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 /arch/alpha/kernel/srm_env.c | |
parent | 3dec7f59c370c7b58184d63293c3dc984d475840 (diff) |
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 'arch/alpha/kernel/srm_env.c')
-rw-r--r-- | arch/alpha/kernel/srm_env.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c index 78ad7cd1bbd6..d12af472e1c0 100644 --- a/arch/alpha/kernel/srm_env.c +++ b/arch/alpha/kernel/srm_env.c @@ -218,7 +218,6 @@ srm_env_init(void) BASE_DIR); goto cleanup; } - base_dir->owner = THIS_MODULE; /* * Create per-name subdirectory @@ -229,7 +228,6 @@ srm_env_init(void) BASE_DIR, NAMED_DIR); goto cleanup; } - named_dir->owner = THIS_MODULE; /* * Create per-number subdirectory @@ -241,7 +239,6 @@ srm_env_init(void) goto cleanup; } - numbered_dir->owner = THIS_MODULE; /* * Create all named nodes @@ -254,7 +251,6 @@ srm_env_init(void) goto cleanup; entry->proc_entry->data = (void *) entry; - entry->proc_entry->owner = THIS_MODULE; entry->proc_entry->read_proc = srm_env_read; entry->proc_entry->write_proc = srm_env_write; @@ -275,7 +271,6 @@ srm_env_init(void) entry->id = var_num; entry->proc_entry->data = (void *) entry; - entry->proc_entry->owner = THIS_MODULE; entry->proc_entry->read_proc = srm_env_read; entry->proc_entry->write_proc = srm_env_write; } |