From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18E53EBE; Fri, 21 Jun 2024 04:37:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718944669; cv=none; b=DiAZlAqCkAaEYAEjamGyEGuqKFCwAdYCza6cq3aMtCj2tJt0x90PMO7Tebispe/xGwJAL+26451oxhOqqVGFeJ1c3o4w44erGVc25Rx3ru2UCDc7ro44bCOpliNHiDSVz++7cCekqEXfi1n0/z2k0RIKfdL/uy44KST8Gr2sMTI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718944669; c=relaxed/simple; bh=dtuG/8FVyfxt6cdJEnSMBi5db48doHCJHLe3KcIUws4=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=MzAyKaSYGUf0IAof7bHeLrbbhNGJmwW285PHeh7PdJD6MZtdxViy7uMA8le8edjt2iaO9x9xsGG/puKUVeuqJpmPfzHDp2F3KoAEml5ETSmGm2nKWetHiGL/bRNswcLsn+3+sPbRj0M/ZTm09A1pt9j8pOicFkQ0CJwcDgQIKbo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k505hdpz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k505hdpz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 216A4C2BBFC; Fri, 21 Jun 2024 04:37:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718944668; bh=dtuG/8FVyfxt6cdJEnSMBi5db48doHCJHLe3KcIUws4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=k505hdpzwMMojH9wRfDeKs5BlNmsCDhP4RZMfHss9GZvJxLyRPPFXiUgVFptQKDL5 S5gsaSJiKe4LG3AqF7BLkgArN2fQ6qmD9TPovctggZUcd3SKbL9/4LgiQ6RebmHXx8 Sa6lkZ4xCYaOuzo7Zws7B8aGMz8VF6yVl5HZS3oaFEGqgpml4yS2vYF6N/jfvJPDIj 4wIEtSyU5vQLJwGLXsMqM/tqNHAvajbwv14JxtQRT0slq+fIxjIz53UIWoTOFHUheC qn8EFjVtrHKjnNWfmNSVO6/Cns8JaNBbD/GTXf78g5DeCI791W20rOIkGVStMEvPqS TWkLY4TaxbGVQ== Date: Fri, 21 Jun 2024 13:37:42 +0900 From: Masami Hiramatsu (Google) To: Yafang Shao Cc: torvalds@linux-foundation.org, ebiederm@xmission.com, alexei.starovoitov@gmail.com, rostedt@goodmis.org, catalin.marinas@arm.com, akpm@linux-foundation.org, penguin-kernel@i-love.sakura.ne.jp, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, audit@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Masami Hiramatsu , Mathieu Desnoyers Subject: Re: [PATCH v3 09/11] tracing: Replace strncpy() with __get_task_comm() Message-Id: <20240621133742.6692d3bda4faafab878f197d@kernel.org> In-Reply-To: <20240621022959.9124-10-laoar.shao@gmail.com> References: <20240621022959.9124-1-laoar.shao@gmail.com> <20240621022959.9124-10-laoar.shao@gmail.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 21 Jun 2024 10:29:57 +0800 Yafang Shao wrote: > Using __get_task_comm() to read the task comm ensures that the name is > always NUL-terminated, regardless of the source string. This approach also > facilitates future extensions to the task comm. Good catch! Looks good to me. Acked-by: Masami Hiramatsu (Google) Thank you, > > Signed-off-by: Yafang Shao > Cc: Steven Rostedt > Cc: Masami Hiramatsu > Cc: Mathieu Desnoyers > --- > kernel/trace/trace.c | 2 +- > kernel/trace/trace_events_hist.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 578a49ff5c32..ce94a86154a2 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -1907,7 +1907,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) > max_data->critical_start = data->critical_start; > max_data->critical_end = data->critical_end; > > - strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN); > + __get_task_comm(max_data->comm, TASK_COMM_LEN, tsk); > max_data->pid = tsk->pid; > /* > * If tsk == current, then use current_uid(), as that does not use > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index 6ece1308d36a..721d4758a79f 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -1599,7 +1599,7 @@ static inline void save_comm(char *comm, struct task_struct *task) > return; > } > > - strncpy(comm, task->comm, TASK_COMM_LEN); > + __get_task_comm(comm, TASK_COMM_LEN, task); > } > > static void hist_elt_data_free(struct hist_elt_data *elt_data) > -- > 2.39.1 > -- Masami Hiramatsu (Google)