The patch titled
per task delay accounting taskstats interface: fix clone skbs for each listener
has been added to the -mm tree. Its filename is
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-cleanup-fix.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: per task delay accounting taskstats interface: fix clone skbs for each listener
From: Shailabh Nagar <nagar@xxxxxxxxxxxxxx>
Use a cloned sk_buff for each netlink message sent to multiple listeners.
Earlier, the same skb, representing a netlink message, was being erroneously
reused for doing genetlink_unicast()'s (effectively netlink_unicast()) to each
listener on the per-cpu list of listeners. Since netlink_unicast() frees up
the skb passed to it, regardless of status of the send, reuse is bad.
Thanks to Chandra Seetharaman for discovering this bug.
Signed-off-by: Shailabh Nagar <nagar@xxxxxxxxxxxxxx>
Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/taskstats.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff -puN kernel/taskstats.c~per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-cleanup-fix kernel/taskstats.c
--- a/kernel/taskstats.c~per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-cleanup-fix
+++ a/kernel/taskstats.c
@@ -125,6 +125,7 @@ static int send_cpu_listeners(struct sk_
struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
struct listener_list *listeners;
struct listener *s, *tmp;
+ struct sk_buff *skb_next, *skb_cur = skb;
void *reply = genlmsg_data(genlhdr);
int rc, ret;
@@ -138,12 +139,22 @@ static int send_cpu_listeners(struct sk_
listeners = &per_cpu(listener_array, cpu);
down_write(&listeners->sem);
list_for_each_entry_safe(s, tmp, &listeners->list, list) {
- ret = genlmsg_unicast(skb, s->pid);
+ skb_next = NULL;
+ if (!list_islast(&s->list, &listeners->list)) {
+ skb_next = skb_clone(skb_cur, GFP_KERNEL);
+ if (!skb_next) {
+ nlmsg_free(skb_cur);
+ rc = -ENOMEM;
+ break;
+ }
+ }
+ ret = genlmsg_unicast(skb_cur, s->pid);
if (ret == -ECONNREFUSED) {
list_del(&s->list);
kfree(s);
rc = ret;
}
+ skb_cur = skb_next;
}
up_write(&listeners->sem);
_
Patches currently in -mm which might be from nagar@xxxxxxxxxxxxxx are
netlink-improve-string-attribute-validation.patch
list_islast-utility.patch
per-task-delay-accounting-setup.patch
per-task-delay-accounting-sync-block-i-o-and-swapin-delay-collection.patch
per-task-delay-accounting-cpu-delay-collection-via-schedstats.patch
per-task-delay-accounting-utilities-for-genetlink-usage.patch
per-task-delay-accounting-taskstats-interface.patch
per-task-delay-accounting-delay-accounting-usage-of-taskstats-interface.patch
per-task-delay-accounting-documentation.patch
per-task-delay-accounting-proc-export-of-aggregated-block-i-o-delays.patch
delay-accounting-taskstats-interface-send-tgid-once.patch
per-task-delay-accounting-avoid-send-without-listeners.patch
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks.patch
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix.patch
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-2.patch
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-3.patch
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-cleanup.patch
per-task-delay-accounting-taskstats-interface-control-exit-data-through-cpumasks-fix-cleanup-fix.patch
per-task-delay-accounting-taskstats-interface-documentation-fix.patch
task-watchers-register-per-task-delay-accounting.patch
-
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