Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Prakash Sangappa <prakash.sangappa@oracle.com>
To:     linux-kernel@vger.kernel.org
Cc:     tglx@linutronix.de, akpm@linux-foundation.org,
        peterz@infradead.org, dave@stgolabs.net, manfred@colorfullife.com,
        Prakash Sangappa <prakash.sangappa@oracle.com>
Subject: [PATCH v2] ipc: Update semtimedop() to use hrtimer
Date:   Thu, 28 Apr 2022 08:07:02 -0700
Message-Id: <1651158422-28014-1-git-send-email-prakash.sangappa@oracle.com>
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 2
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?aRAJ0qNj+DlDV8jpDTOxoJ7PX0yGJxk8aAVtBOSenPJLwwUfU9d2Ab2ftmD6?=
 =?us-ascii?Q?1o+m1u7JAkJ4j323Hr4BzwrR5sc1rr85BhKw2W1H1/91GQeDoDIxLK3xu+Fa?=
 =?us-ascii?Q?/9n9qTZi2KgefmPd1KfzWtJEDJF4fbqL9LYsQKceYNFOL0RFZY2h2G/UsnKl?=
 =?us-ascii?Q?S2On+EKchxBDZ6H/aj2lqcNqnrfIa7D9Y8R+pVYWgPE0RzZ+WySCu7kZvEX/?=
 =?us-ascii?Q?B0QvwZMM/z09DGatKTIf/tQSrjlKz6YPcqeX9gHtn4iyeamBBAr6uGRRRUoD?=
 =?us-ascii?Q?n/5zMORHtUdnFHVcA8ezr/CaNkVAgUczSRroaqAgEhCJzw0Hx+a0G/hzdrl2?=
 =?us-ascii?Q?jkLxecjaaLreV94W0oNLbWUMObVm2mslnX1amDKGt4NaPy1GrMWJrYikY8p+?=
 =?us-ascii?Q?OCYxNnssHSPEm807Py8p6TZ8RI2bUjkeiNbLQa6DaWgujZw6/nAKFfVh0IRZ?=
 =?us-ascii?Q?5O1u+3zULQWDD5zdGAF3BWEjyzHQI1p9ji2s8i0IhXRRZTRZz+GC6necs3on?=
 =?us-ascii?Q?M0aepLGP/+GZqeW4O1Wto+d3ZhRk7Ef1+Vw2DzwWgMbg7P/T1E0bbUNKbJYV?=
 =?us-ascii?Q?tudKwyENzxo6oBeFdYxkj4IOSIxrl8EHKpXHcKB/AGqSYsTqPKYq5+3UzZ+v?=
 =?us-ascii?Q?2y9qH1Xa0JpGNBFh2n1ux/lzYEO5Xdw0MJkoTmpYKrlzy3fux1dOEHD2Rs9y?=
 =?us-ascii?Q?0xUgP+Gs8PIHfF7g1ix5G31LyabSvF/QYMyH7W16I9IPbizMD0xrc5wY2IsU?=
 =?us-ascii?Q?LFOjMCYMRBp9FgVHNOIyCjXomwxw/uGisEt6sSXdZYcx0Tky1SyJWAFpHZ1h?=
 =?us-ascii?Q?pw1QFpMiYD9nLd45SCD+K0lRc2zjEqod/AEGFleu+2w2i8C0w2YE146N5Edb?=
 =?us-ascii?Q?ntt2n9XlLkFdXpyq+hy1fx037CoUgLqw3X7apuvWHa+R/hc9JkOlbx3eirGX?=
 =?us-ascii?Q?w4QAwk5OkPNyac0RLep1b3ySJmufvVPzr8MTQbtqB/hTJikn16Avs5Z/QrXH?=
 =?us-ascii?Q?+riTMSTpISZ/Q5rjacPmF5qFtwiHYsTJKXwd9cWLIGO1pmc1b72uBNaNcSUf?=
 =?us-ascii?Q?af6FZbbayxwkStLSKi4mDtUnHK12KmAbqsDlq9QYfRzQrK9wdMgWPIyy7z8R?=
 =?us-ascii?Q?7bBKbhPrzeIsPxMyF+EFf5z/jJWCnGrW3YQeHUMrnTRBbwGHQb2/G+DuXU5e?=
 =?us-ascii?Q?OWMBmtyoSp5p733UNPFqzN6FTfTTtwRizSxK907HFg1UNuxuKZdlQFtmmUgu?=
 =?us-ascii?Q?fS7sIqXSxphTenpmnwkl0xAiZlV6DFO4L6fFPXnX2jzgQC/7XbuRGVzZ9xdF?=
 =?us-ascii?Q?ggu3zJoo5rqBzJ87Alr4/z15Ptm5r3xwibLQbeX3GOs7n/6NaMZb+3S9nWaq?=
 =?us-ascii?Q?Yt4lGb8WYE6fdQAKVdSeU+fsdsokApQMqi5HGtTBKRqGkKdUnJaPXh1+Pk76?=
