tracing: Set kernel_stack's caller size properly

[ 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@fb.com

Signed-off-by: Josef Bacik <jbacik@fb.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Josef Bacik 2014-09-24 16:14:12 -04:00 committed by Greg Kroah-Hartman
parent 4d04a4da59
commit 72913876dc

View file

@ -179,7 +179,7 @@ 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"