From: Xie Yongji <xieyongji@bytedance.com> To: mst@redhat.com, jasowang@redhat.com, stefanha@redhat.com, sgarzare@redhat.com, parav@nvidia.com, hch@infradead.org, christian.brauner@canonical.com, rdunlap@infradead.org, willy@infradead.org, viro@zeniv.linux.org.uk, axboe@kernel.dk, bcrl@kvack.org, corbet@lwn.net, mika.penttila@nextfour.com, dan.carpenter@oracle.com, joro@8bytes.org, gregkh@linuxfoundation.org Cc: songmuchun@bytedance.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v8 03/10] eventfd: Increase the recursion depth of eventfd_signal() Date: Tue, 15 Jun 2021 22:13:24 +0800 [thread overview] Message-ID: <20210615141331.407-4-xieyongji@bytedance.com> (raw) In-Reply-To: <20210615141331.407-1-xieyongji@bytedance.com> Increase the recursion depth of eventfd_signal() to 1. This is the maximum recursion depth we have found so far, which can be triggered with the following call chain: kvm_io_bus_write [kvm] --> ioeventfd_write [kvm] --> eventfd_signal [eventfd] --> vhost_poll_wakeup [vhost] --> vduse_vdpa_kick_vq [vduse] --> eventfd_signal [eventfd] Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> --- fs/eventfd.c | 2 +- include/linux/eventfd.h | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/eventfd.c b/fs/eventfd.c index e265b6dd4f34..cc7cd1dbedd3 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -71,7 +71,7 @@ __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n) * it returns true, the eventfd_signal() call should be deferred to a * safe context. */ - if (WARN_ON_ONCE(this_cpu_read(eventfd_wake_count))) + if (WARN_ON_ONCE(this_cpu_read(eventfd_wake_count) > EFD_WAKE_DEPTH)) return 0; spin_lock_irqsave(&ctx->wqh.lock, flags); diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index fa0a524baed0..886d99cd38ef 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -29,6 +29,9 @@ #define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) #define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE) +/* Maximum recursion depth */ +#define EFD_WAKE_DEPTH 1 + struct eventfd_ctx; struct file; @@ -47,7 +50,7 @@ DECLARE_PER_CPU(int, eventfd_wake_count); static inline bool eventfd_signal_count(void) { - return this_cpu_read(eventfd_wake_count); + return this_cpu_read(eventfd_wake_count) > EFD_WAKE_DEPTH; } #else /* CONFIG_EVENTFD */ -- 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: Xie Yongji <xieyongji@bytedance.com> To: mst@redhat.com, jasowang@redhat.com, stefanha@redhat.com, sgarzare@redhat.com, parav@nvidia.com, hch@infradead.org, christian.brauner@canonical.com, rdunlap@infradead.org, willy@infradead.org, viro@zeniv.linux.org.uk, axboe@kernel.dk, bcrl@kvack.org, corbet@lwn.net, mika.penttila@nextfour.com, dan.carpenter@oracle.com, joro@8bytes.org, gregkh@linuxfoundation.org Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, iommu@lists.linux-foundation.org, songmuchun@bytedance.com, linux-fsdevel@vger.kernel.org