Fix select on /proc files without ->poll
commitdd23aae4f5edf4e1dbd8f7f8013a754ba3253f48
authorAlexey Dobriyan <adobriyan@gmail.com>
Tue, 11 Sep 2007 22:23:55 +0000 (11 15:23 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Wed, 12 Sep 2007 00:21:20 +0000 (11 17:21 -0700)
treec7babf45f8132876e8a715f0327cf480c05c6131
parent3210f0ecdba6a81c3f8efe6f442d2e1f57db98f9
Fix select on /proc files without ->poll

Taneli Vähäkangas <vahakang@cs.helsinki.fi> reported that commit
786d7e1612f0b0adb6046f19b906609e4fe8b1ba aka "Fix rmmod/read/write races
in /proc entries" broke SBCL + SLIME combo.

The old code in do_select() used DEFAULT_POLLMASK, if couldn't find
->poll handler.  The new code makes ->poll always there and returns 0 by
default, which is not correct.  Return DEFAULT_POLLMASK instead.

Steps to reproduce:

install emacs, SBCL, SLIME
emacs
M-x slime in *inferior-lisp* buffer
[watch it doing "Connecting to Swank on port X.."]

Please, apply before 2.6.23.

P.S.: why SBCL can't just read(2) /proc/cpuinfo is a mystery.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: T Taneli Vahakangas <vahakang@cs.helsinki.fi>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/proc/inode.c
fs/select.c
include/linux/poll.h