From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65430C83F1B for ; Wed, 16 Jul 2025 12:39:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 05EE78D0006; Wed, 16 Jul 2025 08:39:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00FD18D0001; Wed, 16 Jul 2025 08:39:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E40C98D0006; Wed, 16 Jul 2025 08:39:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id CF2078D0001 for ; Wed, 16 Jul 2025 08:39:58 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 7DDFA10F83D for ; Wed, 16 Jul 2025 12:39:58 +0000 (UTC) X-FDA: 83670084876.19.2ECFDD9 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) by imf27.hostedemail.com (Postfix) with ESMTP id C98024000A for ; Wed, 16 Jul 2025 12:39:56 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=igalia.com header.s=20170329 header.b=Ajr6j1qq; spf=pass (imf27.hostedemail.com: domain of bhupesh@igalia.com designates 213.97.179.56 as permitted sender) smtp.mailfrom=bhupesh@igalia.com; dmarc=pass (policy=none) header.from=igalia.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1752669596; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7545PxSU3H8wsmqj1aWHbhRHAR8cl6QGaO7WkNQ7B9w=; b=4sfBm2fp9DleMqqvUBQwRa6/8bemT3lX05o5Xn+LX5DKAq+Lej13fSD3MNMrnH7C2HRXjW MebV2gp1IQIqd4RE7VpKoRLJrf3huux9KcPX3/m2CquUPxVe2nWMTaWVeoRRYeqfiyt6dy aqmN/81GsMBj1cJQjSUv+pKCYITE0XA= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=igalia.com header.s=20170329 header.b=Ajr6j1qq; spf=pass (imf27.hostedemail.com: domain of bhupesh@igalia.com designates 213.97.179.56 as permitted sender) smtp.mailfrom=bhupesh@igalia.com; dmarc=pass (policy=none) header.from=igalia.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1752669596; a=rsa-sha256; cv=none; b=I+RC+c1SD10UaGwfAOc031cBt0xAHRJBfbH/IFvZKn7K3IB9d99NKFu74TmhdWy4FhQS2j S0Rhq7iaVhhGOWahKG/yIh+Ncm9tv+vini6vvUjzL8vb9K2Ow8Er5rmtI/HonkxTRL5EPn Nlc+FRCLZPhoOdf2NCp1USeNckyTgnE= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=7545PxSU3H8wsmqj1aWHbhRHAR8cl6QGaO7WkNQ7B9w=; b=Ajr6j1qqs0S/ebhxkZLQQJ016a SnCHRX8mdHXCJSuPsWYWO8xbXqk/RHKsVOQ7ryhtl43V8kvB+mtoQvawQlabLWcjGC1QKgGoSeqye 5E6CnXqoLv+rarhANSYe48QDglFW4/BgiAFKwG0JoIcfIGM4wTcRHrxBlp1DQzGkA3EGa39wFqll3 AHVKV7EpzacuRA8Zd1+hwCYHjuHgZVaaiXx+3KsUWj/HzRlO+M0r35lgpQPLRJWevw0TGei0uU34a XsA2GCU4OZ8I6MBBNND6n/2OIK1JgqiZthWdqQyIte9Ed+jhn/bN9ODbHY+r6zyCpdTzhzxrWJbmt yaByql+Q==; Received: from [223.233.66.171] (helo=localhost.localdomain) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1uc1QO-00HJWV-46; Wed, 16 Jul 2025 14:39:52 +0200 From: Bhupesh To: akpm@linux-foundation.org Cc: bhupesh@igalia.com, kernel-dev@igalia.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, oliver.sang@intel.com, lkp@intel.com, laoar.shao@gmail.com, pmladek@suse.com, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, arnaldo.melo@gmail.com, alexei.starovoitov@gmail.com, andrii.nakryiko@gmail.com, mirq-linux@rere.qmqm.pl, peterz@infradead.org, willy@infradead.org, david@redhat.com, viro@zeniv.linux.org.uk, keescook@chromium.org, ebiederm@xmission.com, brauner@kernel.org, jack@suse.cz, mingo@redhat.com, juri.lelli@redhat.com, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-trace-kernel@vger.kernel.org, kees@kernel.org, torvalds@linux-foundation.org Subject: [PATCH v5 2/3] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Date: Wed, 16 Jul 2025 18:09:15 +0530 Message-Id: <20250716123916.511889-3-bhupesh@igalia.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20250716123916.511889-1-bhupesh@igalia.com> References: <20250716123916.511889-1-bhupesh@igalia.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: gff4djjmu5zigpixgqwxjso6pceogreq X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: C98024000A X-Rspam-User: X-HE-Tag: 1752669596-635570 X-HE-Meta: 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 vQk9Lypt QPIPS0RxuymB386Pgo1wjsuKrpRRVMk5GTUrHhAEp5EtIrAEKKGyuAP7CNcVSz5gUfkRG9OG6sSz1P3hnV9Zh/zFFFxtHFIVIXBU+ZpDlyFLi28VlOu5Jh/S9TsJd/eo5cIKaGlmIZOEAdcFo/XZD2sXPlvE5oQbhMreDSKVlrAhPLRJWmkvmBaMy6Z4cxXc+ArAJdT2mycx8BbSGu5Kvss3mFsNYn/fN/lbtKeGYJp0ZNKhMhcOR03HwYbiizc0+8u/EP8u3REIOdh4y2Sl8vD2FhHPCLadxawGZqDxlMNQ2N/v/ddydIFchhtF+I9OiMDuQeLdr/OdmOOXa30cgDI6VmuvJOeQT0X0l832VBi09CkU1U5iQh+smlrzPCecrIaIwmZh15wVcAKre/AT4JDu5K02a6L5gjM4778bnVPOq4Ao= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: As Linus mentioned in [1], currently we have several memcpy() use-cases which use 'current->comm' to copy the task name over to local copies. For an example: ... char comm[TASK_COMM_LEN]; memcpy(comm, current->comm, TASK_COMM_LEN); ... These should be modified so that we can later implement approaches to handle the task->comm's 16-byte length limitation (TASK_COMM_LEN) in a more modular way (follow-up patch does the same): ... char comm[TASK_COMM_LEN]; memcpy(comm, current->comm, TASK_COMM_LEN); comm[TASK_COMM_LEN - 1] = '\0'; ... The relevant 'memcpy()' users were identified using the following search pattern: $ git grep 'memcpy.