Subject: [PATCH v8 03/10] eventfd: Increase the recursion depth of eventfd_signal() Date: Tue, 15 Jun 2021 22:13:24 +0800 [thread overview] Message-ID: <20210615141331.407-4-xieyongji@bytedance.com> (raw) In-Reply-To: <20210615141331.407-1-xieyongji@bytedance.com> Increase the recursion depth of eventfd_signal() to 1. This is the maximum recursion depth we have found so far, which can be triggered with the following call chain: kvm_io_bus_write [kvm] --> ioeventfd_write [kvm] --> eventfd_signal [eventfd] --> vhost_poll_wakeup [vhost] --> vduse_vdpa_kick_vq [vduse] --> eventfd_signal [eventfd] Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> --- fs/eventfd.c | 2 +- include/linux/eventfd.h | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/eventfd.c b/fs/eventfd.c index e265b6dd4f34..cc7cd1dbedd3 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -71,7 +71,7 @@ __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n) * it returns true, the eventfd_signal() call should be deferred to a * safe context. */ - if (WARN_ON_ONCE(this_cpu_read(eventfd_wake_count))) + if (WARN_ON_ONCE(this_cpu_read(eventfd_wake_count) > EFD_WAKE_DEPTH)) return 0; spin_lock_irqsave(&ctx->wqh.lock, flags); diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index fa0a524baed0..886d99cd38ef 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -29,6 +29,9 @@ #define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) #define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE) +/* Maximum recursion depth */ +#define EFD_WAKE_DEPTH 1 + struct eventfd_ctx; struct file; @@ -47,7 +50,7 @@ DECLARE_PER_CPU(int, eventfd_wake_count); static inline bool eventfd_signal_count(void) { - return this_cpu_read(eventfd_wake_count); + return this_cpu_read(eventfd_wake_count) > EFD_WAKE_DEPTH; } #else /* CONFIG_EVENTFD */ -- 2.11.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-06-15 14:17 UTC|newest] Thread overview: 193+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-15 14:13 [PATCH v8 00/10] Introduce VDUSE - vDPA Device in Userspace Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 01/10] iova: Export alloc_iova_fast() and free_iova_fast(); Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 02/10] file: Export receive_fd() to modules Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` Xie Yongji [this message] 2021-06-15 14:13 ` [PATCH v8 03/10] eventfd: Increase the recursion depth of eventfd_signal() Xie Yongji 2021-06-17 8:33 ` He Zhe 2021-06-17 8:33 ` He Zhe 2021-06-17 8:33 ` He Zhe 2021-06-18 3:29 ` Yongji Xie 2021-06-18 3:29 ` Yongji Xie 2021-06-18 8:41 ` He Zhe 2021-06-18 8:41 ` He Zhe 2021-06-18 8:41 ` He Zhe 2021-06-18 8:44 ` [PATCH] eventfd: Enlarge recursion limit to allow vhost to work He Zhe 2021-06-18 8:44 ` He Zhe 2021-06-18 8:44 ` He Zhe 2021-07-03 8:31 ` Michael S. Tsirkin 2021-07-03 8:31 ` Michael S. Tsirkin 2021-07-03 8:31 ` Michael