mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-16 02:01:18 -04:00
Code Issues Packages Projects Releases Wiki Activity

net: shaper: flip the polarity of the valid flag

Browse Source 
The usual way of inserting entries which are not yet fully ready
into XArray is to have a VALID flag. The shaper code has a NOT_VALID
flag. Since XArray code does not let us create entries with marks
already set - the creation of entries is currently not atomic.

Flip the polarity of the VALID flag. This closes the tiny race
in net_shaper_pre_insert() of entries being created without
the NOT_VALID flag.

Fixes: 93954b40f6 ("net-shapers: implement NL set and delete operations")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20260510192904.3987113-2-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Jakub Kicinski
2026-05-10 12:28:55 -07:00
committed by Paolo Abeni
parent 36a8d04a82
commit 7cee43fcb0
1 changed files with 17 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
net/shaper/shaper.c
View File

@@ -275,11 +275,13 @@ static void net_shaper_default_parent(const struct net_shaper_handle *handle,
parent->id = 0;
}
/*
* MARK_0 is already in use due to XA_FLAGS_ALLOC, can't reuse such flag as
* it's cleared by xa_store().
/* MARK_0 is already in use due to XA_FLAGS_ALLOC. The VALID mark is set on
* an entry only after the device-side configuration has completed
* successfully (see net_shaper_commit()). Lookups and dumps must filter on
* this mark to avoid exposing tentative entries inserted by
* net_shaper_pre_insert() while the driver call is still in flight.
*/
#define NET_SHAPER_NOT_VALID XA_MARK_1
#define NET_SHAPER_VALID XA_MARK_1
static struct net_shaper *
net_shaper_lookup(struct net_shaper_binding *binding,
@@ -289,8 +291,8 @@ net_shaper_lookup(struct net_shaper_binding *binding,
struct net_shaper_hierarchy *hierarchy;
hierarchy = net_shaper_hierarchy_rcu(binding);
if (!hierarchy || xa_get_mark(&hierarchy->shapers, index,
NET_SHAPER_NOT_VALID))
if (!hierarchy || !xa_get_mark(&hierarchy->shapers, index,
NET_SHAPER_VALID))
return NULL;
return xa_load(&hierarchy->shapers, index);
@@ -370,13 +372,10 @@ static int net_shaper_pre_insert(struct net_shaper_binding *binding,
goto free_id;
}
/* Mark 'tentative' shaper inside the hierarchy container.
* xa_set_mark is a no-op if the previous store fails.
/* Insert as 'tentative' (no VALID mark). The mark will be set by
* net_shaper_commit() once the driver-side configuration succeeds.
*/
xa_lock(&hierarchy->shapers);
prev = __xa_store(&hierarchy->shapers, index, cur, GFP_KERNEL);
__xa_set_mark(&hierarchy->shapers, index, NET_SHAPER_NOT_VALID);
xa_unlock(&hierarchy->shapers);
prev = xa_store(&hierarchy->shapers, index, cur, GFP_KERNEL);
if (xa_err(prev)) {
NL_SET_ERR_MSG(extack, "Can't insert shaper into device store");
kfree_rcu(cur, rcu);
@@ -413,8 +412,7 @@ static void net_shaper_commit(struct net_shaper_binding *binding,
/* Successful update: drop the tentative mark
* and update the hierarchy container.
*/
__xa_clear_mark(&hierarchy->shapers, index,
NET_SHAPER_NOT_VALID);
__xa_set_mark(&hierarchy->shapers, index, NET_SHAPER_VALID);
*cur = shapers[i];
}
xa_unlock(&hierarchy->shapers);
@@ -431,8 +429,9 @@ static void net_shaper_rollback(struct net_shaper_binding *binding)
return;
xa_lock(&hierarchy->shapers);
xa_for_each_marked(&hierarchy->shapers, index, cur,
NET_SHAPER_NOT_VALID) {
xa_for_each(&hierarchy->shapers, index, cur) {
if (xa_get_mark(&hierarchy->shapers, index, NET_SHAPER_VALID))
continue;
__xa_erase(&hierarchy->shapers, index);
kfree(cur);
}
@@ -836,7 +835,8 @@ int net_shaper_nl_get_dumpit(struct sk_buff *skb,
goto out_unlock;
for (; (shaper = xa_find(&hierarchy->shapers, &ctx->start_index,
U32_MAX, XA_PRESENT)); ctx->start_index++) {
U32_MAX, NET_SHAPER_VALID));
ctx->start_index++) {
ret = net_shaper_fill_one(skb, binding, shaper, info);
if (ret)
break;