[PATCH 0/2] tracing/triggers: A couple minor variable name changes

[PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Tom Zanussi]

This changes __tt to tt to for the recently submitted kprobes trigger patch,
and does the same for the syscall trigger invocations, which uses the same
unnecessary naming convention pointed out by Steve Rostedt.

The kprobes patch also had trivial changes resulting from the rebase
to current tracing/for-next.

The following changes since commit e0d18fe063464cb3f1a6d1939e4fcf47d92d8386:

  tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT (2014-01-03 15:27:18 -0500)

are available in the git repository at:

  git://git.yoctoproject.org/linux-yocto-contrib.git tzanussi/kprobes-event-triggers-v2
  http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto-contrib/log/?h=tzanussi/kprobes-event-triggers-v2

Tom Zanussi (2):
  tracing/kprobes: Add trace event trigger invocations
  tracing: Remove double-underscore naming in syscall trigger
    invocations

 kernel/trace/trace_kprobe.c   | 42 ++++++++++++++++++++++++++++++++++++------
 kernel/trace/trace_syscalls.c | 16 ++++++++--------
 2 files changed, 44 insertions(+), 14 deletions(-)

-- 
1.8.3.1

[PATCH 1/2 v2] tracing/kprobes: Add trace event trigger invocations

[Tom Zanussi]

Add code to the kprobe/kretprobe event functions that will invoke any
event triggers associated with a probe's ftrace_event_file.

The code to do this is very similar to the invocation code already
used to invoke the triggers associated with static events and
essentially replaces the existing soft-disable checks with a superset
that preserves the original behavior but adds the bits needed to
support event triggers.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
 kernel/trace/trace_kprobe.c | 42 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 36 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index ce0ed8a..3afa716 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -929,12 +929,20 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	struct ring_buffer *buffer;
 	int size, dsize, pc;
 	unsigned long irq_flags;
+	unsigned long eflags;
+	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		return;
+	eflags = ftrace_file->flags;
+
+	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+			event_triggers_call(ftrace_file, NULL);
+		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+			return;
+	}
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -952,9 +960,16 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	entry->ip = (unsigned long)tk->rp.kp.addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (!filter_check_discard(ftrace_file, entry, buffer, event))
+	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+		tt = event_triggers_call(ftrace_file, entry);
+
+	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+		ring_buffer_discard_commit(buffer, event);
+	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
 		trace_buffer_unlock_commit_regs(buffer, event,
 						irq_flags, pc, regs);
+	if (tt)
+		event_triggers_post_call(ftrace_file, tt);
 }
 
 static __kprobes void
@@ -977,12 +992,20 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	struct ring_buffer *buffer;
 	int size, pc, dsize;
 	unsigned long irq_flags;
+	unsigned long eflags;
+	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		return;
+	eflags = ftrace_file->flags;
+
+	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+			event_triggers_call(ftrace_file, NULL);
+		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+			return;
+	}
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -1001,9 +1024,16 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	entry->ret_ip = (unsigned long)ri->ret_addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (!filter_check_discard(ftrace_file, entry, buffer, event))
+	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+		tt = event_triggers_call(ftrace_file, entry);
+
+	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+		ring_buffer_discard_commit(buffer, event);
+	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
 		trace_buffer_unlock_commit_regs(buffer, event,
 						irq_flags, pc, regs);
+	if (tt)
+		event_triggers_post_call(ftrace_file, tt);
 }
 
 static __kprobes void
-- 
1.8.3.1

Re: [PATCH 1/2 v2] tracing/kprobes: Add trace event trigger invocations

[Masami Hiramatsu]

(2014/01/07 4:44), Tom Zanussi wrote:
> Add code to the kprobe/kretprobe event functions that will invoke any
> event triggers associated with a probe's ftrace_event_file.
> 
> The code to do this is very similar to the invocation code already
> used to invoke the triggers associated with static events and
> essentially replaces the existing soft-disable checks with a superset
> that preserves the original behavior but adds the bits needed to
> support event triggers.
> 
> Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>

Looks good for me :) BTW, we'll need similar code for trace_uprobe.c too.

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thank you,

> ---
>  kernel/trace/trace_kprobe.c | 42 ++++++++++++++++++++++++++++++++++++------
>  1 file changed, 36 insertions(+), 6 deletions(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index ce0ed8a..3afa716 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -929,12 +929,20 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>  	struct ring_buffer *buffer;
>  	int size, dsize, pc;
>  	unsigned long irq_flags;
> +	unsigned long eflags;
> +	enum event_trigger_type tt = ETT_NONE;
>  	struct ftrace_event_call *call = &tk->tp.call;
>  
>  	WARN_ON(call != ftrace_file->event_call);
>  
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> -		return;
> +	eflags = ftrace_file->flags;
> +
> +	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> +		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> +			event_triggers_call(ftrace_file, NULL);
> +		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> +			return;
> +	}
>  
>  	local_save_flags(irq_flags);
>  	pc = preempt_count();
> @@ -952,9 +960,16 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>  	entry->ip = (unsigned long)tk->rp.kp.addr;
>  	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
>  
> -	if (!filter_check_discard(ftrace_file, entry, buffer, event))
> +	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> +		tt = event_triggers_call(ftrace_file, entry);
> +
> +	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> +		ring_buffer_discard_commit(buffer, event);
> +	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
>  		trace_buffer_unlock_commit_regs(buffer, event,
>  						irq_flags, pc, regs);
> +	if (tt)
> +		event_triggers_post_call(ftrace_file, tt);
>  }
>  
>  static __kprobes void
> @@ -977,12 +992,20 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>  	struct ring_buffer *buffer;
>  	int size, pc, dsize;
>  	unsigned long irq_flags;
> +	unsigned long eflags;
> +	enum event_trigger_type tt = ETT_NONE;
>  	struct ftrace_event_call *call = &tk->tp.call;
>  
>  	WARN_ON(call != ftrace_file->event_call);
>  
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> -		return;
> +	eflags = ftrace_file->flags;
> +
> +	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> +		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> +			event_triggers_call(ftrace_file, NULL);
> +		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> +			return;
> +	}
>  
>  	local_save_flags(irq_flags);
>  	pc = preempt_count();
> @@ -1001,9 +1024,16 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>  	entry->ret_ip = (unsigned long)ri->ret_addr;
>  	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
>  
> -	if (!filter_check_discard(ftrace_file, entry, buffer, event))
> +	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> +		tt = event_triggers_call(ftrace_file, entry);
> +
> +	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> +		ring_buffer_discard_commit(buffer, event);
> +	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
>  		trace_buffer_unlock_commit_regs(buffer, event,
>  						irq_flags, pc, regs);
> +	if (tt)
> +		event_triggers_post_call(ftrace_file, tt);
>  }
>  
>  static __kprobes void
> 


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com

[PATCH 2/2] tracing: Remove double-underscore naming in syscall trigger invocations

[Tom Zanussi]

There's no reason to use double-underscores for any variable name in
ftrace_syscall_enter()/exit(), since those functions aren't generated
and there's no need to avoid namespace collisions as with the event
macros, which is where the original invocation code came from.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
 kernel/trace/trace_syscalls.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index fdd955f..a4acf9b 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -306,7 +306,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type __tt = ETT_NONE;
+	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
 	unsigned long eflags;
@@ -352,15 +352,15 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
 	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		__tt = event_triggers_call(ftrace_file, entry);
+		tt = event_triggers_call(ftrace_file, entry);
 
 	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
 		ring_buffer_discard_commit(buffer, event);
 	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
 		trace_current_buffer_unlock_commit(buffer, event,
 						   irq_flags, pc);
-	if (__tt)
-		event_triggers_post_call(ftrace_file, __tt);
+	if (tt)
+		event_triggers_post_call(ftrace_file, tt);
 }
 
 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@@ -370,7 +370,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type __tt = ETT_NONE;
+	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
 	unsigned long eflags;
@@ -414,15 +414,15 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	entry->ret = syscall_get_return_value(current, regs);
 
 	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		__tt = event_triggers_call(ftrace_file, entry);
+		tt = event_triggers_call(ftrace_file, entry);
 
 	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
 		ring_buffer_discard_commit(buffer, event);
 	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
 		trace_current_buffer_unlock_commit(buffer, event,
 						   irq_flags, pc);
-	if (__tt)
-		event_triggers_post_call(ftrace_file, __tt);
+	if (tt)
+		event_triggers_post_call(ftrace_file, tt);
 }
 
 static int reg_event_syscall_enter(struct ftrace_event_file *file,
-- 
1.8.3.1

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Steven Rostedt]

I applied these locally, but I'm also going to apply this patch to get
rid of all that duplicate code. Any objections? (or do you see any
mistakes? I only compiled and boot tested it, nothing more strenuous) I
will do that before pushing it though.