S. Tsirkin 2021-08-25 7:57 ` Yongji Xie 2021-08-25 7:57 ` Yongji Xie 2021-06-15 14:13 ` [PATCH v8 04/10] vhost-iotlb: Add an opaque pointer for vhost IOTLB Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 05/10] vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 06/10] vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 07/10] vdpa: Support transferring virtual addressing during DMA mapping Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 08/10] vduse: Implement an MMU-based IOMMU driver Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-21 9:13 ` Jason Wang 2021-06-21 9:13 ` Jason Wang 2021-06-21 9:13 ` Jason Wang 2021-06-21 10:41 ` Yongji Xie 2021-06-21 10:41 ` Yongji Xie 2021-06-22 5:06 ` Jason Wang 2021-06-22 5:06 ` Jason Wang 2021-06-22 5:06 ` Jason Wang 2021-06-22 7:22 ` Yongji Xie 2021-06-22 7:22 ` Yongji Xie 2021-06-22 7:49 ` Jason Wang 2021-06-22 7:49 ` Jason Wang 2021-06-22 7:49 ` Jason Wang 2021-06-22 8:14 ` Yongji Xie 2021-06-22 8:14 ` Yongji Xie 2021-06-23 3:30 ` Jason Wang 2021-06-23 3:30 ` Jason Wang 2021-06-23 3:30 ` Jason Wang 2021-06-23 5:50 ` Yongji Xie 2021-06-23 5:50 ` Yongji Xie 2021-06-24 3:34 ` Jason Wang 2021-06-24 3:34 ` Jason Wang 2021-06-24 3:34 ` Jason Wang 2021-06-24 4:46 ` Yongji Xie 2021-06-24 4:46 ` Yongji Xie 2021-06-24 8:13 ` Jason Wang 2021-06-24 8:13 ` Jason Wang 2021-06-24 8:13 ` Jason Wang 2021-06-24 9:16 ` Yongji Xie 2021-06-24 9:16 ` Yongji Xie 2021-06-25 3:08 ` Jason Wang 2021-06-25 3:08 ` Jason Wang 2021-06-25 3:08 ` Jason Wang 2021-06-25 4:19 ` Yongji Xie 2021-06-25 4:19 ` Yongji Xie 2021-06-28 4:40 ` Jason Wang 2021-06-28 4:40 ` Jason Wang 2021-06-28 4:40 ` Jason Wang 2021-06-29 2:26 ` Yongji Xie 2021-06-29 2:26 ` Yongji Xie 2021-06-29 3:29 ` Jason Wang 2021-06-29 3:29 ` Jason Wang 2021-06-29 3:29 ` Jason Wang 2021-06-29 3:56 ` Yongji Xie 2021-06-29 3:56 ` Yongji Xie 2021-06-29 4:03 ` Jason Wang 2021-06-29 4:03 ` Jason Wang 2021-06-29 4:03 ` Jason Wang 2021-06-24 14:46 ` Stefan Hajnoczi 2021-06-24 14:46 ` Stefan Hajnoczi 2021-06-24 14:46 ` Stefan Hajnoczi 2021-06-29 2:59 ` Yongji Xie 2021-06-29 2:59 ` Yongji Xie 2021-06-30 9:51 ` Stefan Hajnoczi 2021-06-30 9:51 ` Stefan Hajnoczi 2021-06-30 9:51 ` Stefan Hajnoczi 2021-07-01 6:50 ` Yongji Xie 2021-07-01 6:50 ` Yongji Xie 2021-07-01 7:55 ` Jason Wang 2021-07-01 7:55 ` Jason Wang 2021-07-01 7:55 ` Jason Wang 2021-07-01 10:26 ` Yongji Xie 2021-07-01 10:26 ` Yongji Xie 2021-07-02 3:25 ` Jason Wang 2021-07-02 3:25 ` Jason Wang 2021-07-02 3:25 ` Jason Wang 2021-07-07 8:52 ` Stefan Hajnoczi 2021-07-07 8:52 ` Stefan Hajnoczi 2021-07-07 8:52 ` Stefan Hajnoczi 2021-07-07 9:19 ` Yongji Xie 2021-07-07 9:19 ` Yongji Xie 2021-06-15 14:13 ` [PATCH v8 10/10] Documentation: Add documentation for VDUSE Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-24 13:01 ` Stefan Hajnoczi 2021-06-24 13:01 ` Stefan Hajnoczi 2021-06-24 13:01 ` Stefan Hajnoczi 2021-06-29 