From 49c9dd0df65d547a58642d2f717eeb560e1db140 Mon Sep 17 00:00:00 2001
From: Prakash Sangappa <prakash.sangappa@oracle.com>
Date: Mon, 9 May 2022 18:29:20 -0700
Subject: [PATCH] ipc: update semtimedop() to use hrtimer
semtimedop() should be converted to use hrtimer like it has been done for
most of the system calls with timeouts. This system call already takes a
struct timespec as an argument and can therefore provide finer granularity
timed wait.
Link: https://lkml.kernel.org/r/1651187881-2858-1-git-send-email-prakash.sangappa@oracle.com
Signed-off-by: Prakash Sangappa <prakash.sangappa@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
ipc/sem.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/ipc/sem.c b/ipc/sem.c
index 38ef91a63edd..c8496f98b139 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1993,7 +1993,9 @@ long __do_semtimedop(int semid, struct sembuf *sops,
int max, locknum;
bool undos = false, alter = false, dupsop = false;
struct sem_queue queue;
- unsigned long dup = 0, jiffies_left = 0;
+ unsigned long dup = 0;
+ ktime_t expires, *exp = NULL;
+ bool timed_out = false;
if (nsops < 1 || semid < 0)
return -EINVAL;
@@ -2001,12 +2003,11 @@ long __do_semtimedop(int semid, struct sembuf *sops,
return -E2BIG;
if (timeout) {
- if (timeout->tv_sec < 0 || timeout->tv_nsec < 0 ||
- timeout->tv_nsec >= 1000000000L) {
- error = -EINVAL;
- goto out;
- }
- jiffies_left = timespec64_to_jiffies(timeout);
+ if (!timespec64_valid(timeout))
+ return -EINVAL;
+ expires = ktime_add_safe(ktime_get(),
+ timespec64_to_ktime(*timeout));
+ exp = &expires;
}
@@ -2164,10 +2165,8 @@ long __do_semtimedop(int semid, struct sembuf *sops,
sem_unlock(sma, locknum);
rcu_read_unlock();
- if (timeout)
- jiffies_left = schedule_timeout(jiffies_left);
- else
- schedule();
+ timed_out = !schedule_hrtimeout_range(exp,
+ current->timer_slack_ns, HRTIMER_MODE_ABS);
/*
* fastpath: the semop has completed, either successfully or
@@ -2208,7 +2207,7 @@ long __do_semtimedop(int semid, struct sembuf *sops,
/*
* If an interrupt occurred we have to clean up the queue.
*/
- if (timeout && jiffies_left == 0)
+ if (timed_out)
error = -EAGAIN;
} while (error == -EINTR && !signal_pending(current)); /* spurious */