-- Steve

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 03d2db2..ccda66f 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -370,6 +370,75 @@ extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *fil
 extern void event_triggers_post_call(struct ftrace_event_file *file,
 				     enum event_trigger_type tt);
 
+static inline int
+ftrace_trigger_call_disabled(struct ftrace_event_file *file)
+{
+	unsigned long eflags = file->flags;
+
+	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+			event_triggers_call(file, NULL);
+		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+			return 1;
+	}
+	return 0;
+}
+
+static inline int
+__event_trigger_test_discard(struct ftrace_event_file *file,
+			     struct ring_buffer *buffer,
+			     struct ring_buffer_event *event,
+			     void *entry,
+			     enum event_trigger_type *tt)
+{
+	unsigned long eflags = file->flags;
+
+	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+		*tt = event_triggers_call(file, entry);
+
+	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
+		ring_buffer_discard_commit(buffer, event);
+	else if (!filter_check_discard(file, entry, buffer, event))
+		return 1;
+
+	return 0;
+}
+
+static inline void
+event_trigger_unlock_commit(struct ftrace_event_file *file,
+			    struct ring_buffer *buffer,
+			    struct ring_buffer_event *event,
+			    void *entry, unsigned long irq_flags, int pc)
+{
+	unsigned long eflags = file->flags;
+	enum event_trigger_type tt = ETT_NONE;
+
+	if (__event_trigger_test_discard(file, buffer, event, entry, &tt))
+		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+
+	if (tt)
+		event_triggers_post_call(file, tt);
+}
+
+
+static inline void
+event_trigger_unlock_commit_regs(struct ftrace_event_file *file,
+				 struct ring_buffer *buffer,
+				 struct ring_buffer_event *event,
+				 void *entry, unsigned long irq_flags, int pc,
+				 struct pt_regs *regs)
+{
+	unsigned long eflags = file->flags;
+	enum event_trigger_type tt = ETT_NONE;
+
+	if (__event_trigger_test_discard(file, buffer, event, entry, &tt))
+		trace_buffer_unlock_commit_regs(buffer, event,
+						irq_flags, pc, regs);
+
+	if (tt)
+		event_triggers_post_call(file, tt);
+}
+
 enum {
 	FILTER_OTHER = 0,
 	FILTER_STATIC_STRING,
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 0962968..7a43935 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -546,8 +546,6 @@ ftrace_raw_event_##call(void *__data, proto)				\
 	struct ftrace_event_file *ftrace_file = __data;			\
 	struct ftrace_event_call *event_call = ftrace_file->event_call;	\
 	struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
-	unsigned long eflags = ftrace_file->flags;			\
-	enum event_trigger_type __tt = ETT_NONE;			\
 	struct ring_buffer_event *event;				\
 	struct ftrace_raw_##call *entry;				\
 	struct ring_buffer *buffer;					\
@@ -555,12 +553,8 @@ ftrace_raw_event_##call(void *__data, proto)				\
 	int __data_size;						\
 	int pc;								\
 									\
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {			\
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)		\
-			event_triggers_call(ftrace_file, NULL);		\
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)		\
-			return;						\
-	}								\
+	if (ftrace_trigger_call_disabled(ftrace_file))			\
+		return;							\
 									\
 	local_save_flags(irq_flags);					\
 	pc = preempt_count();						\
@@ -579,17 +573,8 @@ ftrace_raw_event_##call(void *__data, proto)				\
 									\
 	{ assign; }							\
 									\
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)			\
-		__tt = event_triggers_call(ftrace_file, entry);		\
-									\
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT,                 \
-		     &ftrace_file->flags))                              \
-		ring_buffer_discard_commit(buffer, event);              \
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event)) \
-		trace_buffer_unlock_commit(buffer, event, irq_flags, pc); \
-									\
-	if (__tt)							\
-		event_triggers_post_call(ftrace_file, __tt);		\
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry, \
+				    irq_flags, pc);		       \
 }
 /*
  * The ftrace_test_probe is compiled out, it is only here as a build time check
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3afa716..196b427 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -929,20 +929,12 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	struct ring_buffer *buffer;
 	int size, dsize, pc;
 	unsigned long irq_flags;
-	unsigned long eflags;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_call_disabled(ftrace_file))
+		return;
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -960,16 +952,8 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	entry->ip = (unsigned long)tk->rp.kp.addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_buffer_unlock_commit_regs(buffer, event,
-						irq_flags, pc, regs);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
+					 entry, irq_flags, pc, regs);
 }
 
 static __kprobes void
@@ -992,20 +976,12 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	struct ring_buffer *buffer;
 	int size, pc, dsize;
 	unsigned long irq_flags;
-	unsigned long eflags;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_call_disabled(ftrace_file))
+		return;
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -1024,16 +1000,8 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	entry->ret_ip = (unsigned long)ri->ret_addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_buffer_unlock_commit_regs(buffer, event,
-						irq_flags, pc, regs);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
+					 entry, irq_flags, pc, regs);
 }
 
 static __kprobes void
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index a4acf9b..6d407eb 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -306,10 +306,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
-	unsigned long eflags;
 	int pc;
 	int syscall_nr;
 	int size;
@@ -323,14 +321,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	if (!ftrace_file)
 		return;
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_call_disabled(ftrace_file))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -351,16 +343,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	entry->nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_current_buffer_unlock_commit(buffer, event,
-						   irq_flags, pc);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+				    irq_flags, pc);
 }
 
 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@@ -370,10 +354,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
-	unsigned long eflags;
 	int pc;
 	int syscall_nr;
 
@@ -386,14 +368,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	if (!ftrace_file)
 		return;
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_call_disabled(ftrace_file))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -413,16 +389,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	entry->nr = syscall_nr;
 	entry->ret = syscall_get_return_value(current, regs);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_current_buffer_unlock_commit(buffer, event,
-						   irq_flags, pc);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+				    irq_flags, pc);
 }
 
 static int reg_event_syscall_enter(struct ftrace_event_file *file,

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Tom Zanussi]

Hi Steve,

On Mon, 2014-01-06 at 16:13 -0500, Steven Rostedt wrote:
> I applied these locally, but I'm also going to apply this patch to get
> rid of all that duplicate code. Any objections? (or do you see any
> mistakes? I only compiled and boot tested it, nothing more strenuous) I
> will do that before pushing it though.
> 

It's a nice cleanup, and from my reading of it, the logic is all
correct, but there are a couple things that I think are a bit misleading
in the naming, see below..

> -- Steve
> 
> diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
> index 03d2db2..ccda66f 100644
> --- a/include/linux/ftrace_event.h
> +++ b/include/linux/ftrace_event.h
> @@ -370,6 +370,75 @@ extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *fil
>  extern void event_triggers_post_call(struct ftrace_event_file *file,
>  				     enum event_trigger_type tt);
>  
> +static inline int
> +ftrace_trigger_call_disabled(struct ftrace_event_file *file)
> +{
> +	unsigned long eflags = file->flags;
> +
> +	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> +		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> +			event_triggers_call(file, NULL);
> +		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> +			return 1;
> +	}
> +	return 0;
> +}
> +

ftrace_trigger_call_disabled() as a name is OK, but it makes it sound
like the trigger calls are disabled if it returns 1, when it actually
can invoke the triggers when it returns 1, in cases where there's no
reason to delay them.  ftrace_call_triggers_check_soft_disabled() is
more accurate but too unwieldy, so I'm not coming up with anything
better.  Maybe ftrace_trigger_soft_disabled() reads better, or not.
Punting...

> +static inline int
> +__event_trigger_test_discard(struct ftrace_event_file *file,
> +			     struct ring_buffer *buffer,
> +			     struct ring_buffer_event *event,
> +			     void *entry,
> +			     enum event_trigger_type *tt)
> +{
> +	unsigned long eflags = file->flags;
> +
> +	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> +		*tt = event_triggers_call(file, entry);
> +
> +	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
> +		ring_buffer_discard_commit(buffer, event);
> +	else if (!filter_check_discard(file, entry, buffer, event))
> +		return 1;

If the function is called ..._discard() then shouldn't it return 0 if it
didn't discard?

> +
> +	return 0;
> +}
> +
> +static inline void
> +event_trigger_unlock_commit(struct ftrace_event_file *file,
> +			    struct ring_buffer *buffer,
> +			    struct ring_buffer_event *event,
> +			    void *entry, unsigned long irq_flags, int pc)
> +{
> +	unsigned long eflags = file->flags;

eflags isn't used in this function...

> +	enum event_trigger_type tt = ETT_NONE;
> +
> +	if (__event_trigger_test_discard(file, buffer, event, entry, &tt))
> +		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);

The logic is correct overall, but the way it reads is the opposite of
what it used to i.e. it should read 'if you don't discard the event,
then do the trace_buffer_unlock_commit' - it works as written because it
returns 1 if it didn't discard, which is confusing.

> +
> +	if (tt)
> +		event_triggers_post_call(file, tt);
> +}
> +
> +
> +static inline void
> +event_trigger_unlock_commit_regs(struct ftrace_event_file *file,
> +				 struct ring_buffer *buffer,
> +				 struct ring_buffer_event *event,
> +				 void *entry, unsigned long irq_flags, int pc,
> +				 struct pt_regs *regs)
> +{
> +	unsigned long eflags = file->flags;

Ditto here on the unused eflags.

