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Subject[tip:sched/urgent] sched/deadline: Don't use dubious signed bitfields
Commit-ID:  aa5222e92f8000ed3c1c38dddf11c83222aadfb3
Gitweb: https://git.kernel.org/tip/aa5222e92f8000ed3c1c38dddf11c83222aadfb3
Author: Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Fri, 13 Oct 2017 10:01:22 +0300
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 21 Nov 2017 09:25:01 +0100

sched/deadline: Don't use dubious signed bitfields

It doesn't cause a run-time bug, but these bitfields should be unsigned.
When it's signed ->dl_throttled is set to either 0 or -1, instead of
0 and 1 as expected.

The sched.h file is included into tons of places so Sparse generates
a flood of warnings like this:

./include/linux/sched.h:477:54: error: dubious one-bit signed bitfield

Reported-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Cc: luca abeni <luca.abeni@santannapisa.it>
Link: http://lkml.kernel.org/r/20171013070121.dzcncojuj2f4utij@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
include/linux/sched.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index a5dc7c9..21991d6 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -473,10 +473,10 @@ struct sched_dl_entity {
* conditions between the inactive timer handler and the wakeup
* code.
*/
- int dl_throttled : 1;
- int dl_boosted : 1;
- int dl_yielded : 1;
- int dl_non_contending : 1;
+ unsigned int dl_throttled : 1;
+ unsigned int dl_boosted : 1;
+ unsigned int dl_yielded : 1;
+ unsigned int dl_non_contending : 1;

/*
* Bandwidth enforcement timer. Each -deadline task has its
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