[PATCH 19/19] y2038: use __kernel_timespec in sys_sched_rr_get_interval

From: Arnd Bergmann
Date: Wed May 06 2015 - 12:36:48 EST


sys_sched_rr_get_interval is easily converted to use __kernel_timespec,
by changing the function prototype. In order to allow compat handling
on 32-bit architectures, we also move compat_sys_sched_getaffinity
into the same file and unify the implementation, which avoids converting
the structure multiple times.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
include/linux/syscalls.h | 2 +-
kernel/compat.c | 20 --------------------
kernel/sched/core.c | 35 ++++++++++++++++++++++++++++-------
3 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 90c3cd889387..ce41abb4cd0a 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -305,7 +305,7 @@ asmlinkage long sys_sched_yield(void);
asmlinkage long sys_sched_get_priority_max(int policy);
asmlinkage long sys_sched_get_priority_min(int policy);
asmlinkage long sys_sched_rr_get_interval(pid_t pid,
- struct timespec __user *interval);
+ struct __kernel_timespec __user *interval);
asmlinkage long sys_setpriority(int which, int who, int niceval);
asmlinkage long sys_getpriority(int which, int who);

diff --git a/kernel/compat.c b/kernel/compat.c
index ec09c6e1d594..f6d17f06ec3d 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -1288,27 +1288,7 @@ COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
return sys_migrate_pages(pid, nr_bits + 1, old, new);
}
#endif
-#endif
-
-#ifdef CONFIG_COMPAT_TIME
-COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
- compat_pid_t, pid,
- struct compat_timespec __user *, interval)
-{
- struct timespec t;
- int ret;
- mm_segment_t old_fs = get_fs();
-
- set_fs(KERNEL_DS);
- ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t);
- set_fs(old_fs);
- if (compat_put_timespec(&t, interval))
- return -EFAULT;
- return ret;
-}
-#endif

-#ifdef CONFIG_COMPAT
/*
* Allocate user-space memory for the duration of a single system call,
* in order to marshall parameters inside a compat thunk.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fe22f7510bce..498ab3ab46dc 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -35,6 +35,8 @@
#include <asm/mmu_context.h>
#include <linux/interrupt.h>
#include <linux/capability.h>
+#include <linux/compat.h>
+#include <linux/compat_time.h>
#include <linux/completion.h>
#include <linux/kernel_stat.h>
#include <linux/debug_locks.h>
@@ -4468,15 +4470,13 @@ SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
* Return: On success, 0 and the timeslice is in @interval. Otherwise,
* an error code.
*/
-SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
- struct timespec __user *, interval)
+static int sched_rr_get_interval(pid_t pid, struct timespec64 *t)
{
struct task_struct *p;
unsigned int time_slice;
unsigned long flags;
struct rq *rq;
int retval;
- struct timespec t;

if (pid < 0)
return -EINVAL;
@@ -4497,16 +4497,37 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
time_slice = p->sched_class->get_rr_interval(rq, p);
task_rq_unlock(rq, p, &flags);

- rcu_read_unlock();
- jiffies_to_timespec(time_slice, &t);
- retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
- return retval;
+ jiffies_to_timespec64(time_slice, t);

out_unlock:
rcu_read_unlock();
return retval;
}

+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
+ struct __kernel_timespec __user *, interval)
+{
+ struct timespec64 t;
+ int ret = sched_rr_get_interval(pid, &t);
+ if (ret)
+ return ret;
+
+ return put_timespec64(&t, interval);
+}
+
+#ifdef CONFIG_COMPAT_TIME
+COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval, compat_pid_t, pid,
+ struct compat_timespec __user *, interval)
+{
+ struct timespec64 t;
+ int ret = sched_rr_get_interval(pid, &t);
+ if (ret)
+ return ret;
+
+ return compat_put_timespec64(&t, interval);
+}
+#endif
+
static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;

void sched_show_task(struct task_struct *p)
--
2.1.0.rc2

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