Tom

> +	enum event_trigger_type tt = ETT_NONE;
> +
> +	if (__event_trigger_test_discard(file, buffer, event, entry, &tt))
> +		trace_buffer_unlock_commit_regs(buffer, event,
> +						irq_flags, pc, regs);
> +
> +	if (tt)
> +		event_triggers_post_call(file, tt);
> +}
> +
>  enum {
>  	FILTER_OTHER = 0,
>  	FILTER_STATIC_STRING,
> diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
> index 0962968..7a43935 100644
> --- a/include/trace/ftrace.h
> +++ b/include/trace/ftrace.h
> @@ -546,8 +546,6 @@ ftrace_raw_event_##call(void *__data, proto)				\
>  	struct ftrace_event_file *ftrace_file = __data;			\
>  	struct ftrace_event_call *event_call = ftrace_file->event_call;	\
>  	struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
> -	unsigned long eflags = ftrace_file->flags;			\
> -	enum event_trigger_type __tt = ETT_NONE;			\
>  	struct ring_buffer_event *event;				\
>  	struct ftrace_raw_##call *entry;				\
>  	struct ring_buffer *buffer;					\
> @@ -555,12 +553,8 @@ ftrace_raw_event_##call(void *__data, proto)				\
>  	int __data_size;						\
>  	int pc;								\
>  									\
> -	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {			\
> -		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)		\
> -			event_triggers_call(ftrace_file, NULL);		\
> -		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)		\
> -			return;						\
> -	}								\
> +	if (ftrace_trigger_call_disabled(ftrace_file))			\
> +		return;							\
>  									\
>  	local_save_flags(irq_flags);					\
>  	pc = preempt_count();						\
> @@ -579,17 +573,8 @@ ftrace_raw_event_##call(void *__data, proto)				\
>  									\
>  	{ assign; }							\
>  									\
> -	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)			\
> -		__tt = event_triggers_call(ftrace_file, entry);		\
> -									\
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT,                 \
> -		     &ftrace_file->flags))                              \
> -		ring_buffer_discard_commit(buffer, event);              \
> -	else if (!filter_check_discard(ftrace_file, entry, buffer, event)) \
> -		trace_buffer_unlock_commit(buffer, event, irq_flags, pc); \
> -									\
> -	if (__tt)							\
> -		event_triggers_post_call(ftrace_file, __tt);		\
> +	event_trigger_unlock_commit(ftrace_file, buffer, event, entry, \
> +				    irq_flags, pc);		       \
>  }
>  /*
>   * The ftrace_test_probe is compiled out, it is only here as a build time check
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 3afa716..196b427 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -929,20 +929,12 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>  	struct ring_buffer *buffer;
>  	int size, dsize, pc;
>  	unsigned long irq_flags;
> -	unsigned long eflags;
> -	enum event_trigger_type tt = ETT_NONE;
>  	struct ftrace_event_call *call = &tk->tp.call;
>  
>  	WARN_ON(call != ftrace_file->event_call);
>  
> -	eflags = ftrace_file->flags;
> -
> -	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> -		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> -			event_triggers_call(ftrace_file, NULL);
> -		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> -			return;
> -	}
> +	if (ftrace_trigger_call_disabled(ftrace_file))
> +		return;
>  
>  	local_save_flags(irq_flags);
>  	pc = preempt_count();
> @@ -960,16 +952,8 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
>  	entry->ip = (unsigned long)tk->rp.kp.addr;
>  	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
>  
> -	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> -		tt = event_triggers_call(ftrace_file, entry);
> -
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> -		ring_buffer_discard_commit(buffer, event);
> -	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
> -		trace_buffer_unlock_commit_regs(buffer, event,
> -						irq_flags, pc, regs);
> -	if (tt)
> -		event_triggers_post_call(ftrace_file, tt);
> +	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
> +					 entry, irq_flags, pc, regs);
>  }
>  
>  static __kprobes void
> @@ -992,20 +976,12 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>  	struct ring_buffer *buffer;
>  	int size, pc, dsize;
>  	unsigned long irq_flags;
> -	unsigned long eflags;
> -	enum event_trigger_type tt = ETT_NONE;
>  	struct ftrace_event_call *call = &tk->tp.call;
>  
>  	WARN_ON(call != ftrace_file->event_call);
>  
> -	eflags = ftrace_file->flags;
> -
> -	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> -		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> -			event_triggers_call(ftrace_file, NULL);
> -		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> -			return;
> -	}
> +	if (ftrace_trigger_call_disabled(ftrace_file))
> +		return;
>  
>  	local_save_flags(irq_flags);
>  	pc = preempt_count();
> @@ -1024,16 +1000,8 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>  	entry->ret_ip = (unsigned long)ri->ret_addr;
>  	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
>  
> -	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> -		tt = event_triggers_call(ftrace_file, entry);
> -
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> -		ring_buffer_discard_commit(buffer, event);
> -	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
> -		trace_buffer_unlock_commit_regs(buffer, event,
> -						irq_flags, pc, regs);
> -	if (tt)
> -		event_triggers_post_call(ftrace_file, tt);
> +	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
> +					 entry, irq_flags, pc, regs);
>  }
>  
>  static __kprobes void
> diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
> index a4acf9b..6d407eb 100644
> --- a/kernel/trace/trace_syscalls.c
> +++ b/kernel/trace/trace_syscalls.c
> @@ -306,10 +306,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
>  	struct syscall_trace_enter *entry;
>  	struct syscall_metadata *sys_data;
>  	struct ring_buffer_event *event;
> -	enum event_trigger_type tt = ETT_NONE;
>  	struct ring_buffer *buffer;
>  	unsigned long irq_flags;
> -	unsigned long eflags;
>  	int pc;
>  	int syscall_nr;
>  	int size;
> @@ -323,14 +321,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
>  	if (!ftrace_file)
>  		return;
>  
> -	eflags = ftrace_file->flags;
> -
> -	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> -		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> -			event_triggers_call(ftrace_file, NULL);
> -		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> -			return;
> -	}
> +	if (ftrace_trigger_call_disabled(ftrace_file))
> +		return;
>  
>  	sys_data = syscall_nr_to_meta(syscall_nr);
>  	if (!sys_data)
> @@ -351,16 +343,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
>  	entry->nr = syscall_nr;
>  	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
>  
> -	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> -		tt = event_triggers_call(ftrace_file, entry);
> -
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> -		ring_buffer_discard_commit(buffer, event);
> -	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
> -		trace_current_buffer_unlock_commit(buffer, event,
> -						   irq_flags, pc);
> -	if (tt)
> -		event_triggers_post_call(ftrace_file, tt);
> +	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
> +				    irq_flags, pc);
>  }
>  
>  static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
> @@ -370,10 +354,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
>  	struct syscall_trace_exit *entry;
>  	struct syscall_metadata *sys_data;
>  	struct ring_buffer_event *event;
> -	enum event_trigger_type tt = ETT_NONE;
>  	struct ring_buffer *buffer;
>  	unsigned long irq_flags;
> -	unsigned long eflags;
>  	int pc;
>  	int syscall_nr;
>  
> @@ -386,14 +368,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
>  	if (!ftrace_file)
>  		return;
>  
> -	eflags = ftrace_file->flags;
> -
> -	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> -		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> -			event_triggers_call(ftrace_file, NULL);
> -		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> -			return;
> -	}
> +	if (ftrace_trigger_call_disabled(ftrace_file))
> +		return;
>  
>  	sys_data = syscall_nr_to_meta(syscall_nr);
>  	if (!sys_data)
> @@ -413,16 +389,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
>  	entry->nr = syscall_nr;
>  	entry->ret = syscall_get_return_value(current, regs);
>  
> -	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> -		tt = event_triggers_call(ftrace_file, entry);
> -
> -	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
> -		ring_buffer_discard_commit(buffer, event);
> -	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
> -		trace_current_buffer_unlock_commit(buffer, event,
> -						   irq_flags, pc);
> -	if (tt)
> -		event_triggers_post_call(ftrace_file, tt);
> +	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
> +				    irq_flags, pc);
>  }
>  
>  static int reg_event_syscall_enter(struct ftrace_event_file *file,

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Steven Rostedt]

On Mon, 06 Jan 2014 18:47:53 -0600

> > diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
> > index 03d2db2..ccda66f 100644
> > --- a/include/linux/ftrace_event.h
> > +++ b/include/linux/ftrace_event.h
> > @@ -370,6 +370,75 @@ extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *fil
> >  extern void event_triggers_post_call(struct ftrace_event_file *file,
> >  				     enum event_trigger_type tt);
> >  
> > +static inline int
> > +ftrace_trigger_call_disabled(struct ftrace_event_file *file)
> > +{
> > +	unsigned long eflags = file->flags;
> > +
> > +	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
> > +		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
> > +			event_triggers_call(file, NULL);
> > +		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
> > +			return 1;
> > +	}
> > +	return 0;
> > +}
> > +
> 
> ftrace_trigger_call_disabled() as a name is OK, but it makes it sound
> like the trigger calls are disabled if it returns 1, when it actually
> can invoke the triggers when it returns 1, in cases where there's no
> reason to delay them.  ftrace_call_triggers_check_soft_disabled() is
> more accurate but too unwieldy, so I'm not coming up with anything
> better.  Maybe ftrace_trigger_soft_disabled() reads better, or not.
> Punting...

Honestly, I just whipped those names up out of the blue. Yeah,
ftrace_trigger_soft_disabled() sounds better. Will switch.

> 
> > +static inline int
> > +__event_trigger_test_discard(struct ftrace_event_file *file,
> > +			     struct ring_buffer *buffer,
> > +			     struct ring_buffer_event *event,
> > +			     void *entry,
> > +			     enum event_trigger_type *tt)
> > +{
> > +	unsigned long eflags = file->flags;
> > +
> > +	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
> > +		*tt = event_triggers_call(file, entry);
> > +
> > +	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
> > +		ring_buffer_discard_commit(buffer, event);
> > +	else if (!filter_check_discard(file, entry, buffer, event))
> > +		return 1;
> 
> If the function is called ..._discard() then shouldn't it return 0 if it
> didn't discard?