5:43 ` Yongji Xie 2021-06-29 5:43 ` Yongji Xie 2021-06-30 10:06 ` Stefan Hajnoczi 2021-06-30 10:06 ` Stefan Hajnoczi 2021-06-30 10:06 ` Stefan Hajnoczi 2021-07-01 10:00 ` Yongji Xie 2021-07-01 10:00 ` Yongji Xie 2021-07-01 13:15 ` Stefan Hajnoczi 2021-07-01 13:15 ` Stefan Hajnoczi 2021-07-01 13:15 ` Stefan Hajnoczi 2021-07-04 9:49 ` Yongji Xie 2021-07-04 9:49 ` Yongji Xie 2021-07-05 3:36 ` Jason Wang 2021-07-05 3:36 ` Jason Wang 2021-07-05 3:36 ` Jason Wang 2021-07-05 12:49 ` Stefan Hajnoczi 2021-07-05 12:49 ` Stefan Hajnoczi 2021-07-05 12:49 ` Stefan Hajnoczi 2021-07-06 2:34 ` Jason Wang 2021-07-06 2:34 ` Jason Wang 2021-07-06 2:34 ` Jason Wang 2021-07-06 10:14 ` Stefan Hajnoczi 2021-07-06 10:14 ` Stefan Hajnoczi 2021-07-06 10:14 ` Stefan Hajnoczi [not found] ` <CACGkMEs2HHbUfarum8uQ6wuXoDwLQUSXTsa-huJFiqr__4cwRg@mail.gmail.com> [not found] ` <YOSOsrQWySr0andk@stefanha-x1.localdomain> [not found] ` <100e6788-7fdf-1505-d69c-bc28a8bc7a78@redhat.com> [not found] ` <YOVr801d01YOPzLL@stefanha-x1.localdomain> 2021-07-07 9:24 ` Jason Wang 2021-07-07 9:24 ` Jason Wang 2021-07-07 9:24 ` Jason Wang 2021-07-07 15:54 ` Stefan Hajnoczi 2021-07-07 15:54 ` Stefan Hajnoczi 2021-07-07 15:54 ` Stefan Hajnoczi 2021-07-08 4:17 ` Jason Wang 2021-07-08 4:17 ` Jason Wang 2021-07-08 4:17 ` Jason Wang 2021-07-08 9:06 ` Stefan Hajnoczi 2021-07-08 9:06 ` Stefan Hajnoczi 2021-07-08 9:06 ` Stefan Hajnoczi 2021-07-08 12:35 ` Yongji Xie 2021-07-08 12:35 ` Yongji Xie 2021-07-06 3:04 ` Yongji Xie 2021-07-06 3:04 ` Yongji Xie 2021-07-06 10:22 ` Stefan Hajnoczi 2021-07-06 10:22 ` Stefan Hajnoczi 2021-07-06 10:22 ` Stefan Hajnoczi 2021-07-07 9:09 ` Yongji Xie 2021-07-07 9:09 ` Yongji Xie 2021-07-08 9:07 ` Stefan Hajnoczi 2021-07-08 9:07 ` Stefan Hajnoczi 2021-07-08 9:07 ` Stefan Hajnoczi 2021-06-24 15:12 ` [PATCH v8 00/10] Introduce VDUSE - vDPA Device in Userspace Stefan Hajnoczi 2021-06-24 15:12 ` Stefan Hajnoczi 2021-06-24 15:12 ` Stefan Hajnoczi 2021-06-29 3:15 ` Yongji Xie 2021-06-29 3:15 ` Yongji Xie 2021-06-28 10:33 ` Liu Xiaodong 2021-06-28 10:33 ` Liu Xiaodong 2021-06-28 10:33 ` Liu Xiaodong 2021-06-28 4:35 ` Jason Wang 2021-06-28 4:35 ` Jason Wang 2021-06-28 4:35 ` Jason Wang 2021-06-28 5:54 ` Liu, Xiaodong 2021-06-28 5:54 ` Liu, Xiaodong 2021-06-28 5:54 ` Liu, Xiaodong 2021-06-29 4:10 ` Jason Wang 2021-06-29 4:10 ` Jason Wang 2021-06-29 4:10 ` Jason Wang 2021-06-29 7:56 ` Liu, Xiaodong 2021-06-29 7:56 ` Liu, Xiaodong 2021-06-29 7:56 ` Liu, Xiaodong 2021-06-29 8:14 ` Yongji Xie 2021-06-29 8:14 ` Yongji Xie 2021-06-28 10:32 ` Yongji Xie 2021-06-28 10:32 ` Yongji Xie 2021-06-28 10:32 ` Yongji Xie 2021-06-29 4:12 ` Jason Wang 2021-06-29 4:12 ` Jason Wang 2021-06-29 4:12 ` Jason Wang 2021-06-29 6:40 ` Yongji Xie 2021-06-29 6:40 ` Yongji Xie 2021-06-29 7:33 ` Jason Wang 2021-06-29 7:33 ` Jason Wang 2021-06-29 7:33 ` Jason Wang
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