diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2007-10-18 03:05:23 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-18 14:37:22 -0700 |
commit | 49a0c45833c9aa9852ba02c9df0f18029509d0a9 (patch) | |
tree | 0884aec3c522e495aa8a412b44fc6c8c24522639 | |
parent | d8217f076b73441dd3869c0c880df000655084cc (diff) | |
download | linux-49a0c45833c9aa9852ba02c9df0f18029509d0a9.tar.bz2 |
sysctl: Factor out sysctl_data.
There as been no easy way to wrap the default sysctl strategy routine except
for returning 0. Which is not always what we want. The few instances I have
seen that want different behaviour have written their own version of
sysctl_data. While not too hard it is unnecessary code and has the potential
for extra bugs.
So to make these situations easier and make that part of sysctl more symetric
I have factord sysctl_data out of do_sysctl_strategy and exported as a
function everyone can use.
Further having sysctl_data be an explicit function makes checking for badly
formed sysctl tables much easier.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/sysctl.h | 1 | ||||
-rw-r--r-- | kernel/sysctl.c | 66 |
2 files changed, 47 insertions, 20 deletions
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index f73be4cd662e..5ca510b3cbe2 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -972,6 +972,7 @@ extern int do_sysctl_strategy (struct ctl_table *table, void __user *oldval, size_t __user *oldlenp, void __user *newval, size_t newlen); +extern ctl_handler sysctl_data; extern ctl_handler sysctl_string; extern ctl_handler sysctl_intvec; extern ctl_handler sysctl_jiffies; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 73c84b6e7a35..88c8ea8f5e8c 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1443,7 +1443,6 @@ int do_sysctl_strategy (struct ctl_table *table, void __user *newval, size_t newlen) { int op = 0, rc; - size_t len; if (oldval) op |= 004; @@ -1464,25 +1463,10 @@ int do_sysctl_strategy (struct ctl_table *table, /* If there is no strategy routine, or if the strategy returns * zero, proceed with automatic r/w */ if (table->data && table->maxlen) { - if (oldval && oldlenp) { - if (get_user(len, oldlenp)) - return -EFAULT; - if (len) { - if (len > table->maxlen) - len = table->maxlen; - if(copy_to_user(oldval, table->data, len)) - return -EFAULT; - if(put_user(len, oldlenp)) - return -EFAULT; - } - } - if (newval && newlen) { - len = newlen; - if (len > table->maxlen) - len = table->maxlen; - if(copy_from_user(table->data, newval, len)) - return -EFAULT; - } + rc = sysctl_data(table, name, nlen, oldval, oldlenp, + newval, newlen); + if (rc < 0) + return rc; } return 0; } @@ -2381,6 +2365,40 @@ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, * General sysctl support routines */ +/* The generic sysctl data routine (used if no strategy routine supplied) */ +int sysctl_data(struct ctl_table *table, int __user *name, int nlen, + void __user *oldval, size_t __user *oldlenp, + void __user *newval, size_t newlen) +{ + size_t len; + + /* Get out of I don't have a variable */ + if (!table->data || !table->maxlen) + return -ENOTDIR; + + if (oldval && oldlenp) { + if (get_user(len, oldlenp)) + return -EFAULT; + if (len) { + if (len > table->maxlen) + len = table->maxlen; + if (copy_to_user(oldval, table->data, len)) + return -EFAULT; + if (put_user(len, oldlenp)) + return -EFAULT; + } + } + + if (newval && newlen) { + if (newlen > table->maxlen) + newlen = table->maxlen; + + if (copy_from_user(table->data, newval, newlen)) + return -EFAULT; + } + return 1; +} + /* The generic string strategy routine: */ int sysctl_string(struct ctl_table *table, int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, @@ -2569,6 +2587,13 @@ out: return -ENOSYS; } +int sysctl_data(struct ctl_table *table, int __user *name, int nlen, + void __user *oldval, size_t __user *oldlenp, + void __user *newval, size_t newlen) +{ + return -ENOSYS; +} + int sysctl_string(struct ctl_table *table, int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, void __user *newval, size_t newlen) @@ -2616,4 +2641,5 @@ EXPORT_SYMBOL(sysctl_intvec); EXPORT_SYMBOL(sysctl_jiffies); EXPORT_SYMBOL(sysctl_ms_jiffies); EXPORT_SYMBOL(sysctl_string); +EXPORT_SYMBOL(sysctl_data); EXPORT_SYMBOL(unregister_sysctl_table); |