Hmm, this was a ugly helper function (hence the "__" ;-) I really
couldn't think of a good name. Actually, it's called "test_discard"
which means it's just a test to know if it should discard or not.

How about if I switch it to ".._discard_test" and just comment what it
returns? I was going to add comments regardless.

> 
> > +
> > +	return 0;
> > +}
> > +
> > +static inline void
> > +event_trigger_unlock_commit(struct ftrace_event_file *file,
> > +			    struct ring_buffer *buffer,
> > +			    struct ring_buffer_event *event,
> > +			    void *entry, unsigned long irq_flags, int pc)
> > +{
> > +	unsigned long eflags = file->flags;
> 
> eflags isn't used in this function...

Hah, thanks. It originally was before I created the
__event_trigger_test_discard() helper function. My extensive tests would
have caught that too, but thanks. That saved me from having to fix it
before running the tests again.

> 
> > +	enum event_trigger_type tt = ETT_NONE;
> > +
> > +	if (__event_trigger_test_discard(file, buffer, event, entry, &tt))
> > +		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
> 
> The logic is correct overall, but the way it reads is the opposite of
> what it used to i.e. it should read 'if you don't discard the event,
> then do the trace_buffer_unlock_commit' - it works as written because it
> returns 1 if it didn't discard, which is confusing.

Hmm, OK, I think you may have convinced me. I'll swap the return values.

I need to write up some trigger tests to make sure they work the same
before and after this patch.

> 
> > +
> > +	if (tt)
> > +		event_triggers_post_call(file, tt);
> > +}
> > +
> > +
> > +static inline void
> > +event_trigger_unlock_commit_regs(struct ftrace_event_file *file,
> > +				 struct ring_buffer *buffer,
> > +				 struct ring_buffer_event *event,
> > +				 void *entry, unsigned long irq_flags, int pc,
> > +				 struct pt_regs *regs)
> > +{
> > +	unsigned long eflags = file->flags;
> 
> Ditto here on the unused eflags.

This one was cut and pasted added.

Thanks!

-- Steve

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Tom Zanussi]

> 
> > > +	enum event_trigger_type tt = ETT_NONE;
> > > +
> > > +	if (__event_trigger_test_discard(file, buffer, event, entry, &tt))
> > > +		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
> > 
> > The logic is correct overall, but the way it reads is the opposite of
> > what it used to i.e. it should read 'if you don't discard the event,
> > then do the trace_buffer_unlock_commit' - it works as written because it
> > returns 1 if it didn't discard, which is confusing.
> 
> Hmm, OK, I think you may have convinced me. I'll swap the return values.
> 

Sounds great, thanks!

> I need to write up some trigger tests to make sure they work the same
> before and after this patch.
> 

I'll run the next version through my 'testsuite', which unfortunately is
still manual (one of the many things on my todo list is automate it)..

Tom

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Steven Rostedt]

On Mon, 06 Jan 2014 20:51:09 -0600
Tom Zanussi <tom.zanussi@linux.intel.com> wrote:

 
> > Hmm, OK, I think you may have convinced me. I'll swap the return values.
> > 
> 
> Sounds great, thanks!

New patch.

-- Steve

tracing: Consolidate event trigger code

The event trigger code that checks for callback triggers before and
after recording of an event has lots of flags checks. This code is
duplicated throughout the ftrace events, kprobes and system calls.
They all do the exact same checks against the event flags.

Added helper functions ftrace_trigger_soft_disabled(),
event_trigger_unlock_commit() and event_trigger_unlock_commit_regs()
that consolidated the code and these are used instead.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/ftrace_event.h  | 117 ++++++++++++++++++++++++++++++++++++++++++
 include/trace/ftrace.h        |  23 ++-------
 kernel/trace/trace_kprobe.c   |  48 +++--------------
 kernel/trace/trace_syscalls.c |  48 +++--------------
 4 files changed, 137 insertions(+), 99 deletions(-)

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 03d2db2..4e4cc28 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -370,6 +370,123 @@ extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *fil
 extern void event_triggers_post_call(struct ftrace_event_file *file,
 				     enum event_trigger_type tt);
 
+/**
+ * ftrace_trigger_soft_disabled - do triggers and test if soft disabled
+ * @file: The file pointer of the event to test
+ *
+ * If any triggers without filters are attached to this event, they
+ * will be called here. If the event is soft disabled and has no
+ * triggers that require testing the fields, it will return true,
+ * otherwise false.
+ */
+static inline bool
+ftrace_trigger_soft_disabled(struct ftrace_event_file *file)
+{
+	unsigned long eflags = file->flags;
+
+	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+			event_triggers_call(file, NULL);
+		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+			return true;
+	}
+	return false;
+}
+
+/*
+ * Helper function for event_trigger_unlock_commit{_regs}().
+ * If there are event triggers attached to this event that requires
+ * filtering against its fields, then they wil be called as the
+ * entry already holds the field information of the current event.
+ *
+ * It also checks if the event should be discarded or not.
+ * It is to be discarded if the event is soft disabled and the
+ * event was only recorded to process triggers, or if the event
+ * filter is active and this event did not match the filters.
+ *
+ * Returns true if the event is discarded, false otherwise.
+ */
+static inline bool
+__event_trigger_test_discard(struct ftrace_event_file *file,
+			     struct ring_buffer *buffer,
+			     struct ring_buffer_event *event,
+			     void *entry,
+			     enum event_trigger_type *tt)
+{
+	unsigned long eflags = file->flags;
+
+	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+		*tt = event_triggers_call(file, entry);
+
+	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags))
+		ring_buffer_discard_commit(buffer, event);
+	else if (!filter_check_discard(file, entry, buffer, event))
+		return false;
+
+	return true;
+}
+
+/**
+ * event_trigger_unlock_commit - handle triggers and finish event commit
+ * @file: The file pointer assoctiated to the event
+ * @buffer: The ring buffer that the event is being written to
+ * @event: The event meta data in the ring buffer
+ * @entry: The event itself
+ * @irq_flags: The state of the interrupts at the start of the event
+ * @pc: The state of the preempt count at the start of the event.
+ *
+ * This is a helper function to handle triggers that require data
+ * from the event itself. It also tests the event against filters and
+ * if the event is soft disabled and should be discarded.
+ */
+static inline void
+event_trigger_unlock_commit(struct ftrace_event_file *file,
+			    struct ring_buffer *buffer,
+			    struct ring_buffer_event *event,
+			    void *entry, unsigned long irq_flags, int pc)
+{
+	enum event_trigger_type tt = ETT_NONE;
+
+	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
+		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+
+	if (tt)
+		event_triggers_post_call(file, tt);
+}
+
+/**
+ * event_trigger_unlock_commit_regs - handle triggers and finish event commit
+ * @file: The file pointer assoctiated to the event
+ * @buffer: The ring buffer that the event is being written to
+ * @event: The event meta data in the ring buffer
+ * @entry: The event itself
+ * @irq_flags: The state of the interrupts at the start of the event
+ * @pc: The state of the preempt count at the start of the event.
+ *
+ * This is a helper function to handle triggers that require data
+ * from the event itself. It also tests the event against filters and
+ * if the event is soft disabled and should be discarded.
+ *
+ * Same as event_trigger_unlock_commit() but calls
+ * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
+ */
+static inline void
+event_trigger_unlock_commit_regs(struct ftrace_event_file *file,
+				 struct ring_buffer *buffer,
+				 struct ring_buffer_event *event,
+				 void *entry, unsigned long irq_flags, int pc,
+				 struct pt_regs *regs)
+{
+	enum event_trigger_type tt = ETT_NONE;
+
+	if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
+		trace_buffer_unlock_commit_regs(buffer, event,
+						irq_flags, pc, regs);
+
+	if (tt)
+		event_triggers_post_call(file, tt);
+}
+
 enum {
 	FILTER_OTHER = 0,
 	FILTER_STATIC_STRING,
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 0962968..1a8b28d 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -546,8 +546,6 @@ ftrace_raw_event_##call(void *__data, proto)				\
 	struct ftrace_event_file *ftrace_file = __data;			\
 	struct ftrace_event_call *event_call = ftrace_file->event_call;	\
 	struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
-	unsigned long eflags = ftrace_file->flags;			\
-	enum event_trigger_type __tt = ETT_NONE;			\
 	struct ring_buffer_event *event;				\
 	struct ftrace_raw_##call *entry;				\
 	struct ring_buffer *buffer;					\
@@ -555,12 +553,8 @@ ftrace_raw_event_##call(void *__data, proto)				\
 	int __data_size;						\
 	int pc;								\
 									\
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {			\
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)		\
-			event_triggers_call(ftrace_file, NULL);		\
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)		\
-			return;						\
-	}								\
+	if (ftrace_trigger_soft_disabled(ftrace_file))			\
+		return;							\
 									\
 	local_save_flags(irq_flags);					\
 	pc = preempt_count();						\
@@ -579,17 +573,8 @@ ftrace_raw_event_##call(void *__data, proto)				\
 									\
 	{ assign; }							\
 									\
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)			\
-		__tt = event_triggers_call(ftrace_file, entry);		\
-									\
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT,                 \
-		     &ftrace_file->flags))                              \
-		ring_buffer_discard_commit(buffer, event);              \
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event)) \
-		trace_buffer_unlock_commit(buffer, event, irq_flags, pc); \
-									\
-	if (__tt)							\
-		event_triggers_post_call(ftrace_file, __tt);		\
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry, \
+				    irq_flags, pc);		       \
 }
 /*
  * The ftrace_test_probe is compiled out, it is only here as a build time check
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3afa716..bdbae45 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -929,20 +929,12 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	struct ring_buffer *buffer;
 	int size, dsize, pc;
 	unsigned long irq_flags;
-	unsigned long eflags;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -960,16 +952,8 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	entry->ip = (unsigned long)tk->rp.kp.addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_buffer_unlock_commit_regs(buffer, event,
-						irq_flags, pc, regs);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
+					 entry, irq_flags, pc, regs);
 }
 
 static __kprobes void
@@ -992,20 +976,12 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	struct ring_buffer *buffer;
 	int size, pc, dsize;
 	unsigned long irq_flags;
-	unsigned long eflags;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ftrace_event_call *call = &tk->tp.call;
 
