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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/video/via/viafbdev.c | |
parent | 3dec7f59c370c7b58184d63293c3dc984d475840 (diff) | |
download | op-kernel-dev-99b76233803beab302123d243eea9e41149804f3.zip op-kernel-dev-99b76233803beab302123d243eea9e41149804f3.tar.gz |
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/video/via/viafbdev.c')
-rw-r--r-- | drivers/video/via/viafbdev.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c index 37b433a..e327b848 100644 --- a/drivers/video/via/viafbdev.c +++ b/drivers/video/via/viafbdev.c @@ -2059,25 +2059,21 @@ static void viafb_init_proc(struct proc_dir_entry **viafb_entry) if (viafb_entry) { entry = create_proc_entry("dvp0", 0, *viafb_entry); if (entry) { - entry->owner = THIS_MODULE; entry->read_proc = viafb_dvp0_proc_read; entry->write_proc = viafb_dvp0_proc_write; } entry = create_proc_entry("dvp1", 0, *viafb_entry); if (entry) { - entry->owner = THIS_MODULE; entry->read_proc = viafb_dvp1_proc_read; entry->write_proc = viafb_dvp1_proc_write; } entry = create_proc_entry("dfph", 0, *viafb_entry); if (entry) { - entry->owner = THIS_MODULE; entry->read_proc = viafb_dfph_proc_read; entry->write_proc = viafb_dfph_proc_write; } entry = create_proc_entry("dfpl", 0, *viafb_entry); if (entry) { - entry->owner = THIS_MODULE; entry->read_proc = viafb_dfpl_proc_read; entry->write_proc = viafb_dfpl_proc_write; } @@ -2086,7 +2082,6 @@ static void viafb_init_proc(struct proc_dir_entry **viafb_entry) viaparinfo->chip_info->lvds_chip_info2.lvds_chip_name) { entry = create_proc_entry("vt1636", 0, *viafb_entry); if (entry) { - entry->owner = THIS_MODULE; entry->read_proc = viafb_vt1636_proc_read; entry->write_proc = viafb_vt1636_proc_write; } |