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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) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: E9368120003 X-Stat-Signature: jndteqrz3fgrk4p6fjxwx5x8cmicoqcd X-HE-Tag: 1718944669-746246 X-HE-Meta: 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 VYxQNbZi 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 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: 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)