1/*
 2 * Code for tracing calls in Linux kernel.
 3 * Copyright (C) 2009-2016 Helge Deller <deller@gmx.de>
 4 *
 5 * based on code for x86 which is:
 6 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
 7 *
 8 * future possible enhancements:
 9 * 	- add CONFIG_DYNAMIC_FTRACE
10 *	- add CONFIG_STACK_TRACER
11 */
12
13#include <linux/init.h>
14#include <linux/ftrace.h>
15
16#include <asm/assembly.h>
17#include <asm/sections.h>
18#include <asm/ftrace.h>
19
20
 
 
21#ifdef CONFIG_FUNCTION_GRAPH_TRACER
22/*
23 * Hook the return address and push it in the stack of return addrs
24 * in current thread info.
25 */
26static void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 
27{
28	unsigned long old;
29	struct ftrace_graph_ent trace;
30	extern int parisc_return_to_handler;
31
32	if (unlikely(ftrace_graph_is_dead()))
33		return;
34
35	if (unlikely(atomic_read(&current->tracing_graph_pause)))
36		return;
37
38	old = *parent;
39
40	trace.func = self_addr;
41	trace.depth = current->curr_ret_stack + 1;
42
43	/* Only trace if the calling function expects to */
44	if (!ftrace_graph_entry(&trace))
45		return;
46
47        if (ftrace_push_return_trace(old, self_addr, &trace.depth,
48			0 ) == -EBUSY)
49                return;
50
51	/* activate parisc_return_to_handler() as return point */
52	*parent = (unsigned long) &parisc_return_to_handler;
53}
54#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
55
56void notrace ftrace_function_trampoline(unsigned long parent,
57				unsigned long self_addr,
58				unsigned long org_sp_gr3)
59{
60	extern ftrace_func_t ftrace_trace_function;  /* depends on CONFIG_DYNAMIC_FTRACE */
61	extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
62
63	if (ftrace_trace_function != ftrace_stub) {
64		/* struct ftrace_ops *op, struct pt_regs *regs); */
65		ftrace_trace_function(parent, self_addr, NULL, NULL);
66		return;
67	}
68
69#ifdef CONFIG_FUNCTION_GRAPH_TRACER
70	if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
71		ftrace_graph_entry != ftrace_graph_entry_stub) {
72		unsigned long *parent_rp;
73
74		/* calculate pointer to %rp in stack */
75		parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET);
76		/* sanity check: parent_rp should hold parent */
77		if (*parent_rp != parent)
78			return;
79
80		prepare_ftrace_return(parent_rp, self_addr);
81		return;
82	}
83#endif
84}
85

 1/*
 2 * Code for tracing calls in Linux kernel.
 3 * Copyright (C) 2009-2016 Helge Deller <deller@gmx.de>
 4 *
 5 * based on code for x86 which is:
 6 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
 7 *
 8 * future possible enhancements:
 9 * 	- add CONFIG_DYNAMIC_FTRACE
10 *	- add CONFIG_STACK_TRACER
11 */
12
13#include <linux/init.h>
14#include <linux/ftrace.h>
15
16#include <asm/assembly.h>
17#include <asm/sections.h>
18#include <asm/ftrace.h>
19
20
21#define __hot __attribute__ ((__section__ (".text.hot")))
22
23#ifdef CONFIG_FUNCTION_GRAPH_TRACER
24/*
25 * Hook the return address and push it in the stack of return addrs
26 * in current thread info.
27 */
28static void __hot prepare_ftrace_return(unsigned long *parent,
29					unsigned long self_addr)
30{
31	unsigned long old;
32	struct ftrace_graph_ent trace;
33	extern int parisc_return_to_handler;
34
35	if (unlikely(ftrace_graph_is_dead()))
36		return;
37
38	if (unlikely(atomic_read(&current->tracing_graph_pause)))
39		return;
40
41	old = *parent;
42
43	trace.func = self_addr;
44	trace.depth = current->curr_ret_stack + 1;
45
46	/* Only trace if the calling function expects to */
47	if (!ftrace_graph_entry(&trace))
48		return;
49
50        if (ftrace_push_return_trace(old, self_addr, &trace.depth,
51				     0, NULL) == -EBUSY)
52                return;
53
54	/* activate parisc_return_to_handler() as return point */
55	*parent = (unsigned long) &parisc_return_to_handler;
56}
57#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
58
59void notrace __hot ftrace_function_trampoline(unsigned long parent,
60				unsigned long self_addr,
61				unsigned long org_sp_gr3)
62{
63	extern ftrace_func_t ftrace_trace_function;  /* depends on CONFIG_DYNAMIC_FTRACE */
64	extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
65
66	if (ftrace_trace_function != ftrace_stub) {
67		/* struct ftrace_ops *op, struct pt_regs *regs); */
68		ftrace_trace_function(parent, self_addr, NULL, NULL);
69		return;
70	}
71
72#ifdef CONFIG_FUNCTION_GRAPH_TRACER
73	if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
74		ftrace_graph_entry != ftrace_graph_entry_stub) {
75		unsigned long *parent_rp;
76
77		/* calculate pointer to %rp in stack */
78		parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET);
79		/* sanity check: parent_rp should hold parent */
80		if (*parent_rp != parent)
81			return;
82
83		prepare_ftrace_return(parent_rp, self_addr);
84		return;
85	}
86#endif
87}
88