 	WARN_ON(call != ftrace_file->event_call);
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	local_save_flags(irq_flags);
 	pc = preempt_count();
@@ -1024,16 +1000,8 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	entry->ret_ip = (unsigned long)ri->ret_addr;
 	store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_buffer_unlock_commit_regs(buffer, event,
-						irq_flags, pc, regs);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit_regs(ftrace_file, buffer, event,
+					 entry, irq_flags, pc, regs);
 }
 
 static __kprobes void
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index a4acf9b..759d5e0 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -306,10 +306,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
-	unsigned long eflags;
 	int pc;
 	int syscall_nr;
 	int size;
@@ -323,14 +321,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	if (!ftrace_file)
 		return;
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -351,16 +343,8 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	entry->nr = syscall_nr;
 	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_current_buffer_unlock_commit(buffer, event,
-						   irq_flags, pc);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+				    irq_flags, pc);
 }
 
 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@@ -370,10 +354,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	enum event_trigger_type tt = ETT_NONE;
 	struct ring_buffer *buffer;
 	unsigned long irq_flags;
-	unsigned long eflags;
 	int pc;
 	int syscall_nr;
 
@@ -386,14 +368,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	if (!ftrace_file)
 		return;
 
-	eflags = ftrace_file->flags;
-
-	if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
-		if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
-			event_triggers_call(ftrace_file, NULL);
-		if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
-			return;
-	}
+	if (ftrace_trigger_soft_disabled(ftrace_file))
+		return;
 
 	sys_data = syscall_nr_to_meta(syscall_nr);
 	if (!sys_data)
@@ -413,16 +389,8 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	entry->nr = syscall_nr;
 	entry->ret = syscall_get_return_value(current, regs);
 
-	if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
-		tt = event_triggers_call(ftrace_file, entry);
-
-	if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
-		ring_buffer_discard_commit(buffer, event);
-	else if (!filter_check_discard(ftrace_file, entry, buffer, event))
-		trace_current_buffer_unlock_commit(buffer, event,
-						   irq_flags, pc);
-	if (tt)
-		event_triggers_post_call(ftrace_file, tt);
+	event_trigger_unlock_commit(ftrace_file, buffer, event, entry,
+				    irq_flags, pc);
 }
 
 static int reg_event_syscall_enter(struct ftrace_event_file *file,
-- 
1.8.1.4

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Tom Zanussi]

On Mon, 2014-01-06 at 22:27 -0500, Steven Rostedt wrote:
> On Mon, 06 Jan 2014 20:51:09 -0600
> Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
> 
>  
> > > Hmm, OK, I think you may have convinced me. I'll swap the return values.
> > > 
> > 
> > Sounds great, thanks!
> 
> New patch.
> 

Looks good to me and passes my normal testing.

Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>

Just so you know what encompasses my 'normal testing', below is what I
normally run through - if everything checks out, I'm satisfied things
are basically good, though of course it didn't catch your traceoff bug
so it's not complete.

As soon as I get the chance, I'll automate it and add more tests for
completeness - as it is it's grown into something that already takes too
long to do manually, so I need to find the time....

---- basic high-level check
     - quick enable/disable_event, capture limited number of events
     - both counted and not
     - verify flags
     - verify removal

# echo 'enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger;cat ~/junk.txt > /dev/null;echo 'disable_event:kmem:kmalloc' > /sys/kernel/debug/tracing/events/syscalls/sys_exit_read/trigger

# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
0*

# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger
enable_event:kmem:kmalloc:count=0

# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/enable
0*

# cat /sys/kernel/debug/tracing/events/syscalls/sys_exit_read/trigger
disable_event:kmem:kmalloc:unlimited

# cat /sys/kernel/debug/tracing/events/syscalls/sys_exit_read/enable
0*

# cat /sys/kernel/debug/tracing/trace

# echo '!enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger
# echo '!disable_event:kmem:kmalloc' > /sys/kernel/debug/tracing/events/syscalls/sys_exit_read/trigger

# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger
# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/enable
0
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
0

---- basic stacktrace checks
     - both counted and not
     - trigger filter

# echo 'stacktrace' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger

# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
stacktrace:unlimited
# cat /sys/kernel/debug/tracing/trace

# echo '!stacktrace' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# echo > /sys/kernel/debug/tracing/trace

# echo 'stacktrace:5 if bytes_req >= 512' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
stacktrace:count=0 if bytes_req >= 512

# cat /sys/kernel/debug/tracing/trace

# echo '!stacktrace:5 if bytes_req >= 512' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# echo 'stacktrace:5 if bytes_req >= 65536' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
# cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
stacktrace:count=5 if bytes_req >= 65536

# echo '!stacktrace:5' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger

---- basic snapshot
     - enable all block events, capture leadup to event
     - snapshot with filter

# echo 1 > /sys/kernel/debug/tracing/events/block/enable
# echo 'snapshot:1 if nr_rq > 1' > /sys/kernel/debug/tracing/events/block/block_unplug/trigger

# cat /sys/kernel/debug/tracing/snapshot

# cat /sys/kernel/debug/tracing/events/block/block_unplug/trigger
# cat /sys/kernel/debug/tracing/events/block/block_unplug/enable
1*
# echo '!snapshot:1 if nr_rq > 1' > /sys/kernel/debug/tracing/events/block/block_unplug/trigger
# cat /sys/kernel/debug/tracing/events/block/block_unplug/trigger
# cat /sys/kernel/debug/tracing/events/block/block_unplug/enable
1

---- basic traceon/traceoff
     - enable all block events, capture leadup to event
     - traceoff with filter

# echo 'traceoff:1 if nr_rq > 1' > /sys/kernel/debug/tracing/events/block/block_unplug/trigger
# cat /sys/kernel/debug/tracing/events/block/block_unplug/trigger
# cat /sys/kernel/debug/tracing/events/block/block_unplug/enable

# cat /sys/kernel/debug/tracing/trace

# cat /sys/kernel/debug/tracing/tracing_on
0
# echo '!traceoff:1 if nr_rq > 1' > /sys/kernel/debug/tracing/events/block/block_unplug/trigger
# cat /sys/kernel/debug/tracing/events/block/block_unplug/enable
1
# echo 0 > /sys/kernel/debug/tracing/events/block/enable
# cat /sys/kernel/debug/tracing/events/block/block_unplug/enable

# echo 1 > /sys/kernel/debug/tracing/tracing_on

---- multi buffer non-syscall filter test

echo > /sys/kernel/debug/tracing/trace

echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
bytes_alloc > 8192
mkdir /sys/kernel/debug/tracing/instances/test1
echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
bytes_alloc > 8192
cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter
bytes_alloc > 2048

echo 1 > /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
cat /sys/kernel/debug/tracing/trace

echo 1 > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/enable
cat /sys/kernel/debug/tracing/instances/test1/trace

echo 0 > /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
echo 0 > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/enable
echo 0 > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter
echo 0 > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter

rmdir /sys/kernel/debug/tracing/instances/test1

--- multi buffer filter test

echo > /sys/kernel/debug/tracing/trace

echo 'count > 65536' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/filter
echo 1 > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/enable
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/filter
cat /sys/kernel/debug/tracing/trace

mkdir /sys/kernel/debug/tracing/instances/test1

echo 'count > 4096' > /sys/kernel/debug/tracing/instances/test1/events/syscalls/sys_enter_read/filter
echo 1 > /sys/kernel/debug/tracing/instances/test1/events/syscalls/sys_enter_read/enable
cat /sys/kernel/debug/tracing/instances/test1/events/syscalls/sys_enter_read/filter
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/filter
cat /sys/kernel/debug/tracing/instances/test1/trace
cat /sys/kernel/debug/tracing/trace

echo 0 > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/filter
echo 0 > /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/enable

rmdir /sys/kernel/debug/tracing/instances/test1

---- multi-buffer trigger enable

# mkdir /sys/kernel/debug/tracing/instances/hoge
# echo 'enable_event:mce:mce_record' > /sys/kernel/debug/tracing/instances/hoge/events/syscalls/sys_enter_symlink/trigger
# cat /sys/kernel/debug/tracing/instances/hoge/events/syscalls/sys_enter_symlink/enable
0*
# cat /sys/kernel/debug/tracing/instances/hoge/events/mce/mce_record/enable
0*
# cat /sys/kernel/debug/tracing/events/mce/mce_record/enable
0
# ln -sf /dev/null /tmp
# cat /sys/kernel/debug/tracing/instances/hoge/events/mce/mce_record/enable
1*
# cat /sys/kernel/debug/tracing/events/mce/mce_record/enable
0

