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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 22:48:06 +0300 |
|---|---|---|
| committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-31 01:14:44 +0400 |
| commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
| tree | 398178210fe66845ccd6fa4258ba762a87e023ad /drivers/s390 | |
| parent | 3dec7f59c370c7b58184d63293c3dc984d475840 (diff) | |
| download | linux-99b76233803beab302123d243eea9e41149804f3.tar.xz | |
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: Alexey Dobriyan <adobriyan@gmail.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/block/dasd_proc.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c index 2080ba6a69b0..654daa3cdfda 100644 --- a/drivers/s390/block/dasd_proc.c +++ b/drivers/s390/block/dasd_proc.c @@ -320,7 +320,6 @@ dasd_proc_init(void) dasd_proc_root_entry = proc_mkdir("dasd", NULL); if (!dasd_proc_root_entry) goto out_nodasd; - dasd_proc_root_entry->owner = THIS_MODULE; dasd_devices_entry = proc_create("devices", S_IFREG | S_IRUGO | S_IWUSR, dasd_proc_root_entry, @@ -334,7 +333,6 @@ dasd_proc_init(void) goto out_nostatistics; dasd_statistics_entry->read_proc = dasd_statistics_read; dasd_statistics_entry->write_proc = dasd_statistics_write; - dasd_statistics_entry->owner = THIS_MODULE; return 0; out_nostatistics: |