From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BF1732C68B; Mon, 15 Jan 2024 10:06:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B51F12F4; Mon, 15 Jan 2024 02:07:18 -0800 (PST) Received: from FVFF77S0Q05N (unknown [10.57.91.116]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EC7F43F6C4; Mon, 15 Jan 2024 02:06:30 -0800 (PST) Date: Mon, 15 Jan 2024 10:06:24 +0000 From: Mark Rutland To: Erick Archer Cc: Steven Rostedt , Masami Hiramatsu , "Gustavo A. R. Silva" , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH] eventfs: Use kcalloc() instead of kzalloc() Message-ID: References: <20240114105340.5746-1-erick.archer@gmx.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240114105340.5746-1-erick.archer@gmx.com> On Sun, Jan 14, 2024 at 11:53:40AM +0100, Erick Archer wrote: > Use 2-factor multiplication argument form kcalloc() instead > of kzalloc(). > > Link: https://github.com/KSPP/linux/issues/162 > Signed-off-by: Erick Archer Could you put something in the commit message explaining *why* this change should be made? I assume that this is so that overflows during multiplication can be caught and handled in some way, but the commit message doesn't say that, and nor does the linked github page. The patch itself looks fine. Thanks, Mark. > --- > fs/tracefs/event_inode.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c > index fdff53d5a1f8..f8196289692c 100644 > --- a/fs/tracefs/event_inode.c > +++ b/fs/tracefs/event_inode.c > @@ -93,7 +93,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, > /* Preallocate the children mode array if necessary */ > if (!(dentry->d_inode->i_mode & S_IFDIR)) { > if (!ei->entry_attrs) { > - ei->entry_attrs = kzalloc(sizeof(*ei->entry_attrs) * ei->nr_entries, > + ei->entry_attrs = kcalloc(ei->nr_entries, sizeof(*ei->entry_attrs), > GFP_NOFS); > if (!ei->entry_attrs) { > ret = -ENOMEM; > @@ -874,7 +874,7 @@ struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode > } > > if (size) { > - ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL); > + ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL); > if (!ei->d_children) { > kfree_const(ei->name); > kfree(ei); > @@ -941,7 +941,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry > goto fail; > > if (size) { > - ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL); > + ei->d_children = kcalloc(size, sizeof(*ei->d_children), GFP_KERNEL); > if (!ei->d_children) > goto fail; > } > -- > 2.25.1 > >