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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 20:48:06 +0100 |
|---|---|---|
| committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-30 23:14:44 +0200 |
| commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
| tree | 398178210fe66845ccd6fa4258ba762a87e023ad /net/core | |
| 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 'net/core')
| -rw-r--r-- | net/core/pktgen.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 32d419f5ac98..3779c1438c11 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -3806,7 +3806,6 @@ static int __init pg_init(void) pg_proc_dir = proc_mkdir(PG_PROC_DIR, init_net.proc_net); if (!pg_proc_dir) return -ENODEV; - pg_proc_dir->owner = THIS_MODULE; pe = proc_create(PGCTRL, 0600, pg_proc_dir, &pktgen_fops); if (pe == NULL) { |