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| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-04-14 12:05:32 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-04-14 12:05:32 -0300 |
| commit | c23903beefd9eaf1b4572041fbe56c64881f8750 (patch) | |
| tree | fa61b7396a2c73d7d9d580566e430627e9322d8f | |
| parent | affa7edcd7c7bfd7a8304eac1a8a7fddd26ae994 (diff) | |
| download | mediapointer-dvb-s2-c23903beefd9eaf1b4572041fbe56c64881f8750.tar.gz mediapointer-dvb-s2-c23903beefd9eaf1b4572041fbe56c64881f8750.tar.bz2 | |
backport commit 99b76233803beab302123d243eea9e41149804f3
From: Mauro Carvalho Chehab <mchehab@redhat.com>
kernel-sync:
Author: Alexey Dobriyan <adobriyan@gmail.com>
Date: Wed Mar 25 22:48:06 2009 +0300
proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.
We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.
But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.
->read_proc/->write_proc were just fixed to not require ->owner for
protection.
rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.
Removing ->owner will also make PDE smaller.
So, let's nuke it.
Kudos to Jeff Layton for reminding about this, let's say, oversight.
http://bugzilla.kernel.org/show_bug.cgi?id=12454
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | linux/drivers/media/video/cpia.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/linux/drivers/media/video/cpia.c b/linux/drivers/media/video/cpia.c index 9baa70fc9..826cf4464 100644 --- a/linux/drivers/media/video/cpia.c +++ b/linux/drivers/media/video/cpia.c @@ -1382,9 +1382,7 @@ static void proc_cpia_create(void) { cpia_proc_root = proc_mkdir("cpia", NULL); - if (cpia_proc_root) - cpia_proc_root->owner = THIS_MODULE; - else + if (!cpia_proc_root) LOG("Unable to initialise /proc/cpia\n"); } |