Commit a1e2e31d authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

ftrace: Return pt_regs to function trace callback 

Return as the 4th paramater to the function tracer callback the pt_regs.

Later patches that implement regs passing for the architectures will require
having the ftrace_ops set the SAVE_REGS flag, which will tell the arch
to take the time to pass a full set of pt_regs to the ftrace_ops callback
function. If the arch does not support it then it should pass NULL.

If an arch can pass full regs, then it should define:
 ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1

Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.org



Reviewed-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent ccf3672d

include/linux/ftrace.h

+4 −2
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/kallsyms.h>

#include <linux/linkage.h>

#include <linux/bitops.h>

#include <linux/ptrace.h>

#include <linux/ktime.h>

#include <linux/sched.h>

#include <linux/types.h>
@@ -54,7 +55,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, 
struct ftrace_ops;



typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,

			      struct ftrace_ops *op);

			      struct ftrace_ops *op, struct pt_regs *regs);



/*

 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
@@ -188,7 +189,8 @@ static inline int ftrace_function_local_disabled(struct ftrace_ops *ops) 
	return *this_cpu_ptr(ops->disabled);

}



extern void ftrace_stub(unsigned long a0, unsigned long a1, struct ftrace_ops *op);

extern void ftrace_stub(unsigned long a0, unsigned long a1,

			struct ftrace_ops *op, struct pt_regs *regs);



#else /* !CONFIG_FUNCTION_TRACER */

/*

kernel/trace/ftrace.c

+22 −15
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ static struct ftrace_ops control_ops; 


#if ARCH_SUPPORTS_FTRACE_OPS

static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,

				 struct ftrace_ops *op);

				 struct ftrace_ops *op, struct pt_regs *regs);

#else

/* See comment below, where ftrace_ops_list_func is defined */

static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
@@ -121,7 +121,7 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); 
 */

static void

ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,

			struct ftrace_ops *op)

			struct ftrace_ops *op, struct pt_regs *regs)

{

	if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))

		return;
@@ -129,19 +129,19 @@ ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, 
	trace_recursion_set(TRACE_GLOBAL_BIT);

	op = rcu_dereference_raw(ftrace_global_list); /*see above*/

	while (op != &ftrace_list_end) {

		op->func(ip, parent_ip, op);

		op->func(ip, parent_ip, op, regs);

		op = rcu_dereference_raw(op->next); /*see above*/

	};

	trace_recursion_clear(TRACE_GLOBAL_BIT);

}



static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,

			    struct ftrace_ops *op)

			    struct ftrace_ops *op, struct pt_regs *regs)

{

	if (!test_tsk_trace_trace(current))

		return;



	ftrace_pid_function(ip, parent_ip, op);

	ftrace_pid_function(ip, parent_ip, op, regs);

}



static void set_ftrace_pid_function(ftrace_func_t func)
@@ -763,7 +763,7 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) 


static void

function_profile_call(unsigned long ip, unsigned long parent_ip,

		      struct ftrace_ops *ops)

		      struct ftrace_ops *ops, struct pt_regs *regs)

{

	struct ftrace_profile_stat *stat;

	struct ftrace_profile *rec;
@@ -793,7 +793,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip, 
#ifdef CONFIG_FUNCTION_GRAPH_TRACER

static int profile_graph_entry(struct ftrace_graph_ent *trace)

{

	function_profile_call(trace->func, 0, NULL);

	function_profile_call(trace->func, 0, NULL, NULL);

	return 1;

}
@@ -2771,7 +2771,7 @@ static int __init ftrace_mod_cmd_init(void) 
device_initcall(ftrace_mod_cmd_init);



static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,

				      struct ftrace_ops *op)

				      struct ftrace_ops *op, struct pt_regs *pt_regs)

{

	struct ftrace_func_probe *entry;

	struct hlist_head *hhd;
@@ -3923,7 +3923,7 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) 


static void

ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,

			struct ftrace_ops *op)

			struct ftrace_ops *op, struct pt_regs *regs)

