From 349ac52bbc5264d774c7e28c62c4e3941055b9c4 Mon Sep 17 00:00:00 2001 From: Luca Boccassi Date: Wed, 31 Oct 2018 18:39:45 +0000 Subject: [PATCH] eal/linux: handle UIO read failure in interrupt handler If a device is unplugged while an interrupt is pending, the read call to the uio device to remove it from the poll wait list can fail resulting in it being continually polled forever. This change checks for the read failing and if so, unregisters the device as an interrupt source and causes the wait list to be rebuilt. This race has been reported and observed in production. Fixes: 0a45657a6794 ("pci: rework interrupt handling") Cc: stable@dpdk.org Signed-off-by: Brian Russell Signed-off-by: Luca Boccassi --- lib/librte_eal/linuxapp/eal/eal_interrupts.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c index 39252a887f..cbac451e11 100644 --- a/lib/librte_eal/linuxapp/eal/eal_interrupts.c +++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c @@ -700,7 +700,7 @@ eal_intr_process_interrupts(struct epoll_event *events, int nfds) bool call = false; int n, bytes_read; struct rte_intr_source *src; - struct rte_intr_callback *cb; + struct rte_intr_callback *cb, *next; union rte_intr_read_buffer buf; struct rte_intr_callback active_cb; @@ -780,6 +780,23 @@ eal_intr_process_interrupts(struct epoll_event *events, int nfds) "descriptor %d: %s\n", events[n].data.fd, strerror(errno)); + /* + * The device is unplugged or buggy, remove + * it as an interrupt source and return to + * force the wait list to be rebuilt. + */ + rte_spinlock_lock(&intr_lock); + TAILQ_REMOVE(&intr_sources, src, next); + rte_spinlock_unlock(&intr_lock); + + for (cb = TAILQ_FIRST(&src->callbacks); cb; + cb = next) { + next = TAILQ_NEXT(cb, next); + TAILQ_REMOVE(&src->callbacks, cb, next); + free(cb); + } + free(src); + return -1; } else if (bytes_read == 0) RTE_LOG(ERR, EAL, "Read nothing from file " "descriptor %d\n", events[n].data.fd); -- 2.20.1