Skip to contentSkip to conversation

tracing: add ftrace_trace_stack into __trace_puts/__trace_bputs

PATCH In review zhangwei(Jovi) 2 participants 3 messages Jul 18, 2013 – Jul 9, 2014 Tracing

lore
Share & tools
lore

zhangwei(Jovi)

author
#0 lore raw

PATCH 1/3 tracing: add ftrace_trace_stack into __trace_puts/__trace_bputs

Currently trace option stacktrace is not applicable for trace_printk with constant string argument, the reason is there missed ftrace_trace_stack in __trace_puts/__trace_bputs.

In contrast, when using trace_printk with not constant string argument(will call into __trace_printk/__trace_bprintk), then trace option stacktrace is workable, this inconstant result will confusing user a lot.

Signed-off-by zhangwei(Jovi) <[email protected]>
---
 kernel/trace/trace.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
kernel/trace/trace.c +10 -2
index 3d5a931..4d70cc5 100644
@@ -363,13 +363,16 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
+	int pc;
+
+	pc = preempt_count();
 
 	alloc = sizeof(*entry) + size + 2; /* possible \n added */
 
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
 

@@ -386,6 +389,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 		entry->buf[size] = '\0';
 
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
 
 	return size;
 }

@@ -403,11 +407,14 @@ int __trace_bputs(unsigned long ip, const char *str)
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
+	int pc;
+
+	pc = preempt_count();
 
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
 

@@ -416,6 +423,7 @@ int __trace_bputs(unsigned long ip, const char *str)
 	entry->str			= str;
 
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
 
 	return 1;
 }
Signature · 1 line
1.7.9.7
author
#1 lore raw
Quoted 9 lines · zhangwei(Jovi)

Currently trace option stacktrace is not applicable for trace_printk with constant string argument, the reason is there missed ftrace_trace_stack in __trace_puts/__trace_bputs.

In contrast, when using trace_printk with not constant string argument(will call into __trace_printk/__trace_bprintk), then trace option stacktrace is workable, this inconstant result will confusing user a lot.

Hi steven,

How about this patch?
and [PATCH 2/3] "tracing: add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs"

Thanks.

jovi.

Quoted 60 lines
Signed-off-by zhangwei(Jovi) <[email protected]>
---
 kernel/trace/trace.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
kernel/trace/trace.c +10 -2
index 3d5a931..4d70cc5 100644
@@ -363,13 +363,16 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
+	int pc;
+
+	pc = preempt_count();
 
 	alloc = sizeof(*entry) + size + 2; /* possible \n added */
 
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
 

@@ -386,6 +389,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 		entry->buf[size] = '\0';
 
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
 
 	return size;
 }

@@ -403,11 +407,14 @@ int __trace_bputs(unsigned long ip, const char *str)
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
+	int pc;
+
+	pc = preempt_count();
 
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
 

@@ -416,6 +423,7 @@ int __trace_bputs(unsigned long ip, const char *str)
 	entry->str			= str;
 
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
 
 	return 1;
 }
maintainer
#2 lore raw
In reply to zhangwei(Jovi)

Wow! I some how missed your emails. I'm cleaning up my inbox and just stumbled over them now.

I tell people, they can either ping me a few times (keep doing it until you see a response, but spread them out). Otherwise, I will still get to their email. Just a year later ;-)

Yeah, this looks fine. I can queue it up for 3.17.

-- Steve

Quoted 68 lines · On Thu, 18 Jul 2013 16:31:05 +0800 "zhangwei(Jovi)" <[email protected]>…

Currently trace option stacktrace is not applicable for trace_printk with constant string argument, the reason is there missed ftrace_trace_stack in __trace_puts/__trace_bputs.

In contrast, when using trace_printk with not constant string argument(will call into __trace_printk/__trace_bprintk), then trace option stacktrace is workable, this inconstant result will confusing user a lot.

Signed-off-by zhangwei(Jovi) <[email protected]>
---
 kernel/trace/trace.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
kernel/trace/trace.c +10 -2
index 3d5a931..4d70cc5 100644
@@ -363,13 +363,16 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
+	int pc;
+
+	pc = preempt_count();
 
 	alloc = sizeof(*entry) + size + 2; /* possible \n added */
 
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
 

@@ -386,6 +389,7 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 		entry->buf[size] = '\0';
 
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
 
 	return size;
 }

@@ -403,11 +407,14 @@ int __trace_bputs(unsigned long ip, const char *str)
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
+	int pc;
+
+	pc = preempt_count();
 
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
 

@@ -416,6 +423,7 @@ int __trace_bputs(unsigned long ip, const char *str)
 	entry->str			= str;
 
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
 
 	return 1;
 }