sched: more robust sd-sysctl entry freeing
It occurred to me this morning that the procname field was dynamically
allocated and needed to be freed. I started to put in break statements
when allocation failed but it was approaching 50% error handling code.
I came up with this alternative of looping while entry->mode is set and
checking proc_handler instead of ->table. Alternatively, the string
version of the domain name and cpu number could be stored the structs.
I verified by compiling CONFIG_DEBUG_SLAB and checking the allocation
counts after taking a cpuset exclusive and back.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 0da2b26..5e220bf 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5272,11 +5272,20 @@
static void sd_free_ctl_entry(struct ctl_table **tablep)
{
- struct ctl_table *entry = *tablep;
+ struct ctl_table *entry;
- for (entry = *tablep; entry->procname; entry++)
+ /*
+ * In the intermediate directories, both the child directory and
+ * procname are dynamically allocated and could fail but the mode
+ * will always be set. In the lowest directory the names are
+ * static strings and all have proc handlers.
+ */
+ for (entry = *tablep; entry->mode; entry++) {
if (entry->child)
sd_free_ctl_entry(&entry->child);
+ if (entry->proc_handler == NULL)
+ kfree(entry->procname);
+ }
kfree(*tablep);
*tablep = NULL;