[dpdk-dev] [PATCH] lib/librte_vhost: fix vid allocation race
From: Peng He <hidden>
Date: 2021-01-29 09:45:45
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
From: "chenwei.0515" <redacted>
vhost_new_devcie might be called in different threads at the same time.
thread 1(config thread)
rte_vhost_driver_start
->vhost_user_start_client
->vhost_user_add_connection
-> vhost_new_device
thread 2(vhost-events)
vhost_user_read_cb
->vhost_user_msg_handler (return value < 0)
-> vhost_user_start_client
-> vhost_new_device
So there could be a case that a same vid has been allocated twice, or
some vid might be lost in DPDK lib however still held by the upper
applications.
Reported-by: Peng He <redacted>
Signed-off-by: Fei Chen <redacted>
Reviewed-by: Zhihong Wang <redacted>
---
lib/librte_vhost/vhost.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index efb136edd1..db11d293d2 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c@@ -26,6 +26,7 @@ #include "vhost_user.h" struct virtio_net *vhost_devices[MAX_VHOST_DEVICE]; +pthread_mutex_t vhost_dev_lock = PTHREAD_MUTEX_INITIALIZER; /* Called with iotlb_lock read-locked */ uint64_t
@@ -645,6 +646,7 @@ vhost_new_device(void) struct virtio_net *dev; int i; + pthread_mutex_lock(&vhost_dev_lock); for (i = 0; i < MAX_VHOST_DEVICE; i++) { if (vhost_devices[i] == NULL) break;
@@ -653,6 +655,7 @@ vhost_new_device(void) if (i == MAX_VHOST_DEVICE) { VHOST_LOG_CONFIG(ERR, "Failed to find a free slot for new device.\n"); + pthread_mutex_unlock(&vhost_dev_lock); return -1; }
@@ -660,10 +663,13 @@ vhost_new_device(void) if (dev == NULL) { VHOST_LOG_CONFIG(ERR, "Failed to allocate memory for new dev.\n"); + pthread_mutex_unlock(&vhost_dev_lock); return -1; } vhost_devices[i] = dev; + pthread_mutex_unlock(&vhost_dev_lock); + dev->vid = i; dev->flags = VIRTIO_DEV_BUILTIN_VIRTIO_NET; dev->slave_req_fd = -1;
--
2.23.0