This is a note to let you know that I've just added the patch titled pktgen: fix misuse of BUG_ON() in pktgen_thread_worker() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pktgen-fix-misuse-of-bug_on-in-pktgen_thread_worker.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 116ee7ebb66c7020b438a924bad9fc5006ae50e3 Author: Di Zhu <zhudi21@xxxxxxxxxx> Date: Mon Jan 25 20:42:29 2021 +0800 pktgen: fix misuse of BUG_ON() in pktgen_thread_worker() [ Upstream commit 275b1e88cabb34dbcbe99756b67e9939d34a99b6 ] pktgen create threads for all online cpus and bond these threads to relevant cpu repecivtily. when this thread firstly be woken up, it will compare cpu currently running with the cpu specified at the time of creation and if the two cpus are not equal, BUG_ON() will take effect causing panic on the system. Notice that these threads could be migrated to other cpus before start running because of the cpu hotplug after these threads have created. so the BUG_ON() used here seems unreasonable and we can replace it with WARN_ON() to just printf a warning other than panic the system. Signed-off-by: Di Zhu <zhudi21@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210125124229.19334-1-zhudi21@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 433b26feb320..8a72b984267a 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -3555,7 +3555,7 @@ static int pktgen_thread_worker(void *arg) struct pktgen_dev *pkt_dev = NULL; int cpu = t->cpu; - BUG_ON(smp_processor_id() != cpu); + WARN_ON(smp_processor_id() != cpu); init_waitqueue_head(&t->queue); complete(&t->start_done);