{

	if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))

		return;
@@ -3938,7 +3938,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, 
	while (op != &ftrace_list_end) {

		if (!ftrace_function_local_disabled(op) &&

		    ftrace_ops_test(op, ip))

			op->func(ip, parent_ip, op);

			op->func(ip, parent_ip, op, regs);



		op = rcu_dereference_raw(op->next);

	};
@@ -3952,7 +3952,7 @@ static struct ftrace_ops control_ops = { 


static inline void

__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,

		       struct ftrace_ops *ignored)

		       struct ftrace_ops *ignored, struct pt_regs *regs)

{

	struct ftrace_ops *op;
@@ -3971,7 +3971,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 
	op = rcu_dereference_raw(ftrace_ops_list);

	while (op != &ftrace_list_end) {

		if (ftrace_ops_test(op, ip))

			op->func(ip, parent_ip, op);

			op->func(ip, parent_ip, op, regs);

		op = rcu_dereference_raw(op->next);

	};

	preempt_enable_notrace();
@@ -3983,17 +3983,24 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 
 * the list function ignores the op parameter, we do not want any

 * C side effects, where a function is called without the caller

 * sending a third parameter.

 * Archs are to support both the regs and ftrace_ops at the same time.

 * If they support ftrace_ops, it is assumed they support regs.

 * If call backs want to use regs, they must either check for regs

 * being NULL, or ARCH_SUPPORTS_FTRACE_SAVE_REGS.

 * Note, ARCH_SUPPORT_SAVE_REGS expects a full regs to be saved.

 * An architecture can pass partial regs with ftrace_ops and still

 * set the ARCH_SUPPORT_FTARCE_OPS.

 */

#if ARCH_SUPPORTS_FTRACE_OPS

static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,

				 struct ftrace_ops *op)

				 struct ftrace_ops *op, struct pt_regs *regs)

{

	__ftrace_ops_list_func(ip, parent_ip, NULL);

	__ftrace_ops_list_func(ip, parent_ip, NULL, regs);

}

#else

static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)

{

	__ftrace_ops_list_func(ip, parent_ip, NULL);

	__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);

}

#endif

kernel/trace/trace_event_perf.c

+1 −1
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); 
#ifdef CONFIG_FUNCTION_TRACER

static void

perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,

			  struct ftrace_ops *ops)

			  struct ftrace_ops *ops, struct pt_regs *pt_regs)

{

	struct ftrace_entry *entry;

	struct hlist_head *head;

kernel/trace/trace_events.c

+1 −1
Original line number Diff line number Diff line
@@ -1682,7 +1682,7 @@ static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); 


static void

function_test_events_call(unsigned long ip, unsigned long parent_ip,

			  struct ftrace_ops *op)

			  struct ftrace_ops *op, struct pt_regs *pt_regs)

{

	struct ring_buffer_event *event;

	struct ring_buffer *buffer;

kernel/trace/trace_functions.c

+4 −3
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ static void function_trace_start(struct trace_array *tr) 


static void

function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip,

				 struct ftrace_ops *op)

				 struct ftrace_ops *op, struct pt_regs *pt_regs)

{

	struct trace_array *tr = func_trace;

	struct trace_array_cpu *data;
@@ -77,7 +77,8 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip, 


static void

function_trace_call(unsigned long ip, unsigned long parent_ip,

		    struct ftrace_ops *op)

		    struct ftrace_ops *op, struct pt_regs *pt_regs)



{

	struct trace_array *tr = func_trace;

	struct trace_array_cpu *data;
@@ -109,7 +110,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, 


static void

function_stack_trace_call(unsigned long ip, unsigned long parent_ip,

			  struct ftrace_ops *op)

			  struct ftrace_ops *op, struct pt_regs *pt_regs)

{

	struct trace_array *tr = func_trace;

	struct trace_array_cpu *data;

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