[PATCH AUTOSEL 4.9 25/90] tracing: Set kernel_stack's caller size properly

[Sasha Levin]

From: Josef Bacik <jbacik@xxxxxx>

[ Upstream commit cbc3b92ce037f5e7536f6db157d185cd8b8f615c ]

I noticed when trying to use the trace-cmd python interface that reading the raw
buffer wasn't working for kernel_stack events.  This is because it uses a
stubbed version of __dynamic_array that doesn't do the __data_loc trick and
encode the length of the array into the field.  Instead it just shows up as a
size of 0.  So change this to __array and set the len to FTRACE_STACK_ENTRIES
since this is what we actually do in practice and matches how user_stack_trace
works.

Link: http://lkml.kernel.org/r/1411589652-1318-1-git-send-email-jbacik@xxxxxx

Signed-off-by: Josef Bacik <jbacik@xxxxxx>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 kernel/trace/trace_entries.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index d1cc37e78f997..1430f6bbb1a07 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -178,7 +178,7 @@ FTRACE_ENTRY(kernel_stack, stack_entry,
 
 	F_STRUCT(
 		__field(	int,		size	)
-		__dynamic_array(unsigned long,	caller	)
+		__array(	unsigned long,	caller,	FTRACE_STACK_ENTRIES	)
 	),
 
 	F_printk("\t=> (" IP_FMT ")\n\t=> (" IP_FMT ")\n\t=> (" IP_FMT ")\n"
-- 
2.25.1