kernel: fix kernel panic in mtk_ppe

The patch that adds support for hw flow-offloading counters on newer
MediaTek SoCs tries to prints acct->packets and acct->bytes in debugfs,
without checking that acct isn't null. This causes a kernel panic when
trying to read /sys/kernel/debug/ppe0/entries on older MediaTek SoCs.
Fix this by adding a check for acct.

Fixes: openwrt#11756
Fixes: 9721a42a27 ("kernel: support hw flow-offloading counters on newer MediaTek SoCs")
Reported-by: Stijn Tintel <stijn@linux-ipv6.be>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/target/linux/generic/pending-5.15/731-net-ethernet-mediatek-ppe-add-support-for-flow-accou.patch b/target/linux/generic/pending-5.15/731-net-ethernet-mediatek-ppe-add-support-for-flow-accou.patch
index aea6a605a90d4fca969d84fac3b8e2e458a3fd72..c76a00eabd8fc94831d81a1fcb43de4e1bb25be7 100644 (file)
--- a/target/linux/generic/pending-5.15/731-net-ethernet-mediatek-ppe-add-support-for-flow-accou.patch
+++ b/target/linux/generic/pending-5.15/731-net-ethernet-mediatek-ppe-add-support-for-flow-accou.patch
@@ -357,7 +357,7 @@ v2: fix wrong variable name in return value check spotted by Denis Kirjanov
                           h_source, h_dest, ntohs(l2->etype),
 -                         l2->vlan1, l2->vlan2, entry->ib1, ib2);
 +                         l2->vlan1, l2->vlan2, entry->ib1, ib2,
-+                         acct->packets, acct->bytes);
++                         acct ? acct->packets : 0, acct ? acct->bytes : 0);
        }
  
        return 0;