Messages in this thread |  | | From | Linus Torvalds <> | Date | Wed, 16 Aug 2017 11:48:48 -0700 | Subject | Re: [PATCH 0/1] devpts: use dynamic_dname() to generate proc name |
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On Wed, Aug 16, 2017 at 11:26 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > > Hardcoding "/dev/pts/%d" is something that user space can already do. > The kernel can and should do better.
Put another way: there's no point in applying the patch as-is, since existing glibc ptsname() does the same thing better and faster entirely in user space.
Also, we already do special things to get a path for this, but it clearly isn't working. See the
/* We need to cache a fake path for TIOCGPTPEER. */
comment in ptmx_open(). Why doesn't the file d_path get filled in correctly there, I wonder.
Because The regular
readlink("/proc/self/fd/0", ...)
that 'tty' does works correctly. I think we've done something incorrect in pty_open_peer(), which means that the fd path hasn't been fully filled in.
Fixing that *should* fix the readlink() automatically, since it clearly works for the 'tty' binary.
I'm wondering why it's not working as-is. "vfs_open()" does that
file->f_path = *path;
thing. Why aren't we getting the right path? The ptmx_open() code looks ok to me.
Al, do you see what the issue is, and why we don't get a proper path on that readlink?
Linus
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