ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs

In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled.

Steven Rostedt (VMware) committed 6 years ago

Commit d19ad071 parent 58954b318 files · +71 −45Browse files

Showing the changes to kernel (9 of 18 files). Show all

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9 files

kernel/livepatch/patch.c +2 −1
kernel/trace/ftrace.c +15 −12
kernel/trace/trace_event_perf.c +1 −1
kernel/trace/trace_events.c +1 −1
kernel/trace/trace_functions.c +4 −5
kernel/trace/trace_irqsoff.c +1 −1
kernel/trace/trace_sched_wakeup.c +1 −1
kernel/trace/trace_selftest.c +11 −9
kernel/trace/trace_stack.c +1 −1

kernel/livepatch/patch.c+2−1

 static void notrace klp_ftrace_handler(unsigned long ip,
 				       unsigned long parent_ip,
 				       struct ftrace_ops *fops,
-				       struct pt_regs *regs)
+				       struct ftrace_regs *fregs)
 {
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	struct klp_ops *ops;
 	struct klp_func *func;
 	int patch_state;

kernel/trace/ftrace.c+15−12

 #if ARCH_SUPPORTS_FTRACE_OPS
 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
-				 struct ftrace_ops *op, struct pt_regs *regs);
+				 struct ftrace_ops *op, struct ftrace_regs *fregs);
 #else
 /* See comment below, where ftrace_ops_list_func is defined */
 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
 }
 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
-			    struct ftrace_ops *op, struct pt_regs *regs)
+			    struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
 	struct trace_array *tr = op->private;
 	int pid;
 			return;
 	}
-	op->saved_func(ip, parent_ip, op, regs);
+	op->saved_func(ip, parent_ip, op, fregs);
 }
 static void ftrace_sync_ipi(void *data)
 static void
 function_profile_call(unsigned long ip, unsigned long parent_ip,
-		      struct ftrace_ops *ops, struct pt_regs *regs)
+		      struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
 	struct ftrace_profile_stat *stat;
 	struct ftrace_profile *rec;
 				else
 					rec->flags &= ~FTRACE_FL_TRAMP_EN;
 			}
 			if (flag & FTRACE_FL_DIRECT) {
 				/*
 				 * If there's only one user (direct_ops helper)
 }
 static void call_direct_funcs(unsigned long ip, unsigned long pip,
-			      struct ftrace_ops *ops, struct pt_regs *regs)
+			      struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	unsigned long addr;
 	addr = ftrace_find_rec_direct(ip);
 core_initcall(ftrace_mod_cmd_init);
 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
-				      struct ftrace_ops *op, struct pt_regs *pt_regs)
+				      struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
 	struct ftrace_probe_ops *probe_ops;
 	struct ftrace_func_probe *probe;
 static nokprobe_inline void
 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
-		       struct ftrace_ops *ignored, struct pt_regs *regs)
+		       struct ftrace_ops *ignored, struct ftrace_regs *fregs)
 {
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	struct ftrace_ops *op;
 	int bit;
 				pr_warn("op=%p %pS\n", op, op);
 				goto out;
 			}
-			op->func(ip, parent_ip, op, regs);
+			op->func(ip, parent_ip, op, fregs);
 		}
 	} while_for_each_ftrace_op(op);
 out:
  */
 #if ARCH_SUPPORTS_FTRACE_OPS
 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
-				 struct ftrace_ops *op, struct pt_regs *regs)
+				 struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	__ftrace_ops_list_func(ip, parent_ip, NULL, regs);
+	__ftrace_ops_list_func(ip, parent_ip, NULL, fregs);
 }
 NOKPROBE_SYMBOL(ftrace_ops_list_func);
 #else
  * this function will be called by the mcount trampoline.
  */
 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
-				   struct ftrace_ops *op, struct pt_regs *regs)
+				   struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
 	int bit;
 	preempt_disable_notrace();
 	if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching())
-		op->func(ip, parent_ip, op, regs);
+		op->func(ip, parent_ip, op, fregs);
 	preempt_enable_notrace();
 	trace_clear_recursion(bit);

