ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace records
authorAlexei Starovoitov <ast@fb.com>
Mon, 7 Nov 2016 23:14:20 +0000 (15:14 -0800)
committerSteven Rostedt <rostedt@goodmis.org>
Mon, 14 Nov 2016 21:31:41 +0000 (16:31 -0500)
commit977c1f9c8c022d0173181766b34a0db3705265a4
tree8b38040b883d49ced50f39d17e35f7f8d6c2a126
parenta25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6
ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace records

ftrace_shutdown() checks for sanity of ftrace records
and if dyn_ftrace->flags is not zero, it will warn.
It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point,
since some module was loaded, but before ftrace_module_enable()
cleared the flags for this module.

In other words the module.c is doing:
ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED
... // here ftrace_shutdown() is called that warns, since
err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED

Fix it by ignoring disabled records.
It's similar to what __ftrace_hash_rec_update() is already doing.

Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com
Cc: stable@vger.kernel.org
Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions"
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
kernel/trace/ftrace.c