The patch titled
sysctl: Factor out sysctl_data.
has been added to the -mm tree. Its filename is
sysctl-factor-out-sysctl_data.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: sysctl: Factor out sysctl_data.
From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/sysctl.h | 1
kernel/sysctl.c | 66 +++++++++++++++++++++++++++------------
2 files changed, 47 insertions(+), 20 deletions(-)
diff -puN include/linux/sysctl.h~sysctl-factor-out-sysctl_data include/linux/sysctl.h
--- a/include/linux/sysctl.h~sysctl-factor-out-sysctl_data
+++ a/include/linux/sysctl.h
@@ -972,6 +972,7 @@ extern int do_sysctl_strategy (struct ct
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 -puN kernel/sysctl.c~sysctl-factor-out-sysctl_data kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl-factor-out-sysctl_data
+++ a/kernel/sysctl.c
@@ -1457,7 +1457,6 @@ int do_sysctl_strategy (struct ctl_table
void __user *newval, size_t newlen)
{
int op = 0, rc;
- size_t len;
if (oldval)
op |= 004;
@@ -1478,25 +1477,10 @@ int do_sysctl_strategy (struct ctl_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;
}
@@ -2395,6 +2379,40 @@ int proc_doulongvec_ms_jiffies_minmax(st
* 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,
@@ -2583,6 +2601,13 @@ 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)
@@ -2630,4 +2655,5 @@ 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);
_
Patches currently in -mm which might be from ebiederm@xxxxxxxxxxxx are
remove-unused-struct-proc_dir_entryset.patch
dvb_en_50221-convert-to-kthread-api.patch
x86_64-remove-sync_arb_ids.patch
x86_64-clear-io_apic-before-enabing-apic-error-vector.patch
clone-flag-clone_parent_tidptr-leaves-invalid-results-in-memory.patch
handle-the-multi-threaded-inits-exit-properly.patch
sysctl-core-stop-using-the-unnecessary-ctl_table-typedef.patch
sysctl-factor-out-sysctl_data.patch
sysctl-error-on-bad-sysctl-tables.patch
cpuset-zero-malloc-revert-the-old-cpuset-fix.patch
task-containersv11-basic-task-container-framework.patch
task-containersv11-add-tasks-file-interface.patch
task-containersv11-add-fork-exit-hooks.patch
task-containersv11-add-container_clone-interface.patch
task-containersv11-add-procfs-interface.patch
task-containersv11-shared-container-subsystem-group-arrays.patch
task-containersv11-automatic-userspace-notification-of-idle-containers.patch
task-containersv11-make-cpusets-a-client-of-containers.patch
task-containersv11-example-cpu-accounting-subsystem.patch
task-containersv11-simple-task-container-debug-info-subsystem.patch
pid-namespaces-round-up-the-api.patch
pid-namespaces-make-get_pid_ns-return-the-namespace-itself.patch
pid-namespaces-dynamic-kmem-cache-allocator-for-pid-namespaces.patch
pid-namespaces-dynamic-kmem-cache-allocator-for-pid-namespaces-fix.patch
pid-namespaces-define-and-use-task_active_pid_ns-wrapper.patch
pid-namespaces-rename-child_reaper-function.patch
pid-namespaces-use-task_pid-to-find-leaders-pid.patch
pid-namespaces-define-is_global_init-and-is_container_init.patch
pid-namespaces-move-alloc_pid-to-copy_process.patch
make-access-to-tasks-nsproxy-lighter.patch
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