long org_sp_gr3)
{
extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
if (ftrace_trace_function != ftrace_stub) {
/* struct ftrace_ops *op, struct pt_regs *regs); */
ftrace_trace_function(parent, self_addr, NULL, NULL);
return;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
ftrace_graph_entry != ftrace_graph_entry_stub) {
unsigned long *parent_rp;
/* calculate pointer to %rp in stack */
parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET);
/* sanity check: parent_rp should hold parent */
if (*parent_rp != parent)
return;
prepare_ftrace_return(parent_rp, self_addr);
return;
}
#endif
}
|