# rmdir /sys/kernel/debug/tracing/instances/hoge

---- enabled plus trigger test
     - verify triggers work on enabled event

echo > /sys/kernel/debug/tracing/trace

echo 1 > /sys/kernel/debug/tracing/events/syscalls/sys_enter_fsync/enable
echo 'stacktrace' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_fsync/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_fsync/trigger

# do an emacs save to test fsync

cat /sys/kernel/debug/tracing/trace

echo 0 > /sys/kernel/debug/tracing/events/syscalls/sys_enter_fsync/enable
echo '!stacktrace' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_fsync/trigger

---- multi-event trigger test, stack + enable
     - verify multiple triggers on single event

echo > /sys/kernel/debug/tracing/trace

# registers syscall tracepoint
echo 'stacktrace' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo 'enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

# do a perf stat to test

cat /sys/kernel/debug/tracing/trace

cat /sys/kernel/debug/tracing/events/kmem/kmalloc/enable

echo 0 > /sys/kernel/debug/tracing/events/kmem/kmalloc/enable

echo '!stacktrace' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo '!enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

---- multi-event trigger test, two enables
     - verify multiple enable_event triggers on single event

echo > /sys/kernel/debug/tracing/trace

# registers syscall tracepoint
echo 'enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo 'enable_event:kmem:kfree:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

# do a perf stat to test

cat /sys/kernel/debug/tracing/trace

cat /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
cat /sys/kernel/debug/tracing/events/kmem/kfree/enable

echo 0 > /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
echo 0 > /sys/kernel/debug/tracing/events/kmem/kfree/enable

echo '!enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo '!enable_event:kmem:kfree:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

---- multi-event trigger test, two enables, one with filter
     - verify multiple enable_event triggers with filters
     - also verify when only one triggers, other filtered out
     - also verify no multiple same-type events

echo > /sys/kernel/debug/tracing/trace

# registers syscall tracepoint
echo 'enable_event:kmem:kmalloc:1 if common_preempt_count == 2' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
# just to test that same event set with different filter or same event with different count can't be set
echo 'enable_event:kmem:kmalloc:1 if common_preempt_count == 1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo 'enable_event:kmem:kmalloc if common_preempt_count == 1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
  echo: write error: File exists
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/enable
cat /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
echo 'enable_event:kmem:kfree:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

# do a perf stat to test
cat /sys/kernel/debug/tracing/trace

echo '!enable_event:kmem:kmalloc:1 if common_preempt_count == 2' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo 'enable_event:kmem:kmalloc:1 if common_preempt_count == 1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

# do a perf stat to test
cat /sys/kernel/debug/tracing/trace

echo '!enable_event:kmem:kmalloc:1 if common_preempt_count == 1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo 'enable_event:kmem:kmalloc:1 if common_preempt_count <= 1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

# do a perf stat to test
cat /sys/kernel/debug/tracing/trace

echo '!enable_event:kmem:kmalloc:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo '!enable_event:kmem:kfree:1' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

cat /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
cat /sys/kernel/debug/tracing/events/kmem/kfree/enable

echo 0 > /sys/kernel/debug/tracing/events/kmem/kmalloc/enable
echo 0 > /sys/kernel/debug/tracing/events/kmem/kfree/enable

---- multi-event trigger test, two non-enable
     - multiple non-enable/disable triggers

echo > /sys/kernel/debug/tracing/trace

# registers syscall tracepoint
echo 'stacktrace' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo 'snapshot' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

# do a perf stat to test
cat /sys/kernel/debug/tracing/trace
cat /sys/kernel/debug/tracing/snapshot

echo '!stacktrace' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
echo '!snapshot' > /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger
cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_perf_event_open/trigger

---- multi-event trigger test, two non-enable on non-syscall, one with filter
     - verify multiple triggers on non-syscall event
     - one with filter
     - general removal syntax on counted

echo > /sys/kernel/debug/tracing/trace

# registers syscall tracepoint
echo 'stacktrace:5' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
echo 'snapshot:5 if bytes_req >= 4096' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger

cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger

cat /sys/kernel/debug/tracing/trace
cat /sys/kernel/debug/tracing/snapshot

echo '!stacktrace' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
echo '!snapshot' > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger

---- kprobes - basic check
     - stacktrace triggered by kprobe

echo > /sys/kernel/debug/tracing/trace
perf probe -a in_kmalloc=__kmalloc
echo 'stacktrace' > /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger
perf record -e probe:in_kmalloc -aR sleep 10&
perf report
cat /sys/kernel/debug/tracing/trace
cat /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger
echo '!stacktrace' > /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger
perf probe -d in_kmalloc

---- kprobes - enable normal event from kprobe event

echo > /sys/kernel/debug/tracing/trace
perf probe -a in_kmalloc=__kmalloc
echo 'enable_event:kmem:kfree:1' > /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger
cat /sys/kernel/debug/tracing/trace
cat /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger
echo '!enable_event:kmem:kfree:1' > /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger
cat /sys/kernel/debug/tracing/events/kmem/kfree/enable
echo 0 > /sys/kernel/debug/tracing/events/kmem/kfree/enable
perf probe -d in_kmalloc

---- kprobes - enable kprobe event from normal event

echo > /sys/kernel/debug/tracing/trace
perf probe -a in_kmalloc=__kmalloc
echo 'enable_event:probe:in_kmalloc:1' > /sys/kernel/debug/tracing/events/kmem/kfree/trigger
cat /sys/kernel/debug/tracing/trace
cat /sys/kernel/debug/tracing/events/kmem/kfree/trigger
cat /sys/kernel/debug/tracing/events/probe/in_kmalloc/enable
echo 0 > /sys/kernel/debug/tracing/events/probe/in_kmalloc/enable
echo '!enable_event:probe:in_kmalloc:1' > /sys/kernel/debug/tracing/events/kmem/kfree/trigger
perf probe -d in_kmalloc

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Steven Rostedt]

[-- Attachment #1: Type: text/plain, Size: 1710 bytes --]

On Tue, 07 Jan 2014 11:29:05 -0600
Tom Zanussi <tom.zanussi@linux.intel.com> wrote:


> Just so you know what encompasses my 'normal testing', below is what I
> normally run through - if everything checks out, I'm satisfied things
> are basically good, though of course it didn't catch your traceoff bug
> so it's not complete.
> 
> As soon as I get the chance, I'll automate it and add more tests for
> completeness - as it is it's grown into something that already takes too
> long to do manually, so I need to find the time....
> 
> ---- basic high-level check
>      - quick enable/disable_event, capture limited number of events
>      - both counted and not
>      - verify flags
>      - verify removal
> 

Thanks, I may look at these in the future to update my tests. I've
attached some trigger tests that I just wrote up.

ftrace-event-traceon-off : tests the traceon and traceoff triggers.
  - enables tracing, sets traceoff trigger, checks if it disables
  - disables tracing, sets traceon trigger, checks if it enables
  - does a countdown from 3 to make sure the tracing is disabled
     3 times.

ftrace-event-stacktrace  : tests the event stack trace. It
  - checks enabling of events (non trigger)
  - checks enabling only the stack trace
  - checks enabling both the stack trace and events
  - checks if the count works from 1 2 or 3 times

ftrace-event-trigger-event : tests enable/disable_event trigger
  - checks if the event enables another event (several times)
  - checks if the event disables another event (several times)
  - checks if it enables an event count times "1 2 3"
  - then it tests the filter part of the event trigger (enable only)

Feel free to add onto these.

-- Steve

[-- Attachment #2: ftrace-test-event-stacktrace --]
[-- Type: application/octet-stream, Size: 3202 bytes --]

#!/bin/bash

find_debugfs() {
    debugfs=`cat /proc/mounts | while read mount dir type opts a b; do
	if [ $mount == "debugfs" ]; then
	    echo $dir;
	    break
	fi
    done`
    if [ -z "$debugfs" ]; then
	if ! mount -t debugfs nodev /sys/kernel/debug; then
	    echo "FAILED to mount debugfs"
	    exit -1
	fi
	echo "/sys/kernel/debug"
    else
	echo $debugfs
    fi
}

debugfs=`find_debugfs`
TRACEDIR="$debugfs/tracing"
EVENTDIR=$TRACEDIR/events
EVENT=$EVENTDIR/sched/sched_switch
EVENT_ENABLE=$EVENT/enable
TRIGGER_FILE=$EVENT/trigger
TRACE_FILE=$TRACEDIR/trace
TRACING_ON=$TRACEDIR/tracing_on

if [ ! -f $TRIGGER_FILE ]; then
    echo "triggers are not set for this kernel"
    exit 0
fi

function cnt_trace() {
	    grep -v '^#' $TRACE_FILE | wc -l
}

function clear_triggers() {
    grep -v '^#' $TRIGGER_FILE | while read t; do
	tr=`echo $t | sed -e s'/:.*//'`
	if [ $tr == "enable_event" -o $tr == "disable_event" ]; then
	    tr=`echo $t | sed -e s'/\([^:]*:[^:]*:[^:]*\):.*/\1/'`
	fi
	echo "!$tr" > $TRIGGER_FILE
    done
}

function check_events() {
    events=$1
    stack=$2
    count=$3

    if [ $events -eq 1 ]; then
	if ! grep -q 'sched_switch:' $TRACE_FILE ; then
	    echo "Expected event but it wasn't there"
	    exit -1
	fi
    else
	if grep -q 'sched_switch:' $TRACE_FILE ; then
	    echo "Expected no events but events were found"
	    exit -1
	fi
    fi

    if [ $stack -eq 1 ]; then
	if [ $count -eq 0 ]; then
	    # unlimited, find the sleep call
	    if ! grep -q '^ => .*sleep' $TRACE_FILE; then
		echo "Could not find sleep call"
		exit -1
	    fi
	else
	    # count the stack traces
	    cnt=`grep '<stack trace>' $TRACE_FILE | wc -l`;
	    if [ $cnt -ne $count ]; then
		echo "Expected $count hits but only see $cnt"
		exit -1
	    fi
	fi
    else
	if grep -q '^ =>' $TRACE_FILE; then
	    echo "Found stack trace when not enabled"
	    exit -1
	fi
    fi
}

function do_reset() {
    clear_triggers
    echo nop > $TRACEDIR/current_tracer || exit -1
    echo 0 > $TRACEDIR/events/enable || exit -1
    echo > $TRACE_FILE || exit -1
    echo 1 > $TRACING_ON || exit -1
}

