ipc: update semtimedop() to use hrtimer
authorPrakash Sangappa <prakash.sangappa@oracle.com>
Tue, 10 May 2022 01:29:20 +0000 (18:29 -0700)
committerakpm <akpm@linux-foundation.org>
Tue, 10 May 2022 01:29:20 +0000 (18:29 -0700)
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

index 38ef91a..c8496f9 100644 (file)
--- 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 */