Messages in this thread | | | From | Andy Lutomirski <> | Date | Fri, 11 Dec 2015 13:48:35 -0800 | Subject | Re: [PATCH] devpts: Sensible /dev/ptmx & force newinstance |
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On Fri, Dec 11, 2015 at 1:11 PM, Eric W. Biederman <ebiederm@xmission.com> wrote: > Al Viro <viro@ZenIV.linux.org.uk> writes: > >> On Fri, Dec 11, 2015 at 01:40:40PM -0600, Eric W. Biederman wrote: >> >>> + inode = path.dentry->d_inode; >>> + filp->f_path = path; >>> + filp->f_inode = inode; >>> + filp->f_mapping = inode->i_mapping; >>> + path_put(&old); >> >> Don't. You are creating a fairly subtle constraint on what the code in >> fs/open.c and fs/namei.c can do, for no good reason. You can bloody >> well maintain the information you need without that. > > There is a good reason. We can not write a race free version of ptsname > without it.
As long as this is for new userspace code, would it make sense to just add a new ioctl to ask "does this ptmx fd match this /dev/pts fd?"
--Andy
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