*->comm\>' [1]. https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ Signed-off-by: Bhupesh --- include/linux/coredump.h | 3 ++- include/trace/events/block.h | 5 +++++ include/trace/events/oom.h | 1 + include/trace/events/osnoise.h | 1 + include/trace/events/signal.h | 1 + include/trace/events/task.h | 2 ++ 6 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/linux/coredump.h b/include/linux/coredump.h index 68861da4cf7c..988b233dcc09 100644 --- a/include/linux/coredump.h +++ b/include/linux/coredump.h @@ -54,7 +54,8 @@ extern void vfs_coredump(const kernel_siginfo_t *siginfo); do { \ char comm[TASK_COMM_LEN]; \ /* This will always be NUL terminated. */ \ - memcpy(comm, current->comm, sizeof(comm)); \ + memcpy(comm, current->comm, TASK_COMM_LEN); \ + comm[TASK_COMM_LEN - 1] = '\0'; \ printk_ratelimited(Level "coredump: %d(%*pE): " Format "\n", \ task_tgid_vnr(current), (int)strlen(comm), comm, ##__VA_ARGS__); \ } while (0) \ diff --git a/include/trace/events/block.h b/include/trace/events/block.h index 3e582d5e3a57..af40096a7114 100644 --- a/include/trace/events/block.h +++ b/include/trace/events/block.h @@ -214,6 +214,7 @@ DECLARE_EVENT_CLASS(block_rq, blk_fill_rwbs(__entry->rwbs, rq->cmd_flags); __get_str(cmd)[0] = '\0'; memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; ), TP_printk("%d,%d %s %u (%s) %llu + %u %s,%u,%u [%s]", @@ -352,6 +353,7 @@ DECLARE_EVENT_CLASS(block_bio, __entry->nr_sector = bio_sectors(bio); blk_fill_rwbs(__entry->rwbs, bio->bi_opf); memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; ), TP_printk("%d,%d %s %llu + %u [%s]", @@ -435,6 +437,7 @@ TRACE_EVENT(block_plug, TP_fast_assign( memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; ), TP_printk("[%s]", __entry->comm) @@ -454,6 +457,7 @@ DECLARE_EVENT_CLASS(block_unplug, TP_fast_assign( __entry->nr_rq = depth; memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; ), TP_printk("[%s] %d", __entry->comm, __entry->nr_rq) @@ -505,6 +509,7 @@ TRACE_EVENT(block_split, __entry->new_sector = new_sector; blk_fill_rwbs(__entry->rwbs, bio->bi_opf); memcpy(__entry->comm, current->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; ), TP_printk("%d,%d %s %llu / %llu [%s]", diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h index 9f0a5d1482c4..a5641ed4285f 100644 --- a/include/trace/events/oom.h +++ b/include/trace/events/oom.h @@ -24,6 +24,7 @@ TRACE_EVENT(oom_score_adj_update, TP_fast_assign( __entry->pid = task->pid; memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; __entry->oom_score_adj = task->signal->oom_score_adj; ), diff --git a/include/trace/events/osnoise.h b/include/trace/events/osnoise.h index 3f4273623801..0321b3f8d532 100644 --- a/include/trace/events/osnoise.h +++ b/include/trace/events/osnoise.h @@ -117,6 +117,7 @@ TRACE_EVENT(thread_noise, TP_fast_assign( memcpy(__entry->comm, t->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; __entry->pid = t->pid; __entry->start = start; __entry->duration = duration; diff --git a/include/trace/events/signal.h b/include/trace/events/signal.h index 1db7e4b07c01..7f490e553db5 100644 --- a/include/trace/events/signal.h +++ b/include/trace/events/signal.h @@ -68,6 +68,7 @@ TRACE_EVENT(signal_generate, __entry->sig = sig; TP_STORE_SIGINFO(__entry, info); memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; __entry->pid = task->pid; __entry->group = group; __entry->result = result; diff --git a/include/trace/events/task.h b/include/trace/events/task.h index af535b053033..4ddf21b69372 100644 --- a/include/trace/events/task.h +++ b/include/trace/events/task.h @@ -22,6 +22,7 @@ TRACE_EVENT(task_newtask, TP_fast_assign( __entry->pid = task->pid; memcpy(__entry->comm, task->comm, TASK_COMM_LEN); + __entry->comm[TASK_COMM_LEN - 1] = '\0'; __entry->clone_flags = clone_flags; __entry->oom_score_adj = task->signal->oom_score_adj; ), @@ -45,6 +46,7 @@ TRACE_EVENT(task_rename, TP_fast_assign( memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN); + entry->oldcomm[TASK_COMM_LEN - 1] = '\0'; strscpy(entry->newcomm, comm, TASK_COMM_LEN); __entry->oom_score_adj = task->signal->oom_score_adj; ), -- 2.38.1