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author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 20:48:06 +0100 |
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committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-30 23:14:44 +0200 |
commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
tree | 398178210fe66845ccd6fa4258ba762a87e023ad /drivers/platform/x86/toshiba_acpi.c | |
parent | proc 1/2: do PDE usecounting even for ->read_proc, ->write_proc (diff) | |
download | linux-99b76233803beab302123d243eea9e41149804f3.tar.xz linux-99b76233803beab302123d243eea9e41149804f3.zip |
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/platform/x86/toshiba_acpi.c')
-rw-r--r-- | drivers/platform/x86/toshiba_acpi.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c index 40e60fc2e596..9f187265db8e 100644 --- a/drivers/platform/x86/toshiba_acpi.c +++ b/drivers/platform/x86/toshiba_acpi.c @@ -679,8 +679,6 @@ static acpi_status __init add_device(void) toshiba_proc_dir, (read_proc_t *) dispatch_read, item); - if (proc) - proc->owner = THIS_MODULE; if (proc && item->write_func) proc->write_proc = (write_proc_t *) dispatch_write; } @@ -772,7 +770,6 @@ static int __init toshiba_acpi_init(void) toshiba_acpi_exit(); return -ENODEV; } else { - toshiba_proc_dir->owner = THIS_MODULE; status = add_device(); if (ACPI_FAILURE(status)) { toshiba_acpi_exit(); |