kernel/trace/trace_event_perf.c+1−1

@@ -432,7 +432,7 @@ NOKPROBE_SYMBOL(perf_trace_buf_update); · 431 unmodified lines
432	#ifdef CONFIG_FUNCTION_TRACER	432	#ifdef CONFIG_FUNCTION_TRACER
433	static void	433	static void
434	perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,	434	perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip,
435	struct ftrace_ops ops, struct pt_regs pt_regs)	435	struct ftrace_ops ops, struct ftrace_regs fregs)
436	{	436	{
437	struct ftrace_entry *entry;	437	struct ftrace_entry *entry;
438	struct perf_event *event;	438	struct perf_event *event;

kernel/trace/trace_events.c+1−1

@@ -3673,7 +3673,7 @@ static struct trace_event_file event_trace_file __initdata; · 3672 unmodified lines
3673		3673
3674	static void __init	3674	static void __init
3675	function_test_events_call(unsigned long ip, unsigned long parent_ip,	3675	function_test_events_call(unsigned long ip, unsigned long parent_ip,
3676	struct ftrace_ops op, struct pt_regs pt_regs)	3676	struct ftrace_ops op, struct ftrace_regs regs)
3677	{	3677	{
3678	struct trace_buffer *buffer;	3678	struct trace_buffer *buffer;
3679	struct ring_buffer_event *event;	3679	struct ring_buffer_event *event;

kernel/trace/trace_functions.c+4−5

@@ -23,10 +23,10 @@ static void tracing_start_function_trace(struct trace_array *tr); · 22 unmodified lines
23	static void tracing_stop_function_trace(struct trace_array *tr);	23	static void tracing_stop_function_trace(struct trace_array *tr);
24	static void	24	static void
25	function_trace_call(unsigned long ip, unsigned long parent_ip,	25	function_trace_call(unsigned long ip, unsigned long parent_ip,
26	struct ftrace_ops op, struct pt_regs pt_regs);	26	struct ftrace_ops op, struct ftrace_regs fregs);
27	static void	27	static void
28	function_stack_trace_call(unsigned long ip, unsigned long parent_ip,	28	function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
29	struct ftrace_ops op, struct pt_regs pt_regs);	29	struct ftrace_ops op, struct ftrace_regs fregs);
30	static struct tracer_flags func_flags;	30	static struct tracer_flags func_flags;
31		31
32	/* Our option */	32	/* Our option */
@@ -89,7 +89,6 @@ void ftrace_destroy_function_files(struct trace_array *tr) · 56 unmodified lines
89	static int function_trace_init(struct trace_array *tr)	89	static int function_trace_init(struct trace_array *tr)
90	{	90	{
91	ftrace_func_t func;	91	ftrace_func_t func;
92
93	/*	92	/*
94	* Instance trace_arrays get their ops allocated	93	* Instance trace_arrays get their ops allocated
95	* at instance creation. Unless it failed	94	* at instance creation. Unless it failed
@@ -129,7 +128,7 @@ static void function_trace_start(struct trace_array *tr) · 33 unmodified lines
129		128
130	static void	129	static void
131	function_trace_call(unsigned long ip, unsigned long parent_ip,	130	function_trace_call(unsigned long ip, unsigned long parent_ip,
132	struct ftrace_ops op, struct pt_regs pt_regs)	131	struct ftrace_ops op, struct ftrace_regs fregs)
133	{	132	{
134	struct trace_array *tr = op->private;	133	struct trace_array *tr = op->private;
135	struct trace_array_cpu *data;	134	struct trace_array_cpu *data;
@@ -178,7 +177,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip, · 42 unmodified lines
178		177
179	static void	178	static void
180	function_stack_trace_call(unsigned long ip, unsigned long parent_ip,	179	function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
181	struct ftrace_ops op, struct pt_regs pt_regs)	180	struct ftrace_ops op, struct ftrace_regs fregs)
182	{	181	{
183	struct trace_array *tr = op->private;	182	struct trace_array *tr = op->private;
184	struct trace_array_cpu *data;	183	struct trace_array_cpu *data;

kernel/trace/trace_irqsoff.c+1−1

@@ -138,7 +138,7 @@ static int func_prolog_dec(struct trace_array *tr, · 137 unmodified lines
138	*/	138	*/
139	static void	139	static void
140	irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,	140	irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip,
141	struct ftrace_ops op, struct pt_regs pt_regs)	141	struct ftrace_ops op, struct ftrace_regs fregs)
142	{	142	{
143	struct trace_array *tr = irqsoff_trace;	143	struct trace_array *tr = irqsoff_trace;
144	struct trace_array_cpu *data;	144	struct trace_array_cpu *data;

