[tip:sched/core] objtool: Add do_task_dead() to global noreturn list

[tip-bot for Josh Poimboeuf]

Commit-ID:  c1fad9ef7ed14aad464972e6444e7a3bd5670f26
Gitweb:     http://git.kernel.org/tip/c1fad9ef7ed14aad464972e6444e7a3bd5670f26
Author:     Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Thu, 22 Sep 2016 16:21:25 -0500
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 23 Sep 2016 07:28:05 +0200

objtool: Add do_task_dead() to global noreturn list

objtool reports the following new warning:

  kernel/exit.o: warning: objtool: do_exit() falls through to next function complete_and_exit()

The warning is caused by do_exit()'s new call to do_task_dead(), which
is a new "noreturn" function which objtool doesn't know about yet,
introduced by:

  9af6528ee9b6 ("sched/core: Optimize __schedule()")

( objtool has to know all the global noreturn functions so it can follow
  the control flow of any functions which call them.  Unfortunately they
  need to be hard-coded because there's no automated way to detect them. )

Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kbuild-all@xxxxxx
Cc: tipbuild@xxxxxxxxx
Link: 20160922212125.zbuewckqll4yur25@treble">http://lkml.kernel.org/r/20160922212125.zbuewckqll4yur25@treble
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 tools/objtool/builtin-check.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index bd09d0e..143b6cd 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -175,6 +175,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"__stack_chk_fail",
 		"panic",
 		"do_exit",
+		"do_task_dead",
 		"__module_put_and_exit",
 		"complete_and_exit",
 		"kvm_spurious_fault",