#set -x

echo '** CLEAR TRACE'
do_reset

# check stacktrace available
if ! grep -q stacktrace $TRIGGER_FILE; then
    echo "stacktrace trigger not available"
    exit 0
fi

cnt=`cnt_trace`
if [ $cnt -ne 0 ]; then
    echo "Found junk in trace file, exiting"
    exit -1
fi

echo "Enable only events"

echo 1 > $EVENT_ENABLE
sleep 1
echo 0 > $TRACING_ON

check_events 1 0 0
do_reset

echo "Enable only stack trace"

echo 0 > $TRACING_ON
echo stacktrace > $TRIGGER_FILE

echo 1 > $TRACING_ON
sleep 1
echo 0 > $TRACING_ON

check_events 0 1 0
do_reset


echo "Enable both stack trace and events"

echo 0 > $TRACING_ON
echo stacktrace > $TRIGGER_FILE
echo 1 > $EVENT_ENABLE

echo 1 > $TRACING_ON
sleep 1
echo 0 > $TRACING_ON

check_events 1 1 0
do_reset

for i in 1 2 3; do
    if [ $i -gt 1 ]; then
	s='s'
    else
	s=''
    fi
    echo "Enable stack trace only $i time$s"

    echo 0 > $TRACING_ON
    echo stacktrace:$i > $TRIGGER_FILE
    echo 1 > $EVENT_ENABLE

    echo 1 > $TRACING_ON
    sleep 1
    echo 0 > $TRACING_ON

    check_events 1 1 $i
    do_reset
done


echo '** SUCCESS'

exit 0

[-- Attachment #3: ftrace-test-event-traceon-off --]
[-- Type: application/octet-stream, Size: 2408 bytes --]

#!/bin/bash

find_debugfs() {
    debugfs=`cat /proc/mounts | while read mount dir type opts a b; do
	if [ $mount == "debugfs" ]; then
	    echo $dir;
	    break
	fi
    done`
    if [ -z "$debugfs" ]; then
	if ! mount -t debugfs nodev /sys/kernel/debug; then
	    echo "FAILED to mount debugfs"
	    exit -1
	fi
	echo "/sys/kernel/debug"
    else
	echo $debugfs
    fi
}

debugfs=`find_debugfs`
TRACEDIR="$debugfs/tracing"
EVENTDIR=$TRACEDIR/events

if [ ! -f $EVENTDIR/sched/sched_switch/trigger ]; then
    echo "triggers are not set for this kernel"
    exit 0
fi

function cnt_trace() {
	    grep -v '^#' $TRACEDIR/trace | wc -l
}

function check_traceon() {
    val=$1
    cur=`cat $TRACEDIR/tracing_on`
    if [ $val -ne $cur ]; then
	echo "traceon expected to be $val but was $cur"
	exit 1
    fi
}

set -x
      
echo '** DISABLE TRACING'
echo 0 > $TRACEDIR/tracing_on || exit -1
echo > $TRACEDIR/trace || exit -1

check_traceon 0

cnt=`cnt_trace`
if [ $cnt -ne 0 ]; then
   exit -1
fi


echo '** ENABLE FUNCTION TRACING'

echo function > $TRACEDIR/current_tracer || exit -1

echo '** ENABLE TRACING'
echo 1 > $TRACEDIR/tracing_on || exit -1

cnt=`cnt_trace`
if [ $cnt -eq 0 ]; then
   exit -1
fi

echo '** SET EVENT TRACEOFF'

check_traceon 1

echo "traceoff" > $EVENTDIR/sched/sched_switch/trigger
sleep 1
check_traceon 0
cnt=`cnt_trace`
sleep 1
cnt2=`cnt_trace`

if [ $cnt -ne $cnt2 ]; then
   exit -1;
fi

line1=`cat $TRACEDIR/trace | tail -1`
sleep 1
line2=`cat $TRACEDIR/trace | tail -1`

if [ $line1 != $line2 ]; then
   exit -1
fi

echo > $TRACEDIR/trace || exit -1

check_traceon 0

echo "!traceoff" >> $EVENTDIR/sched/sched_switch/trigger

check_traceon 0

echo "traceon" >> $EVENTDIR/sched/sched_switch/trigger

sleep 1

cnt=`cnt_trace`
if [ $cnt -eq 0 ]; then
   exit -1
fi

check_traceon 1


echo "!traceon" >> $EVENTDIR/sched/sched_switch/trigger

check_sleep() {
    val=$1
    sleep 1
    check_traceon $val
}

echo '** TEST COUNT traceoff (3)'

echo "traceoff:3" >> $EVENTDIR/sched/sched_switch/trigger
check_sleep "0"
echo '** TEST COUNT traceoff (2)'
echo 1 > $TRACEDIR/tracing_on
check_sleep "0"
echo '** TEST COUNT traceoff (1)'
echo 1 > $TRACEDIR/tracing_on
check_sleep "0"
echo '** TEST COUNT traceoff (0)'
echo 1 > $TRACEDIR/tracing_on
check_sleep "1"
echo "!traceoff:0" >> $EVENTDIR/sched/sched_switch/trigger

echo nop > $TRACEDIR/current_tracer

echo '** SUCCESS'

exit 0

[-- Attachment #4: ftrace-test-event-trigger-event --]
[-- Type: application/octet-stream, Size: 4079 bytes --]

#!/bin/bash

find_debugfs() {
    debugfs=`cat /proc/mounts | while read mount dir type opts a b; do
	if [ $mount == "debugfs" ]; then
	    echo $dir;
	    break
	fi
    done`
    if [ -z "$debugfs" ]; then
	if ! mount -t debugfs nodev /sys/kernel/debug; then
	    echo "FAILED to mount debugfs"
	    exit -1
	fi
	echo "/sys/kernel/debug"
    else
	echo $debugfs
    fi
}

debugfs=`find_debugfs`
TRACEDIR="$debugfs/tracing"
EVENTDIR=$TRACEDIR/events
EVENT=$EVENTDIR/sched/sched_wakeup
EVENT_ENABLE=$EVENT/enable
TRIGGER_FILE=$EVENT/trigger
TRACE_FILE=$TRACEDIR/trace
TRACING_ON=$TRACEDIR/tracing_on

OTHER="sched:sched_switch"
OTHER_EVENT=$EVENTDIR/sched/sched_switch
OTHER_EVENT_ENABLE=$OTHER_EVENT/enable

if [ ! -f $TRIGGER_FILE ]; then
    echo "triggers are not set for this kernel"
    exit 0
fi

function cnt_trace() {
	    grep -v '^#' $TRACE_FILE | wc -l
}

function clear_triggers() {
    grep -v '^#' $TRIGGER_FILE | while read t; do
	tr=`echo $t | sed -e s'/:.*//'`
	if [ $tr == "enable_event" -o $tr == "disable_event" ]; then
	    tr=`echo $t | sed -e s'/\([^:]*:[^:]*:[^:]*\):.*/\1/'`
	fi
	echo "!$tr" > $TRIGGER_FILE
    done
}

function check_events() {
    events=$1
    stack=$2
    count=$3

    if [ $events -eq 1 ]; then
	if ! grep -q 'sched_switch:' $TRACE_FILE ; then
	    echo "Expected event but it wasn't there"
	    exit -1
	fi
    else
	if grep -q 'sched_switch:' $TRACE_FILE ; then
	    echo "Expected no events but events were found"
	    exit -1
	fi
    fi

    if [ $stack -eq 1 ]; then
	if [ $count -eq 0 ]; then
	    # unlimited, find the sleep call
	    if ! grep -q '^ => .*sleep' $TRACE_FILE; then
		echo "Could not find sleep call"
		exit -1
	    fi
	else
	    # count the stack traces
	    cnt=`grep '<stack trace>' $TRACE_FILE | wc -l`;
	    if [ $cnt -ne $count ]; then
		echo "Expected $count hits but only see $cnt"
		exit -1
	    fi
	fi
    else
	if grep -q '^ =>' $TRACE_FILE; then
	    echo "Found stack trace when not enabled"
	    exit -1
	fi
    fi
}

function test_other_enabled() {
    val=$1

    e=`cat $OTHER_EVENT_ENABLE`
    if [ "$e" != $val ]; then
	echo "Expected $val but found $e"
	exit -1
    fi
}

function do_reset() {
    clear_triggers
    echo nop > $TRACEDIR/current_tracer || exit -1
    echo 0 > $TRACEDIR/events/enable || exit -1
    echo > $TRACE_FILE || exit -1
    echo 1 > $TRACING_ON || exit -1
}

