xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Koodi Ongelmat Pull-pyynnöt Actions Paketit Projektit Julkaisut Wiki Toiminta

proc 2/2: remove struct proc_dir_entry::owner

Selaa lähdekoodia 
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>
This commit is contained in:
Alexey Dobriyan
2009-03-25 22:48:06 +03:00
vanhempi 3dec7f59c3
commit 99b7623380
55 muutettua tiedostoa jossa 26 lisäystä ja 232 poistoa
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/char/ipmi/ipmi_msghandler.c
Näytä tiedosto

@@ -1944,7 +1944,7 @@ static int stat_file_read_proc(char *page, char **start, off_t off,
int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name,
read_proc_t *read_proc,
void *data, struct module *owner)
void *data)
{
int rv = 0;
#ifdef CONFIG_PROC_FS
@@ -1970,7 +1970,6 @@ int ipmi_smi_add_proc_entry(ipmi_smi_t smi, char *name,
} else {
file->data = data;
file->read_proc = read_proc;
file->owner = owner;
mutex_lock(&smi->proc_entry_lock);
/* Stick it on the list. */
@@ -1993,23 +1992,21 @@ static int add_proc_entries(ipmi_smi_t smi, int num)
smi->proc_dir = proc_mkdir(smi->proc_dir_name, proc_ipmi_root);
if (!smi->proc_dir)
rv = -ENOMEM;
else
smi->proc_dir->owner = THIS_MODULE;
if (rv == 0)
rv = ipmi_smi_add_proc_entry(smi, "stats",
stat_file_read_proc,
smi, THIS_MODULE);
smi);
if (rv == 0)
rv = ipmi_smi_add_proc_entry(smi, "ipmb",
ipmb_file_read_proc,
smi, THIS_MODULE);
smi);
if (rv == 0)
rv = ipmi_smi_add_proc_entry(smi, "version",
version_file_read_proc,
smi, THIS_MODULE);
smi);
#endif /* CONFIG_PROC_FS */
return rv;
@@ -4265,7 +4262,6 @@ static int ipmi_init_msghandler(void)
return -ENOMEM;
}
proc_ipmi_root->owner = THIS_MODULE;
#endif /* CONFIG_PROC_FS */
setup_timer(&ipmi_timer, ipmi_timeout, 0);

6
drivers/char/ipmi/ipmi_si_intf.c
Näytä tiedosto

@@ -2899,7 +2899,7 @@ static int try_smi_init(struct smi_info *new_smi)
rv = ipmi_smi_add_proc_entry(new_smi->intf, "type",
type_file_read_proc,
new_smi, THIS_MODULE);
new_smi);
if (rv) {
printk(KERN_ERR
"ipmi_si: Unable to create proc entry: %d\n",
@@ -2909,7 +2909,7 @@ static int try_smi_init(struct smi_info *new_smi)
rv = ipmi_smi_add_proc_entry(new_smi->intf, "si_stats",
stat_file_read_proc,
new_smi, THIS_MODULE);
new_smi);
if (rv) {
printk(KERN_ERR
"ipmi_si: Unable to create proc entry: %d\n",
@@ -2919,7 +2919,7 @@ static int try_smi_init(struct smi_info *new_smi)
rv = ipmi_smi_add_proc_entry(new_smi->intf, "params",
param_read_proc,
new_smi, THIS_MODULE);
new_smi);
if (rv) {
printk(KERN_ERR
"ipmi_si: Unable to create proc entry: %d\n",