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Thu, 17 Oct 2024 00:26:56 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 427fjg433w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 17 Oct 2024 00:26:56 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 49H0QtHW013579; Thu, 17 Oct 2024 00:26:55 GMT Received: from ca-dev112.us.oracle.com (ca-dev112.us.oracle.com [10.129.136.47]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 427fjg4337-1; Thu, 17 Oct 2024 00:26:55 +0000 From: Anjali Kulkarni To: davem@davemloft.net, Liam.Howlett@Oracle.com Cc: edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, jiri@resnulli.us, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, akpm@linux-foundation.org, shuah@kernel.org, linux-kselftest@vger.kernel.org, anjali.k.kulkarni@oracle.com, peili.io@oracle.com Subject: [PATCH net-next v4 0/3] Threads support in proc connector Date: Wed, 16 Oct 2024 17:26:49 -0700 Message-ID: <20241017002652.1474358-1-anjali.k.kulkarni@oracle.com> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-16_18,2024-10-16_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 adultscore=0 spamscore=0 malwarescore=0 bulkscore=0 suspectscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2409260000 definitions=main-2410170001 X-Proofpoint-GUID: featopHk-On2DiJrxrzlQ0Y6HcHfx9ip X-Proofpoint-ORIG-GUID: featopHk-On2DiJrxrzlQ0Y6HcHfx9ip Recently we committed a fix to allow processes to receive notifications for non-zero exits via the process connector module. Commit is a4c9a56e6a2c. However, for threads, when it does a pthread_exit(&exit_status) call, the kernel is not aware of the exit status with which pthread_exit is called. It is sent by child thread to the parent process, if it is waiting in pthread_join(). Hence, for a thread exiting abnormally, kernel cannot send notifications to any listening processes. The exception to this is if the thread is sent a signal which it has not handled, and dies along with it's process as a result; for eg. SIGSEGV or SIGKILL. In this case, kernel is aware of the non-zero exit and sends a notification for it. For our use case, we cannot have parent wait in pthread_join, one of the main reasons for this being that we do not want to track normal pthread_exit(), which could be a very large number. We only want to be notified of any abnormal exits. Hence, threads are created with pthread_attr_t set to PTHREAD_CREATE_DETACHED. To fix this problem, we add a new type PROC_CN_MCAST_NOTIFY to proc connector API, which allows a thread to send it's exit status to kernel either when it needs to call pthread_exit() with non-zero value to indicate some error or from signal handler before pthread_exit(). We also need to filter packets with non-zero exit notifications futher based on instances, which can be identified by task names. Hence, added a comm field to the packet's struct proc_event, in which task->comm is stored. v3->v4 changes: - Reduce size of exit.log by removing unnecessary text. v2->v3 changes: - Handled comment by Liam Howlett to set hdev to NULL and add comment on it - Handled comment by Liam Howlett to combine functions for deleting+get and deleting into one. - Handled comment by Liam Howlett to remove extern in the functions defined in cn_hash_test.h - Some nits by Liam Howlett fixed. - Made threads.c automated, by having an exit.log file created by proc_filter.c, which threads.c checks to see if the values reported for thread exits are correct. This was for a comment by Liam Howlett to make the tests automated. - Added "comm" field to struct proc_event, to copy the task's name to the packet to allow further filtering by packets. v1->v2 changes: - Handled comment by Peter Zijlstra to remove locking for PF_EXIT_NOTIFY task->flags. - Added error handling in thread.c v->v1 changes: - Handled comment by Simon Horman to remove unused err in cn_proc.c - Handled comment by Simon Horman to make adata and key_display static in cn_hash_test.c Anjali Kulkarni (3): connector/cn_proc: Add hash table for threads connector/cn_proc: Kunit tests for threads hash table connector/cn_proc: Selftest for threads drivers/connector/Makefile | 2 +- drivers/connector/cn_hash.c | 221 ++++++++++++++++++ drivers/connector/cn_proc.c | 62 ++++- drivers/connector/connector.c | 75 +++++- include/linux/connector.h | 35 +++ include/linux/sched.h | 2 +- include/uapi/linux/cn_proc.h | 5 +- lib/Kconfig.debug | 17 ++ lib/Makefile | 1 + lib/cn_hash_test.c | 167 +++++++++++++ lib/cn_hash_test.h | 10 + tools/testing/selftests/connector/Makefile | 23 +- .../testing/selftests/connector/proc_filter.c | 34 ++- tools/testing/selftests/connector/thread.c | 202 ++++++++++++++++ .../selftests/connector/thread_filter.c | 96 ++++++++ 15 files changed, 937 insertions(+), 15 deletions(-) create mode 100644 drivers/connector/cn_hash.c create mode 100644 lib/cn_hash_test.c create mode 100644 lib/cn_hash_test.h create mode 100644 tools/testing/selftests/connector/thread.c create mode 100644 tools/testing/selftests/connector/thread_filter.c