#set -x

echo '** CLEAR TRACE'
do_reset

run_enable_disable() {
    enable=$1			# enable
    Enable=$2			# Enable
    check_disable=$3		# 0
    check_enable_star=$4	# 1*

    # check stacktrace available
    if ! grep -q ${enable}_event $TRIGGER_FILE; then
	echo "$enable trigger not available"
	exit 0
    fi

    cnt=`cnt_trace`
    if [ $cnt -ne 0 ]; then
	echo "Found junk in trace file, exiting"
	exit -1
    fi

    echo "$Enable event all the time"

    echo $check_disable > $OTHER_EVENT_ENABLE
    sleep 1

    test_other_enabled $check_disable

    echo "${enable}_event:$OTHER" > $TRIGGER_FILE

    echo " make sure it works 5 times"

    for i in `seq 5`; do
	sleep 1
	echo "  test $i"
	test_other_enabled $check_enable_star

	echo $check_disable > $OTHER_EVENT_ENABLE
    done
    sleep 1
    echo " make sure it's still works"
    test_other_enabled $check_enable_star
    do_reset
}

run_enable_disable enable Enable 0 "1*"
run_enable_disable disable Disable 1 "0*"

for i in 1 2 3; do
    if [ $i -gt 1 ]; then
	s='s'
    else
	s=''
    fi
    echo "Enable event only $i time$s"

    echo 0 > $TRACING_ON
    echo "enable_event:$OTHER:$i" > $TRIGGER_FILE
    echo 1 > $EVENT_ENABLE

    for x in `seq $i`; do
	echo "  test $x"
	sleep 1
	test_other_enabled "1*"
	echo 0 > $OTHER_EVENT_ENABLE
    done

    sleep 1
    echo "Make sure it didn't do it for more"
    test_other_enabled "0*"

    do_reset
done

echo "Now testing filter"

sleep 100&
x=`jobs -l`
pid=`echo $x | cut -d' ' -f2`

echo "enable_event:$OTHER if pid==$pid" > $TRIGGER_FILE

test_other_enabled "0*"
sleep 1
test_other_enabled "0*"
sleep 1
kill $pid
sleep 1
test_other_enabled "1*"

do_reset

echo '** SUCCESS'

exit 0

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Steven Rostedt]

[-- Attachment #1: Type: text/plain, Size: 1646 bytes --]

On Mon, 06 Jan 2014 20:51:09 -0600
Tom Zanussi <tom.zanussi@linux.intel.com> wrote:

> I'll run the next version through my 'testsuite', which unfortunately is
> still manual (one of the many things on my todo list is automate it)..

I have some basic tests, attached is one. Which failed. Here's the
patch that fixes it:

-- Steve

tracing: Fix counter for traceon/off event triggers

The counters for the traceon and traceoff are only suppose to decrement
when the trigger enables or disables tracing. It is not suppose to decrement
every time the event is hit.

Only decrement the counter if the trigger actually did something.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events_trigger.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index f6dd115..a53e0da 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -742,13 +742,16 @@ traceon_trigger(struct event_trigger_data *data)
 static void
 traceon_count_trigger(struct event_trigger_data *data)
 {
+	if (tracing_is_on())
+		return;
+
 	if (!data->count)
 		return;
 
 	if (data->count != -1)
 		(data->count)--;
 
-	traceon_trigger(data);
+	tracing_on();
 }
 
 static void
@@ -763,13 +766,16 @@ traceoff_trigger(struct event_trigger_data *data)
 static void
 traceoff_count_trigger(struct event_trigger_data *data)
 {
+	if (!tracing_is_on())
+		return;
+
 	if (!data->count)
 		return;
 
 	if (data->count != -1)
 		(data->count)--;
 
-	traceoff_trigger(data);
+	tracing_off();
 }
 
 static int
-- 
1.8.1.4



[-- Attachment #2: ftrace-test-event-traceon-off --]
[-- Type: application/octet-stream, Size: 2408 bytes --]

#!/bin/bash

find_debugfs() {
    debugfs=`cat /proc/mounts | while read mount dir type opts a b; do
	if [ $mount == "debugfs" ]; then
	    echo $dir;
	    break
	fi
    done`
    if [ -z "$debugfs" ]; then
	if ! mount -t debugfs nodev /sys/kernel/debug; then
	    echo "FAILED to mount debugfs"
	    exit -1
	fi
	echo "/sys/kernel/debug"
    else
	echo $debugfs
    fi
}

debugfs=`find_debugfs`
TRACEDIR="$debugfs/tracing"
EVENTDIR=$TRACEDIR/events

if [ ! -f $EVENTDIR/sched/sched_switch/trigger ]; then
    echo "triggers are not set for this kernel"
    exit 0
fi

function cnt_trace() {
	    grep -v '^#' $TRACEDIR/trace | wc -l
}

function check_traceon() {
    val=$1
    cur=`cat $TRACEDIR/tracing_on`
    if [ $val -ne $cur ]; then
	echo "traceon expected to be $val but was $cur"
	exit 1
    fi
}

set -x
      
echo '** DISABLE TRACING'
echo 0 > $TRACEDIR/tracing_on || exit -1
echo > $TRACEDIR/trace || exit -1

check_traceon 0

cnt=`cnt_trace`
if [ $cnt -ne 0 ]; then
   exit -1
fi


echo '** ENABLE FUNCTION TRACING'

echo function > $TRACEDIR/current_tracer || exit -1

echo '** ENABLE TRACING'
echo 1 > $TRACEDIR/tracing_on || exit -1

cnt=`cnt_trace`
if [ $cnt -eq 0 ]; then
   exit -1
fi

echo '** SET EVENT TRACEOFF'

check_traceon 1

echo "traceoff" > $EVENTDIR/sched/sched_switch/trigger
sleep 1
check_traceon 0
cnt=`cnt_trace`
sleep 1
cnt2=`cnt_trace`

if [ $cnt -ne $cnt2 ]; then
   exit -1;
fi

line1=`cat $TRACEDIR/trace | tail -1`
sleep 1
line2=`cat $TRACEDIR/trace | tail -1`

if [ $line1 != $line2 ]; then
   exit -1
fi

echo > $TRACEDIR/trace || exit -1

check_traceon 0

echo "!traceoff" >> $EVENTDIR/sched/sched_switch/trigger

check_traceon 0

echo "traceon" >> $EVENTDIR/sched/sched_switch/trigger

sleep 1

cnt=`cnt_trace`
if [ $cnt -eq 0 ]; then
   exit -1
fi

check_traceon 1


echo "!traceon" >> $EVENTDIR/sched/sched_switch/trigger

check_sleep() {
    val=$1
    sleep 1
    check_traceon $val
}

echo '** TEST COUNT traceoff (3)'

echo "traceoff:3" >> $EVENTDIR/sched/sched_switch/trigger
check_sleep "0"
echo '** TEST COUNT traceoff (2)'
echo 1 > $TRACEDIR/tracing_on
check_sleep "0"
echo '** TEST COUNT traceoff (1)'
echo 1 > $TRACEDIR/tracing_on
check_sleep "0"
echo '** TEST COUNT traceoff (0)'
echo 1 > $TRACEDIR/tracing_on
check_sleep "1"
echo "!traceoff:0" >> $EVENTDIR/sched/sched_switch/trigger

echo nop > $TRACEDIR/current_tracer

echo '** SUCCESS'

exit 0

Re: [PATCH 0/2] tracing/triggers: A couple minor variable name changes

[Tom Zanussi]

On Mon, 2014-01-06 at 22:31 -0500, Steven Rostedt wrote:
> On Mon, 06 Jan 2014 20:51:09 -0600
> Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
> 
> > I'll run the next version through my 'testsuite', which unfortunately is
> > still manual (one of the many things on my todo list is automate it)..
> 
> I have some basic tests, attached is one. Which failed. Here's the
> patch that fixes it:
> 
> -- Steve
> 
> tracing: Fix counter for traceon/off event triggers
> 
> The counters for the traceon and traceoff are only suppose to decrement
> when the trigger enables or disables tracing. It is not suppose to decrement
> every time the event is hit.
> 
> Only decrement the counter if the trigger actually did something.
> 
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>

> ---
>  kernel/trace/trace_events_trigger.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
> index f6dd115..a53e0da 100644
> --- a/kernel/trace/trace_events_trigger.c
> +++ b/kernel/trace/trace_events_trigger.c
> @@ -742,13 +742,16 @@ traceon_trigger(struct event_trigger_data *data)
>  static void
>  traceon_count_trigger(struct event_trigger_data *data)
>  {
> +	if (tracing_is_on())
> +		return;
> +
>  	if (!data->count)
>  		return;
>  
>  	if (data->count != -1)
>  		(data->count)--;
>  
> -	traceon_trigger(data);
> +	tracing_on();
>  }
>  
>  static void
> @@ -763,13 +766,16 @@ traceoff_trigger(struct event_trigger_data *data)
>  static void
>  traceoff_count_trigger(struct event_trigger_data *data)
>  {
> +	if (!tracing_is_on())
> +		return;
> +
>  	if (!data->count)
>  		return;
>  
>  	if (data->count != -1)
>  		(data->count)--;
>  
> -	traceoff_trigger(data);
> +	tracing_off();
>  }
>  
>  static int