DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=szeredi.hu; s=google;
        h=from:to:cc:subject:references:date:in-reply-to:message-id
         :user-agent:mime-version:content-type:content-transfer-encoding;
        b=lcM86pEBi36nfdpAvAQBjsdmsLnaiw81C2R/ytID5nscY/NWyhxY8hmyYl/TWZzNlG
         jbGBI0QBMsaWhgokYxmIGBnXh3tC32Mw+dlVATsoYFP5dluCaesvdPXvLac2hGm1lnhS
         pewzLzRsy+ytQlxVvqrGWjjeAwaKbrH1On1ZE=
From: Miklos Szeredi <miklos@szeredi.hu>
To: Phillip Lougher <phillip.lougher@gmail.com>
Cc: Michal Suchanek <hramrach@centrum.cz>, Andreas Dilger <adilger@dilger.ca>,
        Jiri Kosina <jkosina@suse.cz>, Ric Wheeler <ricwheeler@gmail.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        David Howells <dhowells@redhat.com>, Ian Kent <ikent@redhat.com>,
        Jeff Moyer <jmoyer@redhat.com>, Christoph Hellwig <hch@infradead.org>,
        Hugh Dickins <hughd@google.com>, Eric Paris <eparis@redhat.com>
Subject: Re: [PATCH] tmpfs: implement generic xattr support
References: <BANLkTini-g9XVOohKjwpZT-SGozcwx720A@mail.gmail.com>
	<4DA4B6A8.7030804@gmail.com>
	<BANLkTimsAE1ZAJhsSjnh3LqwsN9x0cLaXg@mail.gmail.com>
	<alpine.LRH.2.00.1104131618170.6953@twin.jikos.cz>
	<BANLkTindBULU9KAVWPJQ7oQvfCNQU-BuAg@mail.gmail.com>
	<BANLkTin6CVFOAECWwYg3B5V2AfscFfjt8w@mail.gmail.com>
	<BANLkTik7jasnvqFQohRdU-3crM8fr9pBXg@mail.gmail.com>
	<BANLkTikF_hgYSaZJbZosWwcs715tLXYfmQ@mail.gmail.com>
	<BANLkTikTUo17RncV7bushPTri=LEykep5g@mail.gmail.com>
	<BANLkTikUe_2Uo2_tSYdfNoNXKYO4Bj30iQ@mail.gmail.com>
	<C450CD68-10AE-4527-B6BF-A5D5F0BF005F@dilger.ca>
	<BANLkTinMNL8Q+_MCHDqAGSdYNAvHB2GdLw@mail.gmail.com>
	<87tydu3t4p.fsf_-_@tucsk.pomaz.szeredi.hu>
	<BANLkTinXVDrLnMOo17pqua5+38yQsezG6g@mail.gmail.com>
Date: Wed, 20 Apr 2011 15:43:27 +0200
In-Reply-To: <BANLkTinXVDrLnMOo17pqua5+38yQsezG6g@mail.gmail.com> (Phillip
	Lougher's message of "Wed, 20 Apr 2011 03:18:20 +0100")
Message-ID: <87tydtm41s.fsf@tucsk.pomaz.szeredi.hu>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1675
Lines: 38

Phillip Lougher <phillip.lougher@gmail.com> writes:

> On Tue, Apr 19, 2011 at 9:04 PM, Miklos Szeredi <miklos@szeredi.hu> wrote:
>
>> +static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
>
>> +       spin_lock(&dentry->d_inode->i_lock);
>> +       list_for_each_entry(xattr, &info->xattr_list, list) {
>> +               /* skip "trusted." attributes for unprivileged callers */
>> +               if (!trusted && xattr_is_trusted(xattr->name))
>> +                       continue;
>> +
>> +               used += strlen(xattr->name) + 1;
>> +               if (buffer) {
>> +                       if (size < used) {
>> +                               used = -ERANGE;
>> +                               break;
>> +                       }
>> +                       strncpy(buffer, xattr->name, strlen(xattr->name) + 1);
>>+                        buffer += strlen(xattr->name) + 1;
>
> Why are you doing a strncpy here?  strcpy() isn't going to copy more
> than strlen(xattr->name) + 1 bytes, and you know buffer is large
> enough to hold that because of the previous if (size < used) check?
>
> If you assigned the first strlen(xattr->name) + 1 to a temporary
> variable, you could use memcpy here, and avoid the 3 repeated
> strlen(xattr->name) calls.

Yeah, makes sense.

Thanks,
Miklos
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/