On Mon 2009-10-26 15:37:50, Dan Yefimov wrote: > On 26.10.2009 13:54, psz@xxxxxxxxxxxxxxxxx wrote: > >Dear Dan, > > > >>... in authentic kernels /proc/<PID>/fd/<FD> are symlinks ... > > > >They appear to /bin/ls as symlinks, but observation suggests that they > >"act" as hardlinks. Could that be fixed somehow? (I did look at the > >kernel fs/proc/base.c but did not make much sense to me...) > > > Just looked more carefully at fs/proc/base.c. That behavior is due > to proc_fd_info() called from proc_fd_link() obtains file->f_path, > that in turn contains the reference to the open file dentry and > hence inode. That's exactly why those symlinks behave as hardlinks. > This behavior assumes, that if you were able to open the file, > you've all necessary transition permissions to access it's inode. > But in order to follow them you need privileges to read the process > memory, which hardly restricts the impact of this behavior. I don't > think this should be fixed, since /proc/<PID>/fd/ is mainly for > debugging purposes. guest certianly does not have permission to ptrace() pavel's processes, so... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
