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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/acpi/video.c | |
| 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/acpi/video.c')
| -rw-r--r-- | drivers/acpi/video.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index bb5ed059114a..67cc36dc9b82 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -1125,8 +1125,6 @@ static int acpi_video_device_add_fs(struct acpi_device *device) if (!device_dir) return -ENOMEM; - device_dir->owner = THIS_MODULE; - /* 'info' [R] */ entry = proc_create_data("info", S_IRUGO, device_dir, &acpi_video_device_info_fops, acpi_driver_data(device)); @@ -1403,8 +1401,6 @@ static int acpi_video_bus_add_fs(struct acpi_device *device) if (!device_dir) return -ENOMEM; - device_dir->owner = THIS_MODULE; - /* 'info' [R] */ entry = proc_create_data("info", S_IRUGO, device_dir, &acpi_video_bus_info_fops, @@ -2131,7 +2127,6 @@ static int __init acpi_video_init(void) acpi_video_dir = proc_mkdir(ACPI_VIDEO_CLASS, acpi_root_dir); if (!acpi_video_dir) return -ENODEV; - acpi_video_dir->owner = THIS_MODULE; result = acpi_bus_register_driver(&acpi_video_bus); if (result < 0) { |