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 84BC8C54E71 for ; Wed, 21 May 2025 06:24:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 71E786B0088; Wed, 21 May 2025 02:24:09 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6F6C66B0089; Wed, 21 May 2025 02:24:09 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 633C66B008A; Wed, 21 May 2025 02:24:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 48F246B0088 for ; Wed, 21 May 2025 02:24:09 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id ECF838043A for ; Wed, 21 May 2025 06:24:08 +0000 (UTC) X-FDA: 83465924976.06.8C3E9DE Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) by imf08.hostedemail.com (Postfix) with ESMTP id 4AB1A16000A for ; Wed, 21 May 2025 06:24:07 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=igalia.com header.s=20170329 header.b=JNO5+HGL; spf=pass (imf08.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=1747808647; 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=pU6bSpYB8CPj1DDuT5mIS//XBcxXY2wc6q2aPeo4HGQ=; b=Yb7KIi8vmaGg8KmaQx8H4MvhQReisnR8o9uLtDwArka4oDfL863CIPIQVnvqopGf5yRPHS +ZjQ/SSGBIjMp1QXw4SV53Zt+Fi8MF6AsTtny0W2kR/lNUw/2PXTKnBEUfBCbYPq91ulNU gjyPEzIyIa+dhX691wfqOLOrqD6pcUQ= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=igalia.com header.s=20170329 header.b=JNO5+HGL; spf=pass (imf08.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=1747808647; a=rsa-sha256; cv=none; b=NyvJxjHso3kMhy1ivHFNWAG8Y+DYWPW4r/jz5o9aDphKi6MtyPlzVPZaUQGaOKUEXFlQBw CtkvXRoO7i5dA3uXQZNKIFLbZEZaBN1zI+LOzVXIMNY6FF8CYsO9D1TdaPT6D5WfNFnLrU EfCjIKwxm5SzvhlV87hTyS4l58rZtxA= 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=pU6bSpYB8CPj1DDuT5mIS//XBcxXY2wc6q2aPeo4HGQ=; b=JNO5+HGL1Dc1zYmWHmB1rUUSLj piJFD554YV1qAOBwm3wP6JD+5CfsNkMhT+XL82pn9BmIorkyu77UykXUJcZ2bHjnswyiiAqn9FIBV 84XLl24D6Z0Z13jPHWgTXdEQU4oJoQ5Oo5CjE/RSEmSqaK2pKhZUMWfOgZqPlocycfS0+U0B1OzS7 ovvNEES1S0qW+oYB10H6pXwyF+4hehZZpsQEupxgUUrKaR/sZ8D9vOGY/YXvYhhLiMl/CRYT/T3K/ dtRbhaqm+v6wcuH9m6mh1Wj6iqBggjjGMPrbE26GoBA0XXBqqVkoMzvZl/M3uzAoJ6kdaAJJ4NT2/ KMNoufIw==; Received: from [223.233.70.209] (helo=localhost.localdomain) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1uHcry-00B3oN-Ij; Wed, 21 May 2025 08:24:02 +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 Subject: [PATCH v4 2/3] treewide: Switch memcpy() users of 'task->comm' to a more safer implementation Date: Wed, 21 May 2025 11:53:36 +0530 Message-Id: <20250521062337.53262-3-bhupesh@igalia.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20250521062337.53262-1-bhupesh@igalia.com> References: <20250521062337.53262-1-bhupesh@igalia.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4AB1A16000A X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: n1xjg6czsmn97rzt5s4yky596ze5trxz X-HE-Tag: 1747808647-715050 X-HE-Meta: U2FsdGVkX1/JTHEGxA5/cmOk1QEO30DszQn3PpOMx7yKiTwdZSgNsMY33NUUOcBHZV9zgT4GDxg1Vks2Dcm/sEerG5JSK7Qb50Qp7hF72mL81IyaUR6SuKM/vZ+MvSF7i5AXKG+Xmj52ANmY1TvzCuqTq26S7vWdY7uWU+cFHuuYDsizRkScSrU6JdsVEaMJxz5H3o8V8gS/0EIZs42WAB7uFpN5FwwKdvIhXACAu/kbdJ4WmCUOKd33GZg0NWfoqZ3/Ek6DEAn+3sEhLPQYrHjeg9Za8vb0AjVeinLu2EIZqFDrxFFVE8wgrRcD42B2SZW9n0iZjVAzsPf+bsgo8zmbEbkCBtwBkBveQ+MnNfxGweowrrNnHrhHcVhbDHUoxxx1GV3gr3Qe4KjSSybYh6thESVfPXxYRyfwBpvvBFcYnCo+rkfQFP6cP+r0qFCHSfaXn0vIxRDvgbra/OSoGx5yrpCayCq4sgaLEvEndh8QMXcQ1LHoQuIJnGDxfqIusRtvh7PD8bCaerrn82Bh+DqnhAr3yYkVf6FN7nve5svwObO+lpebfS/clUQmXYjN7/dMsVx3jjDX1PZoMpNQVG3o1sNa62TpUTPzi4CL6Pa5p/Be6YaQX5M9BO8XVDrlsf/sDvDSEvmYh0WrxgO4gmEcfth4mWlHjoDPmiD/RtBZobBKuirpG5HnsEjNv/uQpOK+x9YchOLz2Xrgx7EwBvqsahhRqtoKNIGncYhSBPnpvsY+anbHb+A+kq2JzZKFs2D+3TDjz7fjnlCHBwRNN91JMqBO83XhU3FLHYz5jz0quP5ONlfDH1eBZ+FfQUSrQvMirEDAwZJC5TUv7Ms+quMCM5zu5tj0jVKiCCMVjEK8XMjX9KvunXSpmMxSbWa4AaRvpDik3g2wQ3+3U6QpRcC5SJxT2V8eS6qAss6kAWU1GmETrIJsOt4NtkVLPXEIZdmtlLxLKWtuLhKkRWa Td5xUNzU szJZGCG5sXeFQEDMbFFxfslK0tkNNaM/gucqb6WWxjwetVd8DZ+upvtlBkhKLEfmAC2SdTyTy0fxU3LCzWLr/kKufplO+TJQFzmyWH23/XW9r74LUSb8hPgEXO6CH6ddtU7KzgwvNS1XVoRIeW92m7NcuUyWSVJQmH35TyFRCtdHlr79tryJB4L51fqB7kTSDxBXUlVNDTCFA7rgTidtVaDqe1Ee6GtzZqc29eHdE1u+8HB8VA3wJlqX1E4PhgXT+/tv4g1cLbe1JdYeztEfal5bFlnI13oVBpZDpYLUJn8MjUX2YqJ94j4leckgq+l6/rQY+XUKfd8Us7sUafs6GVU3NM1n+Snwrobs7nb4Q3AhWWWpVsrHO7UYiLodeVKv5oF7rtWiRjluSc0A= 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) is a more modular way (follow-up patches do 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 76e41805b92d..468abc308c24 100644 --- a/include/linux/coredump.h +++ b/include/linux/coredump.h @@ -54,7 +54,8 @@ extern void do_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] = '\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 ad36e73b8579..11aa0b58176d 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]", @@ -424,6 +426,7 @@ 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) @@ -443,6 +446,7 @@ 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) @@ -494,6 +498,7 @@ 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