diff options
| 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 /net/sunrpc | |
| parent | proc 1/2: do PDE usecounting even for ->read_proc, ->write_proc (diff) | |
| download | linux-dev-99b76233803beab302123d243eea9e41149804f3.tar.xz linux-dev-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/sunrpc')
| -rw-r--r-- | net/sunrpc/cache.c | 4 | ||||
| -rw-r--r-- | net/sunrpc/stats.c | 10 |
2 files changed, 2 insertions, 12 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 4735caad26ed..20029a79a5de 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -313,7 +313,6 @@ static int create_cache_proc_entries(struct cache_detail *cd) cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc); if (cd->proc_ent == NULL) goto out_nomem; - cd->proc_ent->owner = cd->owner; cd->channel_ent = cd->content_ent = NULL; p = proc_create_data("flush", S_IFREG|S_IRUSR|S_IWUSR, @@ -321,7 +320,6 @@ static int create_cache_proc_entries(struct cache_detail *cd) cd->flush_ent = p; if (p == NULL) goto out_nomem; - p->owner = cd->owner; if (cd->cache_request || cd->cache_parse) { p = proc_create_data("channel", S_IFREG|S_IRUSR|S_IWUSR, @@ -329,7 +327,6 @@ static int create_cache_proc_entries(struct cache_detail *cd) cd->channel_ent = p; if (p == NULL) goto out_nomem; - p->owner = cd->owner; } if (cd->cache_show) { p = proc_create_data("content", S_IFREG|S_IRUSR|S_IWUSR, @@ -337,7 +334,6 @@ static int create_cache_proc_entries(struct cache_detail *cd) cd->content_ent = p; if (p == NULL) goto out_nomem; - p->owner = cd->owner; } return 0; out_nomem: diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c index 085372ef4feb..1ef6e46d9da2 100644 --- a/net/sunrpc/stats.c +++ b/net/sunrpc/stats.c @@ -262,14 +262,8 @@ void rpc_proc_init(void) { dprintk("RPC: registering /proc/net/rpc\n"); - if (!proc_net_rpc) { - struct proc_dir_entry *ent; - ent = proc_mkdir("rpc", init_net.proc_net); - if (ent) { - ent->owner = THIS_MODULE; - proc_net_rpc = ent; - } - } + if (!proc_net_rpc) + proc_net_rpc = proc_mkdir("rpc", init_net.proc_net); } void |