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b=rbbT45SNiUqNV3TyRh2EOo0pHftvGWFWRH6vBPJudMPmwiLb6WS7wgiK5Q59kVq/l /YJb64mzcTT2KqJ9UYP5d2xZ5n9/Jvr/cWUkrkbGnIXzQjEBIO38AGnM9vTtABopU/ YAJHsePiJIqDiBQELEuWxMPSSa2HKRV53DWvBXptAhBL1IgRu2Lxwm90pLLwMLv38o ONUPyD3uH/jCdrUJkyhbEpCcdp2Ys7NwBdEd1sF/A4gIxp7Hoyh0Cl3b9gddvXT4lz XKzokxWQ8vKM0QK/Wccns5rkNWZemPG6vH3fGD9ZTEESdQgFsLCw6SC2OTh/RL0pZI yU+rwKUcUY4TA== Date: Thu, 3 Apr 2025 09:24:13 -0700 From: Kees Cook To: Bhupesh Cc: akpm@linux-foundation.org, 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, 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 Subject: Re: [PATCH v2 3/3] kthread: Use 'task_struct->full_name' to store kthread's full name Message-ID: <202504030923.1FE7874F@keescook> References: <20250331121820.455916-1-bhupesh@igalia.com> <20250331121820.455916-4-bhupesh@igalia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250331121820.455916-4-bhupesh@igalia.com> X-Rspamd-Queue-Id: 7C9D940007 X-Stat-Signature: heucg1r3de58xf3ekrfs1z9i9mb3jhed X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1743697458-312428 X-HE-Meta: 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 w4oJwR9o SLwKAlouLDntzBwIp0Yf2rVqhuhAQO/bPkfmU3dOXDTa0jli3hlI8vLLNY7LSN2ZYxXBAEZ+Hrzl6yT6vnMg1rtoWC/UHIeAIFVfjPJqoG5hvwEkOiDImGYHrcboEAzIQym1S8D80Je+pbyYu3USGl6hgBXjygdMx0fJzEFQOhSo9fRfWBZPDAP/bpVYdrKXoyPaJyRT/WSXwmQolK4IXUQUJC9rk5BugVjpMCf+gBEBtQEqozvKOuXBhvGNnRu6tbwJM5TSqA5b0ssTcIcGO9to2f1mfLYEaT3X3ejWBPYJzSFqxCyayOsS9iHsYqa43NMv8Wo1/4bt9CmQ1nyAiQu8gJ99RM/+9KoNlFfVAnoRIQGKtGY1Dpx9hLzVJKsD8GD+iEwm8CeU2ljtSBqYwq3mqKuFc+3mqYfVFZmDfhJHlgJc= 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 Mon, Mar 31, 2025 at 05:48:20PM +0530, Bhupesh wrote: > Commit 6986ce24fc00 ("kthread: dynamically allocate memory to store > kthread's full name"), added 'full_name' in parallel to 'comm' for > kthread names. > > Now that we have added 'full_name' added to 'task_struct' itself, > drop the additional 'full_name' entry from 'struct kthread' and also > its usage. > > Signed-off-by: Bhupesh I'd like to see this patch be the first patch in the series. This show the existing use for "full_name". (And as such it'll probably need bits from patch 1.) -Kees > --- > kernel/kthread.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/kernel/kthread.c b/kernel/kthread.c > index 5dc5b0d7238e..46fe19b7ef76 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -66,8 +66,6 @@ struct kthread { > #ifdef CONFIG_BLK_CGROUP > struct cgroup_subsys_state *blkcg_css; > #endif > - /* To store the full name if task comm is truncated. */ > - char *full_name; > struct task_struct *task; > struct list_head hotplug_node; > struct cpumask *preferred_affinity; > @@ -108,12 +106,12 @@ void get_kthread_comm(char *buf, size_t buf_size, struct task_struct *tsk) > { > struct kthread *kthread = to_kthread(tsk); > > - if (!kthread || !kthread->full_name) { > + if (!kthread || !tsk->full_name) { > strscpy(buf, tsk->comm, buf_size); > return; > } > > - strscpy_pad(buf, kthread->full_name, buf_size); > + strscpy_pad(buf, tsk->full_name, buf_size); > } > > bool set_kthread_struct(struct task_struct *p) > @@ -153,7 +151,6 @@ void free_kthread_struct(struct task_struct *k) > WARN_ON_ONCE(kthread->blkcg_css); > #endif > k->worker_private = NULL; > - kfree(kthread->full_name); > kfree(kthread); > } > > @@ -430,7 +427,7 @@ static int kthread(void *_create) > kthread_exit(-EINTR); > } > > - self->full_name = create->full_name; > + self->task->full_name = create->full_name; > self->threadfn = threadfn; > self->data = data; > > -- > 2.38.1 > -- Kees Cook