kernel/trace/trace_sched_wakeup.c+1−1

@@ -212,7 +212,7 @@ static void wakeup_print_header(struct seq_file *s) · 211 unmodified lines
212	*/	212	*/
213	static void	213	static void
214	wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,	214	wakeup_tracer_call(unsigned long ip, unsigned long parent_ip,
215	struct ftrace_ops op, struct pt_regs pt_regs)	215	struct ftrace_ops op, struct ftrace_regs fregs)
216	{	216	{
217	struct trace_array *tr = wakeup_trace;	217	struct trace_array *tr = wakeup_trace;
218	struct trace_array_cpu *data;	218	struct trace_array_cpu *data;

kernel/trace/trace_selftest.c+11−9

 static void trace_selftest_test_probe1_func(unsigned long ip,
 					    unsigned long pip,
 					    struct ftrace_ops *op,
-					    struct pt_regs *pt_regs)
+					    struct ftrace_regs *fregs)
 {
 	trace_selftest_test_probe1_cnt++;
 }
 static void trace_selftest_test_probe2_func(unsigned long ip,
 					    unsigned long pip,
 					    struct ftrace_ops *op,
-					    struct pt_regs *pt_regs)
+					    struct ftrace_regs *fregs)
 {
 	trace_selftest_test_probe2_cnt++;
 }
 static void trace_selftest_test_probe3_func(unsigned long ip,
 					    unsigned long pip,
 					    struct ftrace_ops *op,
-					    struct pt_regs *pt_regs)
+					    struct ftrace_regs *fregs)
 {
 	trace_selftest_test_probe3_cnt++;
 }
 static void trace_selftest_test_global_func(unsigned long ip,
 					    unsigned long pip,
 					    struct ftrace_ops *op,
-					    struct pt_regs *pt_regs)
+					    struct ftrace_regs *fregs)
 {
 	trace_selftest_test_global_cnt++;
 }
 static void trace_selftest_test_dyn_func(unsigned long ip,
 					 unsigned long pip,
 					 struct ftrace_ops *op,
-					 struct pt_regs *pt_regs)
+					 struct ftrace_regs *fregs)
 {
 	trace_selftest_test_dyn_cnt++;
 }
 static void trace_selftest_test_recursion_func(unsigned long ip,
 					       unsigned long pip,
 					       struct ftrace_ops *op,
-					       struct pt_regs *pt_regs)
+					       struct ftrace_regs *fregs)
 {
 	/*
 	 * This function is registered without the recursion safe flag.
 static void trace_selftest_test_recursion_safe_func(unsigned long ip,
 						    unsigned long pip,
 						    struct ftrace_ops *op,
-						    struct pt_regs *pt_regs)
+						    struct ftrace_regs *fregs)
 {
 	/*
 	 * We said we would provide our own recursion. By calling
 static void trace_selftest_test_regs_func(unsigned long ip,
 					  unsigned long pip,
 					  struct ftrace_ops *op,
-					  struct pt_regs *pt_regs)
+					  struct ftrace_regs *fregs)
 {
-	if (pt_regs)
+	struct pt_regs *regs = ftrace_get_regs(fregs);
+	if (regs)
 		trace_selftest_regs_stat = TRACE_SELFTEST_REGS_FOUND;
 	else
 		trace_selftest_regs_stat = TRACE_SELFTEST_REGS_NOT_FOUND;

kernel/trace/trace_stack.c+1−1

@@ -290,7 +290,7 @@ static void check_stack(unsigned long ip, unsigned long *stack) · 289 unmodified lines
290		290
291	static void	291	static void
292	stack_trace_call(unsigned long ip, unsigned long parent_ip,	292	stack_trace_call(unsigned long ip, unsigned long parent_ip,
293	struct ftrace_ops op, struct pt_regs pt_regs)	293	struct ftrace_ops op, struct ftrace_regs fregs)
294	{	294	{
295	unsigned long stack;	295	unsigned long stack;
296		296

ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs

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