 =?us-ascii?Q?SvkBR75MyCLLgFhpbcuzGirGWBhiz7DZ4IbZu/XSDUHONMtHEw9ZJIwgsio0?=
 =?us-ascii?Q?/LvG4V3nRjPtHKU/8iQ8PkUTrfBtIoso8AaWZgljxQxCm3xhtc35kWIIjrjj?=
 =?us-ascii?Q?X1EUfnGxfmIxbwN1GLyS5iCXJbSNsgqq7+ZgCHrT6SiAq/Tu5j7uEImTjMEl?=
 =?us-ascii?Q?iUqz63CX5g4mtF14tmqd9KGjXL1H+iB9C36oATJVuNM24qr4sFZY1oA6l4D3?=
 =?us-ascii?Q?GtAJlVh8HeYg6p2RcxQlt+WaLupyg3UZx6G1M3XZ0wGBBOx6N4tH3o8OxsTs?=
 =?us-ascii?Q?rCtfHEDtB+rR4fnFSAZhR/49ZA2iTOsr4EnyweEJRzWxYHvS8PR3IIWqp7fm?=
X-MS-Exchange-AntiSpam-MessageData-1: Wa1+zt0wA+7i7w==
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 18433d51-3a8a-45e3-ee3a-08da2928ce8d
X-MS-Exchange-CrossTenant-AuthSource: BYAPR10MB2629.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Apr 2022 15:07:27.0466
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 62CvNo5P2+PRDcjAZEVKx7ahhMNM7sN4Ddw8xn0JEZOz3kiDXfNdeRxMBuYxzM9+/BFfEFMLqj7t9kBw/45nsxu15SXe4K3M0wNuEyKxzPM=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR10MB3641
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.486,18.0.858
 definitions=2022-04-28_02:2022-04-28,2022-04-28 signatures=0
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 mlxscore=0
 suspectscore=0 malwarescore=0 spamscore=0 adultscore=0 bulkscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000
 definitions=main-2204280091
X-Proofpoint-GUID: 3AGwScWrbuEPqvNuFM6qeCmGTr8xXyje
X-Proofpoint-ORIG-GUID: 3AGwScWrbuEPqvNuFM6qeCmGTr8xXyje
X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RDNS_NONE,SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE
	autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
	lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

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.

v1->v2:
  - Use timespec64_valid() to validate timeout
     and other changes as suggested by Thomas Gleixner

Signed-off-by: Prakash Sangappa <prakash.sangappa@oracle.com>
---
 ipc/sem.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/ipc/sem.c b/ipc/sem.c
index 0dbdb98..44b65b6 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1995,7 +1995,9 @@ 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;
@@ -2003,12 +2005,11 @@ 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;
 	}
 
 
@@ -2166,10 +2167,8 @@ 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
@@ -2210,7 +2209,7 @@ 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 */
 
-- 
2.7.4