From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schwab Subject: Re: Possible coding issue in udf?? Date: Sun, 15 May 2011 19:13:59 +0200 Message-ID: References: <367853.39582.qm@web130121.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Alex Davis Return-path: In-Reply-To: <367853.39582.qm@web130121.mail.mud.yahoo.com> (Alex Davis's message of "Fri, 13 May 2011 19:57:20 -0700 (PDT)") Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Alex Davis writes: > In fs/udf/inode.c, line 1455, linux 2.6.35, there is the following code: > > udfperms = ((inode->i_mode & S_IRWXO)) | > ((inode->i_mode & S_IRWXG) << 2) | > ((inode->i_mode & S_IRWXU) << 4); > > Shouldn't we be shifting by 3 bits? i.e: > udfperms = ((inode->i_mode & S_IRWXO)) | > ((inode->i_mode & S_IRWXG) << 3) | > ((inode->i_mode & S_IRWXU) << 6); udfperms contains three bit fields of 5 bits each, of which 3 bits are each filled from one of the three RWX parts of i_mode, and 2 bits (DELETE and CHATTR) are added later. Thus each of the three bit fields are expanded from 3 to 5 bits, so that the second one needs to be shifted by 2 and the third one by 4. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."