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author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 22:48:06 +0300 |
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committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-31 01:14:44 +0400 |
commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
tree | 398178210fe66845ccd6fa4258ba762a87e023ad /drivers/rtc | |
parent | 3dec7f59c370c7b58184d63293c3dc984d475840 (diff) | |
download | kernel_samsung_tuna-99b76233803beab302123d243eea9e41149804f3.zip kernel_samsung_tuna-99b76233803beab302123d243eea9e41149804f3.tar.gz kernel_samsung_tuna-99b76233803beab302123d243eea9e41149804f3.tar.bz2 |
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/rtc')
-rw-r--r-- | drivers/rtc/rtc-proc.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/drivers/rtc/rtc-proc.c b/drivers/rtc/rtc-proc.c index 0c6257a..c086fc3 100644 --- a/drivers/rtc/rtc-proc.c +++ b/drivers/rtc/rtc-proc.c @@ -105,14 +105,8 @@ static const struct file_operations rtc_proc_fops = { void rtc_proc_add_device(struct rtc_device *rtc) { - if (rtc->id == 0) { - struct proc_dir_entry *ent; - - ent = proc_create_data("driver/rtc", 0, NULL, - &rtc_proc_fops, rtc); - if (ent) - ent->owner = rtc->owner; - } + if (rtc->id == 0) + proc_create_data("driver/rtc", 0, NULL, &rtc_proc_fops, rtc); } void rtc_proc_del_device(struct rtc_device *rtc) |