[tip:sched/urgent] sched: Add 'flags' argument to sched_{set, get}attr() syscalls

From: tip-bot for Peter Zijlstra
Date: Fri Feb 21 2014 - 15:33:31 EST


Commit-ID: 6d35ab48090b10c5ea5604ed5d6e91f302dc6060
Gitweb: http://git.kernel.org/tip/6d35ab48090b10c5ea5604ed5d6e91f302dc6060
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Fri, 14 Feb 2014 17:19:29 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 21 Feb 2014 21:27:10 +0100

sched: Add 'flags' argument to sched_{set,get}attr() syscalls

Because of a recent syscall design debate; its deemed appropriate for
each syscall to have a flags argument for future extension; without
immediately requiring new syscalls.

Cc: juri.lelli@xxxxxxxxx
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Suggested-by: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20140214161929.GL27965@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/syscalls.h | 6 ++++--
kernel/sched/core.c | 11 ++++++-----
2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 40ed9e9..a747a77 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -281,13 +281,15 @@ asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
asmlinkage long sys_sched_setparam(pid_t pid,
struct sched_param __user *param);
asmlinkage long sys_sched_setattr(pid_t pid,
- struct sched_attr __user *attr);
+ struct sched_attr __user *attr,
+ unsigned int flags);
asmlinkage long sys_sched_getscheduler(pid_t pid);
asmlinkage long sys_sched_getparam(pid_t pid,
struct sched_param __user *param);
asmlinkage long sys_sched_getattr(pid_t pid,
struct sched_attr __user *attr,
- unsigned int size);
+ unsigned int size,
+ unsigned int flags);
asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
unsigned long __user *user_mask_ptr);
asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len,
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a6e7470..6edbef2 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3661,13 +3661,14 @@ SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
* @pid: the pid in question.
* @uattr: structure containing the extended parameters.
*/
-SYSCALL_DEFINE2(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr)
+SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr,
+ unsigned int, flags)
{
struct sched_attr attr;
struct task_struct *p;
int retval;

- if (!uattr || pid < 0)
+ if (!uattr || pid < 0 || flags)
return -EINVAL;

if (sched_copy_attr(uattr, &attr))
@@ -3804,8 +3805,8 @@ err_size:
* @uattr: structure containing the extended parameters.
* @size: sizeof(attr) for fwd/bwd comp.
*/
-SYSCALL_DEFINE3(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
- unsigned int, size)
+SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
+ unsigned int, size, unsigned int, flags)
{
struct sched_attr attr = {
.size = sizeof(struct sched_attr),
@@ -3814,7 +3815,7 @@ SYSCALL_DEFINE3(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
int retval;

if (!uattr || pid < 0 || size > PAGE_SIZE ||
- size < SCHED_ATTR_SIZE_VER0)
+ size < SCHED_ATTR_SIZE_VER0 || flags)
return -EINVAL;

rcu_read_lock();
--
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