patches/old/ipc-update-semtimedop-to-use-hrtimer.patch

From: Prakash Sangappa <prakash.sangappa@oracle.com>
Subject: 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(-)

--- a/ipc/sem.c~ipc-update-semtimedop-to-use-hrtimer
+++ a/ipc/sem.c
@@ -1993,7 +1993,9 @@ long __do_semtimedop(int semid, struct s
 	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 s
 		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 s
 		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 s
 		/*
 		 * 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 */
 
_