* [PATCH 3.14 34/78] sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE
[not found] <20140609224813.282275135@linuxfoundation.org>
@ 2014-06-09 22:48 ` Greg Kroah-Hartman
0 siblings, 0 replies; only message in thread
From: Greg Kroah-Hartman @ 2014-06-09 22:48 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Michael Kerrisk, Peter Zijlstra,
Dario Faggioli, linux-man, Juri Lelli, Linus Torvalds,
Ingo Molnar
3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Peter Zijlstra <peterz@infradead.org>
commit ce5f7f8200ca2504f6f290044393d73ca314965a upstream.
The way we read POSIX one should only call sched_getparam() when
sched_getscheduler() returns either SCHED_FIFO or SCHED_RR.
Given that we currently return sched_param::sched_priority=0 for all
others, extend the same behaviour to SCHED_DEADLINE.
Requested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Dario Faggioli <raistlin@linux.it>
Cc: linux-man <linux-man@vger.kernel.org>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140512205034.GH13467@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/sched/core.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3735,7 +3735,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_
*/
SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
{
- struct sched_param lp;
+ struct sched_param lp = { .sched_priority = 0 };
struct task_struct *p;
int retval;
@@ -3752,11 +3752,8 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, p
if (retval)
goto out_unlock;
- if (task_has_dl_policy(p)) {
- retval = -EINVAL;
- goto out_unlock;
- }
- lp.sched_priority = p->rt_priority;
+ if (task_has_rt_policy(p))
+ lp.sched_priority = p->rt_priority;
rcu_read_unlock();
/*
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